Emerging evidence has shown that two common genetic polymorphisms within the pleckstrin domain-containing protein 5 (DEPDC5), rs1012068 and rs5998152, may be associated with the risk of hepatocellular carcinoma (HCC), especially in those individuals chronically infected with the hepatitis C virus (HCV) or the hepatitis B virus (HBV). However, these findings have not been consistently replicated in the literature due to limited sample sizes or different etiologies of HCC. Thus, the present systematic review and meta-analysis were performed to resolve this inconsistency.  The databases PubMed, Embase, Web of Science, the China National Knowledge Infrastructure, and Scopus were searched up to December 12, 2022. Data from relevant studies were pooled, and odds ratios and 95% confidence intervals were calculated. P = 0.02); the recessive model ; the dominant model ; the homozygous model ; the heterozygous model ). Subgroup analyses based on ethnicity and etiology revealed that the rs1012068 polymorphism, under all five genetic models, was associated with increased HCC risk in Asians or in individuals with chronic HBV infection but not in individuals with chronic HCV infection. A significant association was also observed between rs5998152 and HCV-related HCC risk in Asians chronically infected with HCV under allelic, dominant, and heterozygous models.  A total of 11 case-control studies encompassing 2,609 cases and 8,171 controls on rs1012068 and three encompassing 411 cases and 1,448 controls on rs5998152 were included. Results indicated that the DEPDC5 rs1012068 polymorphism did not significantly increase HCC risk in the total population (allelic model (OR = 1.32, 95% CI = 1.04–1.67,  Our study suggests that the DEPDC5 rs1012068 polymorphism increases HCC risk, especially in Asians with chronic HBV infection, while the rs5998152 polymorphism increases HCC risk in Asians with chronic HCV infection. Liver cancer is the fifth most common cancer and the fourth leading cause of cancer-related death worldwide. Among men, it is the fourth most frequent cancer and the second leading cause of cancer-related deaths . Hepatocβ-catenin pathway, which may contribute to HCV-related fibrosis [Pleckstrin domain-containing protein 5 (DEPDC5) has been implicated in focal epilepsy, brain malformation, and sudden unexplained death in epilepsy –5. DEPDCfibrosis . Such dofibrosis .In addition to these associations between DEPDC5 and various diseases, polymorphisms in the DEPDC5 gene have been linked to the risk of HCC –23. A geThese contradictory results may reflect the relatively small samples in individual studies, heterogeneity among control populations, and different HCC etiologies. We conducted the present systematic review and meta-analysis to clarify the relationship of DEPDC5 polymorphisms rs1012068 and rs5998152 with HCC risk. We also performed subgroup analyses based on ethnicity and the etiology of HCC.This meta-analysis complied with “Preferred Reporting Items for Systematic Reviews and Meta-Analyses” (PRISMA) guidelines . A comprThe study cohorts included DEPDC5 rs1012068 and rs5998152 polymorphisms in patients with HCCHistological features were assessed by liver biopsy, and diagnostic criteria were clearly statedUnrelated case-control studies were includedIf two (or more) studies included the same cohort, only the most recent was includedSufficient data for estimating odds ratios (ORs) and 95% confidence intervals (CIs) on the HCC risk were reported or could be calculatedThe source of cases was unclearNo clear diagnostic criteria for HCC were describedThe study was a duplicate publicationThe study was a review, meta-analysis, comment, or conference abstractGenotyping data were not reported in sufficient detailThe data from the included studies were extracted by two independent investigators. Discrepancies during data extraction were resolved by a third investigator. The extracted information included the first author's surname, publication year, country in which the study was conducted, ethnicity, cohort characteristics of the cases and controls, the total number of patients in the case and control groups, the number of subjects with each genotype, and matched parameters between cases and controls.Quality assessments of the eligible studies were performed using the Newcastle–Ottawa Scale (NOS) . The NOSP < 0.05 considered significant. When P > 0.10 for the Q test, meta-analysis was performed using a fixed-effect model, indicating the absence of heterogeneity among studies; otherwise, a random-effect model was used. Review Manager 5.3 (Cochrane Collaboration) was used for all statistical tests for meta-analyses. Begg's funnel plot and Egger's linear regression in Stata 12.0 software  were used to evaluate publication bias, with P < 0.05 considered significant.The unadjusted odds ratio (OR) and 95% confidence interval (CI) were used to assess the correlation of DEPDC5 rs1012068 and rs5998152 polymorphisms with the risk of HCC based on the genotype frequencies in cases and controls. The Z test was used to evaluate the significance of the association, with The flowchart of study selection is summarized in A total of 11 studies –22 invesP = 0.02); the recessive model ; the dominant model ; the homozygous model ; or the heterozygous model .As shown in P < 0.001); the recessive model ; the dominant model ; the homozygous model ; and the heterozygous model . Subgroup analysis in Caucasian populations was not performed because only two studies reported such data.A meta-analysis based on ethnicity for the subgroup of 2,297 Asian cases and 4,801 Asian controls in 8 studies , 14–20 sP < 0.001); the recessive model ; the dominant model ; the homozygous model ; and the heterozygous model .Then, we conducted a meta-analysis based on the etiology of HCC, in which both cases and controls were chronically infected with HBV. Results for the subgroup of 936 cases and 1,021 controls in 3 studies , 16, 19 P = 0.03); the recessive model ; the dominant model ; the homozygous model ; and the heterozygous model .Next, a meta-analysis was conducted based on the etiology of HCC, in which both cases and controls were chronically infected with HCV. Results for the subgroup of 1,673 cases and 7,150 controls in 8 studies , 20–22 sP = 0.03); the dominant model ; and the heterozygous model ; but not under the recessive model ; or the homozygous dominant model .As shown in The controls in all 8 case-control studies that investigated the association between the rs1012068 polymorphism and HCC risk were chronically infected with HCV, except the controls in one study [P > 0.05).As shown in Figures In the case of rs1012068, an overall meta-analysis of the total population indicated a significant association with increased HCC risk, regardless of HCC etiology and source of controls. Subgroup analysis based on ethnicity supported this association for Asians. Subsequently, meta-analyses of individuals chronically infected with HBV or HCV were performed. The cases and controls in three case-control studies , 16, 19 In the case of rs5998152, three case-control studies examined a potential relationship between this polymorphism and the risk of HCV-related HCC , 15, 23.It may be that these polymorphisms weaken the activity of DEPDC5, preventing it from inhibiting mTORC1 as it does normally, which in turn leads to pathogenic inflammation and cell growth in the liver , 29. FutAlthough positive results were obtained, some limitations that may affect the interpretation of the meta-analysis were presented in this work. First, samples were relatively small due to the lack of case-control studies, especially for rs5998152. Second, among studies investigating the association between the rs1012068 polymorphism and HCC risk, the controls in all case-control studies except one , 31. SinIn summary, our study suggests that the DEPDC5 rs1012068 polymorphism increases HCC risk, especially in Asians with chronic HBV infection, while the rs5998152 polymorphism increases HCC risk in Asians with HCV infection. Further large, well-designed studies are required to validate these findings.


Background: Risk factors for acute kidney injury (AKI) after Stanford type A aortic dissection (TAAD) repair are inconsistent in different studies. This meta-analysis systematically analyzed the risk factors so as to early identify the therapeutic targets for preventing AKI.Methods: Studies exploring risk factors for AKI after TAAD repair were searched from four databases from inception to June 2022. The synthesized incidence and risk factors of AKI and its impact on mortality were calculated.Results: Twenty studies comprising 8223 patients were included. The synthesized incidence of postoperative AKI was 50.7%. Risk factors for AKI included cardiopulmonary bypass (CPB) time >180 min , prolonged operative time (>7 h) , advanced age (per 10 years)  transfusion perioperatively , elevated body mass index (per 5 kg/m2)  and preoperative kidney injury . All results were meta-analyzed using fixed-effects model finally (p < 0.01). The in-hospital or 30-day mortality was higher in patients with postoperative AKI than in that without AKI .Conclusions: AKI after TAAD repair increased the in-hospital or 30-day mortality. Reducing CPB time and pRBCs transfusion, especially in elderly or heavier weight patients, or patients with preoperative kidney injury were important to prevent AKI after TAAD repair surgery. Acute Type A aortic dissection (TAAD) is the most critical condition in cardiovascular diseases with poor outcomes . DespiteTable S1 in Supplementary Material). The reference lists of retrieved articles were reviewed for further identification of potentially relevant studies. All identified articles were systematically assessed using the inclusion and exclusion criteria.This meta-analysis was reported according to the guidelines of the Meta-analysis Of Observational Studies in Epidemiology group  and PrefThe approach of populations, interventions, comparisons, outcomes, and study designs (PICOS) was used to establish the inclusion criteria for our meta-analysis. Studies meeting the following criteria were included: (1) Study populations: Patients older than 18 years old who underwent repair surgery for TAAD. (2) Study intervention and comparators: Patients with or without AKI after TAAD repair surgery. (3) Study outcomes: The primary outcome was the risk factors for AKI after TAAD repair surgery. The secondary outcomes were the synthesized incidence of AKI and its impact on in-hospital or 30-day mortality. (4) Study type: Observational or randomized controlled trial studies that report odds ratio (OR) with 95% confidence interval (CI) or providing raw data which can calculate these values. (5) Definitions: The definitions of all risk factors were similar. The diagnostic criteria of AKI included three most commonly used criteria, that is RIFLE , AKIN (Acute Kidney Injury Network) and KDIGO . AKI was diagnosed as the value of postoperative serum creatinine (sCr) 1.5-fold higher than the baseline level or an increased value of 0.3 mg/dl within 48 h postoperatively.(1) Studies only analyze risk factors of postoperative acute renal failure, or continuous RRT (CRRT), or AKI of stage 2 or 3 after TAAD repair surgery. (2) Studies did not contain outcomes related to risk factors of postoperative AKI after TAAD repair surgery. (3) Review articles, conference abstracts, case reports, letters, editorials, animal studies, repetitive study or same population, articles not available for full texts, and non-English articles.Two investigators (Lei Wang and Xiaochai Lv) independently reviewed the retrieved articles and evaluated the quality assessment. All data were extracted from article texts, tables, and figures and entered into Excel software . Discrepancies between the 2 investigators were resolved by a senior investigator (Yanting Hou). When insufficient data were available from publications, corresponding authors were contacted to provide additional records if possible. Quality assessment was performed using the Newcastle Ottawa Scale, and a total score of ≥6 (of 9) was considered of high quality and low risk of bias .2I test [2I<50% and P for heterogeneity >0.1 was considered low heterogeneity among studies and a fixed-effects model would be used for analysis. 2I>50% and/or P for heterogeneity <0.1 denoted a significant heterogeneity among studies and a random-effects model would be used. The leave-one-out sensitivity analysis was performed to assess the influence of individual studies on the summary effect estimate, in which the meta-analysis estimates were computed by omitting one study at a time. Evidence of publication bias was explored through visual inspection of funnel plots (This applies to the inclusion of more than 10 articles), Egger’s test and Begg’s test [p > 0.05. The results with obvious bias with Egger's p < 0.05 and Begg's p < 0.05 were performed further by trim and fill adjustment. p < 0.05 was considered statistically significant. All p values were two-sided.R software  was used for statistical analysis. The kappa statistic was calculated to assess inter-rater agreement at the title/abstract screening and full text review stages, with thresholds of ≥0.81 indicating substantial perfect agreement, as defined by McHugh . Risk faI2 test . I2<50% g’s test ,34. It iTables S2 and S3 in Supplementary Material). All studies reporting risk factors of postoperative AKI with OR and its 95% CI. Missing data of the incidence of CRRT and postoperative in-hospital or 30-day mortality were present in 2 and 5 included studies, respectively. These studies were excluded when such results were meta-analyzed for the missing data were few and they were all secondary outcomes.A total of 454 references were identified through four electronic database searches, and 20 studies were finally included for the present meta-analysis. The PRISMA flow diagram was shown in Table S4 in Supplementary Material).Study characteristics are summarized in Figures S1 and S2 in Supplementary Material). Besides, subgroup analysis of risk factors of AKI was conducted based on different diagnostic criteria of AKI and different country research . It showed that the incidence of AKI was higher in KIDGO diagnostic criteria than in AKIN or RIFLE criteria, suggesting that KIDGO criteria were more sensitive in diagnosing AKI. In addition, the incidence of AKI in Chinese studies was higher than in other countries, which might be related to a large deviation from the results of fewer study in other countries, and might be because most Chinese studies (11 out of 13) had used KIDGO diagnostic criteria which had higher sensitivity for AKI diagnosis, leading to a higher incidence of AKI.The synthesized incidence of AKI and CRRT after TAAD repair surgery was 50.7%  and 9.1% , respectively, which was similar to the previous studies ((1) Prolonged CPB time. Ten studies [2I=77%, P for heterogeneity <0.01, p < 0.01) . Since the definition of “prolonged CPB time” in the study of “Roh et al. (2012)” and “Qiu et al. (2015)” was “CPB time >180 min” which were different from other studies, subgroup analysis was further conducted according to the different definitions , and the subgroup of “long CPB time” showed moderate heterogeneity , so we concluded that prolonged CPB time, especially CPB time >180 min was a risk factor for AKI after TAAD repair surgery. studies ,23,25 suinitions . The sub(2) Prolonged operative time. Three studies [2I=0, P for heterogeneity >0.1) (p < 0.01), so we concluded that prolonged operative time (>7 h) was a risk factor for AKI after TAAD repair surgery. studies  suggestety >0.1) , so fixe(3) Advanced age. Five studies [2I=90%, P for heterogeneity <0.01, p < 0.01) . Sensitivity analysis showed the study of “Qiu et al. (2015)” and “Fang et al. (2019)” might be the source of heterogeneity , and after excluding these two studies, there was no heterogeneity between studies  (p < 0.01), so we concluded that the advanced age (per 10 years) was a risk factor for AKI after TAAD repair surgery. studies ,17,18,23ty >0.1) . Thus th(4) The increased pRBCs transfusion perioperatively. Five studies [2I=42%, P for heterogeneity >0.1), (p < 0.01), so we concluded that the increased pRBCs transfusion perioperatively was a risk factor for AKI after TAAD repair surgery. studies ,21,23,26y >0.1),  and fixe(5) Elevated BMI. Five studies [2I=88%, P for heterogeneity <0.01, p < 0.01) . Sensitivity analysis showed “Fang et al. (2019)” and “Helgason et al. (2020)” might be the source of heterogeneity . After excluding these two studies, the heterogeneity between studies was lowered  (p < 0.01). So we concluded that elevated BMI (per 5 kg/m2) was a risk factor for AKI after TAAD repair surgery. Elevated studies ,18,20,23ty >0.1) . Therefo(6) Preoperative kidney injury. Five studies [2, renal malperfusion, or chronic kidney disease were risk factors of AKI, and these risk factors are collectively classified as preoperative kidney injury. The forest plot showed low heterogeneity  (p < 0.01), so we concluded that preoperative kidney injury was a risk factor for AKI after TAAD repair. Preopera studies ,20,23 suty >0.1) . TherefoFigure S10 in Supplementary Material). The in-hospital or 30-day mortality in patients with AKI was 2.44-fold higher than that in non-AKI patients  . ( < 0.01) .Figure S11 in Supplementary Material), but the Egger's and Begg's p values were all <0.05, signifying significant publication bias . Egger's and Begg's p values for other risk factors were also shown in p were all >0.05 even though Egger’s p < 0.05 for the risk factors of advanced age and increased pRBCs transfusion. In a word, the publication bias did not significantly affect the results of this meta-analysis.Inspection of the funnel plot for risk factor of prolonged CPB time were nearly symmetrical (ion bias . But thePostoperative AKI is a common complication after TAAD repair surgery. This meta-analysis comprehensively analyzed that the synthesized incidence of postoperative AKI after TAAD repair surgery was 50.7%, which was consistent with previous range of 18–67% ,4. The pStanford type B aortic dissection may also involve renal arteries and lead to renal malperfusion, renal ischemia and injury, and the postoperative AKI may also be associated with age or weight of patients. However, the main surgical method for type B aortic dissection is thoracic endovascular aortic repair, which is obvious different from the open chest surgical repair with CPB for TAAD. Thus, the perioperative risk factors of postoperative AKI, such as operative time, CPB time, perioperative blood transfusions, are significantly different in type B aortic dissection repair from those in TAAD, so we did not include the patients of type B aortic dissection in this meta-analysis.In fact, 30 items of risk factors for AKI after TAAD repair surgery were involved in data extraction. However, some risk factors were only concluded in one or two studies making it difficult to do further statistic. Hence only six risk factors were included in this meta-analysis, and all of them were statistically significant.et al. [et al. [et al. [et al. [via reducing CPB time. Thus, in patients with TAAD, reducing hemolysis, enhancing blood protection, simplifying surgical techniques, and shortening operation and CPB time, are considered to be important in protecting renal function and reducing the incidence of postoperative AKI.The present meta-analysis showed that prolonged CPB time, especially CPB time >180 min was a risk factor for AKI after TAAD repair, which was also consistent with previous meta-analysis  and mostet al.  found thet al. . For Debet al. . Meanwhiet al. , and allet al. . Mamikon [et al.  also fou [et al.  performe [et al.  found thet al. and Zhou et al. found that for every 10 years of the increased age, the incidence of AKI after TAAD repair surgery is increased by 1.3 to 1.37 times [et al. [Our study also showed that advanced age was a combined risk factor for AKI after TAAD repair surgery. This was consistent with the meta-analysis  and prev37 times ,23, whic37 times . In addi37 times . However [et al.  suggesteet al. [et al. [The increased pRBCs transfusion perioperatively was also a combined risk factor for postoperative AKI. Qiu et al.  found th [et al.  found th [et al. . The pos [et al. . Besides [et al. . In addiet al. found that underweight Asian patients are susceptible to AKI in acute hospital settings [Elevated BMI was a risk factor for AKI after TAAD repair surgery in our meta-analysis. The previous studies found that high BMI is an independent predictor of AKI in patients undergoing TAAD repair surgery  as well settings . The reasettings . This maPreoperative kidney injury was also a risk factor of postoperative AKI. Preoperative malperfusion might be caused by cardiac tamponade and cardiogenic shock, or renal artery involvement owing to aortic dissection. Helgason et al.  found thIn the present meta-analysis, DHCA was not associated with postoperative AKI. It may be related to the protective effects of DHCA on organ function, which counterbalance the kidney damage expected from prolonged CPB. Besides, compared with other cardiac surgeries, the TAAD repair surgery is more complex with longer CPB time and larger pRBCs transfusion, and the preoperative renal malperfusion is common. Thus these factors are more important than the factor of DHCA. But other investigations identified that DHCA is an independent risk factor for AKI . These dAKI was common after TAAD repair surgery, and it increased the in-hospital or 30-day mortality. The risk factors for postoperative AKI in the present meta-analysis included the prolonged CPB and operative time, advanced age, perioperative pRBCs transfusion, elevated BMI and preoperative kidney injury. The CPB time, operative time, and pRBCs transfusion was modifiable among the risk factors. Thus, improving surgical techniques and reducing CPB and operative time, and reducing pRBCs transfusion, can reduce the incidence of AKI after TAAD repair surgery and improve clinical outcomes, especially in elderly patients, patients with elevated BMI, or patients with preoperative kidney injury. Early identification of these risk factors enables clinicians to initiate efficient preventive and therapeutic strategies to reduce postoperative AKI.This meta-analysis performed a completed retrieval and a more focused analysis of risk factors for AKI after TAAD repair surgery, and the synthesized incidence of postoperative AKI and its impact on the in-hospital or 30-day mortality was analyzed. However, some risk factors are only concluded in one or two studies, so no further analysis was performed. As a result, some risk factors may be overlooked. Besides, long-term mortality, postoperative complications, threshold BMI value contributing to AKI were not analyzed. Moreover, the included articles were all retrospective studies, and this meta-analysis was not registered online, so randomized controlled trials are needed to identify risk factors so as to improve the clinical outcomes of patients undergoing TAAD repair surgery.Click here for additional data file.


Inflammatory bowel disease (IBD) is an autoimmune inflammatory disorder that affects the gastrointestinal system with an annual increase in incidence and prevalence worldwide. While the precise cause behind IBD remains obscured, certain genetic susceptibilities, in addition to environmental factors, may trigger the stimulation of the immunoinflammatory system against the gastrointestinal system, eventually resulting in IBD. Furthermore, certain medications have been proposed to increase the risk of developing IBD, such as isotretinoin. IBD has been reported during the post-marketing phase of isotretinoin. Subsequently, IBD development was added as a potential gastrointestinal adverse effect of isotretinoin. This review article aims to evaluate the possible association between isotretinoin exposure and the development of inflammatory bowel disease. We enrolled 32 relevant studies, including case reports, case-control, and cohort studies. The results were critically analyzed and reviewed by independent authors to answer the research question and achieve the primary endpoint. Inflammatory bowel disease (IBD) is a chronic autoimmune inflammatory disease that affects the gastrointestinal tract and is classified into Crohn's Disease (CD) and Ulcerative Colitis (UC) . The infRisk factors for IBD include a family history of CD or UC, former smoking (CD/UC), current smoking (CD), appendicectomy (CD), tonsillectomy (CD), meat and meat products (CD), vitamin D deficiency (UC), alteration of the gut microbiota, and psychological stress -5. The rIsotretinoin is a synthetic retinoid derived from vitamin A. It has been used successfully to treat patients with acne vulgaris (AV) by reducing sebum production and keratinization by reducing the sebaceous gland size and function -8. To daMethodThis study is a review article in which relevant studies, including case reports, case-control, cohorts, and systematic reviews were selected. No randomized clinical trials have been found mostly due to the medico-legal obligations. We searched the PubMed database for relevant articles using the following Mesh words: Inflammatory bowel disease, ulcerative colitis, Crohn's disease, isotretinoin, and vitamin A analogue. To minimize bias, three independent authors approved and analyzed the studies and four authors reviewed and validated the results. Moreover, any disagreements concerning the eligibility of the publication were discussed among the researchers, and a consensus was met. The primary endpoint was the development of IBD secondary to isotretinoin exposure. The inclusion and exclusion criteria are outlined in Table DiscussionIsotretinoin and the Immune SystemA possible mechanism of isotretinoin-induced UC is the prevention of epithelial cell growth and the activation of T-cells. Another theory is that the T-cells activated by isotretinoin express the α4β7 and CCR9 receptors, which are crucial to the gastrointestinal system's inflammation process . RetinoiMoreover, several reports show that isotretinoin causes some significant diseases such as sacroiliitis by triggering inflammation . Recent Contrarily, retinoic acid, a form of vitamin A enhances the intestinal barrier function by increasing various tight junction protein expressions, such as occludin, claudin-1, claudin-4, and zonula occludens-1. Impaired intestinal barrier function has been implicated in the pathogenesis of IBD; consequently, isotretinoin might prevent IBD development instead of triggering it . HoweverIsotretinoin Exposure and the Risk of IBD; Evidence-BasedSeveral studies have investigated the possible association between isotretinoin exposure and IBD development. For instance, three patients who developed IBD six months after starting isotretinoin were reported by Passier et al.; two of them developed UC, and one had CD . LikewisFurthermore, Crockett et al. performed a case-control study to evaluate the association between isotretinoin use and IBD development. The study concluded that UC is highly linked to a prior isotretinoin exposure , and no correlation was found between CD and isotretinoin use  . AdditioOn the other hand, Wright et al. compared the risk of IBD among isotretinoin exposed and unexposed AV patients; the retrospective cohort analysis of the study concluded that there was no significant difference in odds of developing IBD at one year between isotretinoin exposed and unexposed AV patients . The study showed that IBD incidence among isotretinoin-exposed AV patients is very low, and the risk appears similar to unexposed patients with AV . A contrConsiderable observational studies found no association or dose-response relationship between isotretinoin use and IBD development. For instance, Etminan et al. included 2159 IBD cases (1056 with UC and 1103 with CD) and corresponded them with 43180 controls in a nested case-control study; IBD adjusted RR was 0.99 . The RRs for UC was 1.10  and CD was 0.91 (0.37-2.25) . The pooRegardless, although it is unrelated to the scope of this paper, a possible association between IBD and AV was proposed by Coughlin . InteresAfter carefully reviewing the current data in the literature, it seems that there is no actual association between isotretinoin exposure and the risk of inflammatory bowel disease development. Also, due to the difficulties of conducting a randomized control trial to answer this question, our search only focused on the available observational studies. While case reports proposed a correlation between isotretinoin exposure and IBD development, most analytic studies (case-control and cohorts) found no significant association.LimitationsThe majority of the positively linked studies are case reports. No randomized control trials had been conducted to answer this question, up to our knowledge. Thus, the available data are only observational studies. One more limitation is that isotretinoin is mainly used by the teenage group, and that population is out of our inclusion criteria. Still, it is worth running a meta-analysis and including teenagers as they represent a remarkable sample size for isotretinoin exposure.In summary, we presume that there is no significant association between isotretinoin exposure and the risk of IBD. However, isotretinoin might trigger the development of UC (not CD) in individuals with high susceptibility to UC. The decreased risk of CD secondary to isotretinoin exposure is another interesting research question that needs further analysis in a different study. We recommend running a meta-analysis on the current available studies to clarify the association between isotretinoin exposure and the risk of IBD development.


Diet and nutrition, as a modifiable risk factor, have been demonstrated to play a significant role in the etiology of biliary diseases, whereas few comprehensive studies have been able to evaluate the strength and quality of these evidence. This umbrella review aims to evaluate the evidence pertaining risk factors for biliary diseases in terms of diet and nutrition-related indicators.An umbrella review method was adopted: evidence from observational studies up to 22 November 2021 were identified using PubMed, Web of Science, the Cochrane database, as well as manual screening. Eligible systematic reviews and meta-analyses were screened according to inclusion and exclusion criteria. The inclusion criteria were: (1) meta analysis or systematic review; (2) The theme of the study is the relationship between diet or nutrition and biliary tract diseases; (3) Summarized and reported OR, RR or HR values and corresponding 95% CI; (4) No restrictions on the use of participants and languages; (5) Only extract the data of biliary tract diseases from multiple health outcomes; (6) Only the most recent studies on the same subject were included. This study had been registered at PROSPERO (CRD42021293908). For each eligible systematic review and meta-analysis, we extracted the data of general characteristics and the main findings. The methodological quality of the meta-analyses included in our study were assessed by AMSTAR2 and the quality of evidence was evaluated by the GRADE.A total of 323 articles were searched, among which 24 articles with 83 unique outcomes were identified as eligible. 35 of these outcomes were downgraded in GRADE evaluation as they reported heterogeneity. In short, among 83 unique outcomes, 5 were rated as moderate, 16 as low, and the rest as very low. For the prevention of biliary tract diseases, emphasis should be placed on appropriately increasing the intake of fruits, vegetables, coffee and tea, and reducing the intake of alcohol, raw fish and foods with high nitrate. Meanwhile, weight, blood sugar and lipid levels should be controlled, and diabetes should be actively prevented and treated. Drinking is not recommended to prevent gallstones, although studies have shown that it may reduce the risk of cholecystolithiasis.Our study summarizes the current multifaceted evidence on the relationship between dietary and nutritional indicators and biliary diseases, but the quality of all evidence was not high. Evidence from additional high-quality prospective studies are needed in the future.The online version contains supplementary material available at 10.1186/s12986-022-00677-1. Gallbladder cancer and cholangiocarcinoma are major malignancies of the biliary tract. Additionally, according to anatomical position, bile duct cancer can be further divided into intrahepatic cholangiocarcinoma (iCCA) and extrahepatic cholangiocarcinoma (eCCA). Biliary cancer is one of the very lethal malignancies arising from the gallbladder or biliary duct epithelium, representing approximately 3–5% of all cancers of the gastrointestinal system . DespiteDiet and nutrition, as modifiable risk factors, play an important role in the prevention of cardiovascular and cerebrovascular diseases , metabolAlthough there have been a number of meta-analyses summarizing evidence of the association between diet and nutrition-related factors  and the risk of biliary tract cancer, some evidence for the same factor varies considerably , 13. MeaIn addition, cholecystolithiasis and other benign gallbladder diseases, as the most common disease of the biliary system , is cloPrevious studies have found that there are extensive links between drinking and common biliary diseases, and there are also some disputes. Therefore, we will elaborate drinking and biliary diseases as a separate topic.Umbrella review is a summary of existing systematic review and meta-analysis, which aims to summarize the evidence from multiple studies around a research topic , 16. We The protocol of this umbrella review was registered on PROSPERO (CRD42021293908).Two of the authors (Yaoqun Wang and Ningyuan Wen) independently conducted a comprehensive literature search using PubMed, Web of Science, and the Cochrane Database of Systematic Reviews. We searched studies published from database inception to 22 November 2021 to identify systematic reviews and meta analyses of retrospective or prospective studies.Gallbladder cancer:  AND  AND .Bile duct cancer:  AND (biliary Cancer OR biliary tumor OR biliary neoplasms OR biliary neoplasm OR biliary mass OR biliary masses OR cholangiocarcinoma OR bile duct cancer OR bile duct tumor OR bile duct neoplasms OR bile duct neoplasm OR bile duct mass OR bile duct masses) AND .Gallstone:  AND  AND .The search algorithm used the following terms/keywords:Furthermore, manual searches on the reference lists of the identified publications, references of other nutrition related umbrella reviews and research registration platform were also conducted to identify additional studies relevant to our umbrella review. Disagreements were resolved by discussion between the two authors. Detailed search strategies and manual searches results can be found in Additional file The topic of our study is the association between diet and nutrition-related factors and disease, which is not applicable to randomized controlled studies. Hence, our study mainly included systematic reviews and meta-analyses based on cohort or case–control studies.The inclusion criteria were as follows: (1) Meta analyses and systematic reviews of retrospective or prospective studies adhering to PRISMA guidelines; (2) Evaluated the association of diet and nutrition related factors and risk of biliary tract disease. Eligible dietary factors included daily foods, beverages  etc. Eligible nutrition related indicators included BMI, glycemic index (including diabetes), blood lipids etc.; (3) Summarized and reported Odds Ratios(OR), Relative Rates(RR) or Hazard Ratios (HR) and corresponding 95% confidence interval (CI) from studies; (4) No participants and language restriction were used in the selection of eligible studies; (5) Whenever there were multiple health outcomes, we only extract the data of the diseases concerning biliary system; (6) If there are multiple meta-analysis and/or systematic review on the same topic, the most recent study with the largest number of studies and effect size was included.The exclusion criteria were: (1) Animal studies; (2) Narrative reviews, original studies, conference proceedings and letters to editors; (3) Systematic reviews or meta-analyses targeting other non-biliary diseases; (4) Studies in which diet, nutritional factors, or nutritional indicators were not the exposure of interest; (5) Studies that did not provide study specific data: Odds Ratios(OR), Relative Rates(RR) or Hazard Ratios (HR) and corresponding 95% confidence interval (CI).Two authors (Yaoqun Wang and Ningyuan Wen) extracted data separately.Any disagreement in the extracted data was re-evaluated by a third author (Jiong Lu). For each eligible systematic review and meta-analysis, we first extracted the following general characteristics: (1) the first author; (2) the publication year; (3) original article retrieval time; (4) journal; (5) dietary factor or nutrition related indicators in the study; (6) number of studies included;(7) outcomes of interest investigated (disease type), country or region of original studies and the number of corresponding studies; (8) study design; (9) number of cases/total participants; (10) quality assessment of each eligible systematic review or meta-analysis.I2) and p-value; (5) publication bias by Egger's test and small study effect; (6) subgroup analyses; (7) type of comparison  was abstracted when possible.Furthermore, the main findings of each study were also abstracted: (1) the type of effect model; (2) meta-analysis metric; (3) estimated summary effect , 95% confidence intervals (CIs) and p-value of test for estimated summary effect; (4) heterogeneity  with its corresponding 95% CI and r’s test  was usedThe process of literature screening is shown in Fig. Table Tables In the studies we included, there were some dietary factors, such as all spicy food , chili pType two diabetes mellitus was associated with an increased risk of gallbladder cancer  . Comparep = 0.001). Due to the limited number of studies, no further study has investigated the effect of different types of tea intake on reducing the risk of bile duct cancer.The consumption of tea was related to a reduced risk of bile duct cancer  (RR = 0.p < 0.001). In term of fruits consumption, the summary RR was 0.47 (95% CI 0.32–0.61) and the summary RR every 100 g increment a day was not statistically significant. Although the summary data show that vegetable and fruits consumption can reduce the risk of bile duct cancer, a cohort study in this meta-analysis showed that neither consumption were associated with a reduced risk of bile duct cancer. Therefore, the relationship between vegetable or fruit consumption and the risk of bile duct cancer remains to be further evaluated by larger and more comprehensive clinical studies.For fruit and vegetable consumption, we found that they have a significant effect on reducing the incidence of bile duct cancer . In termp < 0.00001) and high-nitrate foods [p = 0.024) increases the risk of bile duct cancer. Because these studies are meta-analyses of retrospective case–control studies and the sample size is small, the evidence they can provide is very limited. There was no obvious significant association of coffee [In addition, some studies from Thailand have shown that eating raw fish   and 1.53  respectively.Similarly, some nutritional indicators are also associated with the risk of bile duct cancer. Both overweight and obesity increase the risk of eCCA . OverweiSince many studies did not separate cholecystolithiasis from other gallbladder diseases such as acute cholecystitis, some of the studies we included may not be limited to cholecystolithiasis.p = 0.049) reduction in cholecystolithiasis risk. As for the relationship between vegetable and fruit consumption and cholecystolithiasis, current evidence suggests that vegetable consumption is associated with a 17%  lower risk and fruit with a 12%  lower risk [p = 0.001) and 3% .Although studies have confirmed that coffee consumption has no obvious relationship with the incidence of biliary cancers, coffee consumption is a protective factor in the formation of gallstones . Overallwer risk . Moreovep < 0.0001), Glycemic load rate [p < 0.0001), diabetes mellitus [In addition, some nutritional indicators may be related to the occurrence of gallstone, such as Glycemic index rate  .In these studies, three meta-analyses reported the relationship between alcohol consumption and gallbladder cancer , 27, 31.p = 0.04).Similarly, in the meta-analysis conducted by Clements et al. [In the study of intrahepatic cholangiocarcinoma, Emma E. McGee et al.  found ths et al. ., drinkeAs for cholecystolithiasis or gallbladder disease, although drinking is a risk factor for biliary cancers, Byung et al. . found t2 < 25%); 36 items had moderate-to-high heterogeneity (25% < I2 < 75%), and 19 items had very high levels heterogeneity (I2 > 75%). In addition, there were 7 items that did not report heterogeneity. For evidence with significant heterogeneity (p < 0.05), the quality of evidence will be degraded in the evaluation of evidence quality.Of all the items we summarized  of methodological qualities of the meta-analyses were assessed as “critically low” by AMSTAR2 scale , 14 due to dose response gradient, and 0 due to plausible confounding.In this umbrella review, we summarized 83 independent outcomes Table . RegardiIn short, among 83 independent outcomes, 5 were rated as moderate, 16 as low, and the rest as very low  was associated with increased risk of gallbladder cancer. Our study found that overweight, obesity and diabetes can increase the risk of gallbladder cancer, but the quality of evidence was rated low or very low. That doesn’t mean the conclusion is wrong. At present, existing studies have proposed the biological pathogenesis of gallbladder cancer caused by the above factors. It is generally believed that overweight and obesity contribute to gallbladder cancer by interfering with the metabolism of lipids and endogenous hormones, affecting the movement of the gallbladder and increasing the risk of gallstones . Other sAs for bile duct cancer, it is important to note that in bile duct cancer studies, some have included gallbladder and bile duct cancer together, or have not performed a subgroup analysis by bile duct cancer type. Subgroup analysis were not reworked because of limited data availability. Our study found that drinking tea is a protective factor of cholangiocarcinoma . In termCholelithiasis or gallbladder diease is also one of the most common diseases of the biliary system. There has been clear epidemiological evidence that gallstone is a risk factor for gallbladder cancer . TherefoSince the relationship between alcohol consumption and biliary tract diseases is complex and controversial, we conducted a separate study on this topic. First of all, as far as drinking is concerned, studies have confirmed that alcohol is an important risk factor for the occurrence of upper gastrointestinal malignancies. For example, Boffetta et al.  reportedSurprisingly, in terms of cholecystolithiasis/gallbladder diease, regardless of the level of alcohol consumption or the intake of different types of alcoholic beverages, all evidence suggests that drinking is a protective factor for the incidence of cholecystolithiasis/gallbladder diease, although the level of evidence is not high. But overall, given that many studies have reported that drinking is harmful to health, we do not recommend drinking to prevent cholecystolithiasis/gallbladder diease.Umbrella reviews is one of the highest level of evidence-based medical evidence at present. It critically evaluates all published meta-analyses and systematic reviews on a medical topic and summarizes evidence from multiple sources , 53. In However, possible limitations should be taken into account in the interpretation of this topic. Firstly, our umbrella review relied only on published systematic reviews and meta-analyses. Some missing individual studies may have had an impact on our results, but the impact was slight because the meta-analyses we included were the most recent, with highest number of studies included. Secondly, for some of the associations we included in this study, the number of original studies included in the corresponding meta-analysis was small, which is likely to result in publication bias. Finally, due to the close correlation between the biliary diseases we studied, and different studies have different classification standards for biliary diseases, we could not achieve a completely unified classification of the diseases in our study, which also affected the research results to some extent.Diet and nutrition, as modifiable risk factors, have important implications for prevention, including cancer and other non-communicable diseases. Our study summarizes the current multifaceted evidence on the relationship between dietary and nutritional indicators and biliary diseases. For the prevention of biliary tract diseases, emphasis should be placed on appropriately increasing the intake of fruits, vegetables, coffee and tea, and reducing the intake of alcohol, raw fish and foods with high nitrate. Meanwhile, weight, blood sugar and lipid levels should be controlled, and diabetes should be actively prevented and treated. Drinking is not recommended to prevent gallstones, although studies have shown that it may reduce the risk of cholecystolithiasis. Overall, the quality of all evidence was not high. Evidence from additional high-quality prospective studies are needed in the future.Additional file 1: Table S1. Search terms utilized in the umbrella review.Additional file 2: Table S2. List of excluded studies and exclusion reason.


Fusobacterium nucleatum (Fn) levels the clinicopathological impacts of cancer.To systematically evaluate the significance of Literature from Pubmed, Embase, and Web of Science was retrieved to collect all English literatures on the correlation between Fn and cancer, and the quality of literatures collected was assessed based on the Newcastle-Ottawa Quality Assessment Scale. The heterogeneity and sensitivity were detected by Stata 14.0 software, and the correlation between Fn and cancer clinicopathological as the effect variables was assessed according to the odds ratio (OR) and 95% confidence interval (CI). The forest plot was drawn.I2 = 21.9%, fixed effect model; nerve invasion: OR = 1.36, 95%CI, I2 = 43.1%, fixed effect model; infiltration depth: OR = 1.94, 95%CI, I2 = 67.2%, random effect model; distant metastasis: OR = 1.80, 95%CI, I2 = 3.4%, fixed effect model]. Patients with MLH1 methylation always present a higher Fn levels than those without methylation . Further, Fn was associatedwith the molecular characteristics of cancers . The cancer patients with high levels of Fn often have worse RFS than those with no/low Fn levels.A total of 19 articles meeting the inclusion criteria were selected. The incidence of Fn prevalence varied considerably (range: 6.1 to 83.3%) and was greater than 10% in 13 of 19 studies. Compared with those with no/low Fn levels, the high levels of Fn was positively associated with vascular invasion, nerve invasion, depth of invasion, and distant metastasis [vascular invasion: OR = 1.66, 95%CI, This review and meta-analysis showed that Fn could be used to predict unfavorable prognosis and function as potential prognostic biomarkers in colorectal cancer (CRC). Our data may have implications for targeting Fn to develop strategies for cancer prevention and treatment. Colorectal cancer (CRC) is the third most common cancer and the fourth most common cause of global cancer deaths . AlthougFusobacterium nucleatum  term from each of the following: (i) Neoplasia or Neoplasias or Neoplasm or Tumors or Cancer or Cancers or Malignancy or Malignancies or Malignant Neoplasms or Malignant Neoplasm or Neoplasm, Malignant or Neoplasms, Malignant or Benign Neoplasms or Neoplasms, Benign or Benign Neoplasm or Neoplasm, Benign; (ii) Bacteria or Fusobacteriaor or Fusobacterium or The inclusion criteria were as follows: (1) Tissue specimens from humans were obtained after surgical resection for the primary tumors. None of the patients received radiochemotherapy before surgery. (2) Original research articles were included in the final analysis. (3) Experiments were conducted using conventional quantitative polymerase chain reaction (qPCR) or 16S rRNA sequencing methodology.The exclusion criteria are as follows: (1) Letters, abstracts, books, short conference abstracts/proceedings, and posters. (2) Cell and animal studies. (3) The publications on a small-sized corhort on the same topic from the same team (shared overlapped participants with large-sized studies). (4) Low quality studies (score < 5). (5) Neoadjuvant or adjuvant chemoradiotherapy.The study design information and outcome data were independently extracted by two investigators (Yi Wang and Yuting Wen). We extracted data on the following: study characteristics , measurement methods, outcome measures, and statistical analysis. We assessed study quality using items from the Newcastle-Ottawa Quality Assessment Scale NOS; .All statistical analyses were performed using Stata 14.0 . Data were extracted from the original research articles and converted into 2 × 2 tables. The definitions of study characteristics, measurement methods, outcome measures were set by the authors of each paper, and the data were combined for analysis only if these definitions were sufficiently similar (determined by consensus). Pooled estimates and corresponding 95% CIs were represented by forest plots. Dichotomous variables  were analyzed with odds ratios (ORs) with mean differences at a 95% confidence interval (CI). Continuous variables were analyzed by the HR, and 95% CI was recorded. Recurrence free survival (RFS) was defined as the time from complete remission to recurrence or follow-up deadline.I2) , then a random-effect model was adopted. Sensitivity analysis was performed to explore the influence of an individual study on the pooled results, by deleting a single study each iteration from the pooled analysis. We used subgroup analysis to evaluate for potential sources of heterogeneity. All important results (p < 0.05) were analyzed using Egger’s and Begg’s tests for publication bias. A p value <0.10 was considered as suggesting the publication bias.Statistical heterogeneity across studies was evaluated with the Q statistics (p < 0.05 was considered significant) and the Inconsistency statistics (I2) . I2 = 0–The literature screening process was presented in I2 = 99.0%, indicating a heterogeneity among the studies. Therefore, the random-effect model was chosen. We further analyzed the subgroups according to race (Asian VS. No-Asian). It presented that the analysis results of each subgroup  were basically consistent with the overall results. Thus, the subgroup analysis did not explain the heterogeneity. To further explore the potential source of the heterogeneity across the studies, we performed sensitivity analyses. First, when the 2 studies ]. Then, the heterogeneity was still significant after removing each study . 14 studies : p = 0.41] and with high heterogeneity . We performed a sensitivity analysis to further identify the possible origins of heterogeneity . The above results are provided in Three studies  reported studies  reported studies  reportedP = 0.02; nerve invasion (present VS. absent): P = 0.04; pT(T3/4 VS. T1/2): P = 0.01; pM(M1 VS. M0): P = 0.01]. Furthermore, the present vascular invasion group showed high Fn levels compared to the absent group [OR = 1.66, 95%CI, I2 = 21.9%, fixed effect model, I2 = 43.1%, fixed effect model, I2 = 67.4%, random effect model, I2 = 67.4%), we further performed the analyses to identify potential sources of heterogeneity . Higher Fn levels were observed in the pM1 group compared to pM0 group [pM: OR = 1.84, 95%CI, I2 = 3.6%, fixed effect model, Five studies  reportedP = 0.01, I2 = 57.5%, random effect model, subgroups , P = 0.01, I2 = 63.2%, random effect model, subgroups , P = 0.01, I2 = 64.2%, random effect model, subgroups , P = 0.02, I2 = 27.0%, fixed effect model, Asian: P = 0.01, I2 = 2.5%; Non-Asian: P = 0.99, I2 = 44.4%), P = 0.01, I2 = 24.2%, fixed effect model, Asian: P = 0.16, I2 = 35%; Non-Asian: P = 0.01, I2 = 0%), To further investigate the effect of Fn levels in cancer, we extracted the molecular characteristic data from each study. 6 studies  were anaP = 0.01, I2 = 42.8%, random effect model, shown in Two studies  reportedI2 = 67.4%), but there was no heterogeneity after removing the study of I2 = 1.8%). The heterogeneity of MLH1 methylation was high (I2 = 57.5%), and the heterogeneity was I2 = 27% after the study of I2 = 63.2%). when the study of I2 = 0%). Heterogeneity in sensitivity analysis of CIMP status results remained high after each study was omitted sequentially. All results are provided in For the comparisons with significant heterogeneity, we performed a sensitivity analysis in this meta-analysis. The sensitivity analysis was performed by omitting individual studies one by one to assess their effect on the aggregated results. When To further clarify the heterogeneity source, subgroup analysis was performed according to race, and the results of MLH1 methylation, CIMP status indicated that race was the main source of heterogeneity. However, the results of pT, pN, and MSI status showed the heterogeneity did not decrease in the subgroup analyses of both Asian and No-Asian.P > 0.05; In this meta-analysis, three corresponding methods were used to evaluate publication bias: Begg’s adjusted rank correlation test, and Egger’s regression test. Statistical significance was also not observed according to Egger’s and Begg’s tests . This conclusion might be conducted due to a small corhort (I2 = 74.1%), although the results seemed not statistically significant by a random-effect model. The main source of heterogeneity was introduced by the work of Our results indicated that the high Fn levels were significantly correlated with the presence of vascular and nerve invasion, suggesting that Fn may promote the aggressive potential of tumor cells. On the other hand,  corhort , compare corhort . BesidesIn our study, the high Fn levels of cancer tissue were associated with key tumor molecular features of CRC, including MLH1 methylation, MSI-high, CIMP-high, KRAS mutation, and BRAF mutation, which were associated with clinical outcomes in CRC. The results of Previous meta-analyse  has showIn conclusion, our study results show that the Fn could be quite useful to predict unfavorable prognosis and function as potential prognostic biomarkers in CRC. There is a discrepancy between our research and previous studies. Although No doubt, certain limitations do exist in this study. We may miss some eligible studies published in other languages, while the unpublished data were not identified. In this case, the publication bias always cannot be absolutely excluded, although no significant publication bias was detected. In addition, there are still many unknowns in the study of bacteria and tumors. For example, whether a bacterial infection is a cause or effect has not been confirmed yet. The existing study  has repoJW and YiW conceived and designed the study. YuW and XuZ evaluated study quality. Study tabulations were carried out by YiW and XL, with final review by XiZ, YX, CR, and YuW performed data analyses. YiW and YH drafted the manuscript. All authors contributed to the article and approved the submitted version.This research was funded by the Natural Science Basic Research Program of Shaanxi, grant number 2020JC-01. The article processing charge was funded by the Natural Science Basic Research Program of Shaanxi, grant number 2020JC-01.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.https://www.frontiersin.org/articles/10.3389/fmicb.2022.945463/full#supplementary-materialThe Supplementary material for this article can be found online at: Click here for additional data file.Click here for additional data file.Click here for additional data file.Click here for additional data file.Click here for additional data file.Click here for additional data file.Click here for additional data file.Click here for additional data file.Click here for additional data file.


MTHFR genetic polymorphisms, maternal folic acid intake, and the time when folic acid intake was started with the risk of congenital heart disease (CHD) and investigated the role of their interaction on infant CHD risk in Chinese populations.To systematically evaluate the association of MTHFR gene, maternal folic acid use, and the time when folic acid use was started. We applied the logistic regression model to explore the strength of association.A case–control study involving 592 CHD cases, 617 health controls, and their mothers was performed. The exposures of interest were single nucleotide polymorphisms (SNPs) of the MTHFR gene at rs1801133 and rs1801131 were observed.Our findings showed that mothers lacking folic acid intake had a significantly higher risk of CHD in offspring . Mothers who started to use folic acid from the first trimester of the fetation  or from the second trimester of the fetation , compared with those starting to use folic acid from 3 months previous to the conception, were at a significantly higher risk of CHD in offspring. Genetic variants at rs2066470 , rs1801133 , and rs1801131  were significantly associated with the risk of CHD based on the multivariate analysis. Additionally, statistically significant interactions between maternal folic acid intake and genetic variants of the MTHFR genetic mutations.An association of maternal folic acid intake and the time when intake was started with the risk of CHD in offspring was found. What's more, maternal folic acid fortification may help counteract partial of the risks of CHD in offspring attributable to http://www.chictr.org.cn/edit.aspx?pid=28300&htm=4, identifier: ChiCTR1800016635. Congenital heart disease (CHD) is caused by abnormal cardiac development during the embryonic period, which refers to a cluster of structural heart and vascular defects at birth. It is a primary common cause of the congenital anomaly that led to disability and death in infancy and is responsible for one-third of all major congenital malformations, afflicting ~1% of live birth and birthing the 1.35 million infants with CHD each year worldwide . ConsideMTHFR) gene is frequently involved in the etiology of CHD. The MTHFR, encoded by the MTHFR gene, takes a part in the folate metabolism and catalyzes the conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate  within the presumed regulatory domine also inhibited the enzyme activity  and intracytoplasmic sperm injection (ICSI) were excluded. Mothers who had reported or were diagnosed with depression or a psychiatric illness were excluded.In this, we conducted a case–control study. From November 2017 to January 2020, the recruitment of the case–control study was performed in the Hunan Provincial Children's Hospital, Changsha, Hunan Province, China. Two different apartments in the same hospital performed the present study, one was the Department of Cardiothoracic Surgery that provided cases and the other was the Department of Child Healthcare that recruited controls during the same study period as the cases. Eligible participants in this hospital were conducted health counseling or a medical examination. Children afflicted with CHD and their mothers were included in the case group. As a control, children diagnosed with no occurrence of any congenital deformities after medical examination and their mothers were recruited into the control group. We required that all cases and controls were recruited when children were younger than 1 year to minimize the recall bias of exposure during the pre-pregnancy to the early stage of this pregnancy. Considering potential confounding factors from genetic and cultural differences related to the ethnic background, all eligible participants were of Han Chinese descent. Additionally, eligible participants were interviewed face-to-face in the same way to collect the personal information and professionally trained investigators performed the interview for the quality of a questionnaire. All participants signed informed consent, belong to singleton pregnancies for this pregnancy, and provided the blood sample. However, we excluded cases with syndromic CHDs and structural malformations involving another organ system or known chromosomal abnormalities. The children whose mothers conceived this time by assisted reproductive technology including We also collected information by a standardized questionnaire as follows: child's gender, maternal demographic characteristics , family history , adverse pregnancy history before this pregnancy , personal lifestyle during the periconceptional period , and history of exposure to environmentally hazardous substances in the periconceptional period . In China, each pregnant woman is given a perinatal health care handbook (PHCH) that recorded pregnancy or personal information by a medical professional or the woman, including the basic demographic characteristics, personal habits, family history, folic acid fortification, medical examination results, and medical history during this pregnancy. We confirmed the correspondence of information from the questionnaire with PHCH to control the accuracy of the questionnaire. Face-to-face investigations and PHCH, considered the most trustworthy information source, were the source of relevant information, which could help to collect information accurately and integrally.MTHFR gene  <10% were excluded. In the end, the loci rs2274976, rs4846052, rs7525338, rs1476413, rs1801133, rs4846051, rs2066470, and rs1801131 of the MTHFR gene, all within the coding region, were included as candidate loci in the present study.A previous study expounded on the selection method of candidate loci of the HFR gene . SNPBrowMTHFR gene. We required that the error rate of genotyping ≤ 5% and the sectionalization of the control and case was blinded to the experimenters performing the genotyping.Genotyping was performed by 3 ml of peripheral venous blood from children. EDTA-treated (ethylenediaminetetraacetic acid) anticoagulant tubes reserved blood samples provisionally, which were then centrifuged at 1,300 g for 15 min. After centrifuging blood samples, blood cells were separated and preserved at −80°C before genotyping was conducted. Based on the manufacturer's standard protocol, blood cells extracted genomic DNA, dissolved in sterile TBE (Tris-borate-EDTA) buffer, which was applied to the QIAamp DNA Mini Kit . Ultraviolet spectrophotometry detected the concentration and purity of the DNA solution, which could help detect whether the DNA was appropriate as a template for polymerase chain reaction (PCR). A matrix-assisted laser desorption and ionization time-of-flight mass spectrometry MassARRAY system  tested genetic polymorphisms of the MTHFR gene in the control group. Based on the two-phase analytical method from genetic model selection (GMS), we assessed the association of MTHFR genetic polymorphisms with CHD risk, and the previous study described the calculation process . Odds ratios (OR) and their 95% confidence intervals (95% CI) calculated by the logistic regression analysis were applied to evaluate the strength of associations. Considering confounding factors, adjusted ORs (ORadj), obtained from multivariable logistic regression, were used to evaluate the independent risk factors of CHD. Considering the potential confounders on the interaction term, we entered the covariate-by-environment and the covariate-by-gene interaction terms in the same model when assessing the gene-environment (G × E) interactions  to correct it. All statistical analyses were conducted by SAS 9.1 .In the study, absolute numbers and percentages described the qualitative data, and its comparisons between two groups applied the Pearson chi-square test or Fisher's exact test. For the ordinal categorical variable, the Wilcoxon rank-sum test was applied to calculate the difference across the two groups. The Hardy–Weinberg equilibrium (HWE) was gauged by genotype frequencies of the  process . Accordiractions . All tesP < 0.05 were adjusted when performing the multivariable logistic regression.From November 2017 to January 2020, we recruited a total of 592 mothers and their CHD infants into the case group and 617 mothers and their healthy infants into the control group. A total of 132 (10.9%) cases were diagnosed with atrial septal defects, 434 (35.9%) cases were diagnosed with ventricular septal defects, 25 (2.0%) were diagnosed with atrioventricular septal defects, 163 (13.1%) were diagnosed with patent ductus arteriosus, 32 (2.6%) with tetralogy of Fallot, 7 (0.6%) with aortopulmonary windows, and 3 (0.2%) with complete transposition of great arteries. Notably, some cases were diagnosed with multiple CHD subcategories simultaneously, so the total amount of the various subcategories was not equal to 592. P = 0.000). The present study showed mothers not using folic acid were significantly associated with a higher occurrence of CHD in offspring when compared with those using folic acid . Meanwhile, the time when folic acid intake started was related to the CHD risk. Mothers who started to use folic acid from the first trimester of the fetation  or from the second trimester of the fetation , compared with those starting to use folic acid from 3 months previous to the conception, were at a significantly higher risk of CHD in offspring.As P-value of the HWE test of the MTHFR gene. The frequencies of minor alleles for two loci (rs7525338 and rs4846051) were absent and excluded from further analyses. The HWE test suggested that the genotype frequencies of the MTHFR gene in the control group, shown in ZHWDTT statistic of every locus, whose results were shown in ZHWDTT statistic with C = 1.645, exhibited as follows: The genetic models of SNPs including rs2274976, rs1476413, rs1801133, and rs1801131 were sorted into the additive model. The genetic models of rs4846052 and rs2066470 were sorted into the dominant model. The genetic models of overall SNPs at the MTHFR gene were applied to explore the correlation of SNPs with the CHD risk on the counterpart for the genetic model.The Hardy–Weinberg disequilibrium trend test was applied to calculate the MTHFR gene related to the CHD risk were displayed in Genetic polymorphisms of the MTHFR gene and folic acid fortification on the risk of CHD were summarized in MTHFR gene at rs1801133  and rs1801131 . We performed the crossover analysis to further assess the interaction effects of MTHFR SNPs and maternal folic acid on the occurrence of CHD ; one resulted in the conversion of the amino acid alanine to valine  and the other rendered a Glu-Ala change with decreased enzyme activity  can be found below: The studies involving human participants were reviewed and approved by the Ethics Committee of Xiangya School of Public Health Central South University (No. XYGW-2018-36). Written informed consent to participate in this study was provided by the participants' legal guardian/next of kin.SZ, JL, and YLi performed the experiments. JD and TW analyzed the data and statistical analyses. PZ and YLiu contributed reagents/material/analysis tools. TZ, XS, and JQ wrote the main manuscript text. JS, LC, JW, and MS collected references and managed data. All authors contributed to the article and approved the submitted version.This research was supported by the National Natural Science Foundation of China (Grant Numbers: 82073653 and 81803313), the China Postdoctoral Science Foundation (Grant Number: 2020M682644), the Science and Technology Planning Project of Guangdong Province (Grant Number: 2020A1414010152), the Hunan Provincial Science and Technology Talent Support Project (Grant Number: 2020TJ-N07), the Hunan Provincial Key Research and Development Program (Grant Number: 2018SK2063), and the Open Project from NHC Key Laboratory of Birth Defect for Research and Prevention (Grant Number: KF2020006).The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Colorectal cancer (CRC) is a malignant tumor of the colorectal mucosa epithelial tissue transformed. The fusion of data for medical imaging has become a central issue in such biomedical applications as image-guided surgery and radiotherapy. Currently, CRC has been one of the most threatening tumors affecting people's health worldwide. The excision repair cross-complementation group 1 (ERCC1) is a key enzyme for nucleotide excision repair (NER). Emerging epidemiological studies have indicated that the presence of colorectal cancer (CRC) may be relevant to the ERCC1 rs11615 genetic polymorphism. However, the results of ERCC1 rs11615 on CRC in these studies are controversial. We searched PubMed, Web of Science, Embase, CNKI, and CBM databases for the effects of ERCC1 rs11615 variant on CRC development. There was no meta-analysis focused on the diagnosis of colorectal cancer with ERCC1 rs11615 variant. We creatively carried out a meta-analysis of nine case-control studies and used Stata (version 12.0) software to integrate the pooled odds ratios (ORs) corresponding to a 95% confidence interval (CI) of overall and subgroup analysis. Our results suggest that a significant correlation was observed between rs11615 and the susceptibility of CRC OR 95% CI = 1.13 (1.04-1.23) under an allele genetic model and OR 95% CI = 1.14 (1.01-1.30) under a dominant genetic model for overall CRC. Significant statistical difference was also noted in Asians rather than Caucasians based on the ethnicity subgroups. These results suggested that there is a certain association between rs11615 and the susceptibility of colorectal cancer in the Asian populations. T > C . As one of the most common SNP of ERCC1, rs11615 polymorphism, a base substitution of ancestral allele C to mutation allele T, has been demonstrated that modify the risk for various cancers, for example, non-small-cell lung cancer, glioma and meningioma, esophageal adenocarcinoma, and gynecology tumors like ovarian and cervical cancer [Colorectal cancer (CRC) is a malignant tumor of the colorectal mucosa epithelial tissue transformed. It is transformed under the factors of genes, diets, environment, and other pathogenic reasons . Accordil cancer –17.In the past decade, extensive researches were done to find the biomarker for screening for colorectal cancer . HoweverA search strategy of literature with the following keywords: , (“Excision repair cross-complementation group 1” or “ERCC1”), and (“polymorphism” or “genotype” or “variant” or “SNP”) were utilized to search in various databases. We searched keywords in PubMed, Embase, Web of Science, and CNKI, CBM in English or Chinese, respectively. Two authors finished the search independently, and the final search was until the date of July 2017. Publications in English or Chinese were checked. We also checked related references to included studies to find out if there are any other potentially eligible essays.We will intake the publication if it satisfied with following conditions: (1) studies that assessed the polymorphism of ERCC1 rs11615 in CRC patients; (2) using a case-control study or cohort study design; (3) patients in case group are diagnosed with cancer, and populations in control group or based populations are unrelated with CRC clearly, without limit of age, gender, and nationality; (4) each group has described the frequency of genotype in detail; (5) showed data of an odd ratio (OR) with corresponding 95% confidence interval(CI); (6) provided details of detection technology of genotype.Exclusion criteria: (1) the claim of the study did not mention the relationship of ERCC1 rs11615 polymorphism with colorectal cancer; (2) a meta-analysis or system review; (3) diagnosis of patients is not clear; (4) frequency in each genotype or some important data are not extractable.Two researchers (Zhifeng Qiu and Min Liu) screened all records independently on the basis of inclusions and exclusions and conducted independent data extraction. They asked help from the third person (Wen Liu) if there is a dispute. We discussed to reach at a consensus. If reports are from the same center or cohort study, we will adopt the one which was the most recent one or most participants.We extracted the frequency in each genotype from eligible studies. The first author's name, the year of publication, the object of study in different races, the study design, sample quantity of case and control, based populations, the method of genotyping, and sample source are also extracted by the two authors independently.Z test (P < 0.05 was regarded as having a significant difference). To check the heterogeneity of the between-study, we used Q test and I-square. If P value of Q test is less than 0.1, and I-square is greater than 50%, we selected a random model. Otherwise, we chose a fixed model [P < 0.05 (two-sided) was regarded as statistically significant.We made use of odds ratios (ORs) corresponding to a 95% confidence interval (CI) to assess the strength of the link between ERCC1 rs11615 genotype allele T mutation and CRC compared to allele C. Homozygote model (TT vs. CC), dominant model (TT + TC vs. CC), recessive model (TT vs. TC + CC), and allele model (T vs. C) were applied. We recalculated the ORs after stratification of the ethnicity or other factors that may impact the result. The pool ORs was calculated by the ed model . Egger'sMedical image security is an important issue when digital images and their pertinent patient information are transmitted across public networks. There are ethical and legal obligations for health care providers to preserve the privacy and confidentiality of patient information, which can contain some of the most intimate information conceivable about an individual. Despite the advantages of electronic medical records (EMR), there is a higher chance of disclosure of information to the public compared to other formats such as paper-based records. Three aspects of security arise in relation to dealing with medical images: confidentiality, reliability, and availability.P > 0.05) among seven studies, but not in the study of Yueh et al. and Moreno et al. (P = 0.049 < 0.05) [Six hundred and eighty-nine articles were found after entering key terms. But only 33 articles were chosen to enter the full-text view phase. Finally, 9 case-control studies, including 2,181 clear-diagnosed cases and 2,828 controls, were analyzed after discarding reviews, duplicates, or those fail to meet the inclusion standards. Details for the literature search and screen were presented in  < 0.05) , 25.P = 0.004, Pheterogeneity = 0.51, and I2 = 0.0%), a dominant model , a recessive model , and a homozygote model . Stratification by ethnicity confirmed that subjects carrying T genotype increase significantly associated with CRC in Asians. This significance was also found in other genetic models . However, these associations cannot be found in Caucasians, under any contract model. OR = 1.08, 95% CI = 0.97 − 1.21, Pheterogeneity = 0.51, and I2 = 0% under the allele model; OR = 1.09, 95% CI = 0.90 − 1.32, Pheterogeneity = 0.51, and I2 = 0% under the dominant model; OR = 1.11, 95% CI = 0.94 − 1.32, Pheterogeneity = 0.4, and I2 = 0.7% under the recessive model; OR = 1.16, 95% CI = 0.92 − 1.46, Pheterogeneity = 0.51, and I2 = 0% under the homozygote model. We reanalyzed based on in accordance with HWE. It came out that no significant association between rs11615 polymorphism and colorectal cancer susceptibility.In this merge meta-analysis, all results of the test for association and heterogeneity were displayed in t = 1.77 and P = 0.12 under a dominant model and t = 0.76 and P = 0.0.473 under an allele model (data not shown). In the Begg's test, Pr > ∣z | = 0.348 (continuity corrected) under a dominant model, Pr > ∣z | = 0.754 (continuity corrected) under an allele model. Begg's funnel plots of other genetic models were shown in With the OR-value as the abscissa, the standard deviation of the log (OR) as the ordinate to draw funnel plots. As displayed in The incidence of colorectal cancer between the ages of 30-50 was 50/105 yearly. And the number was double in the age of 50-70. Gradually it rose four times at ages > 70 years . CurrentNucleotide excision repair is a momentous pathway to repair damnifications no matter brought about by endogenic or exogenous reasons. ERCC1-XPF is not similar to other proteins. As a specific endonuclease, it cuts 5′ of the damaged segment in NER. It is also to the recombination and repair of DNA interstrand cross-links . The resT > C polymorphism and risk of lung cancer in Asians rather than Caucasians [This meta-analysis is an attempt to analyze the potential correlation between the genetic variant of ERCC1 rs11615 and colorectal cancer as well. In this merged analysis, we demonstrated that the susceptible risk of colorectal cancer was associated with the TT variant of ERCC1 Asn118Asn (rs11615) and TC heterozygote compared to wild-type CC homozygote in the overall population. It is the same as Gil et al.'s observation that interaction existed between genotypes of T allele mutant site and morbidity of CRC . Howeverucasians . To noteucasians . We agreucasians . Most ofucasians . Li et aucasians . To our ucasians , 42. Seeucasians . Expressucasians , 45. ERCAmong the nine studies we included, some limitations were discovered when we conducted this meta-analysis. First of all, the source of the case, such as classification of pathological diagnosis, and specific location of cancer was not entirely consistent or not mentioned. We need more messages like family history, exposure history of smoke and alcohol, age, and gender to obtain the adjusted OR. Moreover, detection techniques of disease and diagnostic criteria may also contribute a certain impact to these effects. Although we have collected all the relevant literature as far as possible, we may ignore some of the “gray literatures” such as conference articles, special reports, and so on. What is more, it may result in missing some published literature in other languages. Besides, this study only focused on the SNP loci on the ERCC1 rs11615, without considering other sites caused by the linkage disequilibrium, and further haplotype analysis was not taken into account. The factors given above may cause bias.With those limitations in mind, our meta-analysis results indicated that ERCC1 rs11615 polymorphism carrying T variant had an association with colorectal cancer in Asians and are still credible. There is evidence to support a certain predictive effect of ERCC1 and tumor susceptibility. In the future, we need more well-designed and large sample size investigations to confirm the precise correlation between ERCC1 rs11615 polymorphism and CRC susceptibility.


Non-statistically significant negative associations between metformin use and incidence and prognosis of thyroid cancer were found in the current analysis, although the quantity and quality of the evidence were limited. Futher investigation is needed to evaluate the clinical benefits of metformin on thyroid cancer prevention and treatments.Metformin has been suggested to reduce thyroid cancer incidence and to improve thyroid cancer prognosis. We aimed to evaluate the associations between metformin and thyroid cancer incidence and prognosis . Cochrane Library, PubMed, ClinicalTrials.gov, and U.S. National Library of Medicine Clinical Trials were searched through the end of December 2021. Data were collected from original observational studies or clinical trials on the incidence or prognosis of thyroid carcinoma outcomes in type 2 diabetes mellitus (T2DM) patients with and without metformin use. Risk of bias in non-randomized studies of interventions (ROBINS-I) tool and Grading of Recommendations, and Assessment, Development and Evaluations (GRADE) approach were used to evaluate the risk of bias and quality of the body of evidence, respectively. In general, 4 studies were related to the thyroid cancer incidence, including 1,705,123 participants metformin users and non-users and yielding a total of 3,238 thyroid cancer events; 3 studies reported the prognosis of thyroid carcinoma based on a total of 4,972 individuals with primary thyroid carcinoma and comorbid type 2 diabetes, and the number of thyroid cancer prognosis cases ranged from 3 to 79. The overall risk of bias of the included studies ranged from moderate to serious. In the random-effects model, the summary relative risk (SRR) for thyroid cancer incidence was 0.743 (95% CI: 0.453–1.220; I Thyroid carcinoma is one of the most common malignant endocrine tumors cancer in young women , and femRecently, a recognition that hyperinsulinemia is related to an increased risk of most cancers has been raised . These pAccordingly, these findings have led to a keen interest in antidiabetic drugs to prevent cancer. At present, several studies indicate that antidiabetic drugs, particularly metformin, could play a vital role in the development of carcinoma –22. MetfAlthough some evidence indicates that metformin may decrease the incidence and the prognosis of thyroid cancer, such as metastasis, recurrence, and progression-free survival, findings from other studies did not support the hypothesis –31. MoreThe search was restricted observational studies and clinical trials. The PRISMA checklist was applied to guide the analysis’s procedure when developing a systematic review protocol for the current analysis . Of thesst, 1970, to December 1st, 2021.The following predefined inclusion criteria were incorporated in the meta-analysis: (1) in human; population independent from other studies to avoid giving double weight to estimates derived from the same study; (2) patients who were treated with metformin alone or in combination with other antidiabetic treatments; (3) the outcomes of interest were incidence and prognosis of thyroid carcinoma measured by the occurrence of thyroid carcinoma, the metastasis, the recurrence-free survival, and the progression-free survival  of thyroid cancer, respectively; (4) studies have adequate information to assess the relative risk estimates (Odds ratios (ORs)/Hazard ratios (HRs)) with the 95% confidence intervals (CI); or studies were reported such information which could be derived based on the reported results or obtained by contacting the original authors; (5) original observational studies (case-control study or cohort study) or the clinical trials with any duration of follow-up; (6) published full-text report; in English-language; (7) if more than one study were published from the same cohort and objectives, the data were collected from the one with the most detailed information for both outcomes and exposure, or the one with the most comprehensive population; and (8) the search was limited to articles published from January 1The exclusion criteria were: (1) patients with type I diabetes only; (2) abstract, case report, review, meta-analysis, and letter to the editor; and (3) a lack of explicit methodology and results, duplicate publication. A PRISMA flow diagram for the study selection in the meta-analysis was summarized in Data were reviewed and extracted by two authors.  Full-text or report of each study was reviewed to decide its eligibility and then tabulated all the relevant data independently, the discrepancies of data extraction between two authors were resolved by discussion and consensus. The extracted data from each selected article was collected and summarized as (1) general information ; (2) study design; (3) sample size (cases and controls or cohort size); (4) exposure ascertainment: ; (5) comparison group (Non-antidiabetic drug use/Never used metformin); (6) primary outcome (incidence or prognosis of thyroid cancer): a clearly stated diagnosis of thyroid cancer; or thyroid cancer with metastasis or thyroid cancer recurrence-free survival or thyroid cancer progression-free survival; (7) Adjusted variables included in analyses, such as age, gender, BMI, other antidiabetic drugs used, the severity/duration of diabetes, smoking, education level, comorbidity, previous thyroid diseases, and etc. The summary of the characteristics of the included studies is displayed in Risk of bias assessment was conducted by paired authors  independently using the Risk Of Bias In Non-Randomized Studies of Interventions (ROBINS-I) tool . AccordiThe Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach  was applSummary risk ratio (SRR), defined as the exponent of the inverse-variance weighted mean of the natural logarithm of the relative risk estimates (HRs/ORs) , with thI2 index; [I2 ≥ 50% and P-value <0.05 were considered heterogeneous among studies; a fixed-effect model was used to estimate the pooled SRR when I2 < 50%; while the random-effects model was adopted if I2 ≥50%. Forest diagrams were plotted to present the pooling of individual risk ratios to estimate SRRs for all thyroid cancers. Additionally, Egger’s linear regression [The heterogeneity across studies was evaluated using 2 index;  I2 ≥ 50%gression  was condgression .http://www.Rproject.org/)  using the R package “metafor.” [robvis tool was applied to create risk-of-bias plots; [Statistical analyses were conducted using the statistical software R version 3.5.2. , not addressing the research questions (n = 72), and not human studies (n = 4). Three studies from the same cohort –48, and Among all seven included studies (one case-control study and six cohort studies), three were conducted in Korea, one in China, two in the United States, and one in the U.K. Six of the seven studies applied adjusted multivariable analyses; , 33–35 AI2 reflected 88.7% heterogeneity . The funnel plot conducted by Egger’s test , as well. All of these findings are presented in Three studies assessed the prognosis of thyroid carcinoma with a total of 4,972 patients who had thyroid cancer with metastasis , or thyrDespite the risk of bias for both incidence and prognosis of thyroid cancer studies ranged from moderate to serious according to the ROBINS-I Assessment approach , the quaIn general, the current meta-analysis of observational studies assessed the associations of metformin use with the development and prognosis of thyroid cancer; specifically, non-statistically significant negative associations between metformin use and incidence and prognosis of thyroid cancer were found; and the certainty of the evidence was low due to imprecise estimates, heterogeneity across the studies, and risk of bias in the assessment of outcomes.Previous research suggested that an association has been observed between increased IR and the risks of several common carcinomas, including differentiated thyroid carcinoma (DTC) , 53. CleAlthough increasing evidence indicates a potential antitumor effect of metformin in thyroid cancer cell lines in vitro , 61, resMany preclinical studies , 64, 65 The present meta-analysis has several strengths. To the best of our knowledge, no other meta-analysis has been conducted on the association of metformin use with the incidence of thyroid cancer, and the association of metformin with the prognosis of thyroid carcinoma. In addition, most included studies applied to adjusted multivariable analyses, and several important confounders, including age, BMI, the severity/duration of diabetes, other antidiabetic drugs used, and comorbidity, were adjusted for when evaluating the associations between metformin, incidence and prognosis of thyroid cancer in specific populations. Moreover, this study used meta-analysis, a powerful quantitative synthesis skill of data allowing aggregation of studies with similar methodologies and endpoints. Furthermore, we assessed the risk of bias in studies meeting predefined inclusion and exclusion criteria by applying the ROBINS-I tool, and most of the studies were rated as having a moderate risk of bias.Nonetheless, some limitations should be considered. Half of the included studies were based on Real-world data  that was not explicitly designed to assess the association of metformin therapy on thyroid carcinoma. Therefore, possible selection bias from insurance records and recall bias of self-reports cannot be ruled out in our study, and the estimated effects might be biased away from or towards the null . BesidesOverall, the quantity and quality of the evidence were limited in the current analysis, and non-statistically significant inverse associations between metformin use, the incidence and prognosis of thyroid cancer were observed. Further rigorous research, especially well-designed prospective studies with large sample sizes, is needed to disentangle the roles of metformin in thyroid cancer prevention and treatments.S1 Fig(TIF)Click here for additional data file.S2 Fig(TIF)Click here for additional data file.S1 Table(DOCX)Click here for additional data file.S2 Table(DOCX)Click here for additional data file.S1 File(DOCX)Click here for additional data file.S2 File(DOCX)Click here for additional data file.


To combine the current scientific literature evidence and elucidate the differences of lead (Pb) bioaccumulation in human tissues by comparing amyotrophic lateral sclerosis (ALS) patients and healthy controls.We systematically searched for case–control studies on the association of Pb levels with ALS, in human cells, tissues, and body fluids . Then, we performed a meta-analysis for all the tissues in which at least five case–control studies were available: whole blood (9 studies), serum/plasma (5 studies), and cerebrospinal fluid (CSF) (6 studies). Differences between cases and controls were evaluated using standardized mean difference, and combined estimates were derived using random effect maximum likelihood (REML) meta-analyses.p = 0.003), plasma/serum , and CSF .Among 1734 records, we identified 46 full-text studies, of which 14 case–control studies met the meta-analysis inclusion criteria. We found higher Pb levels in ALS cases than controls in blood (standardized mean difference (SMD) = 0.61; 95% confidence interval (CI) 0.20, 1.01; This work provides further evidence of the association between Pb bioaccumulation and ALS in body fluids. The lack of association studies in solid tissues did not allow a robust meta-analysis. Future prospective studies are needed to clarify the causality in the association of Pb bioaccumulation with ALS. Amyotrophic lateral sclerosis (ALS) is an incidence-increasing neurodegenerative disease in adulthood with no cure, which affects the whole compartment of cortical, bulbar, and spinal motor neurons, causing the irreversible collapse of the nervous system control of the voluntary muscle activity, muscular atrophy, and death , 2. The Clinically, fALS and sALS patients undergo similar diagnostic procedures  and pharmacological treatments. However, treatments cannot stop the disease progression, but they can only delay the worsening of the disease. On the other hand, the patients’ age of onset and diagnosis seems to be globally decreasing, with a difference of 5–10-year anticipation in fALS cases in relation to sALS patients, probably attributable to the effect of Mendelian ALS-related gene variants more frequent in fALS rather than in sALS, and not merely to ascertainment bias such the increasingly early diagnosis in healthy individuals with relatives affected by ALS .Along with the environmental factors responsible for sALS, chemicals, toxins , viruses, and others have been counted , diminisRecently, we critically reviewed the ALS–Pb relationship through a systematic review of the scientific literature of the last decade (2011–2020), giving a complete picture of the most recent epidemiological, clinical, and experimental evidence of the pathogenic role of Pb in ALS, reporting also a potential ALS pathogenic mechanism of Pb involving TAR DNA-binding protein misfolding and accumulation . In thatThe research was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement . PrelimiThe reference list of the main reviews on heavy metals and trace elements in ALS patients was also examined to identify additional papers that had been missed. This last task confirmed the lack of specific meta-analysis considering the presence of Pb in human tissues, which is the main aim of this work. Duplicate studies among databases were removed to obtain the first set of papers that focused on Pb and ALS. For search profiles, all titles of the first set of papers were examined and abstracts read of those may be being relevant.Eligible criteria were case–control studies with results on Pb levels, given as mean ± SD or median and interquartile range, measured in any type of tissue of patients with ALS and healthy donors (controls). The eligibility and final inclusion of each manuscript were assessed independently by two groups of authors, and disagreements were deeply discussed between groups to reach a common conclusion. Meta-analysis of selected tissues was performed as described in following paragraph “” sectionmetafor [Combined standardized mean differences between ALS cases and healthy controls and 95% CIs were calculated through a REML meta-analysis to avoid possible heterogeneity between studies . Since, metafor .After an in-depth systematic review of the literature, a total of nine studies with Pb measured in whole blood –23, fivep value = 0.003.The results of the meta-analysis on whole blood Pb are described in Fig. Q  and the I2 statistics (I2 = 84.4%)  and I2 statistics (I2 = 28.9%)  and the I2 statistics (I2 = 80.8%)  Fig. .Fig. 4FoWe have investigated possible publication bias by the analysis of the funnel plot, Galbraith radial plot, and normal quantile–quantile (Q-Q) plot Fig. .Fig. 5FuThe visual inspection of the funnel plots highlights some degree of asymmetric distribution around the central estimates for the analyses in blood and CSF indicating possible source of publication bias. Specifically, one study estimate in blood and one study estimate in CSF fall on the right side of the “funnel triangles” indicating overestimation of the differences between cases and controls. However, no evidence of publication bias can be observed looking at radial and Q-Q plots.To avoid any doubt about the robustness of our results in blood, we run a leave-one-out sensitivity analysis, confirming the significant association in blood Table .Table 1SAmyotrophic lateral sclerosis is a neurodegenerative disease that affects motor neurons. Although it can be defined a rare disease, it leads to a significantly lower quality of life of patients and their families, causing progressive overtime immobility that requires total assistance, resolving with the death of the patients in a period that goes from about 24 to 50 months from diagnosis .Despite the huge attention of research on this topic, much of its etiology is not yet known, suggesting that both environmental and genetic factors contribute to its onset and severity , 4. AmonDue to the reasons mentioned above, this meta-analysis work aims to clarify the association of Pb levels in human tissues with the onset of ALS, a link still not clarified despite the numerous publications on the subject. We conducted a systematic research of the works published until February 2022. The works that met our research criteria were fourteen case–control studies for concentrations of Pb in whole blood, plasma/serum, and CSF. Of these works, nine took whole blood samples, five plasma/serum, and six CSF (some are considering more than a tissue).p = 0.003).For all tissues analyzed, we observed a positive trend that shows an association between the concentrations of Pb and the presence of the disease. However, the only tissue that gave a statistically significant result was whole blood  for all three tissues, we observed in serum/plasma two publications in which Pb concentration was lower in ALS cases than controls. The two articles , 24 repo2+, important component for the formation of the bone matrix [We obtained significant association in whole blood only. This result can be explained by the small number of studies and patients in other matrices, highlighting the importance of further studies in the field. However, it is crucial to consider the distribution of this metal, showing a particular propensity for cellular structures, within which it tends to accumulate. In particular, Pb tends to accumulate inside the erythrocytes rather than into the plasma component –37. One e matrix . The bone matrix , 27.2+) and Ca2+, also binds thiolate proteins (-SH), and as previously seen alters the production of heme groups and induces oxidative stress, also altering systems of protection against this phenomenon [In support of the eligibility of Pb as an etiological factor in ALS is its marked neurotoxic cytotoxicity, also on a charge of the motor neurons, it has been observed that chronic exposure to this metal is accompanied by gradual atrophy of skeletal muscles , 33. Furenomenon , 46. Froenomenon , data thenomenon .Although the present work does not allow to assert a certain correlation between Pb levels in the body and ALS, it positively supports this hypothesis, showing a synergistic enhancement of the literature supporting this thesis and highlighting the usability of Pb levels in whole blood as a biomarker, probably in combination with other factors. Although further studies are necessary in order to increase the statistical power and to better clarify the possible cellular mechanisms underlying the possible role of Pb in the occurrence of ALS, this paper provide a further evidence favoring this hypothesis. Furthermore, as previously discussed, it is not clear if the accumulation of Pb in blood and other biological tissues is the cause or the consequence of the disease making it necessary to clarify this point. Additional epidemiological prospective studies are needed to reduce the risk of misinterpretation due to reverse causation. Besides, the recently developed Mendelian randomization (MR) approach can provide further evidence about causality in this association, as it has recently done to clarify the association of ALS with other traits . As rece