In patients with IgAN, higher u-sCD163 levels were associated with histological lesions of greater severity, as well as more proteinuria and poorer renal function. Additionally, u-sCD163 was correlated with infiltration of tubulointerstitial CD163+ macrophages. High u-sCD163 levels (>3.57 ng/mg Cr) were associated with a 2.66-fold greater risk for IgAN remission failure in adjusted analyses. Adding u-sCD163 levels to the model containing clinical data at biopsy and MEST-C score significantly improved the risk prediction of IgAN remission status (AUC 0.788). Together, our results suggest that u-sCD163 may be a useful noninvasive biomarker to evaluate disease severity and remission status of IgAN.Noninvasive biomarkers of disease activity are needed to predict disease remission status in patients with IgA nephropathy (IgAN). Soluble CD163 (sCD163), shed by monocytes and macrophages, is a potential biomarker in diseases associated with excessive macrophage activation. We investigated the association of urinary sCD163 (u-sCD163) with histopathological activity and clinical manifestations in 349 patients with biopsy-diagnosed IgAN. U-sCD163 was measured  IgA nephropathy (IgAN) is the most common form of primary glomerulonephritis throughout the world and is a leading cause of chronical kidney disease (CKD) and kidney failure . Approxi+ M2c macrophages  are also predictive markers of disease outcome and treatment efficacy , we meas2), secondary mesangial IgA deposition , urinary tract infection or septicemia at time of diagnosis, and use of steroids or immunosuppressants within 3 months before diagnosis.The study retrospectively examined 349 patients with biopsy-diagnosed IgAN. Diagnosis occurred from January 2018 to December 2019 in Zhongshan Hospital, Fudan University. Glomeruli count was required to be at least eight per biopsy section. Patients were excluded if they fit one or more of the following criteria: <18 years old, end-stage kidney disease (ESKD) on admission , mean arterial pressure (MAP), hemoglobin, serum albumin, C-reactive protein (CRP), serum creatinine, 24-hour proteinuria, were collected retrospectively from medical records at the time of kidney biopsy. Hypertension was defined as systolic BP (SBP) of ≥140mmHg, diastolic BP of ≥90mmHg, or use of antihypertension drugs. The eGFR was calculated using the creatinine-based CKD Epidemiology Collaboration (CKD-EPI) equation .Diagnosis of IgAN was based on optical microscopy and immunofluorescence. Evaluation of kidney histologic lesions were graded according to MEST-C score , which w2 or need for renal replacement therapy . Renal RF at 6 is considered short-term RF , partial remission (PR) or remission failure (RF). Absence of proteinuria (proteinuria ≤ 0.3 g/24 h) and lack of worsening of kidney function (<30% reduction in eGFR from baseline) indicated CR. Proteinuria ≤ 1 g/24 h and lack of worsening of kidney function (<30% reduction in eGFR from baseline) indicated PR. Finally, RF was defined as urine protein > 1 g/24 h or proteinuria increase from baseline, worsening of kidney function (≥30% reduction in eGFR), or ESKD . ESKD wa-term RF .Kidney biopsy specimens were fixed with 10% formalin, embedded in paraffin, and cut into 4 μm sections for immunohistochemistry. Sections were labelled with mouse anti-human CD163 monoclonal IgG1 . Average number of CD163-positive cells in glomeruli and interstitium were determined at 400 × magnification. Glomerular infiltrate is expressed as number of positive cells/glomerulus. Interstitial infiltrate is expressed as numbers of positive cells/high power field (HPF). Five fields were selected.U-sCD163, IL-6, and MCP-1 concentrations were measured using enzyme-linked immunosorbent assay (ELISA) kits following manufacturer protocol . Urinary biomarker levels were normalized using urinary creatinine and expressed as ng/g creatinine. All samples were processed in duplicate.P<0.05. Variables with normal distribution were expressed as mean ± standard deviation (SD). Between-group differences were assessed using one-way analysis of variance (ANOVA) and independent-sample t test. Nonparametric variables u-sCD163/Cr, u-IL6/Cr, and u-MCP-1/Cr levels were log-transformed before being compared using ANOVA or t tests.Statistical analyses were performed in SPSS 26.0. All tests were two-tailed, and significance was set at Biomarkers u-sCD163, u-IL6, and u-MCP-1 were categorized into three levels  using tertiles. Uni- and multivariate logistic models were used to examined the effect of biomarker levels on IgAN remission status. Adjusted odds ratio (OR) and 95% confidence interval (CI) were applied to quantify the association between biomarkers and IgAN remission status. Covariates included age, sex, BMI, MAP, eGFR, Oxford MEST-C score, use of RAS inhibitiors, and immunosuppression during follow-up.We created three prediction models to evaluate whether incorporating biomarkers levels will improve the predictive ability. Univariate models included only the biomarkers . Clinical models included major clinical risk factors  at time of biopsy and MEST-C component scores. Predictive power was quantified through the area under the receiver operating characteristic (AUROC) curves. Delong test was used to compare the significant differences between ROC curves.2, and mean proteinuria was 1.47 ± 1.22 g/24 h  IgAN patients with an average age of 40.95 ± 12.73 years were recorded in the database. We summarized patient characteristics, clinical data, and kidney histological evaluations based on u-sCD163/Cr levels Table 1.r = 0.029, p<0.05; r = -0.040, p<0.001; r = 0.311, p<0.001; p<0.0001; We first explore the relationship between u-sCD163 levels with clinical index. Levels of u-sCD163 were positively correlated with serum creatine concentration .In patients with LN and ANCA-GN patients, u-sCD163 is correlated with glomerular CD163rophages , 14. Howp < 0.0001 and p = 0.0002, respectively; p<0.0001; r = 0.056, p<0.0001; r = 0.043, p<0.0001; p<0.0001; r = 0.123, p<0.0001; p<0.0001; r = 0.249, p<0.0001; p<0.0001; p<0.0001; To confirm whether u-sCD163 is a potential biomarker for disease activity assessment, we analyzed the correlation between u-sCD163 concentration and histology in kidney specimens from patients with IgAN. We first analyzed the association between u-sCD163 levels and the Oxford Classification. Our univariate analysis determined that patients with mesangial hypercellularity and those with endocapillary hypercellularity both had higher u-sCD163 levels  with M2c macrophages promoted epithelial-to mesenchymal transition (EMT) of HK-2 cells ; Shanghai Sailing Program (18YF1419800); Clinical and Experimental Research for YSHS Granule (XX); Shanghai Key Laboratory of Kidney and Blood Purification ; Shanghai Medical Centre of Kidney (2017ZZ01015).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.


The optimal blood pressure (BP) management in acute ischaemic stroke (AIS) and acute intracerebral haemorrhage (ICH) remains controversial. These European Stroke Organisation (ESO) guidelines provide evidence-based recommendations to assist physicians in their clinical decisions regarding BP management in acute stroke.The guidelines were developed according to the ESO standard operating procedure and Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. The working group identified relevant clinical questions, performed systematic reviews and meta-analyses of the literature, assessed the quality of the available evidence, and made specific recommendations. Expert consensus statements were provided where insufficient evidence was available to provide recommendations based on the GRADE approach. Despite several large randomised-controlled clinical trials, quality of evidence is generally low due to inconsistent results of the effect of blood pressure lowering in AIS. We recommend early and modest blood pressure control (avoiding blood pressure levels >180/105 mm Hg) in AIS patients undergoing reperfusion therapies. There is more high-quality randomised evidence for BP lowering in acute ICH, where intensive blood pressure lowering is recommended rapidly after hospital presentation with the intent to improve recovery by reducing haematoma expansion. These guidelines provide further recommendations on blood pressure thresholds and for specific patient subgroups.There is ongoing uncertainty regarding the most appropriate blood pressure management in AIS and ICH. Future randomised-controlled clinical trials are needed to inform decision making on thresholds, timing and strategy of blood pressure lowering in different acute stroke patient subgroups.


We investigated whether intraoperative systolic blood pressure (ISBP) is associated with the risk of transient neurologic deficits (TND) following superficial temporal-to-middle cerebral artery (STA-MCA) anastomosis in adult patients with moyamoya disease (MMD). In this retrospective observational study, data from adult patients with MMD who had undergone STA-MCA anastomosis at a single tertiary academic hospital during May 2003–April 2014 were examined. Data on patient characteristics were obtained from electronic medical records, including the details of comorbidities and laboratory findings. TND was the primary outcome of interest. Out of 192 patients (228 hemispheres), 66 (29%) hemispheres had TND after surgery. There were significant differences in ISBP between patients with and without TND. The lowest ISBP quartile was independently associated with TND . Low ISBP might lead to TND after STA-MCA anastomosis in adult patients with MMD. In patients with poor perfusion status, low ISBP was associated with an increased risk of TND. Our findings suggest that strict ISBP control might be required to prevent TND after anastomosis in patients with MMD, in particular, in patients with poor perfusion status. Given limitations due to the retrospective design, further studies are needed to clarify these findings. Superficial temporal-to-middle cerebral artery (STA-MCA) anastomosis is a surgical treatment to reduce the risk of cerebral ischemia in patients with moyamoya disease (MMD) . TransieBlood pressure (BP) variability has been associated with neurologic deterioration following acute ischemic stroke . A commoTherefore, we aimed to elucidate whether intraoperative BP status is associated with the risk of TND following STA-MCA anastomosis in adult patients with MMD, and whether preoperative cerebral perfusion status might mediate this association.This retrospective observational study was approved by the institutional review board of Seoul National University Bundang Hospital (IRB No.B-1411/274-113). The requirement for patient consent was waived due to the retrospective nature of this study and minimal risk to study participants. Data were extracted from electronic medical records.We collected data on patients with adult MMD who had undergone STA-MCA anastomosis at Seoul National University Bundang Hospital between May 2003 and April 2014. Two hundred forty-eight hemispheres of 208 consecutive patients met the inclusion criteria; however, 20 hemispheres were subsequently excluded due to insufficient data (8), postoperative cerebral hemorrhage (6), and postoperative cerebral infarction (6), leaving 228 hemispheres in the final sample.Patient data were extracted from electronic medical records, including patient characteristics, details of comorbidities, and laboratory findings. BP data were collected through routine clinical practice and downloaded from our institution’s clinical data warehouse for the purpose of this study.General indication for revascularization surgery included apparent cerebral ischemia or decreased regional blood flow, vascular response, and reserve in perfusion studies in our hospital . DigitalRegarding anesthetic techniques, similar protocols were followed with study participants. Radial artery cannulation was performed to perioperatively monitor blood pressure. Total intravenous anesthesia with propofol and remifentanil was administered with a target-controlled infusion pump. Intraoperative systolic BP (ISBP) was maintained above the level of the preoperative baseline value. Normocapnia and normovolemia were maintained.After surgery, brain CT was performed to detect any postoperative infarction or hemorrhage. Patients were admitted to a neurological intensive care unit. Neurological examination was performed once patients regained consciousness. Systolic BP (SBP) was kept within 20 mmHg of the preoperative level. Patients’ volume status was maintained as euvolemic.Two nuclear medicine physicians (HYL and JHK) performed independent visual assessments of the SPECT images of each cerebral hemisphere. Disagreements were resolved by discussion and consensus between the physicians. Perfusion status detected on brain SPECT images was classified as “normal”, “mild decreased”, “moderate decreased”, “severe decreased”, or “defect”. Decreased perfusion was defined as cerebral perfusion on basal SPECT within a lower color range compared with contralateral side and/or the surrounding area. Decreased cerebrovascular reserve (CVR) was defined as abnormal cerebral perfusion within a lower color range relative to basal SPECT, after acetazolamide administration. The severity of decreased CVR was classified into “mild”, “moderate”, “severe”, and “defect” . We evalThe primary outcome of interest was the occurrence of TND after surgery. Based on a previous report , TND wasThe following variables were collected and used as confounders in this study: age, sex, mean preoperative SBP, operation time, operation site (right/left), history of smoking, preoperative hemoglobin level, and white blood cell count. In addition, some comorbidities were used as confounders, such as previous stroke, hypertension, diabetes mellitus, coronary artery disease, and thyroid disease. The data on preoperative SBP were collected using the mean value of all SBP readings from hospital admission to entry into the operating room.ISBP data were summarized as a mean, categorized into four groups, using quartiles, and examined for an association with potentially confounding variables. One-way ANOVA or Kruskal–Wallis test was conducted for continuous variables, and chi-square test or Fisher’s exact test was conducted for categorical variables.p-value less than 0.1 in the univariable analysis were included in the multivariable model for adjustment. The following variables were included in the multivariable model: age, cerebral perfusion status, operation duration, operation site, history of stroke, duration of hospitalization, pre-operation mean SBP, preoperative hemoglobin level, and postoperative hemoglobin level.According to TND, the categorized mean ISBP was compared using the chi-square test or Fisher’s exact test. Proportion of confirmed TND cases per mean ISBP category was plotted against the patients’ cerebral perfusion status. The association between TND and mean ISBP was examined by comparing odds ratios (ORs) in a logistic regression model. ORs were adjusted for confounding variables in a multivariable model. Variables with a In the multivariable logistic regression model, a nonlinear term representing the mean ISBP was included to examine a nonlinear relationship between mean ISBP and TND risk. To control for multicollinearity, cantered mean ISBP was used. Moreover, cerebral perfusion status was included as an interaction term to verify its impact on the association between mean ISBP and TND risk.p-values < 0.05 were considered statistically significant.Finally, the proportion of confirmed TND cases per ISBP category predicted by the multivariable regression model was plotted per mean ISBP according to the cerebral perfusion status, controlling for relevant confounders, whereby averages and reference values were used for continuous and categorical variables, respectively. Statistical analyses were performed using SAS 9.4 . p = 0.005, Among 228 hemispheres of 192 patients, 66 hemispheres (29%) had confirmed TND after surgery. Among these patients, 30,853 ISBP measurements were taken, with an average of 136 measurements per patient. Mean  of ISBP per patient was 129.6 (10.9) and 14.8 (4.0). There were no significant differences in baseline characteristics among the groups based on ISBP quartiles . TND wasp = 0.355 and p = 0.157, respectively).The mean ISBP had an effect on the proportion of TND cases , which was independent of the patients’ cerebral perfusion status . The risk of TND decreased as the mean ISBP increased. In addition, preoperative mean SBP, operation site, preoperative hemoglobin level, and hospital stay duration were associated with the proportion of TND cases confirmed within each mean ISBP category. Overall, in each mean ISBP group, patients with a higher mean preoperative SBP or preoperative hemoglobin level, longer hospital stay, and patients operated on the left side were more likely to develop TND . We were not able to discount the possibility that double surgery might affect outcomes. Third, factors related to the type of surgery  were not accounted for in the analysis. Fourth, we divided the mean ISBP into four groups as categorical variables for statistical analysis, and Q2–Q3 (125–133) was used as a reference. However, controlling and maintaining SBP during STA-MCA anastomosis among MMD patients might be difficult in clinical practice. Therefore, SBP of 125–133 should be considered as the target; our results showed that avoiding lower SBP during STA-MCA anastomosis among MMD patients was associated with decreased TND. Fifth, we did not consider postoperative SBP in this study, which may affect the development of TND during the postoperative period. Lastly, we did not consider preoperative ischemic symptoms in this study. As preoperative ischemic symptoms are independent risk factors for postoperative ischemia among MMD patients , they alIn summary, this retrospective cohort study demonstrated that low ISBP might be associated with TND risk following STA-MCA anastomosis in adult patients with MMD. In patients with poor perfusion status, low ISBP increased the risk of TND. Our findings suggest that strict ISBP control might be required to prevent TND in this patient group, in particular, in patients with a poor perfusion status. Given the limitation due to retrospective design, further studies are needed to clarify these findings.


Coarctation of the Aorta (CoA) is a relatively common cardiovascular disorder. The present study aimed to evaluate the effect of COA anatomy and high versus low-pressure balloons on the outcome of balloon angioplasty among neonates and infants.In this retrospective study, the neonates and infants undergoing balloon angioplasty at Namazi hospital were enrolled. After balloon angioplasty, immediate data results were promptly recorded.Moreover, midterm echocardiographic information was collected via electronic cardiac records of pediatric wards and clinical and echocardiographic data at least 12 months after balloon angioplasty. Finally, data were analyzed using SPSS-20.In this study, 42 infants were included. The median age at the time of balloon angioplasty was 1.55 (range 0.1–12) months and 66.7% of the patients were male. The mean pressure gradient of coarctation was 38.49 ± 24.97 mmHg, which decreased to 7.61 ± 8.00 mmHg (P < 0.001). A high-pressure balloon was used in 27, and a low-pressure balloon was used in 15 patients. COA's pressure gradient changed 30.89 ± 18.06 in the high-pressure group and 24.53 ± 20.79 in the low-pressure balloon group (P = 0.282). In the high-pressure balloon group, 14.81% and in the low-pressure group, 33.33% had recoarctation and need second balloon angioplasty (p < 0.021). The infant with discrete coarctation had a higher decrease in gradient and lower recoarctation.Recoarctation rate was lower in the high-pressure balloon. The infant with discrete COA had a better response to the balloon with more decrease in gradient and lower recoarctation rate. Therefore, the stenotic segment anatomy needs to be considered in the selection of treatment methods. Coarctation of the aorta (CoA) is the fifth common congenital heart defect and includes almost 6–8% of all congenital heart diseases, which is estimated to occur one in every 2500 births , 2. LikeIf there is no action to correct CoA, most patients will die during infancy, but in survival cases, it will be associated with cardiac morbidity and mortality. In the largest study on the natural course of the disease by Campbell et al., a mean lifetime of 34 years was reported for patients with CoA if they survived the first year of life. The leading causes of death were heart failure 25%), aortic dissection 21%), bacterial endarteritis (18%), and intracranial hemorrhage (ICH) (12%), respectively [%, aortic%, bacterSurgery was the only option for CoA treatment during four decades. Thereafter, balloon angioplasty was introduced as a less invasive procedure in 1982 . BalloonThe most common complication second to balloon angioplasty is an injury to the femoral artery, which is common in children < 1 year of age. However, its prevalence has decreased since the introduction of the low-profile balloon . Less coThe present study aimed to evaluate the immediate and midterm results of CoA balloon angioplasty among infants with native CoA according to the COA segment's anatomy and tocompare the outcome of low-pressure and high-pressure balloons.In this retrospective study, all infants undergoing balloon angioplasty at Namazi hospital affiliated with Shiraz University of Medical Sciences, Shiraz, Iran, from January 2015 to January 2018 were enrolled. Samples were selected by convenient and available sampling method. Inclusion criteria were neonates and infants (< 1 year of age) who had electronic records and followed-up at least for one year after balloon angioplasty and had a discrete stenosis segment. But the patients with ages > 1 year, no access to follow-up results, COA associated with complex intracardiac congenital heart disease, and long segment hypoplastic aortic arch without discrete stenosis not suitable for balloon angioplasty were excluded.Data of immediate results of balloon angioplasty were recorded from catheterization charts. Also, midterm echocardiographic information was collected from an electronic pediatric cardiac record at least 12 months after balloon angioplasty. Additional information such as age, type of balloon, size of the balloon, ascending aortic pressure, descending aortic pressure, COA gradient, response to balloon dilation, ascending aortic diameter, descending aortic diameter, stenotic site diameter, and complications were also recorded.According to the anatomy of the aortic arch, the patients were grouped to discrete coarctation  group 1), hypoplastic aortic isthmus (Z score of aortic isthmus less than -2) in association with discrete narrowing (group 2), and aortic arch hypoplasia, was defined as an aortic arch diameter less than 50% of the ascending   software (Version 20). The Mann–Whitney U test and Chi-square were used to compare groups and outcomes, respectively. Wilcoxon test was used to evaluate the related samples. Person correlation was used to evaluate the correlation. P less than 0.05 was considered statistically significant.In this study, 42 patients were included. The median age at the time of balloon angioplasty was 1.55 (range 0.1–12) months, and 66.66% were male. In 42.85% of patients, COA was associated with noncomplex chronic heart diseases (CHD) such as the bicuspid aortic valve, mild aortic stenosis, small patent ductus arteriosus, mild mitral stenosis, and small ventricular septal defect (VSD). Six patients had severe heart failure and acidosis and needed starting prostaglandin E1 before the procedure, and other infants had clinically compensated heart failure with dilated left or right ventricle and pulmonary hypertension that needed urgent intervention. The mean diameter and length of the angioplasty balloon were 7.01 ± 1.47 mm and 37.07 ± 11.40 mm.Before the balloon angioplasty, mean ascending and descending aortic systolic pressures were 107.61 ± 32.71 mmHg and 69.21 ± 20.78 mmHg, respectively; with a mean pressure gradient of 38.49 ± 24.97 mmHg that decreased to 7.61 ± 8.00 mmHg (P < 0.001)  with a mean age of 7.82 ± 3.33 months who were mostly boys (77.81%), required second balloon angioplasty. Mean angioplasty balloon length and diameter were 9.11 ± 1.54 and 36.67 ± 5.32, respectively. Before the second balloon angioplasty, the mean gradient was 44.47 ± 34.14 mmHg that decreased to 9.02 ± 4.14 mmHg after angioplasty (P = 0.022). One patient underwent a third balloon angioplasty during the study .Out of 27 patients who had high-pressure balloon angioplasty four patients (14.81%) had recoarctation and needed second balloon angioplasty, and out of 15 patients, who had low-pressure balloon angioplasty, five (33.33%) patients had recoarctation and needed second balloon angioplasty (p < 0.021). One patient in the low-pressure group needed third balloon angioplasty, but no patient in the high-pressure group needed a third balloon .Recoarctation was in one patient (5.26%) in group 1, three patients (25.00%) in group 2, and five patients (45.45%) in group 3.In the follow-up, three cases of aneurysm formation at the site of angioplasty. One aneurysm was with a low-pressure balloon, and two aneurysms were with a high-pressure balloon. All the aneurysms were in group 2 of aortic arch anatomy. Two patients had a loss of pulses for 24 h after the balloon angioplasty that improved by heparin infusion.There was no statistically significant correlation between balloon diameter and change of gradient (P = 0.75).This study aimed to evaluate the effect of coarctation of aorta anatomy and balloon profile on the outcome of balloon angioplasty in infantile coarctation.Recoarctation was lower in infants with discrete coarctation anatomy without arch or isthmus hypoplasia. Therefore balloon angioplasty may be an excellent choice for this patients’ group.In this study, immediate results after balloon angioplasty showed a significant decrease in COA gradient after high pressure and low-pressure balloons, but high-pressure balloons showed more decrease in coarctation gradient.Management of COA is indicated when the gradient during cardiac catheterization is more than 20 mmHg , 16. In In this study, 21% of infants needed reintervention. Other studies have reported a reintervention rate between 6 to 53% for recoarctation of the aorta. There was no statistically significant difference between the patients who need reintervention and others in the age of first balloon angioplasty, the stenotic part's diameter, pressure gradient before the first balloon, and pressure gradient after first balloon angioplasty. Also, other studies showed no difference between the two groups. The recoarctation rates were related to age at angioplasty than to the route, which the procedure was performed, and recoarctation was more in the neonate (< 30 days) .In our study, the pressure gradient of COA decreased more in the high-pressure balloon group, and the rate of recoarctation was significantly lower in this group. For balloon angioplasty of COA, low profile balloons like Tyshak II balloons, which may be introduced through 4-French sheaths or Mini-Tyshack and can be entered via 3-French sheaths should be used. But a new high-pressure balloon for peripheral angioplasty has a low profile and can be entered via 5-Frech sheaths that can be used in infants .Similar studies in all age groups reported the effect of balloon angioplasty immediately after the procedure. A low-pressure balloon is recommended for infants with a small body, particularly in cases with native CoA. In recoarctation cases, the site of aortic tissue usually undergoes some degree of fibrosis. Thus, a low-pressure balloon may result in inconsistent results. However, the infant is usually provided with sufficient time to grow for stenting at an elder age . In the In another study by our team, the rate of recoarctation was reported at four percent in children > 1 year of age , which iIn this study, all age groups had similar immediate responses to decreased gradient, but age groups of < 1 month had more recoarctation than 1–3 months and 3–12 months. Similarly, Sen et al. reported that their studied parameters had no effects on recoarctation, and only the presence of residual coarctation in pre-discharge echocardiography was an independent predicting parameter .In this study, the post-balloon angioplasty aneurysm rate was 7.2%, which varies widely (5–43%) in different studies. This discrepancy can be related to technical differences, duration of the follow-up period, lack of systematic imaging during follow-up in many studies, and differences in the aneurysm detection criteria , 31. It It is still challenging to select the surgical technique or balloon angioplasty because most previous studies were retrospective and single-centered and evaluated the method that selected by health centers and surgeons. In most studies, there is a short follow-up period for the patients and limited data on mortality rates, and both methods are associated with the possibility of aortic rupture, aneurysm, recoarctation, other complications, and even death . HoweverThe present study suffers from some limitations, and small sample size to evaluate all related complications, and a lack of long-term follow-up.Generrally, there was no statistically significant difference between a high-pressure balloon and a low-pressure balloon to decrease the COA pressure gradient. The recoarctation rate was lower in the high-pressure balloon. The infant with discrete COA had a better response to the balloon with more decrease in gradient and lower recoarctation rate. Therefore, the stenotic segment anatomy needs to be considered in the selection of treatment methods.


Of notice, after adjustment on CI, mGFR remained associated with reticulocyte count and albuminuria under ACEI (p = 0.006 and 0.02 respectively). Our results suggest that hyperfiltration is tightly linked to an increased cardiac output which may account for an increased renal blood flow. Chronic hemolysis could be a relevant factor accounting for hyperfiltration potentially acting on glomerular enlargement which appears as a key factor. Our data suggest that cardiac output assessment is a relevant tool in the routine management and monitoring of SCA nephropathy.Glomerular hyperfiltration alone or associated with albuminuria is a well-known feature of sickle cell associated nephropathy. Though, glomerular hyperfiltration is currently considered to be related to a high renal plasma flow and chronic hemolysis, cardiac output influence on measured glomerular filtration rate (mGFR) have not been investigated so far. Thirty seven homozygous sickle cell patients (SCA) from the RAND study investigated before and under angiotensin converting enzyme inhibitor (ACEI) were included. Both mGFR and cardiac index (CI) were high (> 110 ml/min/1.73 m Sickle cell anemia nephropathy may also associate micro and macroalbuminuria and ultimately renal failure9, though the natural history of SCA nephropathy is poorly understood. Nevertheless, this early event, i.e. increased measured glomerular filtration rate (mGFR) was investigated in small but well designed studies10 suggesting that an unusual high renal plasma flow altogether with a low, but sometimes normal filtration fraction was at play11. Though cardiac output is increased in most SCA patients12 altogether with a low blood pressure13 suggesting low systemic vascular resistance (SVR), to our knowledge, cardiovascular parameters associated with mGFR have not been studied so far. We took advantage of our previous RAND trial14 showing a beneficial effect of a 6 months angiotensin converting enzyme inhibitor (ACEI) treatment on macroalbuminuria in adult SCA patients at the time of hyperfiltration to study mGFR correlates with hemodynamic and biological parameters before and under renin-angiotensin system blocker, i.e. presumably in the setting of a normal or low filtration fraction. Our results suggest that mGFR is tighly correlated to cardiac output suggesting an impairment of renal hemodynamic autoregulation.Previous studies reported a very high prevalence of hyperfiltration in young sickle cell anemia (SCA) patients with up to 60–80% in children and 50–60% in young adults2. Thirty three percent of patients were under a long term hydroxycarbamide treatment and 17% with a history of blood transfusions. All patients were normotensive at baseline with a maximum value of 129 and 75 mmHg for systolic and diastolic blood pressure respectively. Pulse pressure (PP) and Pulse Wave Velocity (PWV) median values were 52.8 [49.0–59.0] mmHg and 8.0 [7.1–8.6]m/s respectively. Cardiac index (CI) was high, above 3.5 and 4.5 l/min/m2 in 97% and 51% of patients respectively, and SVR values below normal range (700 dynes/s/cm−5) in 14 cases (38%) with no patients with high SVR values (most below 1000 dynes/s/cm−5). Of notice, CI and SVR did not change under ACEI treatment (4.62 versus 4.66 ml/min/m2 (p = 0.36) and 759 versus 738 dynes/s/cm−5 (p = 0.28) respectively). TRV values were available in 26 patients and above 2.5 m/s in 46% of cases. Mean mGFR assessed by 51Cr EDTA renal clearance was 131 ml/min/1.73 m2 before initiation of ACEI (Table 2) was present in 81% of cases (n = 30) with no significant variation under ACEI treatment whereas DBP and MAP decreased significantly from 57.3 to 54.2 mmHg and 75.2 to 72.8 mmHg (p = 0.02 and p = 0.04 respectively). Before initiation of ACEI, microabuminuria and macroalbuminuria were detected in 48.6% and 43.2% of cases respectively with ACR < 5 mg/mmol only in two patients. Anemia was present in all patients with a median haemoglobin level of 8.3 [7.7–8.9]g/dl, with a high reticulocyte count, plasma LDH and bilirubin concentrations , however renal function was not reported18. Our findings that SVR are below 1000 dynes/s/cm−5 in all cases and low in 40% of patients suggest that renal vascular resistance may also be low. Indeed, an increased renal plasma flow was reported in several studies presumably related to an increased cardiac output though no data were available19. However, renal hemodynamic regulation is expected to increase afferent arteriolar tone in order to counterbalance an increased renal plasma flow20 and thus maintain a GFR within normal values. We may thus speculate that this regulation may be less efficient or possibly impaired in some individuals. Though we cannot fully address the issue of an impaired tubular glomerular feedback, we can rule out in most cases an increased glomerular capillary hydrostatic pressure responsible for hyperfiltration as (1) a low/normal filtration fraction was reported in previous studies11; (2) mGFR was similar before and under ACEI thus pointing out increased renal blood flow (rather than pressure) as a key determinant of hyperfiltration in our patients. We thus speculate that in most SCA patients with glomerular hyperfiltration, filtration occurs along the whole capillary surface due to increased renal plasma flow even in a normal hydrostatic pressure setting . Thus according to this view, normalizing (under ACEI) hydrostatic pressure in a SCA patient would have no short term effect on GFR conversely to ACR which should decrease.Our results show that in our SCA population with glomerular hyperfiltration, mGFR is strongly associated with cardiac output which is increased in most patients altogether with a low SVR in 38% of cases. Of notice, SVR was normal (but not high) in all other cases with no blood hypertension reported despite the presence of albuminuria, thus raising the issue of the pathophysiological process of glomerular hyperfiltration. It has been suggested that glomerular hyperfiltration is driven by increased glomerular perfusion and increased effective glomerular filtration surface area (glomerular enlargement) rather than by increased glomerular capillary hydrostatic pressure, which would separate this condition from early diabetic nephropathy26. This increased glomerular growth can be observed at a time of hyperfiltration as early as in infancy17. Altogether, glomerular hyperfiltration in SCA looks very similar to glomerular hyperfiltration in pregnancy where it is the consequence of increased cardiac output and decreased renal afferent and efferent arteriolar resistance responsible for an increased renal blood flow with glomerular enlargement and no increased filtration fraction16. However, the current view is that relaxin, a pregnancy hormone, which reduces myogenic reactivity of small renal arteries27 is responsible for glomerular hyperfiltration which is not the case in SCA patients, where the basis for renal hyperperfusion remains under debate. Indeed, such hyperperfusion cannot be readily ascribed to anaemia or increased plasma volume because correction of anaemia by HbA-containing RBC transfusions does not reverse hyperperfusion28 and chronic anaemia from causes other than SCA is not usually associated with renal hyperperfusion29. Among other causal factors, chronic hemolysis noteworthy through haem oxygenase–carbon monoxide (HO–CO) system is pointed out as induction of HO–CO might contribute to regional hyperperfusion of the kidney and other vascular beds17. Our previous findings showing that different markers of chronic hemolysis including reticulocyte count were independent risk factors for glomerular hyperfiltration in a SCA population2 are strengthened in this study showing that mGFR is associated with reticulocyte count even after adjustment for cardiac index or SVR in SCA patients under ACEI. Though there may be more than one mechanism by which greater rates of chronic hemolysis could contribute to hyperfiltration in the kidney, our data suggests that chronic hemolysis may be linked to glomerulomegaly dependent hyperfiltration process. According to this view, the reported beneficial effect of hydroxyurea treatment at decreasing hyperfiltration in children30 could be explained either by a sustained improvement of anemia decreasing cardiac output but also a beneficial effect on glomerular remodeling, i.e. glomerulomegaly. We speculate that a glomerular remodeling slowdown could then be an interesting therapeutical target.Alternatively, hemodynamic autoregulation may be preserved and increased effective glomerular filtration surface alone (in the setting of increased glomerular perfusion) may account for mGFR increase by 80% in some cases. Indeed, a glomerulomegaly responsible for an increased glomerular surface/volume and filtration coefficient (Kf) is reported to be a hallmark of SCA nephropathy10, and the high prevalence of albuminuria in SCA patients6. Though an increased glomerular hydraulic pressure (ΔP) is likely to occur at least in macroalbuminuric patients, as a decreased albuminuria under ACEI treatment was detected in this subgroup14, our data showing that mGFR was associated with albuminuria only in patients under ACEI suggests that glomerular remodeling independently of ΔP may account for increased glomerular permeability to albuminuria, presumably through filtration slits stretching. According to this view, ACR values under ACEI would be an interesting bed-side relevant biomarker of glomerulomegaly, i.e. of renal structural remodelling in this population.In addition to hyperfiltration, glomerulomegaly accounts also for the reported increased glomerular permselectivity assessed by fractional clearances of dextran10 or normal11 is unfortunately unknown as renal plasma flow measurement was unavailable for this study. We speculate that alike systemic vascular resistance, low renal vascular resistance may occur in some patients accounting for unusual high mGFR values in the setting of a high cardiac output. Moreover, though we cannot exclude a further decrease renal plasma flow under ACEI, it seems unlikely as CI and SVR did not change. The complex pathological cascades of chronic hemolysis metabolites interplay with cardiovascular/ renal hemodynamics and the relevant determinants of glomerulomegaly responsible for hyperfiltration are obviously beyond the scope of the present study and require to be specifically addressed.Limitation of the study: our data show that hyperfiltration is related to an increased cardiac output, thus leading presumably to a high renal plasma flow. The issue whether in our population, renal vascular resistance would be low as previously reported in SCA patientsTo conclude, our results suggest that hyperfiltration is tightly linked to an increased cardiac output and low systemic vascular resistance which may account for an increased blood flow both in kidneys and likely also in most other organs. These findings stress glomerular enlargement as a likely key step in the history of hyperfiltration and point out cardiac output assessment as a relevant tool in the routine management and monitoring of SCA nephropathy.). All methods were performed in accordance with the relevant guidelines and regulations.All patients signed written informed consents before inclusion in the study. The Regression de l’Albuminurie dans la Nephropathie Drepanocytaire (RAND) study design was approved by the local ethics committee  and registered at ClinicalTrials.gov  was available only in 26 patients). Eligible criteria were adult homozygous SS patients aged > 18 years, with a minimum urine albumin:creatinine ratio (ACR) > 10 mg/mmol creatinine on two different random urine spots performed at least 1 month after any acute SCA complication, and a recent estimated GFR  > 130 ml/min/1.73 m2. Exclusion criteria were acute SCA complication within 1 month prior to study inclusion, patients receiving blood transfusions within a 3-month period or initiation of hydroxycarbamide within 3 months, ongoing pregnancy or treatment with nonsteroidal anti-inflammatory drugs, lithium or antihypertensive agents, human immunodeficiency virus or hepatitis C infection, known allergic reactions to ACEIs or angiotensin II receptor blockers, hereditary or idiopathic angio-oedema, galactosemia or lactase deficiency. Patients were included for 7 months: ramipril was started at 2.5 mg/day after baseline evaluation , increased to 5 mg/day after Visit 2 (V2) 1 month later; treatment was stopped at month 6 following a complete evaluation on Visit 3 (V3). In case of side effects, ramipril was replaced by irbesartan (75 mg up to V2 and then 150 mg/day up to V3). Complete renal and cardiovascular evaluation including measured GFR (mGFR) and doppler echocardiography were performed at baseline and month 6th. ACR ≤ 3 mg/mmol creatinine was considered as normoalbuminuria, microalbuminuria was defined by an ACR of 3–30 mg/mmol creatinine and macroalbuminuria by an ACR > 30 mg/mmol creatinine. mGFR was assessed by 51Cr-EDTA renal clearance, as described previously3. Briefly, 1.8–3.5 MBq of 51Cr-EDTA  was injected intravenously as a single bolus. Average urinary 51Cr-EDTA clearance, average plasmatic 51Cr EDTA and urinary creatinine clearance were determined during five to six consecutive 30-min clearance periods. GFR measurements were average and standardized for body surface area (1.73 m2). Hyperfiltration was defined above a threshold value of 110 ml/min/1.73 m2 for mGFR and renal insufficiency was defined as mGFR < 60 ml/ min/1.73 m2.The RAND study is a prospective multicentric non-randomized trial that took place between September 2010 and September 2014 aimed at studying as a main objective the effect of ACEI treatment on albuminuria after a 6 month-trial (Supplementary information). Forty-two adult patients with sickle cell disease were enrolled and evaluated at month 6, as described in Fig. 32. Briefly, PWV was calculated from measurements of pulse transit time and the distance traveled by the pulse between two recording sites: pulse wave velocity distance (m)/transit time (seconds). It expresses the elastic properties of the descending and abdominal aorta and the iliofemoral segments. PWV was defined as the mean of four determinations. Doppler echocardiography examinations were performed by an experienced physician according to the guidelines33. All the examinations were analyzed off-line blinded to study time point, to clinical and biological data. From M mode, the following measurements were made at end diastole: left ventricular (LV) internal diameter, interventricular, septal and posterior wall thicknesses. LV mass was derived and indexed to body surface area33. From 2D mode, LV volumes and ejection fraction (LVEF) were derived from Simpson’s modified biplane method. Left atrial volume was also measured and indexed to body surface area. From pulsed wave Doppler mode, LV outflow tract time–velocity integral and early peak diastolic velocity of the mitral (E) inflow were measured. Cardiac output was calculated and indexed (CI) to body surface area as recommended35. From continuous wave Doppler, peak tricuspid regurgitation was recorded in multiple views and the highest level of velocity was selected. Elevated pulmonary systolic pressure was defined by a peak tricuspid regurgitation velocity (TRV) > 2.5 m/s36. Systemic Vascular Resistance (SVR) was calculated in units of dyn s cm−5 as: 80 × Mean Arterial Pressure/Cardiac Output .Patients were examined in a quiet, temperature-controlled room. Blood pressure was measured after 15 min of rest in a supine position with an oscillometric method and a cuff of appropriate size. The average of five consecutive measurements was calculated. Aortic stiffness was measured through the carotid to femoral pulsewave velocity (PWV) between the two sites by the foot-to-foot velocity method , as described previously and validated14. Serum and urinary creatinine levels were measured by the enzymatic method on a Konelab 20 analyzer from Thermo Fisher Scientific. Uric acid levels were measured with the Konelab analyzer. Total CO2 in blood, ionized calcium, sodium, and potassium levels were measured with an ABL 815 from Radiometer. Calcium and magnesium serum and urinary levels were measured with the PerkinElmer 3300 atomic absorption spectrometer. Plasma Aldosterone was measured by radioimmunoassay kits (Immunodiagnostics Systems Ltd.) Plasma asymmetric dimethyl arginine (ADMA), symmetric dimethyl arginine (SDMA) and arginin were measured by a high liquid performance chromatography coupled with fluorimeter detection. Other laboratory values were measured using standard hospital laboratory techniques.As previously described assays were performed in our labVariables were expressed as percentages, means ± SD, or medians (IQR: interquartile range), as appropriate. Comparison of biological and hemodynamic data measured at different visits was tested with a non parametric Wilcoxon rank test for quantitative variables. Association between mGFR and variables of interest were tested separately using Spearman correlation test and a multilinear regression analysis when adjustment on CI or SVR was performed. A two-sided P-value < 0.05 indicated statistical significance. Statistical analyses were performed with Statview 5.0.Supplementary Information.


The kidney and the brain, as high-flow end organs relying on autoregulatory mechanisms, have unique anatomic and physiological hemodynamic properties. Similarly, the two organs share a common pattern of microvascular dysfunction as a result of aging and exposure to vascular risk factors  and therefore progress in parallel into a systemic condition known as small vessel disease (SVD). Many epidemiological studies have shown that even mild renal dysfunction is robustly associated with acute and chronic forms of cerebrovascular disease. Beyond ischemic SVD, kidney impairment increases the risk of acute cerebrovascular events related to different underlying pathologies, notably large artery stroke and intracerebral hemorrhage. Other chronic cerebral manifestations of SVD are variably associated with kidney disease. Observational data have suggested the hypothesis that kidney function influences cerebrovascular disease independently and adjunctively to the effect of known vascular risk factors, which affect both renal and cerebral microvasculature. In addition to confirming this independent association, recent large-scale human genetic studies have contributed to disentangling potentially causal associations from shared genetic predisposition and resolving the uncertainty around the direction of causality between kidney and cerebrovascular disease. Accelerated atherosclerosis, impaired cerebral autoregulation, remodeling of the cerebral vasculature, chronic inflammation and endothelial dysfunction can be proposed to explain the additive mechanisms through which renal dysfunction leads to cerebral SVD and other cerebrovascular events. Genetic epidemiology also can help identify new pathological pathways which wire kidney dysfunction and cerebral vascular pathology together. The need for identifying additional pathological mechanisms underlying kidney and cerebrovascular disease is attested to by the limited effect of current therapeutic options in preventing cerebrovascular disease in patients with kidney impairment. Chronic kidney disease (CKD) affects around 10% of the general population globally and has an increasing prevalence, posing a major burden on public health systems . HoweverBoth the kidney and the brain are high-flow end organs that receive blood through the renal arteries and the carotid and vertebrobasilar circulation, respectively. Their microvasculature is composed of small arteries, penetrating arterioles, capillaries, and venules, overall referred to as small vessels. The small vessels of the kidney and the brain are unique as their cells receive continuous high-volume flow throughout systole and diastole against very low vascular resistance.Given the particular anatomy and physiology of small vessel circulation, kidney and brain tissue are susceptible to the same microvascular insults in response to aging and exposure to vascular risk factors. As a result, these two tissues are more prone to developing what is commonly referred as SVD . This teIt has been hypothesized that the pathophysiology of SVD in the kidney is similar to that of the brain. The same features of small arterial dilations and aneurysms as well as lipohyalinosis and fibrinoid necrosis are seen in the brain as in the kidneys. Because of these shared hemodynamic properties between the brain and the kidney, kidney disease has been proposed to progress in parallel with cerebrovascular pathology and particularly SVD.Several epidemiological observations support the hypothesis that kidney impairment is associated with higher risk of stroke, independent of the etiological subtype. When assessing the association between kidney dysfunction and stroke, studies have used reduced estimated glomerular filtration rate (eGFR), albuminuria, and CKD diagnosis as indices of kidney dysfunction. GFR, representing the process of ultrafiltration of plasma from glomerular capillaries into Bowman's space, is estimated from serum concentrations of endogenous filtration markers, such as creatinine or cystatin via equations which account for non-GFR related factors . The glo2) was associated with a 2.5-fold higher risk of developing stroke  . The main sources of ischemic stroke include large artery atherosclerosis, cardioembolism, and cerebral SVD. Although a recent epidemiologic study designed to assess whether CKD is associated with a specific stroke subtype failed to find that CKD increases risk of any individual etiology , associaThe strength of association between kidney function and cerebrovascular disease highlights a pressing need to determine appropriate timing of screening assessments of kidney function. In the United States alone, 14%-15% of individuals aged 20 years or older suffer from some form of kidney dysfunction . PatientCKD appears to increase the risk of cardioembolic stroke predominantly through atrial fibrillation (AF). Population-based studies have confirmed a higher prevalence of AF among patients with CKD. For example, the prevalence of AF was up to 3 times higher in The Chronic Renal Insufficiency Cohort than in the general population . CKD triCKD is an established risk factor for atherosclerosis, and as such may increase the risk of large artery stroke (LAS) via promoting extra- and intracranial atherosclerosis. In the Japanese Suita Study of urban residents, CKD was associated with carotid artery stenosis  independent of hypertension . SimilarArterial stiffness represents another clinical measure proven to be independently predictive of fatal and non-fatal cardiovascular events and as such is a useful surrogate end point for cardiovascular disease outcomes . It reflIn the CHOICE study, which evaluated stroke in dialysis patients, the overall stroke incidence was almost ten times the incidence in the general population, with large-vessel atherosclerosis found in 11% . In a JaThere are few epidemiological studies which have specifically assessed the contribution of CKD to the SVD subtype of ischemic stroke, commonly referred to as lacunar infarction. The Cardiovascular Health Study reported a linear association between decreasing kidney function and prevalence of lacunar infarction  after multivariable adjustments . These fAvailable data of kidney function in patients with ESUS are limited and few studies assess the relationship between CKD and ESUS. In the largest ESUS dataset, patients with intact or impaired renal function had the same risk of suffering from ESUS . As suchCKD increases the risk of ICH. Up to 46% of patients presenting with ICH are also affected by CKD , 39. In The high comorbidity between ICH and CKD is in part attributable to the burden of hypertension. Around 30% of patients affected by CKD have elevated ambulatory BP with normal office BP (masked hypertension), and up to 40% suffer from resistant hypertension . TherefoOther hypothesized mechanisms include metabolic derangements common in advanced renal disease, such as high serum phosphate and low serum calcium levels. Calcium and phosphorus are pivotal in the maintenance of cell function in the endothelium and vascular smooth muscle, hence their abnormality can result in endothelial dysfunction and impairment of cerebral autoregulation . In a prFurther, CKD can increase the risk of ICH via the use of AF-related anticoagulants. As discussed earlier, the incidence and prevalence of AF in patients with CKD are higher than in the general population. A systematic meta-analysis showed that AF in patients with ESRD increased the risk of stroke, ICH and mortality, although with a high degree of variability .Beyond acute manifestations of cerebrovascular disease, there are multiple studies supporting associations between kidney dysfunction and neuroimaging markers of subclinical chronic cerebral SVD. Classical neuroimaging biomarkers for SVD, such as WMH, silent lacunes and cerebral microbleeds each have evidence for association with SVD and are themselves worthy of further exposition outside the context of the present review. Briefly, a meta-analysis of 31 studies and 23,056 participants found microalbuminuria to be associated with a higher risk of all markers of cerebral SVD including WMH , lacunes , cerebral microbleeds , and enlarged perivascular spaces  . SimilarThe complex relationship between kidney dysfunction and cerebrovascular disease can be summarized in three axes: (axis 1) shared unique susceptibility to vascular risk factors and the same resultant tissue pathology; (axis 2) over-representation and accentuation of vascular risk factors in patients with renal disease; (axis 3) sequelae of renal disease playing a role in stroke pathogenesis . These aThe “strain vessel hypothesis,” based on hypertensive vascular damage, has been suggested as a possible mechanism explaining the association between CKD and stroke . Kidney Albuminuria occurs when podocyte density decreases below a certain threshold. It represents a marker of glomerular barrier impairment, specifically glomerular endothelium damage. Given the similarities in the anatomy of the kidney and brain, it has been hypothesized that the endothelial dysfunction which occurs at the glomerular level and causes albuminuria happens simultaneously at a systemic scale , 57. In Additional evidence is provided by research on derivatives of the aminoacid L-arginine, such as asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA). ADMA and SDMA are elevated in patients with kidney dysfunction as well as in patients with other SVD manifestations, independent of classical vascular risk factors . ADMA leAccelerated atherosclerosis has been described in patients with kidney dysfunction. Dyslipidemia is common in patients affected by CKD. As a result of proteinuria and lipoprotein transport impairment, CKD patients often have an increase in serum triglycerides, very-low-density lipoprotein, and low-density lipoprotein (LDL) cholesterol, all of which have significant atherogenic potential , 61. HypModified lipoproteins from elevated LDL have been hypothesized to trigger innate immune reactions, which result in inflammation and accelerated diastasis of lipids in the intima of the vessel. Additionally, CKD has been described as a pro-inflammatory state, and enhanced levels of fibrinogen and matrix metalloproteinases have been variably described in this patient population. Inflammation is known to affect atherosclerotic lesions' stability and risk of rupture.p = 0.001, and 59 vs. 36%, p = 0.039, respectively)  . Howeverctively) .Taking this evidence together, increased atherosclerosis in CKD patients is likely to arise in the setting of combined insults of dyslipidemia and accentuated inflammation , 66. ConClosely related to atherosclerotic changes, even moderate stages of CKD have been associated with changes in the biomaterial and biological characteristics of the vessels, resulting in arterial stiffness . Most liCerebral vasculature is able to maintain stable cerebral blood flow (CBF) despite changes in BP. Impaired kidney function can lead to impaired cerebral autoregulation and subsequently make brain perfusion more strictly dependent on systemic BP , 70. In Impairment of CBF may be a repercussion of an effect of kidney disease on nitric oxide, which is crucial in vascular responsivity. As discussed above, kidney impairment increases ADMA and SDMA, which are inhibitors of nitric oxide synthase, and therefore have been implicated in vascular disease . AlthougLastly, CKD can also lead to CBF dysregulation and hence stroke through anemia. Anemia in fact is a well-known complicating feature of CKD, present in up to two thirds of subjects with severe kidney impairment . Concomivia macrophage and microglia polarization toward a pro-inflammatory phenotype -6, IL-1 and Tumor Necrosis Factor (TNF)-α are higher even in patients in the early stages of CKD, and this inflammation appears to influence CKD progression. As CKD worsens, uremic toxins, indoxyl sulfate, and guanidino compounds enter the central nervous system and promote neuroinflammation henotype .Patients with CKD suffer from impaired production of many antioxidant sources, such as glutathione peroxidases and mitochondrial superoxide dismutase , with coThis oxidative stress and consequent inflammation have profound vascular effects and influence on cerebral blood flow. Free radicals increase endothelial permeability, platelet aggregation, and alter reactivity to vasodilators . OxidatiThe blood–brain barrier (BBB) is made of vascular endothelium, a specialized basement membrane, astrocyte foot processes, and pericytes. Due to this specialized barrier, access to the brain from the blood is highly regulated. Animal experiments have demonstrated impairment of BBB integrity in the setting of both acute kidney injury and CKD . This BBThe aforementioned observational studies and many others have recognized the role of CKD in cerebrovascular disease and quantified the associations between the two. However, conventional analytical methods in observational research are limited in providing evidence for causal effects, and therefore insights about the mechanisms underlying the observed associations are constrained. In particular, it remains unclear whether both the kidney and the brain suffer concomitantly from similar injuries and ultimately perfusion failure or whether damage to one can lead to injury in the other. Human genetics can provide valuable information about the causal networks underlying CKD and cerebrovascular pathologies. Genetic variation is determined at conception and is therefore not influenced by confounding processes occurring later in life. Thus, studying genetic data can provide useful additional and orthogonal anchors to causality.Conventional genetic research, genome wide association studies (GWAS) and post-GWAS research instruments, such as Mendelian randomization (MR), may clarify the complex relationship between the two diseases. In parallel with the axes inferred by epidemiological studies, genetic data may be used to test the following hypotheses: kidney dysfunction and cerebrovascular disease are the result of a single shared biological defect, as is the case in rare monogenic diseases (axis 1); kidney dysfunction and cerebrovascular disease share common pathologic pathways that contribute to both diseases (axis 2); kidney disease causally contributes to the risk of specific cerebrovascular pathologies that increase the risk of stroke (axis 3).COL4A1) mutations have been described in clinical syndromes with invariable involvement of the eye, kidney, and brain. COL4A1 mutations result in vessel abnormality and SVD with stroke and CKD  is further upheld by findings from genetic epidemiology. Recent GWAS have identified variants in genes and associated pathways which may contribute to alteration of renal function , 89. Amoividuals . Althouglar risk .Large-scale human genetic studies have contributed to the study of the relationship between kidney and cerebrovascular disease . PolygenATXN2, which is involved in spinocerebellar ataxia type 2 and is associated with kidney disease, and SH2B3, which is associated with hypertension and vascular disease. These results reinforce the hypothesis that, once in place, the same pathologic pathways can drive both renal and cerebrovascular manifestations. The same study also demonstrated that the observed shared genetic pathways act independently of genetic susceptibility to hypertension. Taken together, these data compliment prior work in supporting the hypothesis that CKD, as estimated by impaired eGFR is associated with LAS risk and lend orthogonal support to the epidemiology theory that a different axis (axis 2) links the kidney and the brain beyond the already known shared susceptibility to vascular risk factors.By applying a pairwise GWAS analysis, which explores shared genomic signals between two traits at the single locus level , genomicNBEAL1, FAM117B and WDR12) within the 2q33 locus were found to be expressed in various cells of the nervous system including astrocytes, oligodendrocytes and neurons  in this category of patients . ExcessiIn terms of antiplatelet or anticoagulant therapies, there are no specific recommendations to reduce stroke risk in patients with CKD. However, patients with CKD have both high thromboembolic risk and high bleeding risk. Patients with CKD may also have altered responsiveness to antiplatelet drugs and enhanced bleeding complications with antithrombotic treatment , 109. AsStatins have not been shown to reduce stroke risk in advanced CKD patients. A meta-analysis that included data from the largest randomized controlled trials showed that statins did not impact stroke risk in dialysis patients . SimilarSodium-glucose cotransporter-2 inhibitors were initially developed to reduce hyperglycemia in diabetic patients, and seem to have beneficial cardiometabolic effects in patients with CKD, independent of diabetes . In the Lastly, a novel approach involves the use of anti-inflammatory therapies to reduce cardiovascular risk. Given the systemic pro-inflammatory status of CKD patients, efforts have specifically tested the benefits of anti-inflammatory compounds in this high-risk group. The CANTOS trial showed a reduction in vascular endpoints among patients with coronary artery disease receiving canakinumab, a monoclonal antibody against IL-1b . FurtherRegarding acute therapies, both intravenous thrombolysis with recombinant tissue plasminogen activator (IV-rtPA) and intra-arterial thrombectomy have been associated with worse overall outcome in patients with acute stroke and advanced CKD compared to patients with normal renal function . IncreasDespite the lack of specific primary prevention of cerebrovascular disease in patients with CKD, the strength of the association between kidney disease and stroke supports development of rational strategies for noninvasive screening of kidney function, to fully capture individual risk for cerebrovascular events.Given the prevalence of kidney dysfunction and its association with stroke, the impact on healthcare is massive and underlines the need for screening interventions and novel therapies. Elucidating mechanisms of shared pathobiology and risk between the kidney and cerebrovascular system is pivotal to developing new strategies to ameliorate both stroke and progressive kidney disease in patients at risk for these conditions. Genetic epidemiology in particular represents a useful means to help clarify the temporality and interactions among the hypothesized pathological mechanisms, with pleiotropy analyses demonstrating genes linking kidney and cerebrovascular damage, and MR analyses offering clues about the directionality of associations between kidney and brain pathology . BuildinSM and MKG: literature search and manuscript writing. CA: manuscript writing and review. All authors contributed to the article and approved the submitted version.MKG was supported by a Walter-Benjamin fellowship from the German Research Foundation  and the FöFoLe program of LMU Munich (FöFoLe-Forschungsprojekt Reg.-Nr. 1120). CA was supported by the NIH (R01NS103924 and U01NS069763), the American Heart Association , and Massachusetts General Hospital.CA receives sponsored research support from Bayer AG, and has served as a consultant for ApoPharma. The remaining 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.


CI = 1.268–3.403]. The TyG index was significantly associated with an increased risk of moderate to severe EPVS in subgroups of age <65 years, male, diastolic blood pressure (DBP) <90 mmHg, low-density lipoprotein cholesterol (LDL-C) ≥2.85 mmol/L, serum homocysteine <10 μmol/L, and estimated glomerular filtration rate (eGFR) <90 ml/min/1.73 m2, as well as those without smoking. Further analysis of EPVS distribution, the TyG index was found to be associated with moderate to severe EPVS in the centrum semiovale (CSO), not in the basal ganglia (BG). Conclusively, the TyG index was independently and positively associated with moderate to severe CSO EPVS. TyG index may serve as an independent risk factor for CSVD in clinical practice.The triglyceride glucose (TyG) index is considered a simple surrogate marker for insulin resistance and has been associated with cerebrovascular diseases. However, limited information is available regarding its association with the subclinical cerebral small vessel disease (CSVD). Here, we investigated the association of TyG index with the burden and distribution of enlarged perivascular space (EPVS) in the non-diabetic population. The data of 531 non-diabetic patients from 2017 to 2020 were assessed. Participants were grouped according to the burden of EPVS. TyG index was calculated using the log scale of fasting triglycerides (mg/dl) × fasting glucose (mg/dl)/2. The association of TyG index with EPVS burden and distribution was evaluated. In the multivariable logistic regression analysis, the TyG index was associated with moderate to severe EPVS [odds ratio (OR): 2.077; 95%  Cerebral small vessel disease (CSVD) represents a cluster of pathologies with a heterogeneous etiology, which can affect the brain vascular system, such as small arteries, capillaries, and small veins. CSVD can cause lacunar infarction and cerebral hemorrhage, which accounts for 20–30% of symptomatic strokes , 2. TypiEnlarged perivascular space, a neuroimaging hallmark of CSVD, is associated with morphological features of CSVD . It is gInsulin resistance (IR) is a pathological condition resulting from the reduced insulin sensitivity in peripheral tissues . StudiesInsulin resistance can alter the systemic lipid metabolism. Excessive lipolysis can increase the synthesis of hepatic triglyceride (TG) and decrease the levels of high-density lipoprotein (HDL) and the appearance of small dense low-density lipoprotein (LDL) , 18. BasAn increased TyG index is significantly correlated with both macrovascular diseases and microvascular diseases . Many stTherefore, this study aims to investigate whether the TyG index is associated with EPVS burden independent of other clinical risk factors in non-diabetic adult population. Our findings may provide experimental evidence for further understanding the pathogenesis of EPVS and may provide guidance for early screening, early diagnosis, early prevention, and treatment of CSVD.This retrospective cross-sectional study was approved by the Institutional Review Board of Quanzhou First Hospital Affiliated to Fujian Medical University (No. [2020]168). The informed consent was waived due to the retrospective design and because only de-identified and anonymized participant information was used. All experiments were performed in accordance with the Declaration of Helsinki and all relevant guidelines and regulations.A total of 531 non-diabetic patients who came to the Department of Inpatient Neurology of the First Affiliated Hospital of Fujian Medical University from January 2017 to December 2020 were enrolled in this study. Inclusion criteria: (1) age between 18 and 85 years. (2) Patients underwent examination with 3.0-T cranial MRI, and the images, such as T1-weighted image (T1WI), T2-weighted image (T2WI), fluid-attenuated inversion recovery (FLAIR), and diffusion-weighted imaging (DWI) were obtained. (3) Patients underwent blood biochemistry, homocysteine, and other related laboratory tests during hospitalization, as well as cranial MRI, head CT scan, and other examinations within 7 days. Exclusion criteria: (1) patients with massive cerebral infarction caused by previous large vessel occlusion, or previous diseases that were not conducive to the discriminant diagnosis of CSVD; (2) patients without MRI examination data; (3) patients with severe heart disease or liver and kidney failure; patients with hematologic diseases or malignant tumors; patients with acute and chronic inflammation; and (4) patients with diseases that may cause ischemic lacunar infarct and white matter damage, such as multiple sclerosis, genetic degenerative diseases, and poisoning.2). Blood pressure was measured using an electronic sphygmomanometer , with subjects in a sitting position after 10 min of rest, and the average of three measurements was used. Hypertension was defined when sitting and resting SBP ≥ was 140 mmHg or DBP was ≥90 mmHg at screening, or when patients were taking antihypertensive medications.Baseline data were collected by the trained study personnel according to standard operating procedures. The contents of the standard questionnaire included age, sex, current medication, previous medical diagnosis, smoking history, and drinking history. Anthropometric parameter measures for the clinical examination included weight, height, systolic blood pressure (SBP), and diastolic blood pressure (DBP). The height and weight of each participant were measured without shoes and heavy clothing. Body mass index (BMI) was calculated as weight (kg)/height , high-sensitivity C-reactive protein (hs-CRP), fasting glucose, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), TG, hemoglobin A1c (HbA1c), serum homocysteine, serum uric acid, and creatinine. The TyG index was calculated by the formula of Ln[fasting triglycerides (mg/dl) × fasting glucose (mg/dl)/2] , 20. TheAll participants underwent brain MRI using 3.0-T MR scanners . EPVS was defined as a round, oval, or linear lesion with diameter <3 mm along the course of a perforating artery with signal intensity similar to cerebrospinal fluid in all sequence spaces and without T2 hyperintense rim on FLAIR . Two neut-test or Mann–Whitney U-test for continuous variables and the chi-square test or Fisher's exact test for categorical variables. Then, statistically significant  and clinically important (sex and BMI) variables were introduced in the multivariate regression analysis. Since the TyG index itself consists of fasting glucose and TG values, fasting glucose and TG were not included as confounders in the multivariate analysis.Statistical tests were performed with SPSS 23.0  and GraphPad Prism 8 . We divided the participants into mild (score of 0–1) and moderate to severe (score of 2–4) groups according to the EPVS burden at BG and CSO . ContinuCI] with adjustment for major covariables. In addition, possible modifications on the association between TyG index and EPVS were evaluated by stratified analyses and interaction testing. The relationship between the TyG index and vascular risk factors was examined using simple linear regression analyses. The values of p < 0.05 were considered statistically significant.The independent association of the TyG index with EPVS was evaluated using the multivariate logistic regression models 168). Written informed consent for participation was not required for this study in accordance with the national legislation and the institutional requirements.YC analyzed the data and wrote the paper. BC collected and analyzed the data. XZ and MX collected the data. XW provided the guidance for the manuscript and statistical analysis. JC conceived the study and revised the study. All authors have read and approved the submission of the manuscript.This work was supported by grants from the Natural Science Foundation of Fujian Province (Nos. 2020J011284 and 2021J011407) and the Science and Technology Project of Quanzhou, Fujian (No. 2019C030R).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.


Treatment of choice in patients with unilateral aldosterone producing adenoma (APA) is adrenalectomy. Following surgery, most patients retain normal adrenal function, while some develop adrenal insufficiency (AI). To facilitate early detection and treatment of AI, we aimed to identify variables measured pre-operatively that are associated with post-operative AI. Variables obtained from 66 patients before and after surgery included anthropometrical data, clinical chemistry, endocrine work-up. LC–MS/MS steroid hormone profiles from tests before surgery  were obtained. Based on 78 variables, machine-learning methods were used in model fitting for classification and regression to predict ACTH-stimulated cortisol after surgery. Among the 78 variables, insulin concentration during pre-operative oral glucose tolerance test (OGTT) correlated positively, and dexamethasone suppressed glucocorticoids correlated negatively with ACTH-stimulated cortisol after surgery. Inclusion of LC–MS/MS measurements allowed construction of better models associated with the occurrence of AI in the training data, but did not allow reliable prediction in cross-validation. Our results suggest that glucocorticoid co-secretion (low insulin during pre-operative OGTT and insufficient suppression of glucocorticoids following dexamethasone) are correlated with the development of post-operative AI. Addition of steroid profiles improved the accuracy of prediction, but cross validation revealed lack of reliability in the prediction of AI. The prevalence of PA ranges between 5 and 15% in the general hypertensive population and between 14 and 21% in resistant hypertension, respectively6. Today, PA is considered the leading cause of secondary hypertension that can be cured by surgery7. Early diagnosis and treatment are important, since PA patients have a higher risk of cardiovascular events and target organ damage than normal hypertensives10. Aldosterone-producing adenoma (APA) and bilateral adrenal hyperplasia (BAH) are the two most common forms of PA11, accounting for 40% and 60% of the cases, respectively12. Therapeutic options differ depending on the subtype. Targeted medical treatment with mineralocorticoid receptor antagonists (MRA) is used in patients with BAH, while surgical removal of the aldosterone producing tumor by laparoscopic unilateral adrenalectomy is recommended in patients with unilateral disease14. After surgery, most patients with APAs achieve complete or partial biochemical remission, and improvements in blood pressure control15. However, besides the intended reduction in mineralocorticoids, in some patients unilateral adrenalectomy results in impaired glucocorticoid secretion16.Primary aldosteronism (PA) is an adrenal disease characterized by inappropriate autonomous production of aldosterone and consecutively suppressed renin concentrations17. A likely reason for the occurrence lays in the fact that some APAs also co-secrete glucocorticoids, leading to minimal suppression of pituitary ACTH secretion and thereby, glucocorticoid production from the contralateral adrenal18. Consequently, after surgical removal of the APA, the suppressed contralateral adrenal would be unable to produce sufficient glucocorticoids until the recovery of the hypothalamic–pituitary–adrenal axis. Since late diagnosis or unawareness of AI would potentially endanger patients, early identification of those at risk to develop AI is desirable. However, in our recently published study we could not identify clinical or biochemical variables allowing to preoperatively predict the risk to develop AI after surgery17. Our hypothesis for the present study was that extending standard biochemical testing by dynamic endocrine tests combined with LC–MS/MS-based steroid profiling would allow us to better characterize the adrenal capacity of the patients, and thereby to predict the individual risk for development of AI following adrenalectomy. Indeed, LC–MS/MS based steroid profiling has recently been demonstrated to be useful in identification of subtypes of PA22. Our objectives were (a) to identify variables before surgery that correlate to cortisol production after surgery; (b) to determine the utility of LC–MS/MS steroid profiling before surgery to predict AI after surgery; and (c) to cross-validate the performance of a prediction model established based on our data.We recently have reported prevalence and clinical characteristics of insufficient glucocorticoid production in a subgroup of APA patients following unilateral adrenalectomy, resulting in transient or even prolonged adrenal insufficiency (AI) and rarely to a life-threatening adrenal crisis. As reported recently, twenty-seven percent of the cohort developed postoperative AI, while those with severe AI (stimulated cortisol < 13.5 µg/dL) needed significantly longer hydrocortisone replacement therapy than those who were classified to have moderate AI (stimulated cortisol 13.5 to 17 µg/dL) : severe AI: 353  vs moderate AI: 74 ; p = 0.016)We identified 9 out of 78 variables collected before surgery which exhibited statistically significant (a = 0.05) correlation with stimulated cortisol after surgery. Two of the variables were cortisol measured by immunoassay at distinct time points : 2.988 (1.802) ng/mL vs. AS 1.7102 (0.977) ng/mL, p = 0.0452, Fig. In order to investigate associations between preoperative variables and the occurrence of postoperative AI, we built linear regression models with the significant variables that we found in the single variable analysis. As mentioned above, nine variables fell into this category. Of those, two could not be used because more than 20% of the data were missing for steroid measurements by LC–MS/MS after dexamethasone suppression test (most were undetectably low). From the remaining seven variables, we excluded another three because they had no significant contribution to the model. The remaining four variables were insulin during OGTT at 60 min, salivary cortisol at 20:00, baseline cortisone and baseline estradiol during ACTH test. According to standard coefficients Table , the str24, random forest25, decision tree26, model-based boosting27, gradient tree boosting28 and xgboost29, were performed to identify the best model. We integrated cross validation (LOOCV) to evaluate the predictive capacity of each model established by the training data on a new observation. In the following, we only report analyses using xgboost and model-based boosting since these methods outperformed the others by far.As mentioned above, the other 69 variables recorded before surgery had no significant correlation to outcome as a single variable. We next explored if a combination of multiple variables could improve prediction and applied machine learning methods. Due to our limited sample size and the large amount of variables, we mainly used the methods with embedded feature selection, such as tree-based methods and regressions with regularization. 7 different statistical methods, namely lasso regression, ridge regressionFor classification analysis, we combined mAI and sAI patients into one “AI group”  and compared this group to the AS group . Without the 15 steroid hormones measured by LC–MS/MS on two occasions included in the variables, xgboost correctly classified 100% of AS patients and 92.3% (12 out of 13) of AI patients by 33 variables  in training data  3.38; mean squared error (MSE) 17.25 Fig. A). When In contrast to the performance of the models in the training data, in the cross-validation R-squared dropped to 0.1795  in a general population35. These findings support that ß-cell function and insulin secretion are reduced by elevated levels of glucocorticoids. Kamba et al. argue that—although high serum glucocorticoid concentrations are positively correlated with insulin resistance and with a compensatory increase of insulin secretion long term—acute suppression of ß-cell function may constitute for another aspect of glucocorticoid effects on glucose metabolism. In this setting, glucocorticoids cause suppression of insulin secretion. When glucocorticoid concentrations further increase over time to consistently elevated levels, insulin resistance develops. Therefore, insulin resistance as well as ß-cell dysfunction lead to impaired glucose metabolism and the development of diabetes35. Our observation of lower peak insulin values during OGTT might reflect this aspect of the interplay between glucocorticoids and insulin secretion. In accordance, sAI patients tended to have lower HOMA-ß values, indicating suppressed ß-cell function. Thus, the lower 60 min. insulin concentrations during OGTT in the patients with higher glucocorticoids (which are at risk to develop AI post-surgery) do not contradict the general understanding on glucocorticoid effects on glucose/insulin homeostasis but might just reflect an early effect of glucocorticoids on the insulin secretion in our patient subgroup. This would explain why patients with lower peak insulin values could have experienced greater glucocorticoid exposure. This would be in line with our observation that dexamethasone suppression of glucocorticoids was less efficient, and that salivary cortisol at night was higher in the AI group. One could speculate about a mechanism where greater glucocorticoid exposure before surgery leads to a stronger suppression of glucocorticoid secretion from the contralateral adrenal, increasing the risk to develop transient adrenal insufficiency following the removal of the APA. Postoperative histopathological tumor sizes were also compared among the groups. PA patients with sAI and mAI tended to have slightly larger tumors, however not reaching statistical significance ; mAI 15 ; AS 11 , p = 0.096).The positive association of insulin secretion during OGTT before surgery to ACTH stimulated cortisol post-surgery was a consistent observation in our analyses. Insulin was also the most important variable in the regression model-based boosting analysis to predict adrenal status post-surgery in our training data Fig. B and had40. Two recent studies41 have demonstrated that—by using slightly different LC–MS/MS based profiles of 15 steroids—it was possible to correctly classify the subtype of PA. Apart from allowing distinguishing between BAH and APA, there were also associations of the steroid profiles obtained by LC–MS/MS with adenoma genotype21. 18-hydroxycortisol and 18-oxocortisol have been shown to be helpful to distinguish BAH and APA41. Unfortunately, our steroid profiles did not include these two steroids and limitations from sample volume did not allow a separate analysis.The use of LC–MS/MS based steroid profiles has contributed significantly to our understanding of adrenal diseaseUntil today, no data have been published on the potential value of pre-surgical LC–MS/MS based steroid profiles to predict the occurrence of AI after surgery. In our study, the steroid profiles obtained at any of the three different time points before surgery alone were not sufficient to establish associations with AI following surgery. We therefore combined the three steroid profiles together with 33 conventional parameters for feature selection, and subsequently compared models for correlation, classification and prediction without and with inclusion of the steroid profiles. We found that LC–MS/MS based steroid profiles can significantly improve the correlation models for ACTH stimulated cortisol post-surgery, and also help to correctly classify the AI and AS groups. Furthermore, inclusion of LC–MS/MS based steroid profiles reduced the error between predicted and true values in cross validation of the linear regression models.42. Consequently, predictive potency in the training data can be optimistically biased. Imbalance in the size of the groups can also dramatically decrease the power of statistical methods43. In our case, the bigger group with 53 AS patients tends to dominate the classification models, and characters of the smaller group with 13 AI patients might not be taken up by the model.However, although the model with LC–MS/MS data in classification achieved 100% accuracy in our training data, the majority of cases in the AI group was misclassified as AS in the cross validation. A discrepancy between the performance of models in the training data and the prediction in cross validation is frequently observed. A likely explanation is that such models tend to be over-fitted to the training data, and do not correctly embody the characters of the dataUnfortunately, since the extended set of dynamic tests performed in our cohort is not part of clinical routine elsewhere, and patients undergoing adrenalectomy still are rare, it was impossible to get an independent new dataset for testing the models. However, we followed a standard approach to evaluate the performance of models by statistical techniques established for cross validation in the absence of independent data sets. The extent of the prediction in cross validation matching with the true values is the key criterion. Only when the prediction in cross validation is better than a featureless model, a model can be assumed to appropriately reflect existing relationships between the predictors and the target in the dataset. In addition to using all features, we also used two to seven of the top features only to build xgboost models to avoid overfitting. Indeed, using only the top four features in the xgboost, allowed correct classification of two more AI patients. However though slightly better, this is still not good enough to predict AI in a clinical setting. This finding supports our hypothesis that adding more variables can cause problems with overfitting. The fact that in our analysis a simplified linear model with the four significant variables was superior to a sophisticated model-based-boosting model with all the variables implies that including more variables must not necessarily lead to improved prediction but might just increase the noise in the data. Instead of just adding more variables, a guided selection of variables based on background knowledge about physiological relationships might be more appropriate to improve the models.In summary our findings support the notion that glucocorticoid co-secretion from aldosterone-producing adenomas might be a risk factor for the development of adrenal insufficiency after adrenalectomy. Based on our findings, a prediction of the risk of AI during the pre-operative period still is not possible with enough reliability. Because of the elevated risk to develop transient adrenal insufficiency after unilateral adrenalectomy, we already do in our institution, and would generally recommend that clinicians should perform ACTH stimulation tests in all subjects with APAs after surgery, as AI is a potentially life-threatening condition. Better characterization of glucose metabolism before surgery could be important to understand the association. Furthermore, our study demonstrates that correlation- and classification models were improved by inclusion of data from LC–MS/MS based steroid profiles. In the training data, it was also possible to develop algorithms for accurate prediction of the adrenal function after surgery based on steroid profiles obtained before surgery. However, we also realized that our prediction models from the training data failed correct classification in cross-validation studies. This exemplifies that—while new technologies including the measurement of steroid profiles by LC–MS/MS allow increasing the number of variables—confirmation of the predictive value of adding more variables through cross-validation is crucial.17. From the original cohort of 100 patients, 66 underwent pre- and postoperative operative ACTH stimulation testing and were therefore included in the current analysis. Patients were classified as lateralized according to standard imaging and biochemical criteria  and underwent unilateral adrenalectomy at our institution from August 2014 to December 2018. All patients also received a preoperative 1 mg overnight dexamethasone suppression test (cut-off serum cortisol: > 1.8 µg/dL), measurement of late-night salivary cortisol (cut-off < 1.5 ng/mL) and 24-h collection of urinary free cortisol (cut-off < 83 µg/L). An oral glucose tolerance test  with insulin and glucose measurements at baseline and after 60 and 120 min was performed in patients who did not have a diagnosis of diabetes mellitus type 1 or 2. In total, three patients had a history of diabetes mellitus type 2. All blood, urine and saliva samplings and dynamic tests were performed according to the standards of the German Conn registry44. Informed consent was obtained from all study participants. The study was designed in agreement with the Declaration of Helsinki and approved by the Ethics Committee of the Medical Faculty of the Ludwig-Maximilians-University, Munich.In this study, we retrospectively analyzed blood samples obtained from 66 patients  who consented to be included in the prospective cohort of the German Conn’s registry and had a confirmed diagnosis of APA based on aldosterone-to-renin ratio (ARR), saline infusion testing (SIT) and underwent non-ACTH stimulated adrenal vein sampling (AVS) for subtyping. Clinical characteristics of the patients’ cohort as well as details of the screening and confirmatory tests have recently been describedPreoperative ACTH stimulation tests were performed one before adrenalectomy. Patients underwent postoperative testing on the day of discharge from the hospital . Tests started at 8 AM after resting in a calm environment for at least 30 min. Serum cortisol levels were measured before and 30 min after intravenous application of 0.25 mg of 1‒24 ACTH (Synacthen). Pre- and postoperatively, adrenal function was classified according to the outcome of the ACTH stimulation test. Since the patients’ treatment was based on our routine cortisol assay, we also used this assay for patient classification. Adrenal sufficiency (AS) was defined by ACTH stimulated serum cortisol ≥ 17 µg/dL, moderate adrenal insufficiency (mAI) between 13.5 and 17 µg/dL, and severe adrenal insufficiency (sAI) by stimulated serum cortisol ≤ 13.5 µg/dL. Postoperatively, 8 of the 66 patients were classified as sAI; 5 patients as mAI and 53 patients as AS. Since the group size was highly unbalanced, for all multiple-variable analyses we combined both, sAI and mAI, as the “AI group” (n = 13).Overall, we included 78 patient variables obtained before surgery in our analysis . Steroid measurements by LC–MS/MS were performed using a commercially available kit  according to the manufacturer’s instructions. In brief, solid phase extraction (SPE) with 500 µL of samples, calibrator solutions and quality control samples was performed. An internal standard mix , containing deuterated analogs of all measured steroids, was added to the samples and each of the calibrator solutions and serum controls. The SPE procedure included two washing steps and an elution step with 500 µL elution buffer . After SPE, the extract was evaporated to dryness and dissolved in reconstitution buffer . The kit included serum calibrator set  provided seven different concentration levels for the calibration and three different concentration levels of serum controls . Additionally, three quality controls from an external supplier  were measured. The steroids were divided in two panels that were measured separately with an injection volume of 20 µL by gradient elution with mobile phase A  and B . Chromatographic separation and detection were performed with 1290 Infinity II HPLC System  coupled to a QTrap 6500 + tandem mass spectrometer . Electrospray ionization in positive and negative mode was used for ionization and measurement mode was multi reaction monitoring. Data analysis was performed using Analyst 1.6.3 Software .45. Missing data were imputed by K-nearest neighbor’s algorithm for multiple-variable analyses. Variables containing more than 20% missing values were excluded. This applied only to 15 steroid concentrations after dexamethasone suppression test measured by LC–MS/MS . R packages “MASS”, “tidyverse”, “glmnet”, “mice”, “DMwR”, “caret”, “randomForest”, “mlr”, “DataExplorer” and “corrplot” were required for analysis. Correlation coefficient was used to assess the correlation between variables obtained before surgery and ACTH stimulated cortisol after surgery. Analysis of variance or Kruskal–Wallis-Test was used to assess the difference between two groups. The equality of variance was tested by Levene's test and Shapiro–Wilk test was used in test of normality. When required, data were logarithmically transformed. Model-based boosting was used in model fitting for regression. Gradient Tree boosting was used for classification. Leave-one-out cross validation (LOOCV) was integrated for the estimation of performance of models. Due to the small sample size we chose to use LOOCV instead of the commonly used k-fold cross validation methods. Permutation importance was used to calculate the importance of the variablesSupplementary Table S1.Supplementary Table S2.