COVID-19 disease may result in a severe multisystem inflammatory syndrome in children (MIS-C), which in turn may alter thyroid function (TF). We assessed TF in MIS-C, evaluating its impact on disease severity.We retrospectively considered children admitted with MIS-C to a single pediatric hospital in Milan (November 2019–January 2021). Non-thyroidal illness syndrome (NTIS) was defined as any abnormality in TF tests  in the presence of critical illness and absence of a pre-existing hormonal abnormality. We devised a disease severity score by combining severity scores for each organ involved. Glucose and lipid profiles were also considered. A principal component analysis (PCA) was performed, to characterize the mutual association patterns between TF and disease severity.Of 26 (19 M/7F) patients, median age 10.7 (IQR 5.8–13.3) years, 23 (88.4%) presented with NTIS. A low FT3 level was noted in 15/23 (65.3%), while the other subjects had varying combinations of hormone abnormalities . Mutually correlated variables related to organ damage and inflammation were represented in the first dimension (PC1) of the PCA. FT3, FT4 and total cholesterol were positively correlated and characterized the second axis (PC2). The third axis (PC3) was characterized by the association of triglycerides, TyG index and HDL cholesterol. TF appeared to be related to lipemic and peripheral insulin resistance profiles. A possible association between catabolic components and severity score was also noted.A low FT3 level is common among MIS-C. TF may be useful to define the impact of MIS-C on children’s health and help delineate long term follow-up management and prognosis. Children have been found to be less affected by Coronavirus disease COVID-19) than adults; in most pediatric cases, SARS CoV-2 is asymptomatic or only causes mild symptoms 9 than ad. HoweverAccording to the Centers for Disease Control and Prevention (CDC), MIS-C may occur in individuals aged < 21 years who test positive for current or recent SARS-CoV-2 infection by RT–PCR, serology, or antigen test or have been exposed to COVID-19 within 4 weeks prior to the onset of symptoms. Patients with MIS-C present with fever, laboratory evidence of inflammation and severe multisystem (≥ 2) organ involvement  requiring hospitalization and no alternative plausible diagnoses.) . IntraveTo define the severity of multisystemic involvement, a score was devised by our group using the parameters defined in the literature and detailed in Table The evaluation of thyroid function included: measurement of serum free T3 (FT3), free T4 (FT4) and TSH obtained within 24 h of admission. We used the chemiluminescence immunoassay by Alinity/Abbott system  and the following normal ranges: FT3 3.5–6.3 pmol/L; FT4 9–19.3 pmol/L and TSH 0.5–4.2 µIU/mL.NTIS was defined as any abnormal TF result in the presence of critical illness and absence of a pre-existing abnormality in the hypothalamic-pituitary-thyroid axis. This definition allows for the identification of usual and unusual patterns of NTIS.To characterize the patients and account for multi-organ involvement we created an overall severity index. This new discrete variable referred to as the “Overall Severity Score” was calculated by summing individual severity scores for each organ. Continuous variables are presented as ranges, median and quartiles with mean ± standard deviation, suitable for symmetric distributions; categorical variables are expressed as numbers and percentage of patients.To explore the hematologic and metabolic characteristics of the patients and to obtain a comprehensive view of their distribution, a univariate statistical analysis was performed. This included a scatterplot and bar chart, showing the mean and standard deviation values. Pearson (linear) and Spearman (monotonic) correlation coefficients were computed and reported in a correlogram.A principal component analysis (PCA) was performed to thoroughly investigate associations among the parameters since pairwise associations do not consider joint relationships with other variables. This method rotates the axes of the multivariate space of the original variables, along orthogonal directions of maximal variance , and creates a new space defined by the PCs. Each of the PCs is characterized by a percentage of explained data variance. If a relevant amount of variance is explained by the first PCs, the projection of the variables as vectors in the subspace defined by the new axes is useful for exploring correlated structures present in the data. If variables are correlated with each other, the vectors are projected close together (positive correlation) or conversely with a distant alignment (negative correlation). An angle approaching 90° among the vectors indicates a lack of correlation. Moreover, if the subspace defined by the two principal components describes the variables well, their vectors are projected towards a circle of radius unity also known as the “circle of correlation”, otherwise they tend to be projected close to the origin of the axes. All of the variables were considered in the analysis and used to compute the principal components. The variable Overall Severity Score was considered a supplementary variable and so it was projected into the multivariate space defined by the PCs without participating in their composition. PCA allowed us to reduce the dimensionality of the dataset by projecting each data point into the first few principal components (up to four) while preserving as much of the data variation as possible. All of the statistical analyses were conducted with R software (version 4.0.0).In the study, we included 26 children and adolescents (19 M/7F) with a median age of 10.69 5.78, 13.28) years. In Tables .28 yearsOxygen therapy was administered in 21/26 subjects. Twenty patients were hospitalized in the pediatric intensive care unit (PICU); the median PICU stay was three days . Ventilator support was required in 11 cases, including continuous positive airway pressure in 10 patients and high flow nasal cannula in one case . Overall, a median hospitalization duration of 12.50 (10.00–16.75) days was recorded. Outcome was positive, all patients making a full clinical recovery.Biochemical data on the study patients are reported in Table Some subjects with NTIS had abnormal levels of only one hormone , while others had variable combinations of hormone abnormalities . In particular, we noted: an isolated decrease in the FT3 level in 15/23 (65.3%) subjects; low FT3 and FT4 levels in 5/23 (21.7%); low FT3, FT4 and TSH values in 2/23 cases (8.7%) and an increase in TSH level in one patient (4.3%).PCA analysis does not allow for any missing values in the matrix. For this reason, only 20 observations from the 26 patients were considered in the descriptive and correlation analysis, since they displayed finite values for all the variables considered. In the bi-plots displayed in Figs. The multivariate PCA analysis of the dataset showed that the first six principal components explained 80% of the variation in the data . We focused our attention on the first three dimensions since they explain much greater variation in the data with respect to the other three and are well characterized by specific variables of interest. While the variables related to organ damage and inflammation such as CK, LDH, procalcitonin and creatinine are represented in the first dimension (PC1), FT3, FT4, total cholesterol were all grouped together, and they characterize the second axis (PC2). Moreover, the third axis (PC3) was mainly characterized by a group of variables related to metabolic features .Considering the graphs showing the projection of variables as vectors in the new plane defined by the PCs Fig. , it was We observed that more than 90% of children with Sars-Cov2 associated MIS-C exhibited NTIS. An isolated decrease in the level of FT3 and a FT3 decrease associated with an increase in TSH level were the most and least represented patterns, respectively. NTIS detection, based on the evaluation of FT3, FT4 and TSH levels, may be helpful in the management of children with MIS-C requiring hospitalization and this phenomenon may be considered an adaptive mechanism to preserve energy during critical illness.Acute and chronic Illnesses may induce profound modulations and interactions in a number of neuroendocrine systems including changes within the HPT axis –26. DataNTIS is characterized by TH abnormalities that represent imbalances in hormonal production, metabolism, and action . UsuallyIn this study we report on NTIS among SARS-CoV-2 associated MIS-C. We observed a high prevalence of low T3 syndrome, which is considered a useful adaptation to preserve energy during critical illness , 28–30. In different cohorts of patients, such as subjects with community-acquired pneumonia, low T3 syndrome has been identified as an independent risk factor associated with a poor 30-day mortality rate . This efPositive outcomes were achieved in all of our patients. The multivariate pattern analysis showed that variables related to organ damage, inflammation and severity of multisystemic involvement did not correlate with thyroid dysfunction. Additionally, other hematological parameters, such as hemoglobin, platelets, leukocytes were not associated with TF??. These results suggest that low T3 syndrome may be a useful adaptation to preserve energy during long periods of critical illness rather than during acute episodes . HoweverAlthough MIS-C varies in severity, the majority of our patients were seriously ill. Our multivariate analysis showed that TF was related to lipemic profiles, particularly triglycerides and HDL cholesterol, and the TyG index of peripheral insulin resistance, suggesting that a hypercatabolic syndrome exists. Future studies on the correlation between catabolic components and overall severity score should confirm these data.This analysis was further complicated by the fact that NTIS pathogenesis is complex and multifactorial. Even though, the optimal therapeutic approach in children with MIS-C has not been defined, the majority of patients are treated with standard therapeutic protocols including: glucocorticoids, intravenous immunoglobulin and anticoagulant agents. Glucocorticoids are known to affect serum TSH levels in humans and heparin is known to interfere with free thyroid hormone assay . HoweverWe recognize that the small sample size limits the strength of the analysis, thus we are working to increase the sample size to extend and validate these first results particularly in relation to the Disease Severity Score. However, we felt these preliminary results were interesting as they explore the mutual association between metabolic and hormonal patterns and their impact on the severity of the clinical condition.In conclusion, NTIS is common among Sars-Cov2 associated MIS-C subjects. NTIS may be interpreted as evidence of an adaptation to preserve energy during critical illness and hypercatabolism. Since the endocrine system critically coordinates and regulates major metabolic and biochemical pathways, an endocrinological profile may prove useful in the diagnosis of MIS-C and help define its real its real impact on children's health, and assist in developing the best long term follow-up management plan and prognosis.


Background: Zinc-alpha 2-glycoprotein (AZGP1), a secreted protein with ubiquitous tissue expression, has been controversially linked to the risk of cardiovascular disease. In a cohort of kidney transplant recipients, we measured serum AZGP1 levels after transplantation over a 2 year period and tested for an association with pulse wave velocity as an important parameter indicating future cardiovascular events.Methods: Annual blood sampling and pulse wave velocity measurements were longitudinally performed in 113 kidney transplant recipients. AZGP1 was measured in serum samples using standard ELISA. Association of AZGP1 with pulse wave velocity was longitudinally assessed during follow up of 2 years by mixed longitudinal modeling.Results: AZGP1 serum levels declined significantly after kidney transplantation. This decline was dependent on allograft function as indicated by inverse correlation with eGFR. When corrected for eGFR multivariable analysis revealed an inverse correlation between AZGP1 and pulse wave velocity. This analysis further showed independent associations of older age, higher blood pressure, and higher calcium phosphate product with higher pulse wave velocity.Conclusions: Improved kidney function after transplantation leads to a decline in AZGP1 serum levels. Independent of kidney function and other cardiovascular risk factors lower AZGP1 levels are associated with higher pulse wave velocity in the 2 years after kidney transplantation. These data suggest that AZGP1 might be a potential biomarker for cardiovascular health and a target for improving cardiovascular outcome. Cardiovascular disease (CVD) is the leading cause of death in patients with end stage renal disease (ESRD) . AlthougZinc-alpha 2-glycoprotein, AZGP1  is a secreted 43 kDa protein which is expressed by many tissues leading to a serum concentration of 30–70 μg/ml in healthy individuals. Despite a multitude of possible implications in different diseases, understanding of this protein's definitive role is still lacking. AZGP1 has been suggested to modify metabolic functions, blood pressure (BP), cancer metastasis, neurological disease and CVD –10. As AHere, we first examined whether serum AZGP1 levels change after kidney transplantation. Secondly, we tested the correlation between AZGP1 levels and pulse wave velocity (PWV) as a measure of arteriosclerosis and cardiovascular health at the time of transplantation and 1 and 2 years afterwards.This single-center longitudinal-retrospective study included 113 patients from a previously well-characterized cohort of kidney transplant recipients . PatientHeight and weight were measured and body mass index (BMI) was calculated. BP measurements were carried out by an automated sphygmomanometer  after a resting phase of 5 min. Hypertension was defined as systolic office BP values ≥ 130 mmHg and/or diastolic BP ≥ 80 mmHg and/or current antihypertensive drug treatment. Normotension was defined as BP < 130/80 mmHg without antihypertensive treatment, controlled hypertension as BP < 130/80 mmHg with treatment, uncontrolled hypertension as BP ≥ 130/80 mmHg with treatment, and untreated hypertension as BP ≥ 130/80 mmHg without treatment. Dyslipidemia was defined as total cholesterol ≥ 200 mg/dl and/or low-density lipoprotein (LDL) ≥ 130 mg/dl and/or high-density lipoprotein (HDL) < 40 mg/dl in men and HDL < 50 mg/dl in women . ResiduaBlood and urine samples were analyzed in a central laboratory  for full blood count, electrolytes, creatinine, cystatin C, total cholesterol, high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), high-sensitive C-reactive protein, and parathyroid hormone. The estimated glomerular filtration rate (eGFR) was calculated by using the creatinine-based CKD-EPI formula . AZGP1  , 21. Meat-test or ANOVA and correlation was evaluated with Spearman correlation coefficient. Categorical variables were analyzed by Chi-squared test. We investigated the association of serum AZGP1 with PWV using longitudinal mixed models during the follow up of 2 years after transplantation. A P-value < 0.05 was considered statistically significant.The statistical analysis was performed using SPSS Version 24.0 . Data are presented in means ± standard deviation or percentage and absolute numbers. Continuous variables were compared by n = 73) aged 51.1 ± 14.7 years were enrolled (age range 18–78 years). At the time of transplantation mean BMI was 26.6 ± 4.3 kg/m2 (range 17.4–37.2). Forty-nine percent (n = 55) had been diagnosed with CVD . Twenty percent (n = 23) suffered from diabetes mellitus and 96 % (n = 108) had arterial hypertension. The dialysis vintage mean was 80.6 ± 45.9 months (range 12–198). Of all recipients, 85 % (n = 96) had not undergone a previous transplantation and 19 % (n = 21) were preemptively transplanted.Clinical characteristics of the study cohort are presented in n = 113) at the time of transplantation. We found no correlation between AZGP1 serum levels and underlying renal disease (P = 0.654), preemptive vs. non-preemptive transplantation (P = 0.804), dialysis modality comparing peritoneal vs. hemodialysis (P = 0.967) and residual renal function while on dialysis (P = 0.264). During the follow up of 2 years serum AZGP1 levels dropped significantly (n = 97) and by 43 %  at 2 years post-transplant , after 1 year  and after 2 years .We performed a longitudinal mixed model analysis of PWV and AZGP1 alone (Model A), AZGP1 together with eGFR (Model B) and AZGP1 together with eGFR and other known modifiers of arterial stiffness  . While tAlthough kidney transplantation offers clear survival benefits compared to dialysis, CVD remains one of the leading causes of premature death after transplantation . As AZGPSecondly, we determined the potential relevance of AZGP1 as a biomarker for CVD prediction after transplantation. For this purpose we investigated whether AZGP1 levels correlated with PWV development as a surrogate parameter for arterial stiffness over 2 years after transplantation. Our analysis revealed a significant inverse association of AZGP1 with PWV. Importantly, this association was only observed when corrected for eGFR. While this pattern is compatible with previous observations in non-CKD patients showing a correlation between higher AZGP1 levels and reduced incidence of coronary heart disease and atherosclerosis scores , 15, it We recognize several limitations inherent to our study: Due to the observational study design we cannot draw conclusions about potential cause-effect relationships. Moreover, findings might not be transferable to other transplant centers and more diverse populations because this is a single-center study with a limited patient number and follow-up period. Another limitation of our study is the lack of clinical endpoints. Although PWV has been validated in transplant patients , 30 as aIn summary, our study provides valuable novel results: (1) Kidney transplantation reduces AZGP1 concentrations which are elevated in ESRD. (2) Lower AZGP1 is independently associated with higher PWV in renal transplant recipients. (3) Protective effects of AZGP1 on the cardiovascular system seem to be restored after kidney transplantation. Together, this suggests that AZGP1 might be a potential biomarker for cardiovascular health in kidney transplant recipients and that it should be explored as a target for improving cardiovascular outcome.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The studies involving human participants were reviewed and approved by Hannover Medical School Institutional Review Board (#504). The patients/participants provided their written informed consent to participate in this study.TK, AM, BS, and RS conceived the study and wrote the manuscript. IS-Z conducted AZGP1 measurements. NM conducted PWV measurements. TK and BS performed bioinformatics analysis. TK, BS, and RS interpreted results with contributions of AM and HH. All authors approved the final version of the manuscript.BS has received lecture fees from Berlin Chemie-Menarini, Daichii-Sankyo, BMS, Pfizer, MSD. RS has received lecture and consulting fees from FMC and Otsuka. HH has received lecture fees, advisory board Consultant fees, and Research funds from Boehringer Ingelheim, Bayer and Astra Zeneca. 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.


Objectives: To determine the association between morning hypertension and target organ damage (TOD) in patients with chronic kidney disease (CKD) and hypertension.Methods: In this cross-sectional study, 447 patients with CKD and hypertension from two centers were enrolled. Ambulatory blood pressure monitoring was conducted in all patients. Linear regression and logistic regression analysis were used to determine the association between morning hypertension and TOD in patients with CKD and hypertension, including assessments of estimated glomerular filtration rate (eGFR), left ventricular mass index (LVMI), urine protein/creatinine ratio (UPCR), and left ventricular hypertrophy (LVH).Results: Overall, 194 (43.4%) participants had morning hypertension. Morning hypertension was strongly correlated with LVH , lower level of eGFR , higher LVMI , and UPCR , independent of nocturnal hypertension and elevated morning blood pressure surge. As a continuous variable, both morning systolic blood pressure (SBP) and diastolic blood pressure (DBP) were found to be associated with LVH and higher level of UPCR and LVMI (p < 0.05), whereas only morning SBP was negatively correlated with eGFR (p < 0.01).Conclusion: Morning hypertension was strongly correlated with cardiac damage and impaired kidney function in CKD patients with hypertension, independent of nocturnal hypertension and morning surge in blood pressure. Morning hypertension in CKD patients warrants further attention. Hypertension is very common in patients with chronic kidney disease (CKD), with the prevalence of 67–92% ; becauseMorning hypertension has been a recent research focus. It was shown to be associated with target organ damage (TOD) including left ventricular mass index (LVMI), urine albumin/creatinine ratio, maximum carotid intima media thickness , 8, and Morning hypertension is consistently accompanied by nocturnal hypertension or elevated morning surge in blood pressure, which are also reported to be associated with TOD , 13. TheWe conducted the present cross-sectional study to further our understanding of the association between morning hypertension and TOD in patients with CKD and hypertension and to determine whether this association is independent of nocturnal hypertension and the morning surge in blood pressure.2 or abnormalities of kidney structure for over 3 months were diagnosed with CKD  in China. Adult patients were eligible if they (1) had CKD, (2) were diagnosed with hypertension, and (3) agreed to undergo 24 h ABPM. Exclusion criteria were patients (1) on dialysis , (2) with history of malignancy, (3) with <70% valid records on 24 h ABPM, and (4) who were pregnant. Patients with albuminuria  or estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 mwith CKD . eGFR wawith CKD . The stuA total of 447 CKD patients formed the cohort of this cross-sectional study. Baseline evaluation including medical history, physical examination, and laboratory tests were recorded at the time patients visited the outpatient clinic or were admitted to hospital. These data included sex, age, body mass index (BMI), current alcohol consumption, current smoking, CV history, antihypertensive drugs, diabetes mellitus (DM), biochemical parameters, urinary protein test, and two-dimensional echocardiogram.Experienced nurses measured office BP when participants were admitted to our hospital or visited the outpatient clinic. After patients were allowed to rest quietly for 5–10 min, the mean value of three consecutive BP measurements at 5-min intervals using a mercury sphygmomanometer was recorded. The 24-h ABPM was performed using Space labs 90217 devices  at West China Hospital and an ABPM 6100  at Chengdu Seventh People's Hospital, with BP readings set at 20-min intervals from 6:00 a.m. to 10:00 p.m., and 30- or 60-min intervals from 10:00 p.m. to 6:00 a.m. Day- and nighttime BPs were defined as mean BP during the period from 6:00 a.m. to 10:00 p.m. and 10:00 p.m. to 6:00 a.m., respectively. Patients were instructed to undergo their usual activities and take antihypertensive drugs as usual and were encouraged to sleep no later than 10:00 p.m. and to get up at approximately 6:00 a.m. ABPM was not conducted if the patient worked nightshifts. The time patients went to bed and woke up was recorded. A measurement with at least 70% of diurnal and nocturnal BP readings was regarded as a successful ABP. The ABP must be taken within 3 days after the measurement of office BP. Both office BP and ABP measurements were taken from the non-dominant arm with an appropriate cuff size based on arm circumference at the time of enrollment.3 – LV internal diameter3] + 0.6 g. Left ventricular hypertrophy (LVH) was defined according to the 2015 American Society of Echocardiography/European Association of Cardiovascular Imaging chamber quantification document, with LVMI per body surface area >95g/m2 in women and 115 g/m2 in men  and GraphPad Prism 8.0.1. Normally distributed data are presented as mean ± standard deviation, skewed data as median values with interquartile range, and categorical variables as numbers with percentage. Log-transformation or square root calculations were applied for normal transformation. Data were analyzed using the chi-square test or Fisher's exact test for categorical variables, the Student's p < 0.05 was considered statistically significant.Receiver-operating characteristic (ROC) curve analysis was conducted, and the area under the curve (AUROC) was calculated to assess the ability of night blood pressure and morning blood pressure surge to predict morning hypertension. Binary logistic regression was applied to detect the factors associated with morning hypertension and to calculate the risk of LVH correlated with morning hypertension. Linear regression analysis was used to identify the association between morning hypertension and eGFR, UPCR, and LVMI. The regression β-coefficient represented the contribution of the independent variables to the dependent variables. To determine whether the correlation between morning hypertension and TOD was independent of night hypertension or morning surge, we added night hypertension and morning surge to the regression model in models 2 and 3, respectively. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated, and a two-tailed In total, 583 patients were enrolled. A total of 136 were excluded because of the following factors: complication with malignant tumors (p < 0.001). No differences were found in SBP, DBP, or HR dipping between the two groups (Baseline features of the participants grouped according to morning BP are shown in o groups .Association between nighttime blood pressure and morning surge in blood pressure with morning hypertension.p < 0.001). Moreover, 97 (50%) patients with morning hypertension had elevated morning surge, while the rate was 21.7% in patients with morning normotension (p < 0.001) (p < 0.001)  . Accordi< 0.001) .p < 0.001), compared with nighttime DBP  and morning surge . The optimal cutoff points for morning hypertension were 130 mmHg for nighttime SBP  and 70 mmHg for nighttime DBP .To assess the ability to use nighttime BP and morning surge in blood pressure for predicting morning hypertension, ROC curve analysis was performed . Nighttip < 0.001), whereas only higher level of UPCR was found to correlate with elevated morning surge in blood pressure (p = 0.026) , and LVH (= 0.026) –3.p < 0.05), higher level of LVMI , UPCR , and LVH  when nocturnal hypertension and elevated morning surge in blood pressure were considered , and the correlation between morning DBP and eGFR was only significant in model 4 . Morning hypertension was strongly correlated with TOD in CKD patients, including cardiac damage  and kidney function decline (higher UPCR and lower eGFR), independent of nocturnal hypertension and morning surge in blood pressure. As a continuous variable, both morning SBP and DBP correlated with UPCR, LVMI, and LVH, whereas only morning SBP was negatively associated with eGFR. These data suggest that morning hypertension plays an important role in TOD in patients with CKD and hypertension.In this cross-sectional study, we found that the prevalence of morning hypertension in CKD patients was 43.4 and 95.9% of these patients also had nocturnal hypertension. Morning hypertension was primarily determined by nighttime BP and morning surge in blood pressure, and nighttime SBP distinguished morning hypertension effectively  . Our stuPrevious studies showed that morning hypertension is associated with higher risk of LVH , which iOur study showed that morning hypertension was associated with increased prevalence of kidney function decline, including higher UPCR and lower eGFR. Similar findings were reported in some previous studies , 14, 15.Based on the results of our study and others, morning hypertension is believed to provide reliable information on BP control and high risk of TOD in CKD patients. Controlling morning BP should be considered an important measure for preventing CV and renal damage. However, current ABPM guidelines do not highlight the importance of morning BP, let alone treatment of morning hypertension , 33. TreOur study had some strengths. First, to our knowledge, this is the first study to investigate the correlation between morning hypertension and TOD in CKD patients. Second, compared with previous studies that measured home morning BP , 14, 15,In conclusion, morning hypertension was strongly correlated with TOD, including LVH, higher UPCR, LVMI, and lower level of eGFR in CKD patients with hypertension, independent of nocturnal hypertension and morning surge in blood pressure. Morning hypertension in CKD patients warrants further attention. Proper management of morning BP may reduce cardiorenal injury in these patients.The original contributions presented in the study are included in the article/The studies involving human participants were reviewed and approved by West China Hospital, Sichuan University. The patients/participants provided their written informed consent to participate in this study.XL, FL, TZ, ZZ, HZ, AQ, YT, and WQ: conception, design, analysis, and interpretation of data. XL and FL: drafting the article or revising it. XL, YT, and WQ: providing intellectual content of critical importance to the work described. XL, FL, TZ, ZZ, HZ, AQ, YT, and WQ: final approval of the version to be published. All authors contributed to the article and approved the submitted version.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.


There are no clinical studies that have investigated the differences in blood serum metabolome between obstructive sleep apnea (OSA) patients and controls. In a single-center prospective observational study, we compared metabolomic profiles in the serum of OSA patients with apnea–hypopnea index (AHI) ≥ 15/h and control individuals. Peripheral blood was obtained at 3 different time points overnight: 9:00 p.m.; 5:00 a.m. and 7:00 a.m. We used a targeted approach for detecting amino acids and biogenic amines and analyzed the data with ranked general linear model for repeated measures. We recruited 31 patients with moderate-to-severe OSA and 32 controls. Significant elevations in median concentrations of alanine, proline and kynurenine in OSA patients compared to controls were detected. Significant changes in the overnight dynamics of serum concentrations occurred in OSA: glutamine, serine, threonine, tryptophan, kynurenine and glycine levels increased, whereas a fall occurred in the same biomarker levels in controls. Phenylalanine and proline levels decreased slightly, compared to a steeper fall in controls. The study indicates that serum profiles of amino acid and biogenic amines are significantly altered in patients with OSA referring to vast pathophysiologic shifts reflected in the systemic metabolism. Untreated OSA is associated with an increased risk of motor vehicle accidents, cardiovascular disease3, atrial fibrillation4, and exacerbations of chronic airway diseases6.Obstructive sleep apnea (OSA) is characterized by a history of habitual snoring and the occurrence of obstructed breathing events, hypopneas, and apneas, during sleep. OSA is a highly prevalent sleep disorder, with an estimated prevalence of 10–49.7% among adult men and 3–23.4% among adult women, depending on the study design7. In most studies designed for finding a biomarker in OSA, the samples have been obtained in the morning after sleep, whereas studies, addressing the differences between the evening and morning samples or the samples taken during sleep, are scarce9.Changes in the metabolome of OSA patients have thus far been studied in search for a biomarker or a set of biomarkers7. It is known that the results for untargeted metabolomic analyses are not always interchangeable between laboratories10, whereas targeted analysis, on the contrary, has shown better interlaboratory reproducibility11.Untargeted analysis of the metabolome in morning urine has been used on patients with OSA, which only partly reflects night-time metabolomic profileThe metabolic pathways involved in OSA have not been thoroughly investigated yet. There have been no metabolomic studies that have investigated the metabolomic changes among patients with OSA during night-time or, more importantly, the dynamic changes taking place from the time of going to bed until waking up.12, but there have been no studies on OSA and its effects on the serum profiles of amino acids and biogenic amines. Haptoglobin, ceruloplasmin and hsCRP have all been previously examined as possible biomarkers for obstructive sleep apnea14, however, prospective trials examining their biomarker potential have been lacking. General biochemical analyses were done to exclude a severe concomitant undiagnosed disease, which could alter the metabolome.The substances examined were selected based upon the previous literature: the effects of sleep deprivation on amino acids and biogenic amine profile have been examinedWe hypothesized that assessing the metabolomic profile at multiple time points in the peripheral blood of OSA patients using a targeted approach could lead to better characterization of obstructive sleep apnea and its systemic effects in particular. This knowledge could improve the treatment and monitoring of OSA patients and lead to a more precise division into subgroups in the future. Together with precise clinical characterization and longitudinal follow-up this approach could lead to better risk assessment among OSA patients. The aim of our study was to assess the amino acid and biogenic amine profile in peripheral blood of OSA patients during multiple time points  in order to characterize the metabolomic differences between OSA patients and controls.p = 0.006) and triglycerides (TG) (p = 0.02) (Table p = 0.042) .The TG values correlated significantly with that of body mass index (BMI)  and ALAT , haptoglobin and ceruloplasmin concentrations between OSA patients and controls  that we analyzed at three different time points is presented in the online supplement , serine (Ser) (p = 0.005), threonine (Thr) (p = 0.001), tryptophan (Trp) (p < 0.001), Kyn (p = 0.001) and glycine (Gly) (p = 0.007) increased in the patients with OSA, whereas a fall occurred in the levels of the same biomarkers in controls  and Pro (p = 0.008) decreased slightly, compared to a steeper fall in controls   and asymmetric dimethylarginine   p = 0.05, serineFinally, repeated measures’ analysis performed inside both groups indicated that the contents of several amino acids and biogenic amines decreased and/or increased significantly between different time points within the OSA group, as well as within the control group 25. The circadian rhythm of interferon gamma has been previously demonstrated not to be significantly different among OSA patients and controls26. A recent meta-analysis demonstrated that TNF-α level in patients with OSA was significantly (1.77 times) higher than in the control group27. Kyn/Trp represents a measure of IDO activity28. The supplementary analysis of Kyn/Trp confirmed that the Kyn/Trp values were significantly higher in the patients with OSA than in the controls and remained higher throughout the whole night as well 32. Increased ALAT levels are shown to occur with NAFD as well32. As the TG concentrations correlated positively with that of ALAT, as well as with BMI in OSA, a possibility exists that the increased levels of ALAT could have a link with increased BMI via NAFD in patients with OSA.In our current study, the levels of ALAT and TG were significantly elevated in OSA patient group, compared to the control population in the morning fasting blood samples. The rise of ALAT and TG concentrations could be explained by the increased BMI of the OSA patients. It has been shown previously that increased TG levels are positively correlated with increased BMI33 might have been important metabolome changing factors, thus obscuring the data. Measuring of the metabolome at different time points was done to minimize the effects of random or clock-time dependent factors on the metabolome. Blood sampling was scheduled to take place during sleep, in order to characterize sleep-time changes.The strengths of this study were the measurement of the metabolome at different time points, usage of strict exclusion criteria and obtaining the analyses via venipuncture. PSG recording on the same night as blood sampling is important for precise linking of molecular phenotype to sleep quality. Venipuncture was thought of as clinically more feasible, as the placing of an indwelling catheter would have made it more difficult to implement our findings into clinical practice. It was also considered that the effects of heparin, used for flushing, and catheter induced local inflammation3 and because the study participants were recruited consequentially.Among the limitations of our study, the sample size of 63 participants is relatively small. However, this limitation was attenuated by samples taken at multiple time point. In our study the patients with OSA were significantly older, had greater BMI and neck circumference, higher STOP-BANG scores and fasting blood glucose (FBG) values. These differences, however, do not represent a bias but were rather due to the fact that OSA itself is more frequent with higher BMI and older ageIn conclusion, we have found that the concentrations of certain amino acids and biogenic amines including Ala, Pro and Kyn are elevated in the peripheral blood of OSA patients between 9 p.m. and 7 a.m. The profile of several amino acids and biogenic amines changed significantly when measured in OSA patients at multiple time points during the night and compared to control population. The differences in the concentrations of Ala, Pro, and Kyn are especially pronounced during the night-time and early morning blood samples.We conducted a single-center prospective observational study to compare the metabolomic blood profiles of moderate-to-severe OSA patients and controls. This study was performed in accordance with the Declaration of Helsinki and the study protocol was approved by the Tallinn Medical Research Ethics Committee (decision number 2270). Written informed consent was obtained from each participant.Adult individuals were recruited from the Department of Psychiatry of the Tartu University Hospital, where they were referred for a standard polysomnography (PSG). Exclusion criteria included acute illness, defined as the presence of symptoms of acute infection, treatment with continuous positive airway pressure (CPAP) whenever during the last 6 months, current diagnosis of a chronic illness like heart failure in New York Heart Association (NYHA) class III–IV, chronic kidney disease stage IV–V, degenerative cerebrovascular disease, other neurological disease, liver disease, pulmonary disease with oxygen saturation below 93%, active malignancy, autoimmune disease, type I and type II diabetes, and treatment with drugs known to affect metabolome including systemic corticosteroids and hormonal contraceptives. The recruitment period lasted from April 2018 to September 2019.15, which included video monitoring, electroencephalography, eletctrooculography, chin and leg electromyography, airflow, thoracoabdominal bands, snoring sensor, body position, electrocardiography, and oxygen saturation. PSG was performed with use of either an Embletta MPR  or a NOX A1  as these were routine standards in our center. PSG data were manually scored by European Sleep Research Society certified sleep technicians according to American Academy of Sleep Medicine (AASM) PSG scoring guidelines15.We used standard PSG recording34. The central apneas were also included in the AHI calculation and AHI was further used to determine the severity class of OSA . In every patient, there were altogether more obstructive than central respiratory events and no patient in our study had central sleep apnea or Cheyne–Stokes breathing diagnosed.The clinical diagnosis of OSA was based on obstructive respiratory events alone as per international recommendations3. Participants with AHI ≥ 15/h were termed as moderate-to-severe OSA group and those with AHI < 15/h were included in control group.The subjects were divided into moderate-to-severe OSA group and control group based on the PSG findings and more specifically, on the AHI® silicone coated  extraction tubes for collection of serum samples for metabolomics. Clotting was allowed for 30 min at room temperature and the samples were then centrifuged at 1500g for 15 min at 4 °C. The resulting sera were aliquoted and frozen at − 80 °C until further analysis. The entire process was completed within 60 min of blood extraction.Blood samples for metabolomics and clinical biochemistry were collected simultaneously with PSG recording via standard peripheral venipuncture at 3 different time points: 9:00 p.m.; 5:00 a.m.; 7:00 a.m. These time points were carefully chosen to characterize in the best way the sleep-time changes among the study population on one hand and to avoid interfering with the normal sleep structure on the other. We used BD Vacutainer14 were taken at all 3 time points mentioned above. Other clinical parameters like sodium (Na), potassium (K), creatinine, urea, ALAT, aspartate aminotransferase (ASAT), cholesterol, LDL (low-density lipoprotein) cholesterol, HDL (high-density lipoprotein) cholesterol, TG were analyzed once at 7:00 a.m. FBG was also measured at 7:00 p.m. For the clinical biochemistry sample collection, we used BD Vacutainer® Heparin  extraction tubes.Analyses for markers of systemic inflammation (hsCRP) and possible proteomic OSA biomarkers 11 was used to determine the serum levels of different amino acids and biogenic amines. Frozen sera were thawed at room temperature and subsequently analyzed on mass-spectrometry QTRAP 4500 , linked to a high-performance liquid chromatography (HPLC) . Preparation of samples and all measurements were done as described by the manufacturer in the test kit manual UM-P180; the specific details are described previously35. Concentrations of the metabolites were calculated automatically by the MetIDQ™ software (BIOCRATES Life Sciences AG). The AbsoluteIDQ™ test kit has internal standards and includes quality control samples, which were evaluated, deviations were noted and corrections were done when necessary in the MetIDQ software before start of data analysis. Analytes that were considered invalid by the software were excluded from later statistical analysis. The kit itself has been estimated to have inter-laboratory coefficients of variation below 10% for most metabolites relevant for the current study11.Amino acids and biogenic amines were measured in sera using liquid chromatography-mass-spectrometry [(LC)–MS/MS] techniques. For measuring of the metabolite levels, we used a targeted approach: previously validated AbsoluteIDQ™ p180 kit ® 6000 c501 analyzer , which has been previously validated36. Ceruloplasmin and haptoglobin were measured fully automatically using immunoturbidimetric assay. These two substances were measured using Cobas® Integra 400 analyzer (Roche Diagnostics), which has been previously validated37.In case of this analysis set, plasma samples were obtained and analyzed at the United Laboratories of the Tartu University Hospital. ALAT, ASAT and Urea levels were measured fully automatically using kinetic photometric method. HDL-cholesterol, LDL-cholesterol, total cholesterol and TG were measured fully automatically using enzymatic colorimetric method. Sodium and potassium concentrations were measured fully automatically using ion-selective electrodes. Creatinine was measured fully automatically using an enzymatic method. hsCRP was measured fully automatically using particle-enhanced immunoturbidimetric assay. All the substances mentioned above were measured using CobasWe used ranked general linear model for repeated measures to detect significant differences in the serum contents of amino acids and biogenic amines between patients with OSA and control individuals, as well as to unravel significant changes occurring overnight. To achieve the best fitting model, we included all independent demographic, clinical and laboratory covariates first and used backward elimination that resulted in BMI, age, gender, current smoking status, oxygen desaturation index that included only desaturations with at least 5% drop in oxygen desaturation (ODI ≥ 5%), oxygen desaturation index that included only desaturations extending below 90% (ODI < 90%) and serum contents of K, Na, ASAT, ALAT, urea, HDL-cholesterol, LDL cholesterol and TG remaining in the final model as covariates the outcomes were adjusted for. Afterwards, a supplementary univariate comparison between the patients and control individuals for the kynurenine-tryptophan (Kyn/Trp) values was performed, also adjusted for the same covariates. All variables were rank transformed prior to all analyses, as were the outcome variables (i.e. the serum contents of amino acids and biogenic amines) assigned standardized ranks over the three time points. Fischer’s least significant difference method was used for correction for multiple comparisons.The pre-analysis characteristics were compared between the patients with moderate-to-severe OSA and controls using Mann–Whitney U test. Spearman correlation analysis was used for assessing correlation between the obtained findings. All data are presented as medians and interquartile ranges (IQR) or numbers (%). The statistical analyses were performed using SPSS software, version 20.0 . On all figures, the boxplots were constructed as follows: central line = median; upper box limit = 3rd quartile; lower box limit = 1st quartile; upper whisker limit = 95th percentile; lower whisker limit = 5th percentile. Black dots represent outliers.Supplementary Information 1.


P < 0.001). Similarly, brain-level mean blood pressure showed smaller reduction in the TC bout than in the control bout . The systolic CBFV was lower but diastolic CBFV was higher in the TC bout. The systemic blood pressure response was blunted in the TC bout, along with similar heart rate increase, smaller decrease, and earlier recovery of total peripheral resistance index than control during the gravitational transition. These data demonstrated that restricting thigh blood flow can effectively mitigate the transient cerebral hypoperfusion induced by rapid shift from −Gz to + Gz, characterized by remarkable improvement of cerebral diastolic flow.Exposure to acute transition from negative (−Gz) to positive (+ Gz) gravity significantly impairs cerebral perfusion in pilots of high-performance aircraft during push—pull maneuver. This push—pull effect may raise the risk for loss of vision or consciousness. The aim of the present study was to explore effective countermeasures against cerebral hypoperfusion induced by the push—pull effect. Twenty healthy young volunteers  were tested during the simulated push–pull maneuver by tilting. A thigh cuff (TC) pressure of 200 mmHg was applied before and during simulated push—pull maneuver (−0.87 to + 1.00 Gz). Beat-to-beat cerebral and systemic hemodynamics were measured continuously. During rapid −Gz to + Gz transition, mean cerebral blood flow velocity (CBFV) was decreased, but to a lesser extent, in the TC bout compared with the control bout (−3.1 ± 4.9 vs. −7.8 ± 4.4 cm/s,  Exposure to acute transition from negative (−Gz) to positive (+ Gz) gravity induces cerebral hypoperfusion, a major risk factor of acceleration-induced loss of consciousness. In this study, we found that restricting thigh blood flow during the rapid shift from −Gz to + Gz could effectively protect against cerebral hypoperfusion mainly through improving cerebral diastolic blood flow and pressure. Our findings may provide effective protective strategy for cerebral perfusion during acute gravitational stress.z) axis of the body (−Gz) and the subsequent positive gravity (+ Gz)  due to cerebral hypoperfusion . Push—puy (+ Gz) , 1995. Ty (+ Gz) . This puy (+ Gz) .The cerebral autoregulation and arterial baroreflex are the primary regulation mechanisms guarding the stability of cerebral blood flow and blood pressure in the face of acute hemodynamic changes . We haveTherefore, the key to prevent cerebral hypoperfusion induced by the push–pull effect is to retard the acute blood shift caused by rapid −Gz to + Gz transition. This could be implemented by blocking thigh blood flow using an inflated cuff at the upper thigh. In this study, we hypothesized that the application of thigh cuff (TC) during simulated PPM could counteract the cardio- and cerebrovascular hemodynamic effects and mitigate the reduction of cerebral perfusion at the rapid gravitational transition.The study conformed to the latest Declaration of Helsinki and was approved by the Ethics Committee of The Fourth Military Medical University. Written informed consents were given by all the subjects.Twenty healthy young volunteers  were recruited from the undergraduate students from our university, who are non-smokers with no history of fainting and/or cardiac arrhythmia or not taking cardiovascular medication. All participants abstained from caffeinated beverages, alcohol, and vigorous exercise at least 24 h before each trial. They all had experienced the tilting test one or two times in class several weeks before the study.Measurements were performed on subjects positioned on a computer-controlled tilt table whose transition speed was set to 45°/s . AbdominBefore actual testing, familiarization was provided at −60° head down tilt (HDT) for 15 s with a rapid transition to 90° HUT, which minimized psychological responses to the posture change. It appears that the potential influence of this familiarization procedure on the baroreflex-related responses during the following experimental bouts was minor according to a previous report of repeated baroreflex sensitivity measurements during tilt tests . As illuHeart rate (HR) was recorded using a 3-lead ECG . Non-invasive measurement of beat-to-beat arterial blood pressure was performed using finger-cuff plethysmography , with height corrected to the heart. Cardiac output (CO) was evaluated by finger arterial pulse wave using Modelflow algorithm that incorporates age, sex, height, and weight to provide stroke volume (SV) estimate . Total pMCA) divided by mean CBFV (CBFVm). Systolic CBFV (CBFVs) and diastolic CBFV (CBFVd) were used to calculate pulsatility index (PI), as (CBFVs−CBFVd)/CBFVm  was continuously measured in the middle cerebral artery (MCA) using a transcranial Doppler  . A 2-MHzd)/CBFVm .2 was sampled through a nasal cannula and analyzed by an infrared-based carbon dioxide measurement module . Before the trial, participants were instructed to breathe only through their noses with the nasal cannula and avoid any Valsalva-like maneuvers. The breathing of participants was monitored by an experimental assistant. End-tidal CO2 (ETCO2) values were converted to millimeters of mercury based on atmospheric temperature and pressure.Breath-to-breath COBaseline HUT data were obtained from the last-minute measurements of the initial 5 min HUT. The 15 s of HDT data were divided to three segments every 5 s. The first 15 s of second HUT data was divided into three segments every 5 s. For the TC bout, the 60-s baseline HUT + TC data were divided into three segments every 20 s. Those specific blocks of time were chosen based on our previous studies about PPM  and obseA priori sample size calculation determined that a minimum of 10 participants would provide sufficient power to detect a difference of 10% ± 10% for change in CBFVm and MAPMCA during tilt tests . Statistical significance was defined by two-tailed P < 0.05.lt tests , with a None of the subjects experienced loss of peripheral vision, central vision, or consciousness during the experiment based on their self-reports.2 were found between HUT and HUT + TC    . CBFVs w< 0.001) . MAPMCA < 0.001) . CVRi de< 0.001) , with siMCA and CVRi were higher with TC over the 15 s following −60° HDT. PI and ETCO2 were lower in the TC bout than in its control.During HUT following −60° HDT, CBFVm of the TC bout was higher than the control bout at the first 5 s and back to the baseline level at 15 s, while CBFVm of the control bout continued to increase . MAPMCA During baseline HUT, the systemic blood pressures, SV, and CO were all increased with TC applied, while no significant change of HR or TPRi was observed .During HDT, MAP, TPRi, and SV were not different between control and TC bouts. HR was higher in the TC bout than its control at 10 s and 15 s . CO was At the rapid −Gz to + Gz transition, HR was elevated similarly in response to the HDT–HUT transition for both bouts. MAP decreased by 22% in the control bout, but only 6% in the TC bout . The TC During HUT following −60° HDT, HR was similar between the control bout and TC bout. MAP and TPRi were higher with TC over the 15 s following the simulated PPM . SV and The current study was designed to explore an effective strategy to counteract cerebral hypoperfusion induced by abrupt transition from −Gz to + Gz. We found that cuff-method thigh blood flow restriction could effectively mitigate the decrease in cerebral blood flow and arterial blood pressure due to simulated PPM and protect the cerebral perfusion, with predominant preservation of the diastolic cerebral blood flow and pressure. This strategy also improved systemic blood pressure control, characterized by systemic blunted blood pressure response combined with similar HR increase, smaller decrease, and earlier recovery of TPRi in the TC bout than the control bout during the simulated PPM.MCA and cerebral perfusion during transition from “pull” (−Gz) to “push” (+ Gz) constitutes the direct reasons for loss of vision or conscious during PPM   . Therefoes)  . The antThere are several limitations that should be mentioned. First, the present study only enrolled male subjects. A previous centrifuge study found Gz tolerances overall to be the same in men and women . HoweverBlood flow restriction by TC applied immediately before and during transition from −Gz to + Gz could afford effective protection against the reduction of cerebral blood flow and pressure, which was mainly attributable to the diastolic protective effect.The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author/s.The studies involving human participants were reviewed and approved by the Ethics Committee of The Fourth Military Medical University. The patients/participants provided their written informed consent to participate in this study.CX, YG, and FG contributed to conception and design of the study. CX, YG, XW, WX, YLiu, and YLei performed the study. CX and YG organized the database. CX performed the statistical analysis. CX wrote the first draft of the manuscript. YG, WX, XZ, SZ, LY, and FG wrote sections of the manuscript. All authors contributed to manuscript revision, read, and approved the submitted version.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.


Chronic heart failure (CHF) leads to an excess of urgent ambulatory visits, recurrent hospital admissions, morbidity, and mortality regardless of medical and non-medical management of the disease. This excess of risk may be attributable, at least in part, to comorbid conditions influencing the development and progression of CHF. In this perspective, the authors examined and described the most common endocrine disorders observed in patients with CHF, particularly in individuals with reduced ejection fraction, aiming to qualify the risks, quantify the epidemiological burden and discuss about the potential role of endocrine treatment. Thyroid dysfunction is commonly observed in patients with CHF, and sometimes it could be the consequence of certain medications . Male and female hypogonadism may also coexist in this clinical context, contributing to deteriorating the prognosis of these patients. Furthermore, growth hormone deficiency may affect the development of adult myocardium and predispose to CHF. Limited recommendation suggests to screen endocrine disorders in CHF patients, but it could be interesting to evaluate possible endocrine dysfunction in this setting, especially when a high suspicion coexists. Data referring to long-term safety and effectiveness of endocrine treatments in patients with CHF are limited, and their impact on several “hard” endpoints  are still poorly understood. Nowadays, around 40 million people live with Chronic Heart Failure (CHF) with a worldwide estimated prevalence of 1–3% in the adult population. Affected patients are usually men, with underlying comorbidities such as coronary artery disease, diabetes mellitus, and arterial hypertension . To datesequelae of adaptive mechanisms  and identified a cluster of individuals with higher mortality risk . The more the number of HDs, the more the cumulative risk of worse prognosis [Hormonal disorders have been described in CHF patients Fig. . These irognosis .Fig. 1OvANP, BNP, and C-type Natriuretic Peptide antagonize both the sympathetic and RAAS hyperactivity, frequently observed in CHF. They promote natriuresis by inhibiting natrium and consequently water reabsorption at the levels of both the proximal and distal renal tubules . In addiBesides the diagnostic role of natriuretic peptides, the therapeutic use of these molecules has been extensively evaluated. For example, the recombinant human BNP Nesiritide was found to reduce heart failure symptoms and pulmonary capillary wedge pressure in patients with acute heart failure , 22 evenp < 0.001), death for any causes , cardiovascular causes . Moreover, the risk of hospital admission due to heart failure recurrence was reduced by 21% (p < 0.001) [In the PARADIGM-HF trial, the efficacy of LCZ696 was compared with enalapril in CHF patients with reduced ejection fraction, and the primary end-point was a composite of death due to cardiovascular causes or hospitalization for heart failure . The res< 0.001) . The ass< 0.001) . More sp< 0.001) , 32.p < 0.001) [p < 0.001). Diastolic dysfunction, assessable in 75 out of 86 patients, was present in 45 of them. However, the levels of copeptin did not correlate with cardiac function but only with NT-proBNP . Prognostic implications of copeptin  were blunted after adjustment for NT-proBNP. In conclusion, copeptin could have a role in a better comprehension of the preserved ejection fraction CHF pathophysiology [AVP is released by the hypothalamic supraoptic nuclei , 34 and < 0.001) . In a cr< 0.001) . Hage etysiology . Howeverysiology .A sustained AVP-dependent antidiuresis in CHF prompts chronic water retention exceeding the RAAS-induced renal natrium reabsorption with a subsequent dilutional (hypervolemic) hyponatremia . ConsistFinally, the activation of AVP receptor 1 induces systemic vascular contraction, hence activating an additional compensative mechanism by which AVP attempts to raise blood pressure and myocardial afterload . At the GH deficiency (GHD) represents one of the most common hormonal deficit observed in patients with CHF. The precise mechanisms explaining this phenomenon remain unclear. Chronic hepatic congestion usually observed in CHF may reduce IGF-1 levels, thus contributing to the decline of the foremost peripheral Growth Hormone (GH) effects. Cittadini et al. found GHD in around 40% of patients with both ischemic and non-ischemic CHF (63 over 158 participants) .GH and IGF-1 reduce peripheral vascular resistence via increasing endothelial synthesis and release of NO and possibly by activating Adenosine Triphosfate sensible potassium channels on smooth muscle cells. GH and IGF-1 may also protect peripheral vasculature from atherosclerosis. Patients with GHD who fail to achieve normal or near-normal IGF-1 levels are prone to develop atherosclerosis and cardiovascular diseases . In an aPatients with CHF are often predisposed to muscular atrophy. Even though several hemodynamic mechanisms may explain this phenomenon, local IGF-1 deficiency has been observed in this cluster of patients. Physical exercise  may improve local IGF-1 deficiency without any relevant systemic effects and antagonize muscle atrophy in individuals with moderate CHF .Cittadini et al. recruited 56 patients diagnosed with GHD for a randomized, single-blind, controlled trial (GH replacement versus placebo). CHF severity was classified as follows: 64.4% (18) of participants were diagnosed with class II New York Heart Association (NYHA) heart failure, 21.4% (6) with class III, 14.3% (4) with class IV. GH replacement was associated with a statistically significant improvement in the quality of life, left ventricle ejection fraction, exercise tolerance, and endothelial dysfunction after 6 months of treatment . SimilarLeft ventricle function and myocardial remodeling are unlikely to improve after GH replacement therapy in patients with reduced ejection fraction  due to coronary artery disease but without GHD .GH therapy may improve left ventricle function, ameliorate resistance to fatigue, and quality of life. However, data are available for a short follow-up . Therefore, it is challenging to confirm GH replacement therapy as a possible medical strategy for improving CHF prognosis over time. In addition, GH administration seems to ameliorate myocardial pump efficiency only in patients with a previously confirmed GHD, not in those without . NeverthSubclinical and overt hypothyroidism have been frequently observed in patients with CHF , 74 and p < 0.02) [From a pathophysiological point of view, T3 plays a capital role in regulating the expression of genes involved in myocardial contractility and intracellular calcium handling, and the modifications induced by hypothyroidism or NTIS contribute, at least in part, to decrease pump efficiency in CHF , 76. Chr < 0.02) .Different studies evaluated the prognostic impact of hypothyroidism in patients with CHF. In one study conducted in CHF outpatients on top of the standard care  and 15 months of active follow-up, a slight increase in TSH concentration was independently associated with the occurrence of heart failure progression . AnotherThese results suggest that thyroid replacement therapy aimed to restore euthyroidism in patients with hypothyroidism and CHF should be considered for avoiding poor outcomes . In clinp < 0.001) in patients with acutely decompensated heart failure [Since triiodothyronine (T3) has a relevant role in myocardial homeostasis, low circulating free T3 (fT3) levels usually observed in CHF may affect cardiovascular prognosis . Patient failure  even if  failure . Hamilto failure .Evidence supporting the use of levothyroxine or, more specifically, triiodothyronine supplementation for treating the NTIS in patietns with CHF is currently weak. In most of the cases, clinical trials have been made recriuting a restricted number of participants, most of them admitted to hospital care due to acutely decompensed heart failure, and for a limited number of days or weeks. Despite amelioration in left ventricle kinetic was observed in patients receiving triiodothyronine supplementation intravenously or orally, long-term effictiveness and safety of triiodothyronine supplementation are still unknown . FurtherDevelopment and progression of CHF can also be favored by hyperthyroidism and thyrotoxicosis. Hyperthyroidism, thyrotoxicosis, and CHF are not usually related to each other, differently from how is observed with NTIS. For example, hyperthyroidism may be the consequence of a clinical complication in patients assuming amiodarone . ThyrotoAmiodarone-induced thyrotoxicosis (AIT) may be a specific issue among patients with CHF, as the use of amiodarone is more frequently observed in this cluster of patients. AIT has two kinds of typical presentation that may occur at any time of treatment or even months after its discontinuation . Type 1 Amiodarone can also lead to hypothyroidism . AmiodarJankowska et al. reported T deficiency among hormonal disorders observed in men with CHF . Male hyFrom a pathophysiological point of view, T increases muscle strength and resistance as it promotes muscle hypertrophy of both type I or oxidative and type II or glycolytic muscle fibers , 150. MoTRT was found to improve glucose control, also reducing adipose mass in hypogonadal men with diabetes mellitus , 166. T Among patients with CHF, hypotestosteronemia is not an unusual finding and it may correlate directly to cardiac output. In one observational study, patients with CHF receiving intramuscular T preparations compared to those on placebo (every 2 weeks for 12 weeks) displayed a more significant improvement of physical performance after 12 weeks of treatment .These studies demonstrated that T-related anabolic actions could serve muscle strength in patients with CHF, particularly those with lower baseline serum TT concentration. As poor cardio-respiratory fitness is related to higher mortality rate in patients with CHF , it coulIn addition, TRT ameliorates insulin resistance, lipid profile, hyperglycemia that are well-recognized risk factors of atherosclerosis and may affect exercise capacity in patients with CHF . Also, TOn the other hand, data from animal models suggested that T might be implicated in cardiomyocyte hypertrophy, apoptosis, and myocardial fibrosis , 174, thMale hypogonadism is considered a predisposing condition favoring worse clinical outcomes in patients with cardiovascular diseases, including CHF, as observed during the ongoing pandemic of Coronavirus disease 2019 or COVID-19 , 177. T Erectile Dysfunction (ED) can be considered a “sentinel marker” of acute cardiovascular events, especially in men under 65 years or in those with type 2 diabetes mellitus, and may raise the suspicion of cardiovascular complications. ED in CHF may result from pathophysiological and pharmacological treatment, and the medical management of sexual dysfunction may be complicated in this cluster of patients. However, patients with NYHA class I/II and ED receiving type 5 phosphodiesterase inhibitors  usually exhibit slight adverse events, while cardiopulmonary parameters and quality of life are improved significantly  besides A piece of evidence from both preclinical and clinical studies has highlighted the crucial role of gender in driving cardiac remodeling lastly leading to overt CHF . MyocardObese patients display different types of ventricular hypertrophy according to gender. Men usually exhibit concentric cardiac hypertrophy, while women show either concentric or eccentric one. Concentric over eccentric cardiac hypertrophy is considered a relevant risk factor for cardiovascular mortality. These observations may explain the gender difference in obese-related cardiovascular mortality . In addiEstrogens exert antihypertrophic effects by binding to their receptors (ERα and ERβ) and attenuating the MEK1/2- ERK1/2-Elk1 signaling cascade. ER stimulation increases intracytoplasmic MKP-1 levels to reduce p38 activation, therefore inducing gene-reprogramming and suppressing hypertrophic response. In addition, ER activation blocks the calcineurin-mediated hypertrophic effect through the NFAT- MEF2/GATA4 mechanism. Moreover, ER induces eNOS-sGCcGMP-PKGIα signaling cascade, which curbs cardiac hypertrophy and facilitates cardioprotection , 191. InDiabetes mellitus is a well-recognized risk factor for CHF. The role of insulin resistance and poor glycemic control in the pathophysiology of CHF and therapeutic approaches to manage hyperglycemia have been extensively reviewed elsewhere –195. At The sodium-glucose cotransporter type 2 inhibitors (SGLT2is), one of the new classes of anti-hyperglycemic medications, hinders renal glucose reabsorption at the level of the proximal tubules and produces a reduction in blood glucose levels in an insulin-independent manner . In addiEndocrine dysfunction is frequently observed in patients with CHF. It is more prevalent in CHF patients with reduced ejection fraction and most of the evidence is related to this kind of condition. Data about endocrine dysfunction in CHF patients with mildly reduced or preserved ejection fraction are limited but it is thought that it coexists in a smaller percentage. In some cases, endocrine dysfunction may be the consequence of a maladaptive mechanism, and it remains unclear if medical correction of the imbalance is necessary or not . In other cases, endocrine dysfunction may either coexist or anticipate the CHF onset, also fostering the CHF progression over time. Some guidelines currently recommend to assess thyroid function in all patients with CHF as both hypo- and hyperthyroidism may cause or precipitate CHF . In addiAs another issue, medical correction of endocrine dysfunction should be made with caution upon the diagnosis has occurred, particularly considering patients’ characteristics , baseline CHF severity, chronic comorbidities, and residual life expectancy. In fact, limited data suggest that endocrine therapies in CHF patients with endocrine dysfunction may improve some of the leading clinical symptoms typically observed in CHF, hence ameliorating the quality of life. Moreover, currently available data are limited to a short-term follow-up and specific clinical settings . Therefore, scanty or null long-term evidence is available considering these treatments as reinforcing therapies to standard chronic care Table  and furtSupplementary Information


The goal of this study was to examine associations of measures of maternal glucose metabolism and blood pressure during pregnancy with blood pressure at follow up in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) cohort. The HAPO Follow-Up Study included 4747 women who had a 75-g oral glucose tolerance test (OGTT) at ~28 weeks’ gestation. Of these, 4572 women who did not have chronic hypertension during their pregnancy or other excluding factors, had blood pressure evaluation 10–14 years after the birth of their HAPO child. Primary outcomes were systolic blood pressure (SBP), diastolic blood pressure (DBP) and hypertension (SBP ≥140 and/or DBP≥90 or treatment for hypertension) at follow-up.Blood pressure during pregnancy was associated with all blood pressure outcomes at follow-up independent of glucose and insulin sensitivity during pregnancy. The sum of glucose z-scores was associated with blood pressure outcomes at follow-up but associations were attenuated in models that included pregnancy blood pressure measures. Associations with SBP were significant in adjusted models, while associations with DBP and hypertension were not. Insulin sensitivity during pregnancy was associated with all blood pressure outcomes at follow-up, and although attenuated after adjustments, remained statistically significant .In conclusion, maternal glucose values at the pregnancy OGTT were not independently associated with maternal blood pressure outcomes 10–14 years postpartum; however, insulin sensitivity during pregnancy was associated independent of blood pressure, BMI and other covariates measured during pregnancy. It is well recognized that gestational diabetes (GDM) is associated with an increased risk of developing type 2 diabetes in the years after delivery . More reNormal pregnancy is associated with greater insulin resistance and associated metabolic changes. GDM may result in part from an exaggeration of this insulin resistance, but increased insulin resistance may still be present in the absence of GDM. Greater insulin resistance in pregnancy is also associated with hypertension in pregnancy, and this insulin resistance may be present before the onset of hypertension . HyperteThe HAPO Study was an observational study designed to examine associations of glucose levels during pregnancy with adverse perinatal and maternal outcomes. HAPO Study methods have been described in detail , 14. BriFor the HAPO FUS, mothers from the HAPO cohort were recruited during 2013–2016 (10–14 years later) from 10 of the 15 original HAPO field centers. Eligibility criteria for HAPO FUS included gestational age at delivery ≥ 37 weeks and no major neonatal malformations or fetal/neonatal death. This yielded 15812 eligible mothers. The recruitment target was 7000 and 4747 participated in the follow-up assessment. Comparison of the characteristics of the participants and non-participants revealed almost identical characteristics for key confounders  on the right arm brachial artery with the appropriate cuff size after sitting for 5 minutes with 1–2 minute intervals between measurements. The mean of the second and third measurements was used for analyses.The primary outcome for this analysis was a dichotomous variable for maternal hypertension, either identified at follow-up, defined as SBP ≥ 140 mmHg and/or DBP ≥90 mmHg, or by the reported use of antihypertensive medication at the time of the FUS visit. Secondary outcomes were systolic and diastolic blood pressure analysed as continuous variables.OGTT C-pep) values was calculated according to the equation of Radaelli et al., with a numerator adjustment for scaling: ISOGTT C-pep = 1,000/ √(FPG × fasting C-peptide ×G ×C), where G and C are the means of fasting and 1-h PG (mmol/L) and C-peptide (ug/L), respectively , systolic blood pressure (SBP) and diastolic blood pressure (DBP). Blood pressure measurements during pregnancy were used to classify hypertensive disorders in pregnancy according to the International Society for the Study of Hypertension in Pregnancy guidelines . Hyperteectively . ContinuSummary statistics from pregnancy were compared for eligible mothers who did and did not participate in the HAPO FUS, including field center summaries weighted by the proportion of the total eligible at each field center . HistogrModels of individual associations of maternal blood pressure were considered first, with maternal MAP, SBP, DBP and hypertension during pregnancy examined for associations with maternal hypertension, SBP and DBP at follow-up, respectively. Next, individual associations were examined for maternal sum of glucose z-scores, GDM and insulin sensitivity with all maternal hypertension and blood pressure outcomes at follow-up. Lastly, joint models of maternal blood pressure and glycemia were examined in pairs as follows: maternal MAP and maternal sum of glucose z-scores, GDM and insulin sensitivity during pregnancy for the maternal hypertension at follow-up outcome; maternal SBP and maternal sum of glucose z-scores, GDM and insulin sensitivity during pregnancy for the maternal SBP at follow-up outcome; and maternal DBP and maternal sum of glucose z-scores, GDM and insulin sensitivity during pregnancy for the maternal DBP at follow-up outcome. Joint models of categorical hypertension predictors during pregnancy with maternal sum of glucose z-scores, GDM and insulin sensitivity during pregnancy were also examined for all follow-up outcomes. All of the analyses described above were performed using a baseline model that included adjustment for known potential confounders and adjustments as already used in HAPO analyses : field crms R package . In contrast, GDM according to IADPSG criteria is not independently associated with subsequent hypertension, SBP or DBP. However, when blood pressure measures are analysed as continuous outcomes, the pregnancy OGTT sum of glucose z-scores was associated with SBP at follow-up independently of SBP in pregnancy; no such relationships were demonstrated for DBP (independent of pregnancy DBP) or hypertension (independent of pregnancy MAP). Although GDM is not independently associated with subsequent SBP and DBP or hypertension, insulin resistance during pregnancy is independently associated with subsequent hypertension as well as SBP and DBP. Similar relationships were demonstrated in women with hypertensive disorders in pregnancy. Multiple measures of blood pressure were evaluated to confirm robustness of findings. In conclusion, identification of women with greater insulin resistance during pregnancy may help to identify those at risk for subsequent hypertension.Although some studies have shown no association between GDM and subsequent hypertension , 7, manyWhile the association of insulin resistance and hypertension outside of pregnancy is well recognised, we are not aware of previous reports on the relationship of insulin resistance in pregnancy and the development of subsequent hypertension. The extent to which the mechanisms underlying insulin resistance in pregnancy differ compared to the non-gravid state is not known. Factors that contribute to pregnancy-induced insulin resistance include the secretion of adipokines  and cytokines , oxidative stress and, possibly, the gut microbiome . RecentlWhile the glucose values during the OGTT identify women at risk of dysglycemia but not hypertension during follow-up , greaterA limitation of this study is that in the original HAPO Study women who gave birth before 37 weeks were excluded. This likely included some who had developed hypertension or pre-eclampsia, but they were not eligible for the HAPO FUS. However, some of these women will have had underlying renal disease and therefore would have been excluded from our analysis. A further limitation is that during the HAPO Study, 1.8% of participants with an OGTT value higher than predefined thresholds were unblinded and excluded from the HAPO Study and thus, the HAPO FUS. These subgroups of women delivered before 37 weeks and those who were unblinded probably included women at higher risk of subsequent blood pressure elevation; accordingly, the reported associations are likely to be underestimates. There are further reasons for considering these as underestimates. Firstly, women with treated hypertension should have had lower SBP and DBP recordings at follow up. Secondly, in the HAPO FUS dropping the first measurement probably provided a fairer representation of “true” blood pressure at follow up, whereas in the HAPO Study the average of the two blood pressure measurements obtained was used, so it is probable that overall “true” blood pressure was marginally lower than the values recorded. Accordingly, the “true” difference in blood pressure between pregnancy and follow-up may be greater than what we have documented. Another limitation is that, without data collection in the intervening period, it was not possible to ascertain whether associations between glucose metabolism during pregnancy and long-term blood pressure outcomes are mediated via other factors. Finally, follow-up of the original HAPO participants over a long interval was a challenge, but the pregnancy characteristics of those who did not attend the HAPO FUS visit were similar to those of HAPO FUS participants.In conclusion, this study has clarified the controversy in the literature concerning the relationship between GDM and subsequent maternal hypertension. It has shown that although GDM is not independently associated with subsequent elevated blood pressure, underlying insulin resistance is independently associated with subsequent hypertension as well as both systolic and diastolic blood pressure. Furthermore, this study has shown that insulin resistance is associated with these outcomes even in the absence of GDM.


We analyzed the ability of machine learning incorporating 123I-MIBG heart-to-mediastinum ratio (HMR). ArE comprised arrhythmic death and appropriate therapy with an implantable cardioverter defibrillator. The probability of ArE and HFD at 2 years was separately calculated based on appropriate classifiers. The probability of HFD significantly increased as HMR decreased when any variables were combined. However, the probability of arrhythmic events was maximal when HMR was intermediate (1.5-2.0 for patients with NYHA class III). Actual rates of ArE were 3% (10/379) and 18% (27/147) in patients at low- (≤ 11%) and high- (> 11%) risk of developing ArE (P < .0001), respectively, whereas those of HFD were 2% (6/328) and 49% (98/198) in patients at low-(≤ 15%) and high-(> 15%) risk of HFD (P < .0001).A model was created based on patients with documented 2-year outcomes of CHF . Classifiers were trained using 13 variables including age, gender, NYHA functional class, left ventricular ejection fraction and planar 123I-MIBG differentially predicted ArE and HFD as causes of cardiac death.A risk model based on machine learning using clinical variables and The online version of this article (10.1007/s12350-020-02173-6) contains supplementary material, which is available to authorized users. Chronic heart failure (CHF) has become a major public health burden associated with aging of the global population.123I-metaiodobenzylguanidine (MIBG) activity comprise prognostic biomarkers for patients with CHF when combined with conventional clinical parameters. Several studies including multicenter investigations have shown that 123I-MIBG has powerful ability to predict cardiac mortality risk due to sudden cardiac or pump failure death.123I-MIBG activity.Changes in cardiac sympathetic function and innervation assessed by 123I-MIBG parameters, and to evaluate relationship between 123I-MIBG activity and events depending on clinical variables. The diagnostic accuracy of the classifier was also determined using training and validation databases that were built based on a cohort of Japanese patients with CHF.This study was designed to establish a means of differentiating the probabilities of cardiac death due to ArE and HFD using a machine learning-based classifier combined with clinical and 123I-MIBG imaging at one of four participating hospitals. The patients who had completed follow-up of at least 2 years when lethal cardiac events were not documented within the initial 2 years, were retrospectively selected from the patient medical records. The mean follow-up interval was 30 ± 20 months. Cardiac 123I-MIBG studies proceeded between 2005 and 2016, when the patients were clinically stable. No patients had lethal acute myocardial infarction for 2 years. In addition, due to the small number of non-cardiac death events, they were excluded from the statistical analysis so that this study could focus on discriminating ArE and HFD risks. Standard optimal medical care for CHF continued at each hospital after 123I-MIBG imaging. We analyzed patient data only when at least 2-year outcomes were confirmed. Among the patients, 77% and 23% had NYHA functional classes I-II and III-IV, respectively, and a mean LVEF of 38% ± 14% determined by two-dimensional echocardiography or gated myocardial perfusion scintigraphy , then anterior planar scintigrams were acquired 15-30 minutes (early phase) and 3-4 hours (late phase) later at the participating institutions. Standard acquisition protocol was used for 123I-MIBG imaging123I-MIBG activity was assessed at each hospital by drawing cardiac and upper mediastinal regions, then calculating heart-to-mediastinum average count ratios (HMR) of 123I-MIBG.123I-MIBG washout rate was calculated using the formula: (early HMR − late HMR)/early HMR.16Patients were injected with 111 MBq of 123I-MIBG study. Because both BNP and NT-ProBNP data were included, these biomarkers were categorically classified for assessment as grades 0, 1, 2, 3 and 4; as follows: BNP < 40, 40-99, 100-199, 200-560 and > 560 pg·mL−1, respectively, and NT-ProBNP < 125, 125-399, 400-899, 900-4800 and > 4,800 pg·mL−1, respectively.10Blood BNP or NT-ProBNP was measured at the participating hospitals. Data were acquired from clinically stable patients around the time of the The primary endpoint of this study was cardiac death due to end-stage heart failure and arrhythmic or sudden cardiac death, which were recorded in the medical records. Sudden cardiac death was defined as witnessed cardiac arrest and death within 1 hour of onset of acute symptoms or unexpected death in patients known to have been well within the previous 24 hours. Appropriate therapies against life-threatening arrhythmic events including ICD discharge and/or anti-arrhythmic pacing, were also included as ArE for patients under therapy with an ICD or a CRT device with a defibrillator (CRT-D).The Ethics Committees at Kanazawa University and at each participating hospital approved this multicenter study. The need for written informed consent from each patient was waived because of the retrospective nature of this study.123I-MIBG HMR and LVEF were combined.We described a statistical four-variable model to assess cardiac death risk in which age, NYHA functional classes I-II or III-IV, 123I-MIBG indices (late HMR and washout rate), age, NYHA functional class, estimated glomerular filtration rate (eGFR), LVEF, hemoglobin and BNP/NT-ProBNP grade .The following 13 variables were selected by ROC analysis: cardiac P < .05 and P ≥ .05 were considered significant and non-significant (n. s.), respectively. All data were analyzed using the SAS statistical package JMP version 12 .Variables are expressed as means ± standard deviation (SD). Mean values between groups were compared using analyses of variance (ANOVA). Pairs of groups were compared using t tests and contingency analyses, respectively, with Pearson statistics for continuous and categorical variables. The accuracy of the model was determined by calculating the AUC of the dataset. Optimal cutoff values for groups with and without events were determined using the greatest true positive plus true negative rates. Values with 123I-MIBG images as one patient with specific clinical variables that can be selected depending on the characteristics of individual patients, including age, gender, eGFR, NYHA functional class, LVEF, BNP category and 123I-MIBG variables.During a 2-year followup, 137 (26%) patients succumbed to cardiac death . Forty-one patients used an ICD or CRT-D and 12 received appropriate therapy. Arrhythmic events including sudden cardiac death and appropriate ICD/CRT-D therapy occurred in 37 (7%) of 526 patients. Figure A comparison of prognostic variables between ArE and HFD Table  showed t123I-MIBG HMR . At an ArE cutoff of 11%, the actual event rates were 3% (10/379) for the low-risk category with ≤ 11% probability and 18% (27/147) for the high-risk category with a probability > 11% (P < .0001). Figure P < .0001).The optimal cutoff probability with the highest sum of sensitivity and specificity in each cardiac death mode was 15% for HFD and 11% for ArE. At an HFD cutoff of 15%, actual event rates were 2% (6/328) for the low-risk category with ≤ 15% probability and 49% (98/198) for the high-risk category with a probability ≥ 15%  can be selected. We selected age, gender, NYHA class, LVEF and 123I-MIBG HMR to create models that could predict 2- or 5-year cardiac death.Univariate and multivariate analyses are usually applied in conventional statistical analysis, and variables with good probability  were at significantly lower risk of cardiac death, arrhythmic events, sudden cardiac death, or potentially life-threatening arrhythmias, but whether these risks were evident at intermediate HMR was not documented.27Characteristics curves of relationships differed when the probabilities of HFD and ArE were plotted against HMR. The ADMIRE-HF study using the multivariate Cox proportional hazards model identified LVEF, BNP and 123I-MIBG HMR in patients with NYHA functional classes I and II.Our machine learning-based modeling showed that risk for ArE was the highest at the intermediate range of HMR in association with NYHA class. The peak of the bell-shaped curve for ArE probability vs HMR shifted rightwards with increasing NYHA class. Since ADMIRE-HF and European studies enrolled only patients with NYHA functional classes II and III, the characteristics of this bell-shaped correlation was only partly evident.123I-MIBG can be explained by the arrhythmogenicity of the injured/denervated but viable myocardium. An imbalance between preserved myocardial perfusion and impaired sympathetic innervation is the most likely pathophysiological cause of serious arrhythmias. A regional mismatch between myocardial perfusion and 123I-MIBG uptake is associated with ventricular arrhythmias, and large 123I-MIBG defects are significantly related to more appropriate ICD therapy.123I-MIBG activity. Patients with advanced heart failure are far more likely to experience progressive heart failure leading to pump failure death rather than arrhythmic events at a relatively earlier stage of the clinical course. Thus, in contrast to the consistent correlation between the likelihood of HFD and cardiac 123I-MIBG activity (HMR), ArE risk was less likely at a low HMR range of cardiac 123I-MIBG activity.The increased risk of ArE at intermediate 123I-MIBG for predicting a need for ICD has also been evaluated.123I-MIBGactivity, whereas HFD was more frequent in older patients with a worse NYHA class, comorbidities and far less 123I-MIBG activity. Besides information about cardiac sympathetic nerve function, these features were similar to the clinical observations of the ESC-Failure Pilot study.Patients with CHF at increased risk for fatal cardiac events need an effective prophylactic strategy. The potential value of 123I-MIBG studies have identified a significant incremental prognostic value of 123I-MIBG together with clinical information for the overall cardiac mortality of patients at low and high risk.Although multiple factors are involved in the development of fatal outcomes, cardiac sympathetic innervation assessed by neuroimaging tracers has the potential to identify patients at increased risk of sudden/arrhythmic death who are likely to benefit the most from appropriate ICD treatment.11C-hydroxyephedrine (HED)18F-labeled norepinephrine transporter (LMI1195)123I tracers. In ischemic cardiomyopathy the potential utility of 11C-HED to identify patients most likely benefit from ICD therapy has been investigated (PARAPET study). Whether these new radiotracers have roles in risk stratification in conjunction with machine learning needs to be evaluated.Positron tracers such as This study used a CHF database that were retrospectively created by combining medical charts from four hospitals. Cutoffs for risk stratification of ArE can be influenced by the database used for machine learning. Inclusion of acute myocardial infarction, which was not included in this database, may enhance the clinical applicability in CHF patients. However, although MIBG studies may be indicated in patients with CHF, it is not usually indicated to those who have high likelihood of acute myocardial infarction in clinical practice. A prospective cohort study using more accurate clinical information and outcomes is desirable to improve the predictive accuracy of the risk model. The low (7%) event rate of ArE might have been insufficient for clinically reliable analysis, indicating a need for a larger and more long-term cohort study to develop a high-performance risk model. Finally, a prospective interventional study is required to establish not only the clinical implications of machine learning-based risk assessment, but also risk-based therapeutic strategies.123I-MIBG HMR and fatal events can be estimated. The probability of fatal arrhythmic events was separately determined for the first time.Based on machine learning, the likelihood of death from heart failure and fatal arrhythmic events can be arbitrarily simulated by the probability function, and relationship between 123I-MIBG activity, LVEF, NYHA class, age, gender, and other clinical variables. Our findings revealed differences in the probabilities of these two modes of cardiac death as well as in the pathophysiology of lethal cardiac events in chronic heart failure. Therefore, this information should contribute to more precise selection of prophylactic strategies tailored to the risk status of individual patients.We differentiated serious arrhythmias from end-stage heart failure as adverse cardiac event risks using a machine learning-based prognostic model created using variables that included cardiac Electronic supplementary material 1 (PPTX 2593 kb)Below is the link to the electronic supplementary material.