Associations of Visceral Adipose Tissue, Circulating Protein Biomarkers, and Risk of Cardiovascular Diseases: A Mendelian Randomization Analysis

Mediators between body mass index and atrial fibrillation: a Mendelian randomization study

Background

Although obesity is a recognized risk factor of atrial fibrillation (AF), the mechanisms are not fully understood.

Objective

We aimed to identify the potential mediators between body mass index (BMI) and AF.

Methods

We conducted a two-sample Mendelian randomization (MR) analysis using publicly available summary-level data from genome-wide association studies. Univariable MR analyses were applied to identify potential mediators, and then the multivariable MR analyses were conducted to explore the mediated roles of circulating biomarkers, metabolic markers and comorbidities in the association between BMI and AF.

Results

This MR study found a significant causal association between BMI and AF (OR = 1.41, 95% CI = 1.33-1.50; p < 0.001), which was attenuated to 1.21 (95% CI = 1.03-1.43) after being adjusted for leptin, in which 48.78% excess risk was mediated. After further adjustment for leptin and some cormorbidies, the association was attenuated to null (adjusted for leptin and sleep apnoea: OR=1.05, 95% CI = 0.85-1.30; adjusted for leptin and coronary heart disease: OR = 1.08, 95% CI = 0.90-1.30; adjusted for leptin and systolic blood pressure: OR = 1.11, 95% CI = 0.88-1.41), resulting in 87.80%, 80.49% and 73.17% excess risk being mediated, respectively.

Conclusion

These results identified an important mediated role of leptin, particularly for individuals with sleep apnoea, coronary heart disease or hypertension, providing some clues for the underlying mechanisms behind the impact of obesity on AF risk.

Relationship of interleukin-16 with different phenogroups in acute heart failure with preserved ejection fraction

AIMS

Interleukin-16 (IL-16) has been reported to mediate left ventricular myocardial fibrosis and stiffening in patients with heart failure with preserved ejection fraction (HFpEF). We sought to elucidate whether IL-16 has a distinct impact on pathophysiology and prognosis across different subphenotypes of acute HFpEF.

METHODS AND RESULTS

We analysed 211 patients enrolled in a prospective multicentre registry of acute decompensated HFpEF for whom serum IL-16 levels after stabilization were available (53% female, median age 81 [interquartile range 75-85] years). We divided this sub-cohort into four phenogroups using our established clustering algorithm. The study endpoint was all-cause death. Patients were subclassified into phenogroup 1 ('rhythm trouble' [n = 69]), phenogroup 2 ('ventricular-arterial uncoupling' [n = 49]), phenogroup 3 ('low output and systemic congestion' [n = 41]), and phenogroup 4 ('systemic failure' [n = 52]). After a median follow-up of 640 days, 38 patients had died. Among the four phenogroups, phenogroup 2 had the highest IL-16 level. The IL-16 level showed significant associations with indices of cardiac hypertrophy, diastolic dysfunction, and congestion only in phenogroup 2. Furthermore, the IL-16 level had a significant predictive value for all-cause death only in phenogroup 2 (C-statistic 0.750, 95% confidence interval 0.606-0.863, P = 0.017), while there was no association between the IL-16 level and the endpoint in the other phenogroups.

CONCLUSIONS

Our results indicated that the serum IL-16 level had a significant association with indices that reflect the pathophysiology and prognosis of HFpEF in a specific phenogroup in acute HFpEF.

Genetic insight into putative causes of xanthelasma palpebrarum: a Mendelian randomization study

Xanthelasma palpebrarum (XP) is the most common form of cutaneous xanthoma, with a prevalence of 1.1%~4.4% in the population. However, the cause of XP remains largely unknown. In the present study, we used Mendelian randomization to assess the genetic association between plasma lipids, metabolic traits, and circulating protein with XP, leveraging summary statistics from large genome-wide association studies (GWAS). Genetically predicted plasma cholesterol and LDL-C, but not HDL-C or triglyceride, were significantly associated with XP. Metabolic traits, including BMI, fasting glucose, type 2 diabetes, systolic and diastolic blood pressure, were not significantly associated with XP. Furthermore, we found genetically predicted 12 circulating proteins were associated with XP, including FN1, NTM, FCN2, GOLM1, ICAM5, PDE5A, C5, CLEC11A, CXCL1, CCL2, CCL11, CCL13. In conclusion, this study identified plasma cholesterol, LDL-C, and 12 circulating proteins to be putative causal factors for XP, highlighting the role of plasma cholesterol and inflammatory response in XP development.

Adipose Signals Regulating Distal Organ Health and Disease

Excessive adiposity in obesity is a significant risk factor for development of type 2 diabetes (T2D), nonalcoholic fatty liver disease, and other cardiometabolic diseases. An unhealthy expansion of adipose tissue (AT) results in reduced adipogenesis, increased adipocyte hypertrophy, adipocyte hypoxia, chronic low-grade inflammation, increased macrophage infiltration, and insulin resistance. This ultimately culminates in AT dysfunction characterized by decreased secretion of antidiabetic adipokines such as adiponectin and adipsin and increased secretion of proinflammatory prodiabetic adipokines including RBP4 and resistin. This imbalance in adipokine secretion alters the physiological state of AT communication with target organs including pancreatic β-cells, heart, and liver. In the pancreatic β-cells, adipokines are known to have a direct effect on insulin secretion, gene expression, cell death, and/or dedifferentiation. For instance, impaired secretion of adipsin, which promotes insulin secretion and β-cell identity, results in β-cell failure and T2D, thus presenting a potential druggable target to improve and/or preserve β-cell function. The cardiac tissue is affected by both the classic white AT-secreted adipokines and the newly recognized brown AT (BAT)-secreted BATokines or lipokines that alter lipid deposition and ventricular function. In the liver, adipokines affect hepatic gluconeogenesis, lipid accumulation, and insulin sensitivity, underscoring the importance of adipose-liver communication in the pathogenesis of nonalcoholic fatty liver disease. In this perspective, we outline what is currently known about the effects of individual adipokines on pancreatic β-cells, liver, and the heart.

Visceral adipose tissue and osteoarthritis, a two-sample Mendelian randomized study

Background

The relationship between visceral adipose tissue and osteoarthritis is not clear. The purpose of our study was to explore the relationship between visceral adipose tissue and osteoarthritis.

Methods

We used a two-sample Mendelian randomization method to select single-nucleotide polymorphisms (SNPs) significantly associated with visceral adipose tissue as instrumental variables to explore the relationship between visceral adipose tissue and all osteoarthritis, hand osteoarthritis, hip osteoarthritis, knee osteoarthritis, and spine osteoarthritis. The reliability of the results was tested using sensitivity analysis.

Results

Our findings indicated that visceral adipose tissue was associated with all osteoarthritis, hip osteoarthritis, knee osteoarthritis, and spine osteoarthritis (all osteoarthritis: OR = 1.399, 95% CI: 1.335-1.467, p = 7.95e-44; hip osteoarthritis: OR = 1.399, 95% CI: 1.284-1.524, p = 1.41e-14; knee osteoarthritis: OR = 1.794, 95% CI: 1.662-1.937, p = 1.33e-50; and spine osteoarthritis: OR = 1.445, 95% CI: 1.314-1.589, p = 2.89e-14). Sensitivity analysis demonstrated the reliability of these results.

Conclusion

Our study suggests that genetically predicted visceral adipose tissue is associated with osteoarthritis. Reducing the accumulation of visceral adipose tissue could potentially have an impact on the incidence of osteoarthritis.

Appraising the Causal Role of Risk Factors in Coronary Artery Disease and Stroke: A Systematic Review of Mendelian Randomization Studies

BACKGROUND Mendelian randomization (MR) offers a powerful approach to study potential causal associations between exposures and health outcomes by using genetic variants associated with an exposure as instrumental variables. In this systematic review, we aimed to summarize previous MR studies and to evaluate the evidence for causality for a broad range of exposures in relation to coronary artery disease and stroke. METHODS AND RESULTS MR studies investigating the association of any genetically predicted exposure with coronary artery disease or stroke were identified. Studies were classified into 4 categories built on the significance of the main MR analysis results and its concordance with sensitivity analyses, namely, robust, probable, suggestive, and insufficient. Studies reporting associations that did not perform any sensitivity analysis were classified as nonevaluable. We identified 2725 associations eligible for evaluation, examining 535 distinct exposures. Of them, 141 were classified as robust, 353 as probable, 110 as suggestive, and 926 had insufficient evidence. The most robust associations were observed for anthropometric traits, lipids, and lipoproteins and type 2 diabetes with coronary artery; disease and clinical measurements with coronary artery disease and stroke; and thrombotic factors with stroke. CONCLUSIONS Despite the large number of studies that have been conducted, only a limited number of associations were supported by robust evidence. Approximately half of the studies reporting associations presented an MR sensitivity analysis along with the main analysis that further supported the causality of associations. Future research should focus on more thorough assessments of sensitivity MR analyses and further assessments of mediation effects or nonlinearity of associations.

Splenic Infarction with Myocardial Injury in a Diabetic Patient: A Case Report

Splenic infarction (SI) is an uncommon complication of type 2 diabetes (T2D). Diabetes predisposes individuals to blood vessel abnormalities, such as atherosclerosis or thrombosis, increasing the risk of vessel occlusion and subsequent tissue infarction. If the diabetic patient has other serious diseases, such as a severe pneumonia infection and acute cardiac infarction, SI incidence may go unrecognized, making it challenging for physicians to identify. This case report discussed an 80-year-old hospitalized diabetic woman with a history of chronic bronchitis and 20 years of T2D who suffered an SI. The patient was at elevated risk for thrombosis of atrial fibrillation, manifested as an embolism of the spleen characterized by a high concentration of white blood cells. This patient also demonstrated a rapid increase in cardiac biomarkers troponin I, suggesting acute myocardial infarction (AMI) and increased amylase, which could not preclude the concern about the existence of acute pancreatitis. Abdominal CT displayed the calcification of only the splenic and other arteries, and low-density shadows were observed at the center portion of the spleen. This case demonstrated the significant occurrence of thrombotic complications in various blood vessels of multiple organs in T2D patients. Thus, clinicians should be aware of the possibility of simultaneous acute vascular infarction of several organs in diabetic patients with prior vascular constriction.

Ischemic Stroke and Cerebral Microbleeds: A Two-Sample Bidirectional Mendelian Randomization Study

INTRODUCTION

Recent observational studies have reported the association between ischemic stroke (IS) and cerebral microbleeds (CMBs). Whether this reflects a causal association remains to be established. Herein, we adopted a two-sample bidirectional Mendelian randomization (MR) analysis to comprehensively evaluate the causal association of IS and CMBs.

METHODS

The summary-level genome-wide association studies (GWASs) data of IS were obtained from the GIGASTROKE consortium (62,100 European ancestry cases and 1,234,808 European ancestry controls). All IS cases could be further divided into large-vessel atherosclerosis stroke (LVS, n = 6399), cardio-embolic stroke (CES, n = 10,804) and small-vessel occlusion stroke (SVS, n = 6811). Meanwhile, we used publicly available summary statistics from published GWASs of CMBs (3556 of the 25,862 European participants across 2 large initiatives). A bidirectional MR analysis was conducted using inverse-variance weighting (IVW) as the major outcome, whereas MR-Egger and weighted median (WM) were used to complement the IVW estimates as they can provide more robust estimates in a broader set of scenarios but are less efficient (wider CIs). A Bonferroni-corrected threshold of p < 0.0125 was considered significant, and p values between 0.0125 and 0.05 were considered suggestive of evidence for a potential association.

RESULTS

We detected that higher risk of IS [IVW odds ratio (OR) 1.47, 95% confidence interval (CI) 1.04-2.07, p = 0.03] and SVS (IVW OR 1.62, 95% CI 1.07-2.47, p = 0.02) were significantly associated with CMBs. Reverse MR analyses found no significant evidence for a causal effect of CMBs on IS and its subtypes.

CONCLUSIONS

Our study provides potential evidence that IS and SVS are causally linked to increased risk of CMBs. Further research is needed to determine the mechanisms of association between IS and CMBs.

Association of the time course of Chinese visceral adiposity index accumulation with cardiovascular events in patients with hypertension

BACKGROUND

The Chinese visceral adiposity index (CVAI), a simple surrogate measure of visceral fat, is significantly associated with cardiovascular disease (CVD) risk in the general population. This study aimed to evaluate the association of cumulative CVAI (cumCVAI) exposure and its accumulation time course with CVD risk among patients with hypertension.

METHODS

This prospective study involved 15,350 patients with hypertension from the Kailuan Study who were evaluated at least three times in the observation period of 2006 to 2014 (2006-2007, 2010-2011, and 2014-2015) and who were free of myocardial infarction and stroke before 2014. The cumCVAI was calculated as the weighted sum of the mean CVAI for each time interval (value × time). The time course of CVAI accumulation was categorized by splitting the overall accumulation into early (cumCVAI_06 - 10) and late (cumCVAI_10 - 14) accumulation, or the slope of CVAI versus time from 2006 to 2014 into positive and negative.

RESULTS

During the 6.59-year follow-up period, 1,184 new-onset CVD events were recorded. After adjusting for confounding variables, the hazard ratios (HRs) and 95% confidence intervals (CIs) for CVD were 1.35 (1.13-1.61) in the highest quartile of cumCVAI, 1.35 (1.14-1.61) in the highest quartile of the time-weighted average CVAI, 1.26 (1.12-1.43) in those with a cumulative burden > 0, and 1.43 (1.14-1.78) for the group with a 10-year exposure duration. When considering the time course of CVAI accumulation, the HR (95% CI) for CVD was 1.33 (1.11-1.59) for early cumCVAI. When considering the combined effect of cumCVAI accumulation and its time course, the HR (95% CI) for CVD was 1.22 (1.03-1.46) for cumCVAI ≥ median with a positive slope.

CONCLUSIONS

In this study, incident CVD risk depended on both long-term high cumCVAI exposure and the duration of high CVAI exposure among patients with hypertension. Early CVAI accumulation resulted in a greater risk increase than later CVAI accumulation, emphasizing the importance of optimal CVAI control in early life.

Elevated Chinese visceral adiposity index increases the risk of stroke in Chinese patients with metabolic syndrome

Introduction

Patients with Metabolic Syndrome (MetS) are considered at high-risk for incident stroke. An indicator of visceral adiposity dysfunction, the Chinese Visceral Adiposity Index (CVAI) is used to evaluate the dysfunction of visceral fat. Given the impact of visceral adiposity dysfunction on elevating cardiovascular hazards, this study aimed to examine the association between CVAI and stroke risk in MetS patients.

Method

Between November 2017 and December 2018, a total of 18,974 individuals aged ≥40 underwent standardized in-person clinical interviews in Hunan Province, with 6,732 meeting the criteria for MetS. After the baseline survey was completed, subsequent surveys were conducted biennially. The study was split into two stages performed at baseline and after two years. During the former, receiver-operating characteristic curves were used to assess the accuracy of using baseline CVAI in diagnosing MetS. After two years, we examined the association between CVAI and incident stroke in MetS patients using logistic regression, subgroup analysis, and restricted cubic spline (RCS) analysis.

Result

As evidenced by a higher AUC (AUC:0.741), CVAI demonstrated superior diagnostic performance relative to body mass index (AUC:0.631) and waist circumference (AUC:0.627) in diagnosing MetS. After a 2-year follow-up, 72 MetS patients had a stroke event. There was a robust positive correlation between incident stroke and CVAI in patients with MetS. Each 1 SD increase in CVAI was associated with a 1.52-fold higher risk of stroke after adjustment for confounding factors (aOR=1.52, 95%CI: 1.18-1.95). The RCS demonstrated a reduced risk of stroke for MetS patients when the CVAI was below 110.91. However, no significant correlation was detected between CVAI and stroke in non-MetS patients.

Conclusion

Our findings recommend CVAI as a superior screening tool for detecting MetS and suggest that reducing CVAI can mitigate the risk of stroke in patients with MetS.

Association of abdominal obesity and systolic blood pressure indices with cardiovascular disease risk prediction among community-dwelling older adults

<b>Background:</b> Excess adiposity is an established risk factor for cardiovascular disease (CVD), therefore the early screening indies with predicted CVD risk is more useful for older adults. The current study evaluated the associations between anthropometric, body composition and dietary indices and elevated 10-year CVD risk in older people.<br /> <b>Methods:</b> This research, which involved 55 to 94-year-olds living in the community. Standard techniques were used to determine anthropometric factors and body composition indicators. The risk prediction chart created by World Health Organization and International Society of Hypertension was used to calculate the CVD risk score. Odds ratio (OR) and 95% confidence interval (CI) were determined.<br /> <b>Results:</b> CVD risk prediction was positively correlated with the anthropometric and body composition parameters. After controlling for confounding variables, the logistic regression analysis revealed that waist circumference (OR=16.34; 95% CI: 7.22, 36.98; <i>p</i>&lt;0.001), systolic blood pressure (BP) (OR=9.53; 95% CI: 4.52, 20.07; <i>p</i>&lt;0.001), and visceral adipose tissue percentage (OR=5.47; 95% CI: 2.98, 10.01; <i>p</i>&lt;0.001) were correlated with cardiovascular risk prediction.<br /> <b>Conclusions:</b> Abdominal obesity and increase of systolic BP were associated to increased risk for CVD. Additionally, a positive association between the risk factors for CVD (%visceral adipose tissue) and diet (cholesterol consumption) was established.

Effects of aromatase inhibitor therapy on visceral adipose tissue area and cardiometabolic health in postmenopausal women with early and locally advanced breast cancer

OBJECTIVE

Aromatase inhibitor (AI) therapy provides oncological benefits in postmenopausal women with oestrogen receptor-positive breast cancer. However, AI treatment has been associated with increased cardiovascular risk. In nonbreast cancer populations, experimentally induced low oestrogen states and natural transition to menopause have been associated with increases in visceral adipose tissue (VAT), a known surrogate marker for cardiometabolic risk. Given that AI treatment blocks oestradiol production, we hypothesized that AI treatment would increase VAT.

METHODS

We conducted a prospective 12-month cohort study of 52 postmenopausal women newly initiating AI treatment (median age: 64.5 years) and 52 women with breast pathology not requiring endocrine therapy (median age: 63.5 years). VAT area and other body composition parameters were measured at baseline, 6 months and 12 months using dual X-ray absorptiometry. Other risk markers of cardiometabolic health were also assessed.

RESULTS

In women initiating AI treatment, there was no statistically significant difference in VAT area after 12 months when compared to controls, with a mean adjusted difference of -5.00 cm² (-16.9, 6.91), p = .55. Moreover, changes in total fat mass, lean mass, subcutaneous adipose tissue area, hepatic steatosis and measures in endothelial function were also not statistically different between groups after 12 months. Findings were similar after adjustments for activity levels and coronavirus disease 2019 lockdown duration.

CONCLUSIONS

These data provide reassurance that over the initial 12 months of AI therapy, AI treatment is not associated with metabolically adverse changes in body composition, hepatic steatosis or vascular reactivity. The impact of extended AI therapy on cardiometabolic health requires further study.

Depot-specific adipose tissue modulation by SGLT2 inhibitors and GLP1 agonists mediates their cardioprotective effects in metabolic disease

Sodium-glucose transporter-2 inhibitors (SGLT-2i) and glucagon-like peptide 1 (GLP-1) receptor agonists are newer antidiabetic drug classes, which were recently shown to decrease cardiovascular (CV) morbidity and mortality in diabetic patients. CV benefits of these drugs could not be directly attributed to their blood glucose lowering capacity possibly implicating a pleotropic effect as a mediator of their impact on cardiovascular disease (CVD). Particularly, preclinical and clinical studies indicate that SGLT-2i(s) and GLP-1 receptor agonists are capable of differentially modulating distinct adipose pools reducing the accumulation of fat in some depots, promoting the healthy expansion of others, and/or enhancing their browning, leading to the suppression of the metabolically induced inflammatory processes. These changes are accompanied with improvements in markers of cardiac structure and injury, coronary and vascular endothelial healing and function, vascular remodeling, as well as reduction of atherogenesis. Here, through a summary of the available evidence, we bring forth our view that the observed CV benefit in response to SGLT-2i or GLP-1 agonists therapy might be driven by their ameliorative impact on adipose tissue inflammation.

Associations of the Cardiometabolic Index with the Risk of Cardiovascular Disease in Patients with Hypertension and Obstructive Sleep Apnea: Results of a Longitudinal Cohort Study

Purpose

We aimed to explore the relationship between the cardiometabolic index (CMI) and cardiovascular disease (CVD) and its subtypes (coronary artery disease and stroke) in patients with hypertension and obstructive sleep apnea (OSA).

Methods

We conducted a retrospective cohort study enrolling 2067 participants from the Urumqi Research on Sleep Apnea and Hypertension study. The CMI was calculated as triglyceride to high‐density lipoprotein cholesterol ratio × waist‐to‐height ratio. Participants were divided into three groups (T1, T2, and T3) according to the tertile of CMI. The Kaplan-Meier method helped to calculate the cumulative incidence of CVD in different groups. We assessed the association of CMI with the risk of CVD and CVD subtypes by estimating hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox models.

Results

During a median follow-up of 6.83 years (interquartile range: 5.92-8.00 years), 326 incident CVD were identified, including 121 incident stroke and 205 incident coronary heart disease (CHD). Overall, after adjusting for confounding variables, CMI was positively associated with the risk of new-onset CVD (per SD increment, adjusted HR: 1.31; 95% CI: 1.20, 1.43), new-onset CHD (per SD increment, adjusted HR: 1.33; 95% CI: 1.20, 1.48), and new-onset stroke (per SD increment, adjusted HR: 1.27; 95% CI: 1.10, 1.47). Similar results were obtained in various subgroup and sensitivity analyses. Adding CMI to the baseline risk model for CVD improved the C-index (P < 0.001), continuous net reclassification improvement (P < 0.001), and integrated discrimination index (P < 0.001). Similar results were observed for CHD and stroke.

Conclusion

There was a positive association between CMI levels and the risk of new-onset CVD in patients with hypertension and OSA. This finding suggests that CMI may help identify people at high risk of developing CVD.

Metabolism Score for Visceral Fat (METS-VF): A New Predictive Surrogate for CKD Risk

PURPOSE

Metabolic disorders are closely related to the occurrence and development of chronic kidney disease (CKD). We explored the prospective association between the Metabolic Score for Visceral Fat (METS-VF) and CKD in a 5-year follow-up study.

PATIENTS AND METHODS

In this cohort study, 631 adults not suffering from CKD from Wanzhai Town, in China in 2012 were included at baseline and followed up in 2017 and 2018. Multivariable logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between METS-VF and CKD risk. Area under the receiver operating characteristic curve (AUC) analyses were used to evaluate the ability of METS-VF, waist-to-height ratio (WhtR), visceral adiposity index (VAI), homeostatic model assessment of insulin resistance (HOMA-IR), body mass index (BMI) to predict CKD risk.

RESULTS

We identified 103 CKD cases during follow-up. After adjustment for confounding factors, comparing the lowest quartile of METS-VF, the OR (95% CI) of CKD risk in the highest quartile was 3.04 (1.39-6.64). The per Standard deviation (SD) increase in METS-VF was positively correlated with CKD risk. The AUC of METS-VF for predicting CKD risk was, in general, higher than that for WhtR, VAI, HOMA-IR, and BMI.

CONCLUSION

METS-VF may be an indicator for predicting CKD risk.