Epicardial fat thickness is associated with impaired coronary flow reserve in hemodialysis patients

The Relationship of Epicardial Adipose Tissue and Cardiovascular Disease in Chronic Kidney Disease and Hemodialysis Patients

Cardiovascular diseases remain the most common cause of morbidity and mortality in chronic kidney disease patients undergoing hemodialysis. Epicardial adipose tissue (EAT), visceral fat depot of the heart, was found to be associated with coronary artery disease in cardiac and non-cardiac patients. Additionally, EAT has been proposed as a novel cardiovascular risk in the general population and in end-stage renal disease patients. It has also been shown that EAT, more than other subcutaneous adipose tissue deposits, acts as a highly active organ producing several bioactive adipokines, and proinflammatory and proatherogenic cytokines. Therefore, increased visceral adiposity is associated with proinflammatory activity, impaired insulin sensitivity, increased risk of atherosclerosis, and high morbidity and mortality in hemodialysis patients. In the present review, we aimed to demonstrate the role of EAT in the pathophysiological mechanisms of increased cardiovascular morbidity and mortality in hemodialysis patients.

Epicardial adipose tissue in patients with chronic kidney disease: a meta-analysis study and trial sequential analysis

BACKGROUND

Cardiovascular disease is the most common cause of death in patients with chronic kidney disease (CKD). Epicardial adipose tissue (EAT) is an independent predictor of cardiovascular disease in the general population, and usually increases in the patients with cardiovascular disease risk. The change of EAT in patients with CKD was still controversial. For further understanding, we conducted a meta-analysis of the relevant literature.

METHODS

Eligible studies were searched in PubMed, EMBASE, Web of Science, and Scopus on March 13, 2020. The summarized standard mean difference (SMD) with 95% confidence intervals (CIs) were used to assess the association between EAT (thickness and volume) and CKD. Trial sequential analysis was conducted to estimate whether the evidence of the results is sufficient.

RESULTS

In total, 17 studies with 1961 participants (1205 patients in the CKD group and 756 participants in the control group) were involved. The EAT thickness was significantly increased in the CKD group compared to the control group (SMD = 1.31, 95% CI 0.89-1.73, P < 0.001) in eleven studies. The EAT volume was significantly increased in the CKD group compared to the control group (SMD = 0.77, 95% CI 0.63-0.91, P < 0.001) in six studies. Trial sequential analysis indicated that the available samples were sufficient and confirmed that firm evidence was reached.

CONCLUSIONS

Patients with CKD have higher EAT thickness and volume compared to control subjects without CKD.

Relationship Between Epicardial Adipose Tissue and Body Composition as Determined by Multi-Frequency Bioelectrical Impedance Analysis in Patients with Stage 5 Chronic Kidney Disease

Background

The main cause of mortality among chronic kidney disease (CKD) patients is cardiovascular disease (CVD). Epicardial adipose tissue (EAT) is considered to be novel cardiovascular risk factor. We assessed EAT in non-dialyzed stage 5 CKD patients and explored the association of EAT with body composition as determined by multi-frequency BIA.

Material/Methods

The present included 70 stage 5 CKD patients who had not undergone dialysis and 40 healthy control subjects. EAT thickness was assessed by echocardiography. Hydration status and body composition were evaluated by multi-frequency bioelectrical impedance analysis.

Results

Stage 5 CKD patients had significantly higher EAT thickness than healthy subjects (6.56±1.18 vs. 4.05±1.45, p<0.001). Fat tissue mass, systolic blood pressure (SBP), age, fat tissue index, and body mass index were positively correlated with EAT thickness in the CKD patient group (p<0.05). Lean tissue mass, lean tissue index (LTI), and high-density lipoprotein (HDL) were negatively correlated with EAT thickness in the CKD patient group (p<0.05). Stepwise multiple regression analysis showed that age, SBP, and LTI were independently associated with EAT thickness in CKD patients.

Conclusions

We found significantly higher EAT thickness in stage 5 CKD patients who were not on dialysis compared to healthy controls. EAT was significantly associated with age, SBP, and LTI in CKD patients. Interventions to reduce the risk factors associated with EAT thickness might protect against CVD disease in CKD patients.

Epicardial adipose tissue is a predictor of decreased kidney function and coronary artery calcification in youth- and early adult onset type 2 diabetes mellitus

PURPOSE

To examine the association of epicardial and pericardial fat volume (EFV, PFV) with cardiovascular risk factors and kidney function in Native Americans of southwestern heritage with youth and early adult onset type 2 diabetes mellitus (T2DM) versus healthy controls.

METHODS

Using computed tomography, we quantified EFV and PFV in 149 Native Americans (92 women, 57 men), 95 of which had T2DM (38 diagnosed prior to age 20 years). Duration of T2DM, mean carotid arterial mass (AM), coronary artery calcification (CAC), IL-6, and estimated glomerular filtration rate eGFR_cr(CKD-EPI) were measured.

RESULTS

EFV and PFV were associated with BMI (r = 0.37, p < 0.0001; r = 0.26, p = 0.001) and did not differ between onset age-groups and controls (p > 0.05). EFV was associated with AM only in controls (r = 0.51, p < 0.0001). After adjustment for BMI, T2DM duration, HbA1C, age, and sex, EFV was a predictor of CAC and IL-6 concentrations in early adult onset T2DM (β = 0.05 ± 0.02 cm³, p = 0.03; β = 0.05 ± 0.01 pg/ml/cm³, p = 0.002). EFV and PFV were independent predictors of reduced eGFR_cr(CKD-EPI) in the youth onset T2DM group (β = -0.3 ± 0.08 ml/min/cm³, p = 0.001; β = -0.25 ± 0.05 ml/min/cm³, p < 0.0001).

CONCLUSIONS

Epicardial fat volume may be a risk factor for heart disease in individuals with early adult onset T2DM and a predictor of decreased kidney function in individuals with youth onset T2DM.

Pericardial, But Not Hepatic, Fat by CT Is Associated With CV Outcomes and Structure: The Multi-Ethnic Study of Atherosclerosis

OBJECTIVES

The study sought to determine the associations between local (pericardial) fat and incident cardiovascular disease (CVD) events and cardiac remodeling independent of markers of overall adiposity.

BACKGROUND

The impact of pericardial fat-a local fat depot encasing the heart-on myocardial function and long-term CV prognosis independent of systemic consequences of adiposity or hepatic fat is an area of active debate.

METHODS

We studied 4,234 participants enrolled in the MESA (Multi-Ethnic Study of Atherosclerosis) study with concomitant cardiac magnetic resonance imaging and computed tomography (CT) measurements for pericardial fat volume and hepatic attenuation (a measure of liver fat). Poisson and Cox regression were used to estimate the annualized risk of incident hard atherosclerotic CVD (ASCVD), all-cause death, heart failure, all-cause CVD, hard coronary heart disease, and stroke as a function of pericardial and hepatic fat. Generalized additive models were used to assess the association between cardiac magnetic resonance indices of left ventricular (LV) structure and function and pericardial fat. Models were adjusted for relevant clinical, demographic, and cardiometabolic covariates.

RESULTS

MESA study participants with higher pericardial and hepatic fat were more likely to be older, were more frequently men, and had a higher prevalence of cardiometabolic risk factors (including dysglycemia, dyslipidemia, hypertension), as well as adiposity-associated inflammation. Over a median 12.2-year follow-up (interquartile range: 11.6 to 12.8 years), pericardial fat was associated with a higher rate of incident hard ASCVD (standardized hazard ratio: 1.22; 95% confidence interval: 1.10 to 1.35; p = 0.0001). Hepatic fat by CT was not significantly associated with hard ASCVD (standardized hazard ratio: 0.96; 95% confidence interval: 0.86 to 1.08; p = 0.52). Higher pericardial fat was associated with greater indexed LV mass (37.8 g/m2.7 vs. 33.9 g/m2.7, highest quartile vs. lowest quartile; p < 0.01), LV mass-to-volume ratio (1.2 vs. 1.1, highest quartile vs. lowest quartile; p < 0.01). In adjusted models, a higher pericardial fat volume was associated with greater LV mass (p < 0.0001) and concentricity (p < 0.0001).

CONCLUSIONS

Pericardial fat is associated with poorer CVD prognosis and LV remodeling, independent of insulin resistance, inflammation, and CT measures of hepatic fat.

Naturally Occurring Compounds: New Potential Weapons against Oxidative Stress in Chronic Kidney Disease

Oxidative stress is a well-described imbalance between the production of reactive oxygen species (ROS) and the antioxidant defense system of cells and tissues. The overproduction of free radicals damages all components of the cell (proteins, lipids, nucleic acids) and modifies their physiological functions. As widely described, this condition is a biochemical hallmark of chronic kidney disease (CKD) and may dramatically influence the progression of renal impairment and the onset/development of major systemic comorbidities including cardiovascular diseases. This state is exacerbated by exposure of the body to uremic toxins and dialysis, a treatment that, although necessary to ensure patients' survival, exposes cells to non-physiological contact with extracorporeal circuits and membranes with consequent mitochondrial and anti-redox cellular system alterations. Therefore, it is undeniable that counteracting oxidative stress machinery is a major pharmacological target in medicine/nephrology. As a consequence, in recent years several new naturally occurring compounds, administered alone or integrated with classical therapies and an appropriate lifestyle, have been proposed as therapeutic tools for CKD patients. In this paper, we reviewed the recent literature regarding the "pioneering" in vivo testing of these agents and their inclusion in small clinical trials performed in patients affected by CKD.

Epicardial adipose tissue in patients with end-stage renal disease on haemodialysis

PURPOSE OF REVIEW

Epicardial adipose tissue (EAT) is the visceral fat of the heart, sharing many of the pathophysiological properties of other visceral fat depots. EAT is a metabolically active paracrine and vasocrine organ that causes local cardiac inflammation and is strongly implicated in the pathogenesis of coronary atherosclerosis. This article highlights the findings of recent observational studies in patients on haemodialysis that link the quantity of EAT to increased rates of cardiovascular and coronary artery disease and review the proposed methods of pathogenesis and the possible role of EAT quantification to improve cardiovascular risk assessment.

RECENT FINDINGS

Increasing volumes of EAT in patients on haemodialysis correlate with increased inflammatory mediators, higher rates of cardiovascular disease and coronary artery calcification, independent of general adiposity. EAT is an independent predictor of mortality and a potentially modifiable target for therapeutic interventions.

SUMMARY

EAT is likely to play a central role in the pathogenesis of cardiovascular disease in patients on haemodialysis, adds incrementally to conventional cardiovascular risk stratification models and is a potential target for therapeutic intervention.