A Low Serum Free Triiodothyronine Level is Associated with Epicardial Adipose Tissue in Peritoneal Dialysis Patients

Abstract

Aim: Cardiovascular disease is a major cause of mortality in dialysis patients. Epicardial adipose tissue (EAT) has been proposed as a cardiovascular risk marker in this population. Subclinical hypothyroidism and low free triiodothyronine (fT3) levels are associated with EAT in patients without chronic renal failure. The aim of this study was to investigate the relationship between EAT and low free T3 levels in peritoneal dialysis (PD) patients. Methods: A total of 125 prevalent PD patients were enrolled in this cross-sectional study. The epicardial fat thickness (EFT) was measured by echocardiography, and the endothelial function was assessed by flow mediated dilatation (FMD). Thyroid function tests were performed by an enzyme immunoassay. Results: The mean age of the patients was 51±13, and the time on PD was 36 months. The mean EFT was 6.7±2.9 mm. The EFT correlated positively with the patient age, systolic blood pressure (BP), mean BP, high sensitivity C-reactive protein (hs-CRP) level and body mass index (BMI), and negatively with the fT3 level and FMD. The median fT3 value was 2.53, and patients were divided according to their serum fT3 values (within the normal range and below the reference level). Compared with patients in the low fT3 group, the subjects in the normal fT3 group had higher serum albumin levels and FMD, but a lower BMI, plasma fasting glucose level, EFT, TSH level, hs-CRP level, low density lipoprotein (LDL) cholesterol level and mean BP in office measurements, and both the diastolic BP and mean BP by ambulatory blood pressure measurement. A multivariate linear regression analysis showed that the EFT was predicted by the hs-CRP and fT3 levels. Conclusion: Low free T3 levels are associated with the epicardial fat thickness in PD patients. Further studies are needed to evaluate the pathogenesis and to support these findings.

Obesity and Endothelial Function

“…Excess visceral adiposity is frequently accompanied by ectopic fat accumulation such as fat accumulation in the liver, heart, and blood vessels [ 36 ]. It has been demonstrated that endothelial function is impaired in patients with non-alcoholic fatty liver disease [ 37 ], patients with increased epicardial adipose tissue [ 38 , 39 ], and subjects with increased perivascular adipose tissue [ 40 ]. It has been suggested that ectopic fat deposition is associated with insulin resistance and an increased risk of cardiovascular complications [ 41 , 42 ].…”

“…Adipose tissue transplant studies in mice demonstrated that perivascular adipose tissue harvested from obese mice promotes inflammation and endothelial dysfunction in recipient mice [ 49 , 50 ]. In addition, a number of clinical studies have suggested links between ectopic fat deposition and endothelial function [ 38 , 39 , 40 , 42 , 51 , 52 , 53 ]. The thickness of epicardial fat has been shown to be associated with endothelial dysfunction [ 38 , 52 ].…”

Correlation Between Epicardial Fat Thickness and Cardiovascular Risk in Hemodialysis Patients

“…Manes and his colleagues, in their study of Left ventricular geometric patterns and cardiac function in patients with chronic renal failure undergoing hemodialysis also found that diastolic dysfunction was found in 87% of patients. The relatively higher percentage in their study may be explained by their enrollment of diabetic patients in their study [70].…”

Cardiac CT scanning in coronary artery disease: Epicardial fat volume and its correlation with coronary artery lesions and left ventricular function

“…Previous studies have reported that EAT potentially causes local inflammation and may be seen as a marker for the risk of cardiovascular disease ( 16 ). Studies have indicated that EAT is an important risk factor for atherosclerotic diseases and metabolic syndrome ( 17 , 18 ). The correlation between EAT and CAD has been previously reported; however, it is controversial whether EAT may be regarded as a marker to predict the occurrence and development of CAD ( 19-21 ).…”