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

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.