Relationship of para- and perirenal fat and epicardial fat with metabolic parameters in overweight and obese subjects

Background: The accumulation of visceral body fat, has been shown to be associated with higher risk of metabolic and cardiovascular disease. This study was addressed to examine whether para- and perirenal fat thickness and epicardial fat thickness were correlated with anthropometric- and cardiometabolic risk factors.

Methods: A cohort of 102 uncomplicated overweight and obese patients was examined. BMI, waist circumference, blood pressure, fasting insulin, glucose, triglycerides, total cholesterol, HDL-cholesterol, LDL-cholesterol serum levels, and insulin resistance (assessed by HOMA_IR) were measured. Para- and perirenal fat thickness (PUFT) and epicardial fat thickness (EUFT) were measured by ultrasounds.

Results: PUFT was positively correlated with BMI (p < 0.001), waist circumference (p < 0.001), insulin (p < 0.001), HOMA_IR (p < 0.001), triglycerides (p < 0.05), systolic (p < 0.05) and diastolic (p < 0.05) blood pressure, and negatively correlated with HDL-cholesterol (p < 0.01). EUFT was positively associated with age (p < 0.01), BMI (p < 0.001), waist circumference (p < 0.001), systolic (p < 0.01) and diastolic (p < 0.001) blood pressure, and LDL-cholesterol (p < 0.05). A multivariate analysis by multiple linear regression was performed, and the final model showed a direct association of waist circumference with both PUFT and EUFT, a correlation of PUFT with HOMA_IR (positive) and HDL-cholesterol (negative), and a direct association of EUFT (both long axis and short axis) with LDL-cholesterol. All these correlations were independent of other anthropometric, metabolic and hemodynamic parameters.

Conclusions: This study shows that accumulation of central fat in apparently healthy overweight and obese subjects is associated to a simultaneous increase of pararenal, perirenal and epicardial fat. Moreover, it shows that only para- and perirenal fat is independently associated to insulin resistance and lower HDL-cholesterol, and only epicardial fat is independently associated to higher LDL cholesterol. Level of evidence Level V, cross-sectional descriptive study.