Aims: The influence of different regional adipose tissue (AT) compartments on insulin resistance and dyslipidaemia may account for variations in risk of diabetes and cardiovascular disease. The purpose of this study was to examine the association of intraperitoneal and posterior subcutaneous abdominal AT with very-low-density lipoprotein apolipoprotein B-100 (VLDL-apoB) kinetics in overweight/obese men.
Methods: Intraperitoneal, anterior subcutaneous and posterior subcutaneous abdominal AT mass (IPATM, ASAATM and PSAATM respectively) were quantified in 51 overweight/obese men using magnetic resonance imaging. Hepatic secretion of VLDL-apoB was measured using an intravenous infusion of 1-[13C]-leucine. Isotopic enrichment of VLDL-apoB was measured using gas chromatography mass spectrometry and a multicompartmental model used to estimate VLDL-apoB metabolic parameters. Insulin resistance was estimated by homeostasis model assessment (HOMA) score.
Results: In univariate analysis, IPATM, ASAATM and PSAATM were significantly associated with HOMA score (r = 0.554, 0.425 and 0.440 respectively; p < 0.01). Intraperitoneal abdominal AT mass was also associated with plasma triglycerides (r = 0.292, p < 0.05), VLDL-apoB concentrations (r = 0.407, p < 0.01) and VLDL-apoB secretion (r = 0.390, p < 0.05). Intraperitoneal abdominal AT mass remained significantly associated with VLDL-apoB secretion (r = 0.344, p < 0.05) and HOMA score (r = 0.368, p < 0.01) after adjusting for total body fat. In multiple regression analysis including IPATM, non-esterified fatty acids and age, IPATM was the best predictor of VLDL-apoB secretion (R2 = 17%, p < 0.01) and HOMA score (R2 = 32%, p < 0.001). None of the fat compartments were significantly associated with VLDL-apoB catabolism.
Conclusions: In overweight/obese men the intraperitoneal AT mass is a better predictor of VLDL-apoB secretion and insulin resistance than either posterior or anterior subcutaneous abdominal AT mass.