Lower-Body Adiposity and Metabolic Protection in Postmenopausal Women

Context: It has been suggested that the propensity to store fat in the gluteal-femoral region may be cardioprotective. Objective: The primary aim of this study was to test whether the favorable associations of leg fat with risk factors for cardiovascular disease persist after controlling for the highly unfavorable effects of abdominal (visceral or sc) adiposity in postmenopausal women. Study Participants: The study included 95 postmenopausal women [age, 60 ± 8 yr (mean ± sd)]. Main Outcomes: Whole-body and regional fat distribution was measured using dual-energy x-ray absorptiometry and abdominal computed tomography. Markers of insulin resistance and dyslipidemia were determined from oral glucose tolerance tests and fasted lipid and lipoprotein measurements, respectively. Primary outcomes were: fasting insulin (INS0), area under the insulin curve (INSAUC), product of the oral glucose tolerance test insulin and glucose AUC (INSAUC — GLUAUC), serum triglycerides (TG), and high-density lipoprotein (HDL) cholesterol. Results: Controlling for trunk fat revealed a favorable effect of leg fat on INS0, INSAUC, INSAUC × GLUAUC, TG, and HDL. However, after controlling for either visceral or sc abdominal adiposity, TG was the only risk factor for which the favorable effect of leg fat persisted. Conclusions: The lack of an association between leg fat and most of the risk factors, after adjusting for abdominal visceral or sc fat, suggests an overriding deleterious influence of abdominal adiposity on cardiovascular risk. Nevertheless, our finding that regional adipose tissue depots have apparent independent and opposing effects on serum TG supports the need for further research into the physiological mechanisms governing these effects.