Leg fat mass as measured by dual X‐ray absorptiometry (DXA) impacts insulin resistance differently in obese women versus men

Abstract

Objective. To investigate the association between regional fat mass (FM) and insulin resistance and dyslipidaemia in obese women and men. Material and methods. Body composition was measured by dual‐energy X‐ray absorptiometry (DXA) in 109 obese women and 113 obese men. Insulin resistance was measured by (HOMA‐IR); insulin sensitivity was estimated by metabolic clearance rate (MCRestOGTT) and insulin secretion by HOMAsecr. Serum lipids were assessed. Results. In women, leg FM was negatively (favourably) associated with HOMA‐IR and cholesterol/HDL‐cholesterol ratio (p<0.05). Trunk FM was positively (unfavourably) associated with HOMA‐IR. Leg/trunk FM ratio was negatively associated with HOMA‐IR (p<0.001), cholesterol/HDL‐cholesterol ratio (p<0.001) and triglycerides (p<0.01); positively (favourably) with MCRestOGTT (p<0.01) and HDL‐cholesterol (p<0.05). No associations were found in men. In women, multiple regression analysis demonstrated that leg/trunk FM ratio was the only explanatory FM for HOMA‐IR and MCRestOGTT (R² = 0.23 and R² = 0.13, respectively; p<0.001), but postmenopausal status was also of importance (R² = 0.23, p = 0.019 and R² = 0.29, p = 0.015, respectively). Conclusions. Leg FM has a favourable influence on insulin resistance and dyslipidaemia in obese women, but not demonstrated in this cohort of obese men.

• DXA
• dyslipidaemia
• insulin resistance
• leg fat mass
• trunk fat mass