Sex differences in glucose and fatty acid metabolism in Asians who Are nonobese

• Main Authors: Chan, Zhiling, Chooi, Yu Chung, Ding, Cherlyn, Choo, John, Sadananthan, Suresh Anand, Michael, Navin, Velan, S. Sendhil, Leow, Melvin Khee-Shing, Magkos, Faidon
• Other Authors: Lee Kong Chian School of Medicine (LKCMedicine)
• Format: Article
• Language: English
• Published: 2021
• Subjects: Science::Medicine; Insulin-mediated Suppression; Body-mass Index
• Online Access: https://hdl.handle.net/10356/147056
• Institution: Nanyang Technological University

Context - The prevalence of diabetes is increasing throughout Asia, even in the absence of obesity, and is lower in women than in men. The underlying mechanisms are not well understood. Objective - To evaluate the sex differences in glucose and fatty acid metabolism in Asians who are nonobese. Design - Cross-sectional study. Setting - Clinical Nutrition Research Centre, Singapore. Participants - Healthy Asian men (n = 32; body mass index, 21.8 ± 1.5 kg/m2; age, 42 ± 14 years) and women (n = 28; body mass index, 21.4 ± 2.0 kg/m2; age, 41 ± 13 years). Main Outcome Measures - Insulin sensitivity (insulin-mediated glucose uptake normalized for steady-state insulin; hyperinsulinemic-euglycemic clamp), postprandial glucose, insulin and fatty acid concentrations, insulin secretion (mixed meal tolerance test with mathematical modeling), insulin clearance, body composition and fat distribution (dual-energy X-ray absorptiometry, MRI, and spectroscopy), cardiorespiratory fitness (maximal oxygen uptake; graded exercise test), and handgrip strength (dynamometry). Results - Women had more total body fat but less visceral fat than men; liver and muscle lipid contents were not different. Maximal oxygen uptake and handgrip strength were lower in women than men. The postprandial glucose concentrations were ~8% lower, the insulin-mediated glucose uptake was ~16% greater, and the meal-induced suppression of fatty acid concentrations was significantly greater in women than in men (P < 0.05 for all). However, muscle insulin sensitivity was not different between the sexes. No differences were found in postprandial insulin secretion and clearance rates; however, the steady-state insulin clearance was ~17% lower in women. Conclusions - Asian women who are nonobese are more insulin-sensitive than men at the level of adipose tissue but not skeletal muscle. Therefore, sex differences in glucose tolerance are likely the result of sexual dimorphism in hepatic insulin action.