2761-LB: Effects of Supervised Vigorous Exercise on Tissue-Specific Insulin Resistance in South Asian and Nordic Women with Previous Gestational Diabetes

Introduction and Objective: South Asians (SA) have higher risk of developing type 2 diabetes (T2D) than Nordics (NO), especially after gestational diabetes (GDM). The impact of vigorous exercise on insulin resistance (IR) in this population has not been investigated. We aimed to examine whether vigorous exercise could reduce tissue-specific IR in SA and NO women with previous GDM. Methods: Eighteen SA and 22 NO largely sedentary women completed 8 weeks of supervised training with two full-body strength and two high-intensity aerobic sessions weekly. Before and after the intervention, tests were performed to assess fitness level and body composition, and a 6-hour prime continuous intravenous infusion of ([6,6-D2]glucose / [1,1,2,3,3-D5]glycerol) and 2.5 g[U-13C]glucose was performed with the 75 g oral glucose tolerance test (OGTT). Data are given as mean ± standard error of the mean or percentage change [95% confidence interval]. Results: Attendance rates for exercise (>90%) were similar in SA and NO, with increases in VO2max [3.5±0.52 vs 3.8±0.5 ml/min/kg, both p<0.001], chest press [4.8±0.8 vs 5.4±0.9 kg, both p<0.001], leg press [30.8±2.5 vs 22.8±2.5 kg, both p<0.001], lean body mass [1.4±0.27 vs 1.28±0.22 kg, both p<0.001] and reductions in visceral fat [-99±33 vs -83±25 g, both p<0.01 ]. Markers of muscle IR were reduced in both groups: the postprandial glucose clearance rate relative to insulin (MCR/I) in SA (1.0±0.5 ml min−1kg−1per nmol/l, p=0.03) and the Matsuda index in NO (12 [0.62-26] %, p=0.04). We also observed some differences between the groups: improved hepatic IR index only in NO (-0.2±0.87 mmol min−1 kg FFM−1 pM, p=0.02), and greater lipolysis suppression mainly in SA (10±2.44 %, p<0.001). Conclusion: Both groups improved fitness and body composition. We observed some ethnic-specific effects of training on IR, which may improve our understanding and management of T2D risk across different ethnic groups. Disclosure T. Kalleklev: None. A. Sharma: None. A. Kvist: None. F.A. Norheim: None. K.I. Birkeland: Research Support; Ended; Boehringer Ingelheim International GmbH. Research Support; Current; AstraZeneca. Research Support; Ended; Abbott Diagnostics. Advisory Panel; Current; F. Hoffmann-La Roche Ltd. Research Support; Ended; Lilly Diabetes. Research Support; Current; Novo Nordisk Foundation, Novo Nordisk, Vertex Pharmaceuticals Incorporated. S. Lee-Ødegård: Advisory Panel; Current; Novo Nordisk, Eli Lilly and Company.