Improvements in insulin sensitivity after aerobic exercise and weight loss in older women with a history of gestational diabetes and type 2 diabetes mellitus

Abstract

Purpose: To determine whether a hypocaloric diet alone (WL) or with exercise training (AEX + WL) is effective in improving body composition, fitness, glucose utilization and CVD risk factors in sedentary women with a history of gestational diabetes (GDM) and with type 2 diabetes (T2DM).

Materials and methods: Longitudinal clinical investigation of 25 overweight/obese (BMI: 32 ± 1 kg/m(2)) women (59 ± 1 yrs) with a GDM history (n = 20) or T2DM (n = 5). Women completed 6 months WL (n = 10) or AEX+WL (n = 15) with VO2max, body composition, and glucose tolerance testing. Insulin sensitivity was measured during the last 30 min of 2 h hyperinsulinemic-euglycemic clamps (40 mU·m(-2.)min(-1)) before and after interventions.

Results: Body weight decreased ~7% after WL and AEX+WL (p < 0.001), with an 11-12% decrease in fat mass (p < 0.0001). Visceral fat and subcutaneous abdominal fat decreased 27 and 10% after WL (p < 0.01) and 14 and 11% after AEX + WL (p < 0.05). VO2max increased 16% after AEX + WL (p < 0.001) and did not change after WL. Glucose AUC decreased 14 and 13% after WL (p < 0.05) and AEX + WL (p < 0.01) with a 42% decrease in insulin AUC after AEX + WL (p < 0.01). Glucose utilization increased 25% (p = 0.05) with AEX + WL and 7% with WL.

Conclusions: A six-month aerobic exercise program combined with moderate weight loss reduces body weight, visceral and subcutaneous abdominal fat, and improves insulin sensitivity in older women who had previously been diagnosed with GDM and those with T2DM. These findings should encourage women with a history of GDM to engage in an active lifestyle and reduce caloric intake to lower the risk for the development of T2DM.

Keywords: Aging; exercise; insulin sensitivity; nutrition; obesity.

Figure 1

Abdominal adiposity before and after WL and AEX+WL. Values are means ±SEM. Significantly different before vs. after the intervention, *P<0.05; †P <0.01

Figure 2

Glucose utilization (M) before and after WL and AEX+WL. Values are means ±SEM. Significantly different before vs. after the intervention, *P<0.05; **P=0.05