Evaluation of the effects of exercise on insulin sensitivity in Arabian and Swedish women with type 2 diabetes.

AIMS: The purpose of this study was to evaluate the effects of exercise on cardio-respiratory fitness and insulin sensitivity in sedentary, overweight Arabian and Swedish women with type 2 diabetes. METHODS: Eighteen Arabian and 14 Swedish women participated in a supervised 6-month resistance training and aerobic program of moderate intensity. Insulin sensitivity and VO(2max) were measured at entry to the study and after 3 and 6 months training. RESULTS: After 6 months exercise, insulin sensitivity (M-value) increased (2.7+/-1.4mgkg(-1)min(-1) vs. 3.4+/-2mgkg(-1)min(-1), p<0.05) in all patients and accounted for by an increase in non-oxidative glucose metabolism (0.3+/-1.1mgkg(-1)min(-1) vs. 1.5+/-1.5mgkg(-1)min(-1), p<0.005) with no significant difference between the ethnic groups. Notably, significant improvement in HbA1c was only seen in the Swedish patients who achieved greater exercise intensity (73.3+/-4.8% vs. 63.3+/-5.2% of maximum heart rate, p<0.005). No changes were observed regarding VO(2max) or lipid profile in either group. CONCLUSIONS: Although a 6-month exercise intervention of moderate intensity in Arabian and Swedish patients with type 2 diabetes can improve insulin sensitivity it is hampered by the metabolic inflexibility of switching between oxidation of glucose or fat.