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

AimsThe 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.MethodsEighteen Arabian and 14 Swedish women participated in a supervised 6-month resistance training and aerobic program of moderate intensity. Insulin sensitivity and VO2max were measured at entry to the study and after 3 and 6 months training.ResultsAfter 6 months exercise, insulin sensitivity (M-value) increased (2.7 ± 1.4 mg kg−1 min−1 vs. 3.4 ± 2 mg kg−1 min−1, p < 0.05) in all patients and accounted for by an increase in non-oxidative glucose metabolism (0.3 ± 1.1 mg kg−1 min−1 vs. 1.5 ± 1.5 mg kg−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 VO2max or lipid profile in either group.ConclusionsAlthough 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.