Impact of exercise-nutritional state interactions in patients with type 2 diabetes

Abstract

Introduction: This study examines the role of nutritional status during exercise training in patients with type 2 diabetes mellitus by investigating the impact of endurance-type exercise training in the fasted versus the fed state on clinical outcome measures, glycemic control, and skeletal muscle characteristics in male type 2 diabetes patients. Methods: Twenty-five male patients (HbA1c 57±3 mmol/mol (7.4±0.3%)) participated in a randomized 12-week supervised endurance-type exercise intervention, with exercise being performed in an overnight fasted state (FastEx, n=13) or after consuming breakfast (FedEx, n=12). Patients were evaluated for glycemic control, blood lipid profiles, body composition and physical fitness, and skeletal muscle gene expression. Results: Exercise training was well tolerated without any incident of hypoglycemia. Exercise training significantly decreased whole-body fat mass (-1.6kg) and increased HDL concentrations (+2mg*dL-1), physical fitness (+1.7mL*min-1*kg-1) and fat oxidation during exercise in both groups (PTIME<0.05), with no between group differences (PTIME*GROUP>0.05). HbA1c concentrations significantly decreased after exercise training (PTIME<0.001), with a significant greater reduction in FedEx (-0.30±0.06%) compared to FastEx (-0.08±0.06%; mean difference 0.21%; PTIME*GROUP=0.016). No interaction effects were observed for skeletal muscle genes related to lipid metabolism or oxidative capacity. Conclusion: Endurance-type exercise training in the fasted or fed state do not differ in their efficacy to reduce fat mass, increase fat oxidation capacity, increase cardiorespiratory fitness and HDL concentrations or their risk of hypoglycemia in male patients with type 2 diabetes. Glycated haemoglobin seems to be improved more with exercise performed in the post-prandial compared with the post-absorptive state.