Effects of a 12-week exercise training on insulin sensitivity, quality of life, and depression status in patients with type 2 diabetes

Background: Exercise is one of the optimal and alternative treatments for type 2 diabetes (T2DM). Although the effect of a single bout of exercise on insulin sensitivity is reported to persist only for 2–3 days, effects remain unclear of a 12-week aerobic exercise training on insulin sensitivity, quality of life (QOL), and depression status over time as exercise training duration increases in patients with T2DM. Objectives: To investigate the effects over time in patients with T2DM of a 12-week aerobic exercise training on insulin sensitivity, QOL, and depression status. Materials and Methods: Purposive sampling was used to recruit 17 T2DM patients. Participants underwent a 12-week, supervised, moderate-intensity aerobic exercise training three times per week, 30 min per session. Outcome indicators including insulin sensitivity (measured by a 2-h oral glucose tolerance test [OGTT] and homeostatic model assessment-insulin resistance [HOMA-IR]), QOL (Medical Outcomes Study Short Form 36), and depression status (beck depression inventory scale) were evaluated at baseline and at 4-week intervals. Results: A final 13 eligible participants completed the study. For every 4-week increase in duration of exercise training, there was an increase over time in insulin sensitivity, including a decrease over time in OGTT glucose area under the curve of 66.92 min/mmol/L. Glucose concentrations decreased over time at 60, 90, and 120 min after an oral glucose challenge. Further, the HOMA-IR decreased over time as the duration of exercise training increased. QOL and depression status improved significantly during the training. Conclusions: Moderate-intensity exercise training improves insulin sensitivity, QOL, and depression status in T2DM patients, particularly over time within a 12-week exercise training course.