Effects of exercise training on HbA1c and VO2peak in patients with type 2 diabetes and coronary artery disease: A randomised clinical trial

Abstract

Objective: Few exercise trials have focused on patients with both type 2 diabetes and coronary artery disease. We investigated the effects of 1 year of exercise training on HbA1c and VO(2peak) in these patients.

Methods: Patients with type 2 diabetes and coronary artery disease (n = 137) were randomised to combined exercise training or control group. HbA(1c) was measured at the beginning and end of the study. Changes in VO(2peak), and also ventilatory threshold and time to exhaustion, were assessed by cardiopulmonary exercise testing.

Results: No differences in changes between the randomised groups were observed in HbA1c and VO(2peak), whereas ventilatory threshold and time to exhaustion increased significantly in the exercise group compared with the controls (p = 0.046 and p = 0.034). In patients without previous acute myocardial infarction and diabetes microvascular complications (n = 46), the exercise group did improve HbA1c and VO(2peak) compared with the controls (p = 0.052 and p = 0.035).

Conclusion: No significant effects of exercise training on HbA(1c) or VO(2peak) were observed in patients with type 2 diabetes and coronary artery disease, although improvements were seen in patients without vascular complications beyond coronary artery disease, implying that the degree of vascular disease may influence exercise responses. Ventilatory threshold and time to exhaustion did increase significantly, indicating improved exercise performance despite the minor change in VO(2peak).

Keywords: Type 2 diabetes; cardiovascular disease; exercise capacity; glycaemic control; peak oxygen uptake; ventilatory threshold.