Effects of cardiac rehabilitation on exercise capacity in Type 2 diabetic patients with coronary artery disease

Abstract

Aim: To determine whether Type 2 diabetic patients with coronary disease can obtain, after cardiac rehabilitation, a similar benefit on exercise capacity to non-diabetic coronary individuals.

Research design and methods: Fifty-nine Type 2 diabetic patients and 36 age-matched non-diabetic patients were enrolled in a 2-month cardiac rehabilitation programme, after an acute coronary event. At the beginning and at the end of the cardiac rehabilitation programme, each subject underwent a cardiopulmonary exercise test to assess exercise capacity as measured by peak workload, duration of test, maximal heart rate, peak VO2 and anaerobic threshold. The two groups of patients were not different in age, sex ratio, type of coronary event or left ventricular ejection fraction.

Results: The baseline exercise capacity parameters were not different between diabetic and non-diabetic subjects. After cardiac rehabilitation, improvement of exercise capacity was significantly less in patients with diabetes compared with those without diabetes: peak workload (19% vs. 29%, P = 0.022), peak VO2 (13% vs. 30%, P = 0.002), anaerobic threshold (12% vs. 31%, P = 0.017). In the diabetic patients, a significant inverse relation between fasting blood glucose and change in peak VO2 was observed on both univariate (r = -0.40, P = 0.002) and multivariate (P = 0.001) analyses.

Conclusions: The benefit of cardiac rehabilitation, after an acute ischaemic heart event, in exercise capacity is significantly lower in Type 2 diabetic patients. The response to cardiac rehabilitation in those with diabetes appears to be influenced by blood glucose levels.