Effects of Cardiac Rehabilitation in Diabetic Patients: Both Cardiac and Noncardiac Factors Determine Improvement in Exercise Capacity

Abstract

Background Diabetic patients have a worse prognosis than nondiabetic patients after myocardial infarction. Although exercise improves risk factors, exercise capacity, and mortality, it is still unclear if these benefits are the same as in nondiabetics. Furthermore, although exercise tolerance is predicted by systolic and diastolic dysfunction in nondiabetics, its role as a predictor of exercise capacity in diabetics remains unclear. Hypothesis Diabetics and nondiabetics see a similar improvement in their cardiac risk factors and exercise parameters from exercise‐based cardiac rehabilitation (CR). Methods A series of 370 diabetics and 942 nondiabetics entered a 36‐session outpatient CR program after interventions for coronary heart disease or after bypass or cardiac valve surgery. The program consisted of physical exercise, lifestyle modification, and pharmacotherapy. Results Quality of life, weight, blood pressure, and lipid profiles improved significantly in both groups during the 12‐week program. Baseline metabolic equivalents (METs) were lower in diabetics vs nondiabetics at the start of CR (2.4 vs 2.7, P < 0.001). Although both groups increased their exercise capacity, diabetics had less improvement (change in METs 1.7 vs 2.6, P < 0.001). Significant predictors for improvement after CR included age, sex, and weight, as well as both systolic and diastolic function. After adjustment for these, diabetes remained a significant predictor of reduced improvement in exercise capacity. Conclusions Diabetics saw a significant benefit in quality of life, weight, exercise tolerance, and cardiac risk factors, but to a lesser extent when compared with nondiabetics. The mechanisms for poorer improvement in diabetics following CR also include noncardiac factors and require further study.

Predictors of cardiorespiratory fitness improvement in phase II cardiac rehabilitation

“…Similar to prior studies, diabetes proved again to be a negative factor when it comes to functional benefit from CR. [24][25][26] This may stem from the fact that patients with diabetes are less likely to be enrolled in CR, 21,27 and less likely to be adherent. 20,28 Another possible explanation is lower baseline fitness.…”

Cardiac rehabilitation completion is associated with reduced mortality in patients with diabetes and coronary artery disease

“…However, these changes were not as well maintained in patients with diabetes at the 1 year follow-up. Other studies have reported mixed results, with some reporting similar benefits to patients with and without diabetes [25,27,35,36] and others reporting that patients with diabetes had a less marked overall improvement in exercise capacity [37,38]. Although aerobic training is probably the most important component of CR, it should be noted that the TotalCardiology programme also involved addressing conventional risk factors such as lipid control, stress management, nutrition and cessation of cigarette smoking.…”

Benefits of Cardiac Rehabilitation on Cardiovascular Outcomes in Patients With Diabetes Mellitus After Percutaneous Coronary Intervention

“…However, mortality has not been widely evaluated. [14][15][16] In a recent and large cohort of 13 000 patients with CAD (2956 with DM), reported by Armstrong et al, 17 CR was associated with significant reductions in mortality and cardiac hospitalizations in patients with DM, similar to outcomes in patients without DM. Although these studies are consistent with our findings, they differ from our study in that they have not been specifically focused on patients who have undergone PCI.…”

“…However, several studies have reported that completion of CR in patients with DM is associated with significant benefits on activities of daily living, quality of life, weight control, exercise tolerance, cardiac risk factor control, and risk of mortality. However, mortality has not been widely evaluated . In a recent and large cohort of 13 000 patients with CAD (2956 with DM), reported by Armstrong et al, CR was associated with significant reductions in mortality and cardiac hospitalizations in patients with DM, similar to outcomes in patients without DM.…”

“…Among the 700 patients with DM in our study cohort, 38% (n=263) participated in at least 1 session of CR during the 3 months after PCI; however, we had available data about the number of sessions for only 168 patients. The median number of sessions attended by those patients was 9 (interquartile range, [13][14][15][16][17][18][19], with 18 patients (11%) participating in 25 sessions or more. Table 1 shows clinical, angiographic, and procedural characteristics of patients with DM, grouped by CR participation status.…”