Effect of Type-2 Diabetes Mellitus on Cardiac Rehabilitation Outcomes: A Meta-analysis

To determine the effect of cardiac rehabilitation (CR) on changes in functional capacity among patients with cardiovascular disease (CVD) and a type 2 diabetes mellitus (T2D) comorbidity compared with patients without T2D.

A systematic review and meta-analysis of randomized controlled trials were completed using PubMed, Cumulative Index to Nursing and Allied Health, and Web of Science in January 2021.

Articles were included if they compared patients CR with T2D with those without T2D.

The primary outcome variable was functional capacity change from pre- to post CR reported as maximum or peak oxygen consumption and peak metabolic equivalent (METs). Risk of bias was assessed using the Cochrane Risk of Bias Tool. A random-effects model subgroup meta-analysis was conducted. A diabetes comorbidity was selected for the subgroup analysis with patients with CVD having conditions reported as T2D or non-T2D.

Twelve studies with total sample of 15,672 patients were extracted. Average change in peak METs was 1.41±1.76 among non-T2D and 1.08±1.57 among T2D after CR. Change in functional capacity was significantly lower among patients with T2D (z value=2.14; g=-0.42; 95% CI, -0.86 to -0.01; P=.03).

Patients with CVD with T2D experience less robust improvements in functional capacity in response to CR compared with patients with CVD alone. A better understanding of the relationship between T2D and functional capacity vital step in informing exercise prescription in CR for patients with T2D and CVD. The lack of understanding the role of T2D onset and progression is a limitation to this study.