Change in Cardiometabolic Health Following Participation in Cardiac Rehabilitation for Coronary Heart Disease: Effect Modification by Metabolic Syndrome Status.

Objective: To investigate changes in cardiometabolic risk factors after completion of cardiac rehabilitation (CR) for coronary heart disease (CHD) and ascertain whether the magnitude of improvement in cardiometabolic health differs between those with and without metabolic syndrome (MetS).

Methods: In this observational cohort study, data were analyzed from 1984 patients enrolled in CR at the University of Michigan between 2011-01-01 and 2020-02-29 for the indication of CHD. Patient characteristics were collected from standardized health questionnaires and during CR intake evaluations. Cardiometabolic biomarkers were recorded from baseline laboratory data and re-examined upon completion of CR. Differences in baseline patient characteristics by MetS status were compared using chi-square tests. Wilcoxon rank-sum tests were used to compare baseline differences, and signed-rank tests were used to evaluate the change in variables between baseline and completion of CR. The difference of change by MetS status was assessed using difference-in-differences regression models.

Results: Of the 1984 patients, 1070 (53.9%) met the criteria for MetS at baseline, of which 770 were male (72.0%). Those with MetS lost 1.43 pounds more (95% CI: 0.56, 2.31, P = 0.001), experienced a 0.21 larger drop in body mass index (95% CI: 0.03, 0.37, P = 0.02), and had a 0.31 greater reduction in waist circumference (95% CI: 0.08, 0.54, P = 0.008). Difference-in-differences regression models revealed those with MetS experienced a greater reduction in triglycerides and fasting glucose, with a difference of change of -8.70 for triglycerides (95% CI: -15.04, -2.37, P = 0.007) and -5.48 for glucose (95% CI: -10.44, -0.53, P = 0.03). There was no significant difference in the change in HDL-C or LDL-C for MetS status.

Conclusion: Compared to those without MetS, patients with MetS experienced a comparable or greater benefit from CR, particularly with respect to improvements in MetS components.