Transforming Cardiometabolic Health: Impact of Cardiac Rehabilitation on Heart and Metabolism
Introduction
Metabolic syndrome (MetS) involves a group of risk factors that increase the chance of cardiovascular disease (CVD) and diabetes. Common diagnostic criteria for MetS include abdominal obesity, high triglycerides, low HDL cholesterol, hypertension, and impaired fasting blood sugar. The combination of these factors raises the risk of diabetes and various CVDs, like coronary heart disease and stroke.
Cardiac rehabilitation (CR) is an evidence-based program aimed primarily at preventing CVD. Studies show that CR is effective in improving overall health and reducing the risks of heart disease. Evidence suggests CR also improves MetS and its components. Some research indicates that intrinsic factors like age, sex, and body mass index (BMI) might affect improvement levels during CR. Additionally, CR has shown smaller improvements in those with type II diabetes compared to those without. However, the influence of MetS on CR’s effects on health remains unclear.
Materials and Methods
Participants and Data Collection
Data were analyzed retrospectively from participants at the University of Michigan CR program. Information gathered included age, sex, race, ethnicity, physical activity, smoking status, and medical history. Pre-existing health conditions were identified through diagnostic codes. Psychological distress was measured using the Brief Symptom Inventory.
Biomarkers were collected from health records around the time of the CR evaluation. Blood pressure was measured following guidelines. Body weight, height, and body fat percentage were recorded using a bioelectrical impedance analysis scale, and waist circumference was measured at the midpoint between the lowest ribs and the iliac crest. MetS was defined according to American Heart Association standards. Peak oxygen consumption (VO2peak) was assessed to measure cardiorespiratory fitness.
The research followed institutional ethical guidelines and received approval from the University of Michigan Medical School’s Institutional Review Board.
Outcomes
The primary outcome was the change in cardiometabolic risk factors from before CR to after completion, comparing those with and without MetS.
Statistical Analysis
We compared characteristics by MetS status using Wilcoxon rank-sum tests and Chi-square tests. Changes in risk factors from baseline to completion of CR were analyzed with non-parametric tests. Patients missing data at either time point were excluded. We used regression models to evaluate changes by MetS status while adjusting for relevant demographics.
Results
The final sample included 1,984 participants with an average age of 63.4 years. Of these, 1,070 (53.9%) met the criteria for MetS. Individuals with MetS were more likely to be female and had lower educational attainment than those without MetS.
At completion of CR, significant improvements were observed in most body composition and cardiometabolic risk factors, with participants with MetS showing greater or similar improvements compared to those without MetS. Both groups experienced weight loss, but those with MetS lost an average of 1.43 pounds more. Participants with MetS also had better reductions in triglycerides and fasting glucose levels. There were improvements in psychological health for both groups.
Discussion
This study shows that CR positively affects cardiometabolic health, improving various risk factors and psychological well-being. Participants with MetS experienced improvements similar to or greater than those without MetS. The differences in patient characteristics and study designs may explain variations in past studies.
While CR is effective at reducing recurrent cardiovascular events, the long-term benefits in patients with MetS require further investigation.
Conclusion
This study supports the use of CR to enhance cardiometabolic health in patients with coronary heart disease. It shows that patients with metabolic syndrome can achieve significant health benefits through participation in cardiac rehabilitation programs.