Physical activity in relation to cardiac risk markers in secondary prevention of coronary artery disease

BackgroundThe relationship between physical activity and cardiac risk markers in secondary prevention for patients with coronary artery disease (CAD) is uncertain. The aims of the study were therefore to examine the level of physical activity in patients with CAD, and to investigate the association between physical activity and cardiac risk markers.MethodsIn total, 332 patients, mean age, 65 ± 9.1 years, diagnosed with CAD at a university hospital were included in the study 6 months after their cardiac event. Physical activity was measured with a pedometer (steps/day) and two questionnaires. Investigation of cardiac risk markers included serum lipids, oral glucose-tolerance test, twenty-four hour blood pressure and heart rate monitoring, smoking, body-mass index (BMI), waist-hip ratio, and muscle endurance. The study had a cross-sectional design.ResultsThe patients performed a median of 7027 steps/day. After adjustment for confounders, statistically significant correlations between steps/day and risk markers were found with regard to; high-density lipoprotein cholesterol (HDL-C) (r = 0.19, p < 0.001), muscle endurance measures (r ranging from 0.19 to 0.25, p = 0.001 or less) triglycerides (r = − 0.19, p < 0.001), glucose-tolerance (r = − 0.23, p < 0.001), BMI (r = − 0.21, p < 0.001), 24-h heart rate recording during night (r = − 0.17, p = 0.004), and average 24-h heart rate (r = − 0.13, p = 0.02).ConclusionsA relatively high level of physical activity was found among patients with CAD. There was a weak, but significant, association between pedometer steps/day and HDL-C, muscle endurance, triglycerides, glucose-tolerance, BMI and 24-h heart rate, indicating potential positive effects of physical activity on these parameters. However, before clinical implications can be formed, more confirmatory data are needed.