Background. Physical activity may lower the risk for coronary heart disease by mitigating inflammation, which plays a key role in the pathophysiology of atherosclerosis. The purpose of this study was to examine the association between physical activity and C-reactive protein concentration in a national sample of the U.S. population.
Methods. The analytic sample included 13,748 participants ≥20 years of age in the National Health and Nutrition Examination Survey III (1988–1994) with complete data for the main study variables.
Results. After adjusting for age, sex, ethnicity, education, work status, smoking status, cotinine concentration, hypertension, body mass index, waist-to-hip ratio, high-density lipoprotein cholesterol concentration, and aspirin use, the odds ratios for elevated C-reactive protein concentration (dichotomized at the ≥85th percentile of the sex-specific distribution) were 0.98 (95% confidence interval = 0.78–1.23), 0.85 (0.70–1.02), and 0.53 (0.40–0.71) for participants who engaged in light, moderate, and vigorous physical activity, respectively, during the previous month compared with participants who did not engage in any leisure-time physical activity. In addition, leisure-time physical activity was positively associated with serum albumin concentration and inversely associated with both log-transformed plasma fibrinogen concentration and log-transformed white blood cell count.
Conclusions. These results add to mounting evidence that physical activity may reduce inflammation, which is a critical process in the pathogenesis of cardiovascular disease.