The associations between physical activity and inflammatory markers in high-functioning older persons: MacArthur studies of successful aging

OBJECTIVES: To determine the relationships between recreational activity, house/yard work activity, work activity, and total physical activity and high levels of two peripheral blood markers of inflammation: interleukin-6 (IL-6) and C-reactive protein (CRP). DESIGN: Cross-sectional study. SETTING: Three communities (Durham, NC; New Haven, CT; and East Boston, MA). PARTICIPANTS: Eight hundred seventy persons aged 70 to 79 who were in the top third of community-dwelling older persons with respect to physical and cognitive functioning. MEASUREMENTS: Blood levels of IL-6 and CRP and self-reported recreational activity, house/yard work activity, work activity, and total physical activity. RESULTS: The adjusted odds ratios (AORs) for individuals with high levels of recreational activity to have values in the top tertiles of IL-6 and CRP were 0.65 (95% confidence interval (CI) = 0.48-0.87) and 0.70 (95% CI = 0.51-0.95), respectively. The AORs for those with a high level of house/yard work activity to have values in the top tertile of IL-6 and CRP were 0.90 (95% CI = 0.67-1.20) and 0.70 (95% CI = 0.50-0.96), respectively. High levels of house/yard work and recreational activity were independently associated with lower risk of high CRP. CONCLUSION: The association between high levels of recreational activity and lower levels of the inflammatory markers IL-6 and CRP suggests a mechanism for its protective effect and supports interventions that increase physical activity in older persons. Such potential benefits of increased physical activity on inflammatory markers will need to be confirmed in clinical trials.