Long-term Physical Activity and Inflammatory Biomarkers In Older Adults

Abstract

PURPOSE: To determine the effects of a 12-month physical activity intervention on inflammatory biomarkers in elderly men and women. METHODS: 424 elderly (aged 70-89 years), nondisabled, community-dwelling men and women at risk for physical disability were enrolled in a multicenter, single-blind, randomized controlled-trial. Participants were randomized to participate in either a 12-month moderate-intensity physical activity (PA) intervention or a successful aging (SA) health education intervention. Biomarkers of inflammation (IL-6sR, IL-1sRII, sTNFRI, sTNFRII, IL-8, IL-15, adiponectin, IL-1ra, IL-2sRa, and TNF-a) were measured at baseline, 6 and 12 months. RESULTS: After adjustment for gender, clinic site, diabetes status, and baseline outcome measure, IL-8 was the only inflammatory biomarker affected by the PA intervention (p=0.03). The adjusted mean IL-8 at month 12 was 9.9% (0.87 pg/mL) lower in the PA compared to the SA group. Secondary interaction analyses between baseline biomarker status and treatment showed one significant interaction (p=0.02) such that the PA intervention reduced IL-15 concentrations in participants with a baseline IL-15 above the median value of 1.67 g/mL. However, these associations were no longer significant after consideration for multiple comparisons. CONCLUSIONS: Overall, this study does not provide definitive evidence for an effect of regular exercise for altering systemic concentrations of the measured inflammatory biomarkers in older adults.