Long-term physical activity and inflammatory biomarkers in older adults

The purpose of this study was to determine the effects of a 12-month physical activity (PA) intervention on inflammatory biomarkers in elderly men and women.

Four hundred and twenty-four elderly (age = 70-89 yr), 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 PA intervention or a successful aging health education intervention. Biomarkers of inflammation (interleukin (IL)-6sR, IL-1sRII, soluble tumor necrosis factor receptors 1 and 2 (sTNFRI, sTNFRII), IL-8, IL-15, adiponectin, IL-1ra, IL-2sRα, and TNFα) were measured at baseline, at 6 months, and at 12 months.

A baseline blood sample was successfully collected from 368 participants. 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 with the successful aging 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 pg·mL. However, these associations were no longer significant after consideration for multiple comparisons.

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.