Association of Inflammation with Loss of Ability to Walk 400 Meters: Longitudinal Findings from the Invecchiare in Chianti Study

Abstract

To examine relationships between eight markers of inflammation (interleukin (IL)-6, IL-6 receptor (R), C-reactive protein (CRP), tumor necrosis factor (TNF)-alpha, TNF receptor 1 (R1), TNFR2, IL-1 receptor antagonist, IL-18) and incident loss of ability to walk 400 m. Prospective cohort study. Older adults enrolled in the Invecchiare in Chianti Study. Community-dwelling participants aged 65 and older (N = 1,006). The eight inflammatory markers were measured at baseline, and an inflammation score was calculated based on the number of inflammatory markers for which the participant was in the highest quartile. Incidence of mobility disability was determined in participants able to walk 400 m at baseline. Logistic regression models were used to determine whether each of the inflammatory markers and the inflammation score predicted loss of the ability to walk 400 m at 6-year follow-up. After adjusting for covariates, individuals with a TNFR1 level in each of the highest three quartiles (Q2, 3, 4) were more likely to be unable to walk 400 m at follow-up than those with TNFR1 levels in Q1. When adjusting for the same covariates, participants with an inflammation score of 3 or 4 were more likely to become unable to walk 400 m at follow-up than participants with a score of 0. These results provide additional evidence that inflammation is a factor in the mechanisms that cause incident mobility disability and suggest that a combined measure of inflammatory markers may improve prediction of functional prognosis.