Association between C-reactive protein (CRP) level and physical performance in community-dwelling elderly in Japan

Inflammatory cytokines may contribute to lower physical function in elderly. The purpose of this study was to clarify the relation between circulating level of C-reactive protein (CRP) and physical performance among the community-dwelling elderly in Japan. Participants were 803 (329 men and 474 women) aged 65 years and over. Four physical performances were assessed using hand-grip strength, length of time standing on one leg, and walking speed (usual and maximal). Low physical performance was defined as the lowest 25% of study sample in each sex. Multiple logistic regression analysis showed that CRP was negatively associated with physical performance in hand-grip strength (odds ratio = OR = 1.86, 95% confidence interval = 95% CI = 1.32–3.05, OR = 2.92, 95% CI = 1.53–5.58, for the middle and highest, respectively), time of one leg standing (OR = 1.96, 95% CI = 1.28–3.00, OR = 2.16, 95% CI = 1.19–3.92, for the middle and highest, respectively) and maximal walking speed (OR = 2.46, 95% CI = 1.23–4.93, for the highest) when adjusted for the confounding factors. The results showed the negatively associated between CRP level and physical performance when adjusted for the confounding factors. CRP level may be a useful indicator for detecting the lower physical performance in elderly.