Association of C-reactive protein and muscle strength in the English Longitudinal Study of Ageing

Sarcopenia has been associated with systemic inflammation and a range of other biological risk factors. The purpose of this study was to assess the systemic inflammation–muscle strength relationship in a large representative community-based cohort of older adults, and to determine the independence of this association from other biological and psychosocial risk factors. Participants were 1,926 men and 2,260 women (aged 65.3 ± 9.0 years) from the English Longitudinal Study of Ageing, a study of community dwelling older adults. We assessed hand grip strength and lower body strength (time required to complete five chair stands). Biological measures included C-reactive protein (CRP), fibrinogen, cholesterol, haemoglobin, glycated haemoglobin, adiposity, and blood pressure. Approximately 33% of the sample demonstrated elevated concentrations (≥3 mg/L) of CRP. After adjustments for age, smoking, physical activity, education, inflammatory diseases, and all other biological factors, elevated CRP was associated with poorer hand grip strength and chair stand performance in women but only chair stand performance in men. Low haemoglobin levels were consistently associated with poorer performance on both tests in women and men. These results confirm an independent association between low grade systemic inflammation (as indexed by CRP) and muscle strength that appears to be more robust in women.