No strong correlations between serum cytokine levels, CMV serostatus and hand-grip strength in older subjects in the Berlin BASE-II cohort.

Abstract

Hand-grip strength is strongly correlated with measures of muscle mass and can be taken to predict morbidity and mortality. The aim of this study was to investigate the relationship between hand-grip strength and other markers associated with immune ageing, such as Cytomegalovirus (CMV) infection, leukocyte telomere length and serum levels of inflammatory and anti-inflammatory markers in the elderly. We have assessed grip strength with the Smedley Dynamometer in younger (22-37 years) and older (60-85 years) men and women in a sample of people living in Berlin (the BASE-II study). Serum cytokine levels were determined by flow-cytometry, CMV serostatus via ELISA and leukocyte telomere length by quantitative PCR. IL-1β levels tended to be negatively associated with grip strength, but we did not find a significant association with IL-6 levels. CMV-seropositivity was not associated with higher levels of IL-1β, IL-6 or TNF, nor with weaker grip strength in men or women at any age. A putative general measure of organismal ageing, overall leukocyte telomere length, was also found not to be associated with lower grip strength in the elderly. Hand-grip strength remains an important biomarker independent of CMV infection or shorter telomere lengths, and poorly reflected in peripheral pro-inflammatory cytokine levels, all of which have been associated in some studies with frailty and mortality.