PLASMA LEVELS OF INTERLEUKIN-6 AND SOLUBLE TUMOR NECROSIS FACTOR RECEPTOR ARE ASSOCIATED WITH MUSCLE PERFORMANCE IN PRE-FRAIL COMMUNITY-DWELLING OLDER WOMEN?

Abstract

Aim: Increased plasma levels of interleukin (IL)-6 and tumor necrosis factor (TNF)-α have been associated with frailty syndrome and reduced muscle strength in older. Sarcopenia influenced loss of mobility and functional independence, and contributed to frailty syndrome. Furthermore, sarcopenia mainly entails a decrease in type II muscle fibers, with consequent loss of muscle power; this could occur as a result of a lack of physical activity. Objective: To examine the correlation of muscular performance and the plasma levels of IL-6 and soluble TNF receptor (sTNFr) in pre-frail community-dwelling women. Methods: The study included 32 pre-frail women (≥ 65ys). The measurements were plasma concentrations of IL-6 and sTNFr1 (ELISA); muscle strength (isokinetics Biodex System). The muscle resistance program constituted 75% of maximum load (3 times/week, 10 weeks). Statistical analysis were made through Pearson and Spearman correlation (α = 5%). Results: There was a significant inverse correlation between sTNFr1 and muscle strength, pre- (r = −0.36, P = .04) and post-training (r = −0.37, P = .04) and, a significant positive correlation between IL-6 and muscle strength (r = 0.45, P = .01). Conclusion: The correlations found between the inflammatory mediators and the measures of muscular performance evaluated before and after training suggest that, as the muscles increase their ability to generate power, sTNFr concentrations decrease, and the levels of IL-6 increase. Muscle resistance exercises should be encouraged in pre-frail older women to induce the release of cytokines.