Serum concentrations of myostatin and myostatin-interacting proteins do not differ between young and sarcopenic elderly men

Abstract

Sarcopenia is the loss of muscle size and function during ageing. The aim of this study was to test whether serum concentrations of myostatin and interacting proteins (GASP-1, FLRG, and follistatin) differed between young and elderly sarcopenic men. Isometric knee extensor maximal voluntary contraction and quadriceps cross-sectional area (magnetic resonance imaging measurement) were significantly higher in young (22 ± 2 years; 266 ± 54 N/m; 8,686 ± 1,154 mm2) than in mildly sarcopenic (69 ± 3 years; 183 ± 17 N/m; 6,621±718 mm2) and severely sarcopenic men (76 ± 6 years; 127 ± 23 N/m; 5,846 ± 591 mm2), respectively (p ≤ .01 for all comparisons). There was a trend (p = .06) toward higher FLRG in young (20 ± 8 ng/mL) than in mildly (15 ± 6 ng/mL) and severely sarcopenic men (17 ± 8 ng/mL). Myostatin, follistatin, GASP-1, tumor necrosis factor a, and interleukin-6 did not differ significantly. Insulin-like growth factor-1 and free testosterone were both significantly lower in sarcopenic men (p < .001). This suggests that altered serum concentrations of myostatin and myostatin-interacting proteins are not contributing to sarcopenia with the possible exception of FLRG. © 2011 The Author.