The novel myokine irisin: clinical implications and potential role as a biomarker for sarcopenia in postmenopausal women

PurposeTo clarify the association of circulating irisin with muscle, liver and bone, and to evaluate irisin as a biomarker for sarcopenia in postmenopausal women.MethodsQuadriceps cross-sectional area (QcCSA), bone mineral density (BMD), liver attenuation (measured in Hounsfield units (HU)) were assessed using quantitative computed tomography in 153 postmenopausal women, mean age of 72.205.96 years. Muscle strength and physical performance were evaluated by handgrip test and short physical performance battery, respectively. Serum irisin was measured by an enzyme-linked immunosorbent assay kit. In addition, 147 young women were recruited as a reference group to define cut-off values for sarcopenia.ResultsCirculating irisin was positively correlated with QcCSA/body weight (BW) and liver HU even after adjusting for multiple covariates, and the serum level was significantly lower in the sarcopenia group (QcCSA/BW<-2SD of the mean values for young women) than in the presarcopenia (-2SDQcCSA/BW<-1SD) or control groups (1SDQcCSA/BW<2SD). Logistic regression models showed that the relationship between circulating irisin and prevalence of sarcopenia remained significant after adjusting for confounding factors (per 1.0ng/mL decrease of irisin, odds-ratio=1.95, 95% confidence interval 1.33-2.87, p-value=0.001).Conclusions p id=Par4 In postmenopausal women, serum irisin may be used as a biomarker for sarcopenia, and we showed the potential for the development of irisin-based early screening and staging tool for sarcopenia.