Measurement of skeletal muscle mass of japanese men and women aged 18-84 by bioelectrical impedance analysis focusing on the difference in measured values produced by different equipment

Abstract

[Purpose] In this study, bioelectrical impedance analysis (BIA), based on magnetic resonance imaging, was used to measure the skeletal muscle mass (SMM) of Japanese male and female, in order to gather SMM data for setting cut-off points for the diagnosis of sarcopenia. Differences in age-associated SMM changes according to sex and body part were investigated. [Subjects] The subjects were 1,347 Japanese male and female (622 male, 725 female) aged 18–84 years. [Methods] The results of arm, leg, and whole-body muscle mass measuremalets and SMM index (SMI) calculations were compared by sex and age. [Results] Calculations of the rate of muscle mass loss for each body part in male and female revealed a markedly low rate of loss in arm muscle mass and SMI in female. Cutoff points were 4.0 kg/m2for male and 2.9 kg/m2for female. [Conclusion] The present findings demonstrate that, although muscle mass loss occurred in both male and female, muscle loss rates were greater in male. The present findings also suggest that BIA values might differ depending on the measuring instruments.