Study on the prevalence of sarcopenia and dynapenia in outpatient hemodialysis patients in urban areas of Japan: a multicenter cross-sectional study

[Purpose] This study aimed to classify patients undergoing outpatient hemodialysis into four groups (sarcopenia, dynapenia, presarcopenia, and controls) to clarify their distribution and compare clinical characteristics. [Participants and Methods] A total of 177 patients undergoing outpatient hemodialysis in the Tokyo urban area were classified into four groups according to skeletal muscle mass index (SMI) and muscle strength. Between-group comparisons were conducted for basic characteristics, body mass index, nutritional indicators, and body fat percentage. [Results] Among the 177 participants, the prevalence of sarcopenia, dynapenia, and presarcopenia was 35.6%, 28.8%, and 5.1%, respectively, and 30.5% were controls. Among participants, those with dynapenia were significantly younger and had higher SMI and than those with sarcopenia. Men participants with dynapenia also had higher extracellular-water to total-body-water ratio and markedly lower grip strength and Five Repetition Sit-to-Stand Test performance compared with controls. Among participants, those with dynapenia had significantly higher SMI and than those with sarcopenia and showed lower grip strength than controls. [Conclusion] Early detection of dynapenia may benefit from test batteries that takes sex differences into consideration.