Identification of dynapenia in Japanese kidney transplant recipients based on Asian Working Group of Sarcopenia 2019 criteria : a cross sectional study

Abstract

【Introduction】Dynapenia, defined as loss of muscle strength without a decrease in muscle mass, is observed in patients undergoing chronic hemodialysis. However, details on dynapenia in kidney transplant (KTx) recipients are scarce. Therefore, this study aimed to clarify the prevalence and clinical characteristics of dynapenia in Japanese KTx recipients.【Methods】This cross-sectional study, conducted at Kameda Medical Center between April 2024 and June 2024, enrolled 24 KTx recipients and retrospectively reviewed their medical records. Sarcopenia was diagnosed according to the Asian Working Group for Sarcopenia 2019 criteria, as low handgrip strength and skeletal muscle mass index (SMI). Dynapenia was defined according to a previous proposal by Manini and Clark as low handgrip strength with normal SMI. Participants were categorized into dynapenia, sarcopenia, and normal groups.【Results】Dynapenia and sarcopenia were observed in 16.7％ (n＝4) and 4.2％ (n＝1) of the participants, respectively. BMI and SMI were similar among the three groups ; however, the decrease in grip strength was most pronounced in the dynapenia group (p＝0.0078).【Conclusions】In conclusion, dynapenia is more frequent than sarcopenia in KTx recipients due to significantly lower handgrip strength. Nonetheless, future follow-up and larger-scale studies are warranted to determine whether dynapenia is associated with a worse prognosis.