The aim of this study was to detect dynapenia in elderly hemodialysis patients using only muscle strength and physical function assessment based on the sarcopenia diagnostic criteria of the Asian Working Group for Sarcopenia 2019 (AWGS2019) and to examine its association with patient characteristics, other physical functions, physical activity (PA), and perceived difficulty in activities of daily living (ADL difficulty).
This retrospective study was conducted at a single center. The subjects were hemodialysis outpatients aged 65 years or older who could complete a physical function assessment between 2021 and 2024. The handgrip strength and 5-time chair stand test were used to categorize the groups according to the AWGS 2019 assessment of muscle strength and physical function. Those who exceeded both cutoffs were classified as robust; those who fell below either were classified as pre-dynapenia; and those who fell below both were classified as dynapenia. Age, sex, BMI, dialysis vintage, Geriatric Nutritional Risk Index, and Charlson Comorbidity Index were considered by patients as their characteristics. Knee extensor strength, Short Physical Performance Battery (SPPB), and maximum 10-m walking speed were used to assess other physical functions. Interviews were conducted to assess PA and ADL difficulty. PA was assessed using the Low Physical Activity Questionnaire, and ADL difficulty was assessed using “Questionnaire for assessing perceived difficulty in performing daily activities related to lower-limb function”. Bonferroni correction was used to perform multiple comparison tests for each group.
The study included 71 subjects (age 75.9±5.96). 28 (39%) were in the robust group, 21 (28%) in the pre-dynapenia group, and 22 (31%) in the dynapenia group. In the comparison of patient characteristics, only age was lower in the robust group (p0.01). Knee extensor strength, SPPB, and gait speed were significantly lower in the dynapenia group than in the robust and pre-dynapenia groups (p0.01). An age-adjusted covariance analysis confirmed these results. On the other hand, there was no significant difference in the circumference of the lower leg (p=0.38). Both PA and ADL difficulty were significantly decreased in the dynapenia group compared with the robust and pre-dynapenia groups.
The detection of dynapenia in elderly hemodialysis patients using muscle strength and physical function as part of assessment of the sarcopenia diagnostic criteria may help to identify not only the decline in physical function but also individuals experiencing a decline in PA and ADL difficulty. The absence of group differences in leg circumference, which was strongly correlated with muscle mass, suggests that muscle strength and physical function may not be associated with muscle mass.
Our findings indicated that muscle strength and physical function, which are used as diagnostic criteria for sarcopenia, can predict overall function in elderly hemodialysis patients.
Dynapenia
Sarcopenia
