SUN-064 4,000 Steps of Physical Activity for Risk Stratification of Hemodialysis Patients with or without Sarcopenia

Abstract

Sarcopenia is associated with low survival in hemodialysis (HD) patients. Thus, effective intervention for sarcopenia is essential for disease management. However, there are few evidence-based studies on management of sarcopenia. Recent clinical guidelines recommended completing 4,000 steps/day as a physical activity goal. This study aimed to investigate the complementary role of completing at least 4,000 steps/non-HD day in risk stratification of HD patients withsarcopenia. This retrospective cohort study included 363 Japanese HD patients (median age 65 [57-73] years, 200 men) in 2 hemodialysis units between April 2002 and April 2017. Age, sex, body mass index, primary kidney disease, HD duration, serum albumin, the geriatric nutritional risk index [GNRI], comorbidity score, skeletal muscle index, handgrip strength, usual gait speed, and physical activity were evaluated at study baseline. Sarcopenia was defined according to the recommended diagnostic algorithm of the Asian Working Group for Sarcopenia. Physical activity was defined as the number of steps/non-HD day recorded with an accelerometer. Patients were stratified into 4 groups according to the presence of sarcopenia and whether they completed at least 4,000 steps/non-HD day: sarcopenia/inactive group, sarcopenia/active group, non-sarcopenia/inactive group, and non-sarcopenia/active group. The endpoint was all-cause mortality. Kaplan-Meier, log-rank test, and Cox regression analyses were performed to evaluate prognostic predictive capacity. In addition, to calculate increases in predictive capacity for sarcopenia with physical activity (≥4,000 steps or <4,000 steps), we constructed receiver-operating characteristic curves for all-cause mortality using 3 models: GNRI plus comorbidity score; GNRI, comorbidity score, plus sarcopenia; GNRI, comorbidity score, sarcopenia, plus physical activity. The area under the curve [AUC], integrated discrimination improvement [IDI], and net reclassification improvement [NRI] were compared. Over a median follow-up period of 3.9 (2.1-7.1) years, 109deaths occurred. Compared with the sarcopenia/inactive group, both the sarcopenia/active group (hazard ratio [HR]: 0.39; 95% confidence interval [CI]: 0.16-0.97) and the non-sarcopenia/active group (HR: 0.54; 95% CI: 0.30-0.96) showed comparably better prognoses after adjusting for several preexisting prognostic factors, including age, sex, GNRI, and comorbidity score. Adding the presence of sarcopenia to the model (GNRI and comorbidity score) improved discrimination of patients at high risk of mortality (⊿AUC: 0.04; IDI: 0.022, p<0.01; NRI: 0.285, p=0.01). Furthermore, adding physical activity (≥4,000 steps or <4,000 steps) to the model (GNRI, comorbidity score, and sarcopenia) also improved discrimination of those at risk (⊿AUC: 0.01; IDI: 0.01, p=0.04; NRI: 0.365, p<0.01). Completing at least 4,000 steps/non-HD day played a complementary role in predicting prognosis in HD patientswith sarcopenia. The cutoff point of 4,000 steps/day was useful in risk stratification of hemodialysis patients with or without sarcopenia. The results of this study suggest that physical activity is important for disease management, even in those with sarcopenia.