Sarcopenia and its individual criteria are associated, in part, with mortality among patients on hemodialysis

Abstract

The relative importance of sarcopenia and its individual components as independent predictors of mortality in the dialysis population have not been determined. We estimated whole-body muscle mass using pre-dialysis bioimpedance spectroscopy measurements in 645 ACTIVE/ADIPOSE enrolled prevalent hemodialysis patients from San Francisco and Atlanta. Low muscle mass was defined as two standard deviations below sex-specific means for young adults from NHANES and indexed to height2, body weight, body surface area, or body mass index. We evaluated the association of sarcopenia (low muscle mass) by four indexing methods, weak handgrip strength, and slow gait speed with mortality. Seventy-eight deaths were observed during a mean follow-up of 1.9 years. Sarcopenia was not significantly associated with mortality after adjusting for covariates. No muscle mass criteria were associated with death, regardless of indexing metrics. In contrast, having weak grip strength or slow walking speed was associated with mortality in the adjusted model. Only gait slowness significantly improved the predictive accuracy for death with an increase in C-statistic from 0.63 to 0.68. However, both gait slowness and hand grip weakness significantly improved the net reclassification index compared to models without performance measures (50.5% for slowness and 33.7% for weakness), whereas models with muscle size did not. Neither sarcopenia nor low muscle mass by itself was a better predictor of mortality than functional limitation alone in patients receiving hemodialysis. Thus, physical performance measures, including slow gait speed and weak hand grip strength, were associated with mortality even after adjustment for muscle size and other confounders.

SARC‐F Questionnaire: Rapid and Easy Tool for Identifying Physical Limitations in Hemodialysis Patients

“…In this study, SARC-F was strongly related with impaired physical function in hemodialysis patients, including decreased handgrip strength, leg strength, gait speed, and SPPB, and these parameters are strong predictors of cardiovascular complications, morbidity, and mortality [4,9,25,35]. The observations in the present study are consistent with those of previous studies for the general community-dwelling elderly population and patients with cardiovascular disease [12,13,16].…”

The obesity paradox: A further consideration in dialysis patients

“…New evidence suggests that it is muscle function not actual muscle mass that mediates the association between muscle mass and mortality . In a prospective cohort using data from the United State Renal Data System, HD patients with BIS‐derived low muscle mass by different indexing methods (height, percentage of body weight, body surface area, and BMI) had a higher risk of death in unadjusted analysis . However, these associations were no longer statistically significant after adjustment for covariates.…”

Preventive Nephrology: The Role of Obesity in Different Stages of Chronic Kidney Disease

“…Increasing BMI in dialysis patients does not exclude concurrent muscle wasting. Sarcopenia and its individual criteria (hand grip strength, slow gait speed) are associated with mortality in hemodialysis patients [26]. Otherwise, intervention by structured exercise programs, which increase muscle mass in these patients, is proven to ameliorate functional parameters, body composition, quality of life, and survival [27][28][29].…”