Variables Associated with Low Muscle Mass Among End-Stage Renal Disease Patients Submitted to Hemodialysis: A cross-Sectional Study

Abstract Background: We aimed to compare lean tissue index between patients with low and normal muscle strength in order to determine a cutoff to classify low muscle mass and find variables associated with low muscle mass among end-stage renal disease patients undergoing hemodialysis. Methods: We studied 245 end-stage renal disease patients on hemodialysis in the only two dialysis centers located in the north region of Ceará state, Brazil, in October 2019. Demographic, clinical, laboratory and anthropometric measurements were collected. Patients’ functional ability was assessed by the Brazilian version of the Stanford Health Assessment Questionnaire Disability Index. Bioimpedance analysis and handgrip testing were used, respectively, to evaluate lean tissue index and muscle strength. We classified low muscle mass according to muscle strength, and compared variables between patients with normal and low muscle mass. Variables that differed in the comparison were analyzed with a logistic regression model to detect independent predictors of low muscle mass. Results: According to a cutoff of less than or equal to 15 kg/m 2 of lean tissue index to classify low muscle mass, we found a prevalence of 41.2% of low muscle mass. Patients with low muscle mass presented higher prevalence of functional disability. In multivariate logistic regression (considering low muscle mass as a dependent variable), age (older), female gender, creatinine level, fat tissue index and abnormal waist-to-hip ratio were found to be independent predictors of low muscle mass. Conclusions: Older patients, women, patients with low creatinine, with high fat tissue index and with abnormal waist-to-hip ratio should be classified as at risk of low muscle mass. Dietary improvements, encouragement of resistance exercise and the use of androgens should be tried in this group of patients. Keywords: End-stage renal disease, Hemodialysis, Sarcopenia, Muscle mass, Muscle strength, Bioimpedance, Handgrip test