Associations of Body Composition, Muscle Function, and Physical Activity with Mortality in Peritoneal Dialysis Patients

Introduction. Loss of skeletal muscle mass and muscle strength is common in dialysis patients. Therefore, this investigation was designed to determine the association between body composition, muscle function, and physical activity with mortality in peritoneal dialysis (PD) patients. Methods. This was a multicenter cohort study on all eligible PD patients (n = 79) in Tehran PD centers. At baseline, skeletal muscle mass and muscle strength were determined using bioelectrical impedance analysis and handgrip strength, respectively. Physical performance was assessed by a 4-meter walk gait speed test. Physical activity level was estimated by using the long-form International Physical Activity Questionnaire at baseline. The mortality of PD patients was evaluated two years after the start of this study. Results. The total dialysis adequacy was significantly lower in dead patients in comparison with live patients (P < .05). In contrast, serum hs-CRP (P < .05), and the total amount of glucose absorbed daily from PD solutions (P < .05) were significantly higher in dead patients in comparison with live patients. There were no significant associations between body fat mass, skeletal muscle mass, skeletal muscle mass index, muscle strength and physical performance with mortality in PD patients. However, in PD patients with physical activity ≤ median, odds of mortality was 7.4 times higher than those with physical activity > median (OR = 7.4, 95% CI: 1.3 to 43.3; P < .05). Conclusion. This study indicates that low physical activity; low dialysis adequacy, high serum hs-CRP, and high amount of glucose absorbed from PD solutions are related with high mortality in PD patients.