Physical Activity Levels, Functional Capacity and their Association with Cognitive Function in Patients with Chronic Kidney Disease on Hemodialysis: A Cross-Sectional Study

Abstract

Introduction: Hemodialysis is the most common renal replacement therapy in the final stages of chronic kidney disease (CKD). This treatment imposes a demanding routine, lifestyle changes, and even sedentary behavior. Low levels of physical activity in hemodialysis patients are associated with adverse clinical outcomes. Objective: To investigate the level of physical activity, physical performance, and their association with cognitive function in hemodialysis patients. Methods: This was a cross-sectional and secondary analysis of data from the Porto Alegre center included in the multicenter SARC-HD study, which considered only the participating center in Porto Alegre, one of the 19 dialysis units across Brazil. Participants were evaluated for physical activity level (International Physical Activity Questionnaire – Short Form), muscle strength (handgrip strength), physical performance (4-meter gait speed test and Sit-to-Stand test). Cognitive function was assessed using the Mini-Mental State Examination. Results: Twenty-four patients were included, with a mean age of 55.96 (±17.1) years and a mean HD duration of 51.63 (±52.6) months. A total of 79.16% participated in an intradialytic exercise program. Regarding the independent variables, higher levels of physical activity and better physical performance were observed, including handgrip strength (HGS). As an outcome, better cognitive function was associated with higher levels of physical activity (r=0.394; p=0.05) and HGS (r=0.407; p=0.048). There was also a trend toward a negative correlation between physical performance and cognitive function (r=-0.382; p=0.072). Conclusion: Higher levels of physical activity and HGS were significantly associated with better cognitive function. These findings reinforce the importance of a physically active lifestyle in individuals with CKD.