Background: Patients undergoing dialysis experience decreases in physical function; however, few data exist on physical function in pre-dialysis patients with chronic kidney disease (CKD). The primary objective of this study was to clarify physical function in pre-dialysis patients according to CKD stage.
Methods: This was a cross-sectional study of 120 ambulant pre-dialysis CKD stage 2 or higher patients (85 male, 35 female; mean age 66.5 years) who visited St. Marianna University School of Medicine Hospital. Participants were grouped according to CKD stage as follows: stage 2 (n = 17), stage 3 (n = 55), stage 4 (n = 25), and stage 5 (n = 23). Handgrip strength, knee extensor muscle strength, single-leg stance time, and maximum gait speed were used to assess physical function. Clinical laboratory tests were also examined at the same time as physical function measurements.
Results: All indices of physical function decreased according to the progression of CKD. Each physical function index was significantly lower in CKD stage 4 or 5 patients than CKD stage 2 or 3 patients. All physical function indices showed a positive correlation with estimated glomerular filtration rate (eGFR), blood hemoglobin level, and serum albumin level, and a negative correlation with urinary protein levels. In multiple regression analysis, age, female sex, body mass index, eGFR and urinary protein were significantly correlated with indices of physical function.
Conclusion: Physical function in pre-dialysis CKD patients decreased as the disease progressed according to stage. Early intervention in CKD patients might delay the loss of physical function.