Determinants of Slow Walking Speed in Ambulatory Patients Undergoing Maintenance Hemodialysis

Walking ability is significantly lower in hemodialysis patients compared to healthy people. Decreased walking ability characterized by slow walking speed is associated with adverse clinical events, but determinants of decreased walking speed in hemodialysis patients are unknown. The purpose of this study was to identify factors associated with slow walking speed in ambulatory hemodialysis patients. Subjects were 122 outpatients (64 men, 58 women; mean age, 68 years) undergoing hemodialysis. Clinical characteristics including comorbidities, motor function (strength, flexibility, and balance), and maximum walking speed (MWS) were measured and compared across sex-specific tertiles of MWS. Univariate and multivariate logistic regression analyses were performed to examine whether clinical characteristics and motor function could discriminate between the lowest, middle, and highest tertiles of MWS. Significant and common factors that discriminated the lowest and highest tertiles of MWS from other categories were presence of cardiac disease (lowest: odds ratio [OR] = 3.33, 95% confidence interval [CI] = 1.26-8.83, P<0.05; highest: OR = 2.84, 95% CI = 1.18-6.84, P<0.05), leg strength (OR = 0.62, 95% CI = 0.40-0.95, P<0.05; OR = 0.57, 95% CI = 0.39-0.82, P<0.01), and standing balance (OR = 0.76, 95% CI = 0.63-0.92, P<0.01; OR = 0.81, 95% CI = 0.68-0.97, P<0.05). History of fracture (OR = 3.35, 95% CI = 1.08-10.38; P<0.05) was a significant factor only in the lowest tertile. Cardiac disease, history of fracture, decreased leg strength, and poor standing balance were independently associated with slow walking speed in ambulatory hemodialysis patients. These findings provide useful data for planning effective therapeutic regimens to prevent decreases in walking ability in ambulatory hemodialysis patients.