In Hemodialysis Patients, Intradialytic Resistance Exercise Improves Osteoblast Function: A Pilot Study

Objective: Abnormalities in mineral and bone metabolism are frequent in chronic kidney disease patients. Physical exercise can improve many indicators of physical functioning, and recent studies showed beneficial effects on bone mineral density in the general population. The aim of this study was to evaluate the effects of resistance exercise training on bone markers and body composition in hemodialysis (HD) patients. Design: This was a randomized controlled trial. Subjects: The study included 13 HD patients (46.2% men). Intervention: Patients were divided into a control group and an exercise group, which performed 8 weeks of intradialytic resistance exercise. Serum sclerostin, bone alkaline phosphatase (BAP), insulin, leptin, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, and body composition were measured before and after the exercise period. Results: In the exercise group, BAP levels increased from 11.4 +/- 6.5 to 14.6 +/- 6.4 U/L (P<.05) and serum 1,25-dihydroxyvitamin D levels from 46.0 +/- 23.5 to 87.2 +/- 31.8 ng/mL (P<.05). After exercise, serum BAP levels were inversely correlated with serum sclerostin (r = -0.96, P<.05). There was no change in body composition in either group. Conclusion: Resistance exercise training appears to be an interesting approach for stimulating BAP production in HD patients and may prevent bone loss and stimulate bone formation. (C) 2016 by the National Kidney Foundation, Inc. All rights reserved.