Bone mineral density after exercise training in patients with chronic kidney disease stages 3 to 5 : a sub-study of RENEXC—a randomized controlled trial

Background. We evaluated the effects of 12 months of exercise training on bone mineral density (BMD) in patients with chronic kidney disease (CKD) stages 3–5 not on kidney replacement therapy (KRT). Methods. A total of 151 patients were randomized to 12 months of either balance or strength training, both together with endurance training. Some 112 patients completed and 107 (69 men, 38 women) were analysed, with a mean age 66 ± 13.5 years and 31% having diabetes. The exercise training was self-administered, prescribed and monitored by a physiotherapist. Total body, hip and lumbar BMD, T score and Z score were measured at baseline and after 12 months using dual energy X-ray absorptiometry. Results. Both groups showed increased physical performance. The prevalence of osteoporosis and osteopenia was unchanged. The strength group (SG) decreased total body BMD (P < .001), the balance group (BG) increased total body T score (P < .05) and total body Z score (P < .005). Total body ∆T score was negative in the SG and unchanged in the BG (P < .005). Total body ∆Z score was negative in the SG and positive in the BG (P < .001). The proportion of progressors measured by ∆T (P < .05) and ∆Z scores (P < .05) was significantly lower in the BG compared with the SG. In multivariate logistic regression analysis, belonging to the BG was the only factor with a lower risk of deterioration of total body BMD, T and Z scores. Conclusions. Twelve months of balance training together with endurance training seemed to be superior to strength training in maintaining and improving BMD in patients with CKD not on KRT.