Voluntary Wheel Running Has Beneficial Effects in a Rat Model of CKD-Mineral Bone Disorder (CKD-MBD)

Abstract

Background Reduced bone and muscle health in individuals with CKD contributes to their higher rates of morbidity and mortality. Methods We tested the hypothesis that voluntary wheel running would improve musculoskeletal health in a CKD rat model. Rats with spontaneous progressive cystic kidney disease (Cy/+ IU) and normal littermates (NL) were given access to a voluntary running wheel or standard cage conditions for 10 weeks starting at 25 weeks of age when the rats with kidney disease had reached stage 2–3 of CKD. We then measured the effects of wheel running on serum biochemistry, tissue weight, voluntary grip strength, maximal aerobic capacity (VO2max), body composition and bone micro-CT and mechanics. Results Wheel running improved serum biochemistry with decreased creatinine, phosphorous, and parathyroid hormone in the rats with CKD. It improved muscle strength, increased time-to-fatigue (for VO2max), reduced cortical porosity and improved bone microarchitecture. The CKD rats with voluntary wheel access also had reduced kidney cystic weight and reduced left ventricular mass index. Conclusions Voluntary wheel running resulted in multiple beneficial systemic effects in rats with CKD and improved their physical function. Studies examining exercise interventions in patients with CKD are warranted.