Safety of chronic exercise in a rat model of kidney disease.

PURPOSE: The objective of this study was to determine the effect of treadmill running on polycystic kidney disease (PKD) progression and bone mineral density in Han:SPRD-cy rats, an animal model of PKD.

METHODS

Using a 2 x 2 design, normal and polycystic male rats were divided randomly into exercise and sedentary groups at 4 wk of age. The exercising group performed treadmill exercise (14 m x min(-1)) for 30 min 3 d x wk(-1) for 6 wk, whereas the control group remained sedentary. This 6-wk period represents the period of greatest cyst growth in this model.

RESULTS

Both exercised and sedentary polycystic animals had significantly greater kidney weights, as well as greater concentrations of serum urea nitrogen and serum creatinine than control animals. Exercise did not alter these parameters in either normal or polycystic animals. In addition, bone mineral density and bone mineral content, determined by dual-energy x-ray absorptiometry, were not altered by exercise in these animals. Bone mineral content, however, was marginally lower in polycystic animals.

CONCLUSIONS

These results support the safety of moderate exercise in PKD. Additional research in this area is needed since there may be other benefits that are derived from exercise in this population.