Effect of a low-impact exercise program on bone mineral density in Crohn's disease: a randomized controlled trial

Physical exercise increases bone mineral density (BMD) in healthy young adults and slows the rate of bone loss in later life. The aim of this randomized controlled trial was to investigate the effect of exercise on BMD in patients with Crohn's disease.

A total of 117 patients with Crohn's disease were randomized to a control group or a low-impact exercise program of increasing intensity. BMD (g/cm2) was measured at baseline and 12 months at the hip and spine (L2-L4) by dual energy x-ray absorptiometry.

Nonsignificant gains in BMD occurred at the hip and spine in the exercise group compared with controls (P > 0.05). In fully compliant patients, BMD increased by 3.54% (7.95%) at the femoral neck, 2.97% (7.7%) at the spine, 4.1% (10.26%) at Ward's triangle, and 7.77% (8.2%) at the greater trochanter. Compared with controls, gain in BMD at the greater trochanter was statistically significant (difference in means, 4.67; 95% confidence interval, 0.86-8.48; P = 0.02). Increases in BMD were significantly related to the number of exercise sessions completed (femoral neck; r = 0.28; 95% confidence interval, 0.10-0.45; P = 0.04).

Progressive low-impact exercise is a potentially effective method of increasing BMD in Crohn's disease. If sustained, the increases in BMD may reduce the risk of osteoporotic fracture.