Efficacy of risedronate administration in osteoporotic postmenopausal women affected by inflammatory bowel disease

Patients with inflammatory bowel disease (IBD) have frequently a bone mineral density (BMD) significantly lower than age-matched healthy subjects. The low BMD observed in IBD patients is related also to a higher incidence of bone fractures. In this prospective randomized study we evaluated the effect of 1-year risedronate administration on bone mass and turnover, and on vertebral fractures in osteoporotic postmenopausal women with IBD in remission. Ninety osteoporotic postmenopausal women were randomized to receive oral risedronate 35 mg/week (risedronate group) or placebo tablets (placebo group; one tab/week). The duration of treatment was 12 months. At entry and after treatment, lumbar spine and hip BMD, and serum osteocalcin (OC) and urinary deoxypyridinoline/creatinine ratio (DPD-Cr) levels were evaluated. Vertebral fractures were assessed from thoracic and lumbar lateral and anterior-posterior spinal radiographs taken at baseline, and from lateral spinal radiographs taken at the end of the study. At study entry, no difference between groups was also detected in BMD and in bone turnover markers. At the end of the study, lumbar spine, trochanter and femoral neck BMD was significantly ( p < 0.05) higher in comparison with baseline in the risedronate group, whereas a significant ( p < 0.05) decrease was observed in the placebo group. For the same visit, a significant ( p < 0.05) difference in lumbar spine, trochanter and femoral neck BMD was detected between groups. After 12-month follow-up, serum OC and urinary DPD-Cr levels were significantly ( p < 0.05) lower and higher in comparison with basal values in risedronate and placebo group, respectively. At the same time, a significant ( p < 0.05) difference in serum OC and urinary DPD-Cr levels was observed between groups. Throughout the study, the incidence of vertebral fractures was significantly ( p < 0.05) lower in the risedronate group than in the placebo group (12.5% vs 34.1%). The relative risk (RR) to develop a new vertebral fracture after 1 year of risedronate administration was of 0.36 (95% confidence interval, 0.14-0.85). In conclusion, risedronate administration is an effective anti-osteoporotic treatment in osteoporotic postmenopausal women with IBD in remission.