Ileum resection is the most predictive factor for osteoporosis in patients with Crohn's disease

Crohn's disease is associated with a host of factors potentially increasing the risk for osteoporosis and fractures. The aim of our study was to identify the most predictive factors for skeletal pathology in this patients. Using a cross-sectional study design, 146 randomly selected patients with Crohn's disease of variable disease activity who were given standard therapy to control disease activity, including glucocorticoids, and who attended the outpatient clinic of the Gastroenterology Unit on regular follow-up visits were studied. Bone mineral density (BMD) measurements and lateral X-rays of the spine were performed, and biochemical parameters of bone turnover, gonadal hormones and C-reactive protein (CRP) as markers of disease activity were measured in all patients. There were 61 men and 85 women, with a mean age of 43 years and mean disease duration of 20 years. The majority of patients (86%) had been treated with glucocorticoids at some stage during their illness at a median dose of 7.5 mg/day, 43% were currently using these agents and 66% had undergone an intestinal resection. Twenty-one percent of patients had below-normal 25-hydroxy vitamin D levels. Osteoporosis was documented in 26% of patients, predominantly at the femoral neck, but also at the lumbar spine or at both sites; osteopenia was documented in 45% of patients. Prevalence of vertebral and non-vertebral fractures was, respectively, 6% and 12%. Ileum resection was the most predictive factor for osteoporosis: RR 3.84 (CI 1.24-9.77, p=0.018), followed by age: RR 1.05 (CI 1.02-1.08, p < 0.001) and current or past glucocorticoid use: RR 1.94 (CI 0.92-4.10, p=0.08). Our data suggest that in patients with Crohn's disease, the risk of osteoporosis is best predicted by a history of ileum resection.