Bone density reduction in patients with Crohn disease and associations with demographic and disease variables: Cross-sectional data from a population-based study

Background: The extent of hone density reduction in patients with Crohn dis ease is still being debated. The aim of this study was to examine bone mine ral density (BMD) and factors associated with reduced BMD in a representati ve population of patients with Crohn disease aged between 20 and 70 years. Methods: BMD (using dual energy X-ray absorptiometry) was measured in spine and hip in 55 patients with Crohn disease recruited from the entire Crohn population (n = 96) in a defined area of southern Norway. Demographic and c linical data were also collected. The patients were compared with 52 age-an d gender-matched healthy controls. Potential demographic and disease-relate d factors associated with BMD reduction were statistically tested with bi- and multivariate analysts. Results: The BMD reduction in patients with Croh n disease was 7.1% (P = 0.02) in spine L1-4, 6.1% (P = 0.08) in femoral nec k and 8.4% (P = 0.02) in total hip as compared with the controls. In total hip and femoral neck, age, body weight and gender were independently associ ated with reduced BMD, but in the spine only body weight. Among the disease -related variables, only ever use of prednisolone was independently associa ted with reduction in BMD but this only in the femoral neck. Conclusions: T he spine and hip BMD reduction of 6%-8% is similar to that found in a compa rable population-based study performed in another area in Norway. Among the disease-related variables tested for, only the use of prednisolone was ind ependently associated with BMD reduction. However, the BMD reduction measur ed in this study indicates that disease-related mechanisms are involved.