Predictors of risk of fracture in inflammatory bowel diseases: a prospective study using FRAX score.

Background: Despite the well-known risk of osteoporosis and bone fractures among patients with inflammatory bowel diseases, the WHO FRAX tool has been used in a limited number of studies in this specific population. The purpose of this study was to search for predictors of risk of fractures assessed by FRAX score.

Methods: We prospectively calculated FRAX score for hip and major osteoporotic fractures in inflammatory bowel disease patients consecutively recruited.

Results: The mean risk of hip fractures at 10 years, for the 80 recruited patients, resulted 1.4%, while the mean risk of major osteoporotic fractures was 7.8%. The risk of hip fractures was 1.3% among the 30 Crohn's disease patients versus 1.4% (P=0.82) among 50 ulcerative colitis patients. A prolonged use of corticosteroids correlated with a tendency to a greater risk of hip fracture (r=0.38, P=0.08). Patients with normal erythrocyte sedimentation rate (ESR) values had a risk of osteoporotic hip fractures of 0.75%, while those with high ESR values had a risk of 1.86% (P=0.04). Regarding the risk of major bone fractures, patients with normal ESR values had a risk of 5.9%, versus a risk of 18% in those with elevated ESR (P=0.03).

Conclusions: The correlation between increase of inflammatory markers and increased risk of osteoporotic fractures and the lack of difference between Crohn's disease and ulcerative colitis suggest a central role of inflammation over malabsorption in this population.