Vertebral fractures and role of low bone mineral density in Crohn's disease

Background & Aims: Vertebral fractures in Crohn's (CD) patients with low bone mineral density (BMD) have been documented as between 14%-22%. Vertebral fractures in CD patients with normal BMD have not been reported. The objectives were to identify the prevalence of vertebral fractures in CD patients and associated predictive factors. Methods: Two hundred twenty-four CD patients underwent vertebral BMD analysis and radiographs. Fractures were identified by using quantitative height reduction morphometry, and severity was assessed by spinal fracture index. Results: Mean age was 40.6 +/- 11.0 years. Sixty percent reported corticosteroid use during the preceding year. Forty-five of 224 (20.0%) patients had 88 vertebral fractures. Sixteen of 45 patients with vertebral fractures had normal BMD (19.0% of all patients with normal BMD). Analysis of patients with or without vertebral fractures did not demonstrate significant differences in BMD or in corticosteroid use. Linear regression analysis demonstrated that elevations in body mass index, C-reactive protein, and parathyroid hormone were significantly predictive of vertebral fractures (r = 0.415, P < .05), and height reduction was > 20% (r = 0.417, P < .05). Conclusions: This study demonstrates that vertebral fractures in CD patients occur with an equal frequency in those with low and with normal BMD, regardless of corticosteroid use. The mean age of CD patients with vertebral fractures was much lower than that reported in the general population for these fractures. Elevations in body mass index and C-reactive protein and parathyroid hormone levels were predictive of vertebral fractures.