Quantitative ultrasound of the proximal phalanges and dual-energy X-ray absorptiometry in Crohn's disease patients with osteopenia

Background:

Osteopenia and osteoporosis are frequent complications in Crohn's disease, and these features are associated with an increased risk of vertebral and appendicular fractures. Bone mineral density (BMD) measurements are widely accepted to assess the fracture risk in postmenopausal osteoporosis. In recent years, quantitative ultrasound (QUS) has become attractive for the diagnosis of osteopenia as a nonionizing method. The aim of the present study was to investigate QUS and BMD measurements in osteopenic patients with Crohn's disease. Methods: BMD of the lumbar spine and femoral neck and QUS of proximal phalanges II-V (DBM Sonic 1200; IGEA) were performed prospectively in 171 patients with Crohn's disease. The amplitude-dependent sound-of-speed (AD-SoS) and the ultrasound bone profile score (UBPS) were calculated using the WinSonic PRO 1.1 software program. X-ray examination of the spine was performed in 131 patients. Vertebral deformity was morphometrically defined according to the published methods of McCloskey and Eastell. Results: BMD of the lumbar spine and femoral neck correlated significantly (r = 0.62), but no correlation between BMD and QUS could be demonstrated. Vertebral deformities (VD) were detected in 28/131 (21.4%) patients. Two patients had a history of femoral fracture (FF). Lumbar BMD was lower in patients with either VD or FF than in those patients with no preexisting fractures (T-score: −2.46 vs −2.04; P = 0.0233). QUS parameters correlated negatively to patients' age but could not be used to discriminate between patients with and without VD/FF. Conclusions: Osteoporosis-related fractures are associated with a low lumbar bone density in Crohn's disease patients. QUS of the proximal phalanges cannot detect manifest osteoporosis in Crohn's disease patients and is therefore not valuable as a screening tool for these patients.