Longitudinal monitoring of bone measured by quantitative multisite ultrasound in patients with Crohn's disease

Background: Crohn's disease (CD) is characterized, among other features, by intestinal malabsorption of minerals, vitamins, and various food ingredients. This may cause a suboptimal peak bone mass and thereby susceptibility to osteoporosis at an early age. Objective: Longitudinal measurement of bone in CD during active disease and during remission. Design: We evaluated 24 patients with CD (16 males) 14 to 16 years of age longitudinally, every 3 months over 12 months, for disease activity. Longitudinal follow-up by quantitative ultrasound measurement using a bone sonometer (Sunlight Omnisense, Tel Aviv, Israel) that obtains axial speed of sound (SOS) was also performed. Eight of the CD patients were in remission (R-CD), characterized by accelerated weight and height gain and near-normal erythrocyte sedimentation rate and serum iron. Eight patients had active CD (A-CD), and 8 patients were under treatment with oxandrolone. Results: By two-way repeated-measures analysis of variance, the change in SOS Z-score of tibia at 0, 6, and 12 months was as follows: -0.5 +/- 0.2 to -0.3 +/- 0.2, -0.6 +/- 0.2 to -1.0 +/- 0. 5 and - 0.6 +/- 0.2 to -0.4 +/- 0.2 in the remission, active disease, and oxandrolone-treated groups, respectively (P < 0.001). Similarly, the change in SOS Z-score of radius during the study was as follows: - 0.5 +/- 0.3 to -0.6 +/- 0.3, -0.6 +/- 0.3 to -1.0 +/- 0.3 and -0.6 +/- 0.2 to -0.4 +/- 0.2 in the remission, active disease, and oxandrolone-treated groups, respectively (P < 0.001). While a small change over time in patients in remission was noted, SOS decreased in patients with active disease and increased in oxandrolone-treated patients. Despite the fact that SOS remained in the normative range in all patients, a clear deterioration was demonstrated for patients with active disease. Conclusions: We conclude that longitudinal follow-up of patients with active disease may detect an early pattern of deterioration in quality of bone.