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.