Bone mineral density in children and young adults with Crohn's disease

Reduced bone mineral density (BMD) has been reported in adults with Crohn's disease (CD). Less is known about abnormal BMD in children and young adult s with CD. The aims of this study are to determine the prevalence of low BM D and to evaluate the effect of growth and pubertal development on BMD in c hildren and young adults with CD. One hundred-nineteen patients with CD und erwent dual-energy Xray absorptiometry (DXA) to determine BMD. Anthropometr y and pubertal development were measured. Bone age was measured only in pat ients older than 8 years of age and who had not grown in height during the last year. One hundred-nineteen patients (72 male, 47 female) were evaluate d. Seventy percent of patients had BMD z-scores less than or equal to -1.0 and 32% had z-scores less than or equal to -2.0. Weight and height z-scores were significantly associated with BMD z-scores. BMD z-scores based on bon e age and on chronological age were highly correlated, except when the chro nological age BMD z-score was less than or equal to -2.0. BMD z-score was s ignificantly different between males and females for the group (-1.75 +/- 1 .06 vs. -1.08 +/- 1.00), respectively. Children and young adults with CD ha ve a high prevalence of low BMD and routine evaluation by DXA is indicated. In patients with a chronological age-based BMD z-score I -2.0, a bone age- based BMD should be considered.