LONGITUDINAL ASSESSMENT OF GROWTH, MINERAL METABOLISM, AND BONE MASS IN PEDIATRIC CROHNS-DISEASE

In children with inflammatory bowel disease, controversy continues abo ut the use of long-term alternate day prednisone therapy (ADP) to supp ress disease activity and to encourage appetite and growth. One possib le side effect of both disease process and prednisone therapy is risk of development of osteoporosis. To evaluate this risk factor, growth, biochemical indices of mineral and vitamin D status, and bone mass wer e measured in nine adolescents with Crohn's disease (CD) who were trea ted with ADP (0.3 mg/kg > 3 months per year) compared with eight adole scents treated with minimal ADP exposure (< 3 months per year). Single photon densitometry was used to measure bone mineral mass at the 1/3 distal radius three times over 2 years. Mean age of the 17 CD boys was 13.9 +/- 2.1 years at baseline. CD patients had lower bone BMC/BW min eral content/bone width (BMC/BW) compared with age- and height-matched normal boys at all times. The difference was less when compared to he ight-matched normal values as CD patients were shorter than healthy re ference boys. Plasma 1,25-dihydroxyvitamin D, alkaline phosphatase, an d parathyroid hormone significantly increased with treatment of diseas e but there were no differences between treatment groups. CD patients treated with ADP had similar heights and weights at baseline and demon strated similar linear growth over 2 years (9.1 cm/2 years) to CD pati ents without ADP (10.3 cm/2 years). In both groups, BMC/BW increased s ignificantly from year 1 to year 2, but absolute values for bone mass did not differ between the groups. These data suggest that over a 2-ye ar treatment period male CD patients with chronic low-dose ADP exposur e achieve linear growth rates and maintain bone mineralization at leas t as well as male CD patients who do not receive ADP.