BONE-MINERAL DENSITY ASSESSMENT IN CHILDREN WITH INFLAMMATORY BOWEL-DISEASE

Background & Aims: Children with inflammatory bower disease (IBD) are at risk for osteoporosis because of undernutrition, delayed puberty, a nd prolonged corticosteroid use. The aim of this study was to compare bone mineral density (BMD) in children with IBD with that in normal ch ildren and to assess the effects of nutritional and hormonal factors a nd corticosteroid dosages on BMD. Methods: One hundred sixty-two subje cts (99 with IBD and 63 healthy sibling controls) were enrolled. Patie nts underwent anthropometric assessment, pubertal staging, bone age ra diography, and BMD assessment by dual energy x-ray absorptiometry of t he lumbar spine, femoral neck, and radius. Laboratory evaluations incl uded serum calcium, phosphate, alkaline phosphatase, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, parathyroid hormone, osteocalcin, urinary N-telopeptides, albumin, insulin-like growth factor I, and testostero ne or estradiol. Cumulative corticosteroid doses were calculated. Resu lts: BMD Z scores at the lumbar spine and femoral neck were lower in p atients with IBD, and lower in those with Crohn's disease compared wit h those with ulcerative colitis. Low BMD persisted after correction fo r bone age in girls with Crohn's disease (lumbar spine, P = 0.004; fem oral neck, P = 0.002). Cumulative corticosteroid dose was a significan t predictor of reduced BMD. BMD did not correlate with measures of cal cium homeostasis, except elevated serum phosphate and urine calcium le vels in girls. Conclusions: Low BMD occurs in children with IBD (more in Crohn's disease than in ulcerative colitis), especially pubertal an d postpubertal girls. Cumulative corticosteroid dose is a predictor of low BMD, but other factors in Crohn's disease remain undetermined.