[Low bone mineral density in children with Crohn's disease]

Recent studies have reported low bone mineral density in children with Crohn's disease. The aims of this retrospective study were to quantify its frequency and to search for risk factors.

Bone mineral density of 29 children with Crohn's disease was measured by dual-energy X-ray absorptiometry. All the children were taking calcium and vitamin D, during all the follow-up.

Osteoporosis (Z-score < or = -2.5 S.D.) was found in 38% of the children, and osteopenia in 38% (Z-score between -1 and -2.5 S.D.). Low bone mineral density was correlated with age, suggesting it begins with puberty. Daily corticosteroid exposure was significantly higher for patients with osteoporosis. Disease severity measured with Harvey-Bradshaw index and exposure to immunosuppressive drugs were almost statistically significant. Sex, height, duration and site of disease, nutritional assistance exposure were not associated with low bone mineral density.

This study confirms the high frequency of low bone mineral density in children with Crohn's disease, mainly during puberty. Corticosteroid exposure is a risk factor, and the disease severity, a probable one (non significant). New treatment strategy has to be defined to prevent and to treat this complication.