Effects of high-dose inhaled corticosteroids on bone metabolism in prepubertal children with asthma.

We studied the effect of inhaled corticosteroids on the increase in bone mineral content in prepubertal children with asthma. Forty-eight asthmatic, prepubertal children receiving either inhaled beclomethasone dipropionate or budesonide were evaluated. Nine children of similar age not receiving inhaled steroids served as controls. The average age of corticosteroid-treated children was 7.8 +/- 2.4 years, and of control children, 8.4 +/- 2.1 years (NS). The average dose of inhaled corticosteroids in the treated children was 0.67 +/- 0.48 mg/m(2)/day, and they were followed over a 9-20-month period. Total bone mineral content (TBMC) was measured at baseline and after 9-20 months. A derived value for 12 months' TBMC was calculated, assuming that changes in TBMC were linear with the passage of time. The change in TBMC over a 12-month period was 264 +/- 68 mg for the corticosteroid-treated children and 330 +/- 84 mg for control children (P < 0.025). In a multiple regression analysis in which adjustments were made for the effects of age, height, and weight, the change in TBMC in corticosteroid-treated children was inversely related to the inhaled steroid dose/m(2)/day (P = 0.016). The increase in the lumbar vertebral bone mineral density in control children was also significantly greater than in the corticosteroid-treated children (P < 0.025). We conclude that inhaled steroids, at an average dose of 0.67 mg/m(2)/day, when used in the treatment of asthma reduce the acquisition of bone mineral in prepubertal children.