According to this study:

* Multiple oral corticosteroid bursts decrease bone mineral accretion and increase osteopenia risk in boys, but not in girls.

* Long-term inhaled corticosteroid use also reduces bone mineral accretion in boys, but doesn't increase the risk of osteopenia.

Administration of multiple bursts (more than 2.5 courses a year) of oral corticosteroids and long-term use of inhaled corticosteroids in children with persistent asthma are associated with a reduction in bone mineral accretion in boys, but not in girls. Boys' risk of osteopenia is also increased with multiple oral corticosteroid bursts, but not with long-term use of inhaled corticosteroids.

In following up on the 1,041 children who participated in the Childhood Asthma Management Program study, researchers continued to monitor 877 children (531 boys and 346 girls; ages five to 12 at baseline) to determine the effects of corticosteroid use on bone mineral accretion over a median of seven years. Lumbar spine bone mineral density was determined at baseline, annually during the treatment period, and seven and nine years after randomization.

Yearly bone mineral accretion decreased significantly with corticosteroid use, but only in boys. The decreases with oral corticosteroid use were dose dependent, with five or more bursts during a year resulting in the greatest decrease. The risk of osteopenia in boys increased as the number of bursts increased (10%, 14%, and 21% for 0, 1 to 4, and 5 or more bursts, respectively). No significant effects were found in girls. Long-term inhaled corticosteroid use was also associated with decreased bone mineral accretion in boys only, but the effect was not dose dependent.