[Inhaled corticosteroid therapy and bone metabolism in asthmatic children]

To explore the association between inhaled corticosteroids (ICS) therapy and bone metabolism.

The sample was composed of 151 children, aged between 1 and 17 years. There were 71 asthmatics treated with ICS for at least 6 months (group 1), 44 asthmatics treated occasionally with ICS during exacerbations (group 2), and 36 healthy children (group 3). Bone mineral density (BMD) and markers of bone formation and resorption were measured. These measures, as well as other related factors, were compared among groups. Regression models for osteopenia and BMD were used with the group as the independent variable adjusted by factors with differences between groups. A two-tailed level of p < 0.05 was used in all tests.

No differences in BMD were found between groups 1 and 2 but significant differences were found between groups 1 and 3 (p = 0.003). No differences were found in markers of bone formation and resorption among the groups. No association was found between BMD and the type, daily dose or accumulated dose of ICS. Group 1 showed an osteopenia odds ratio relative to group 3 of 2.94 (95 % CI: 1.49-5.78) and an average reduction of BMD of 0.50 (95 % CI: 0.32-0.68) was found from group 3 to 2 and from group 2 to 1. In group 1, markers of bone resorption significantly increased in asthmatics with osteopenia compared with those without osteopenia.

ICS treatment in asthmatic children seems to affect BMD. Markers of bone formation and resorption are unaffected. Osteopenia in these children could also be related to other factors that increase bone resorption.