Bone mineral density in normal and asthmatic children

Background: The largest increase in bone mass occurs during childhood and adolescence. A subnormal bone mass is associated with increased risk of fracture. Bone mass is influenced by height, age, race, exercise, and stage of puberty. It is adversely affected by chronic disease states and corticosteroid use. We performed a cross-sectional study of bone density in children with moderate to severe asthma who were treated with inhaled corticosteroids, inhaled cromolyn, oral corticosteroids, or a combination of these, and we compared them with normal children. Methods: A cross-sectional study of bone density, measured either by dual-photon or dual-energy absorptiometry, was performed on 97 normal white and 30 asthmatic white children, aged 5 to 18. Average daily calcium intake, height, weight, and Tanner stage were determined. The total daily and lifetime doses of inhaled corticosteroids in children with asthma were calculated. T tests, multiple regression, chi square analysis, and analysis of covariance were performed. Results: No significant difference in bone density was demonstrated between children with asthma and normal control subjects. No measure (including calcium intake, Tanner stage, daily or lifetime inhaled corticosteroid dose, or duration of illness), except for height and age, provided a significant contribution to the explanation of bone density in children with asthma. Conclusion: Children and adolescents with moderate to severe asthma, including those treated with inhaled corticosteroids, do not appear to have adversely affected bone mass. There was, however, the possibility of a type II error in this study because of the sample size.