Laurie Barclay & Désirée Lie
July 7, 2008 — Long-term use of corticosteroids for asthma treatment may increase fracture risk in male children and teens, according to the results of a cohort follow-up study reported in the July issue of Pediatrics.
"Systemic corticosteroids are known to induce osteoporosis and increase the risk for fractures in adults and children," write H. William Kelly, PharmD, from the University of New Mexico Health Sciences Center in Albuquerque, and colleagues from the Childhood Asthma Management Program (CAMP) Research Group.
"Inhaled corticosteroids have been shown to increase the risk for osteoporosis and fractures in adults at risk; however, long-term prospective studies of children to assess risks of multiple short courses of oral corticosteroids and chronic inhaled corticosteroids have not been performed. Thus, we assessed the effects of multiple short courses of oral corticosteroids and long-term inhaled corticosteroids on bone mineral accretion over a period of years."
This study was a follow-up of children with mild to moderate asthma who were initially randomized in the CAMP trial. All patients had serial dual-energy radiographic absorptiometry scans of the lumbar spine for bone mineral density. Median duration of follow-up was 7 years. Of the initial cohort, 84% of those with asthma who were aged 5 to 12 years at baseline (531 boys and 346 girls) underwent calculation of annual bone mineral accretion.
In boys but not girls, therapy with oral corticosteroid bursts was associated with a dosage-dependent decrease in bone mineral accretion (0.052, 0.049, and 0.046 g/cm2 per year) and an increased risk for osteopenia (10%, 14%, and 21%) for 0, 1 to 4, and 5 or more courses, respectively.
Cumulative inhaled corticosteroid use was linked to a small reduction in bone mineral accretion in boys but not in girls, but not to an increased risk for osteopenia in children of either sex.
Limitations of this study include therapy during follow-up controlled by the primary care clinician, failure to control for asthma severity, and lack of accepted normal values for bone mineral density in children to establish z scores to define osteopenia and osteoporosis.
"Multiple oral corticosteroid bursts over a period of years can produce a dosage-dependent reduction in bone mineral accretion and increased risk for osteopenia in children with asthma," the study authors write.
"Inhaled corticosteroid use has the potential for reducing bone mineral accretion in male children progressing through puberty, but this risk is likely to be outweighed by the ability to reduce the amount of oral corticosteroids used in these children."