Vitamin D levels significantly modified the effect of oral corticosteroids on bone mineral accretion in children, particularly boys, with asthma, according to recent study results.
Researchers conducted a multicenter study of 780 children, aged 5 to 12 years, with mild-to-moderate asthma. The patients, who had lower vitamin D levels (≤30 ng/mL), were randomly assigned corticosteroids or placebo (twice daily) to examine whether they were more susceptible to the negative effects of corticosteroids on bone mineral accretion (BMA) during time. The patients were administered inhaled corticosteroids (200 mcg budesonide twice daily) or oral corticosteroids (OCS, 8 mg nedocromil twice daily), their total doses were recorded, and they were evaluated for a mean of 4.3 years. Researchers also measured patients’ vitamin D levels at baseline and their lumbar spines (L1-L4) by conducting dual energy X-ray absorptiometry scans. BMA rates were defined as (bone mineral density [BMD] at 4 years’ follow-up – BMD at baseline)/4 years.
Vitamin D levels in boys at baseline significantly altered the correlation between OCS and BMA (vitamin D x OCS interaction, P=0.23). With an increased use of OCS in boys only who were vitamin D insufficient, there was a decrease in BMA (P<.001). Boys who were vitamin D insufficient and had been exposed to more than two courses of OCS annually showed twice the decrease in BMA rates compared with boys who were vitamin D sufficient (≥30 ng/mL) and unexposed to OCS.
“Our study demonstrates a dosage-dependent effect of intermittent OCS use on BMA in boys with asthma, which is significantly modified by baseline serum vitamin D levels,” researchers said. “Our data suggest that children, particularly boys, with asthma who have frequent exacerbations requiring OCS treatment might benefit from a vitamin D assessment and that vitamin D supplementation in these children might help to preserve BMD.”
Disclosure: See the study for a full list of relevant disclosures.