Assessment of the effect of inhaled corticosteroids on bone mineral content in asthmatic children

ABSTRACT

The use of inhaled corticosteroids [ICS] as a prophylaxis is now recommended in international guidelines for all patients using an inhaled bronchodilator more than once a day. We evaluated the effect of long term ICS therapy on bone mineral content of the lumbar spine, and the potential risk of impaired bone density in prepubertal children. The study was performed on two groups. Group I included 40 asthmatic children [mean age 8.3 +/- 0.5 years] on ICS in the form of beclomethasone dipropionate, 200 to 600 micro g/day [mean dosage 392 +/- 53.5 micro g/day]] for at least 6 months [mean 1.3 +/- 0.5 years]. Group II included 40 mild asthmatic children [mean age 8.2 +/- 0.6 years]. They are not receiving regular corticosteroids whether inhaled or systemic, but were treated only with inhaled beta[2]-stimulants whenever needed. The bone mineral density [BMD] was measured by dual energy X-ray absorptiometry [DEXA] densitometer. Measurements for the two groups were performed at the lumbar spine [L[2]-L[4]. Laboratory measurements included serum calcium, phosphorus and bone specific alkaline phosphatase. The study showed significantly higher BMD measurements in group II [mean 0.597 +/- 0.101 g/cm[2]] than group 1 [mean the 0.522 +/- 0.122 g/cm[2]] [P<0.05]. There were no statistically significant differences between level of serum calcium, phosphorus or bone specific alkaline phosphatase in both groups. A significant positive correlation was found between BMD and both weight and height of the children in both groups [r= 0.766, r= 0.859 in group I and 0.789, 0.825 in group II]. Our findings indicated that long term use of ICS slightly reduced the gain in bone mass in mild to moderately severe asthmatic prepubertal children. We recommended the use of lowest effective dose of ICS, the use of ICS with least oral bioavailability and follow up bone density of the lumbar spine at 6 months intervals