Purpose of the Study
To determine whether inhaled fluticasone propionate (FP) has long-term effects on growth in children with persistent asthma.
Three hundred twenty-five prepubescent children 4 to 11 years of age with persistent asthma and in the recent past normal growth rates.
The patients were divided into three groups; 106 patients received placebo, 111 patients received FP 50 μg bid, and 108 patients received FP 100 μg bid via a diskhaler. Of 325 patients, 57 showed signs of puberty during the study (19 from the placebo group, 26 from the FP 50 μg group, 12 from the FP 100 μg group) and were excluded from the study. Of the remaining 268 patients, 23% of the patients withdrew from the placebo group and 2% and 4% withdrew from the FP 50 μg and 100 μg, respectively, because of lack of efficacy. The patients were evaluated initially for a 2-week run-in period to confirm their asthma stability, obtain baseline data, and assess the compliance with the diskhaler. The patients were then followed after the first, second, and fourth weeks of treatment and then every 4 weeks throughout the 52-week treatment period. Growth was measured monthly. Radiographic determination of bone age of the left hand and wrist was performed at baseline and at 24 and 52 weeks and the compliance was assessed by counting number of package blisters used.
There were no statistically significant differences in mean height, growth velocity, or mean skeletal age between any of the treatment groups at any time. Over a period of 1 year, mean height (± SE) increased 6.15 ± 0.17 cm in the placebo group, 5.94 ± 0.16 cm in the FP 50 μg group, and 5.73 ± 0.13 cm in the FP 100 μg group (P = .308, overall). At the end of treatment corresponding mean changes in growth velocity from baseline were −0.11 ± 0.15, −0.40 ± 0.20, −0.46 ± 0.15 cm/year, respectively. These changes in height were comparable to normal growth rates for patients of a similar age.
FP in doses of 50 μg bid and 100 μg bid administered for 1 year via a diskhaler did not have any significant effect on growth velocity or bone age.
Although prolonged treatment with inhaled corticosteroids is generally well-tolerated, some concern remains about the potential for an adverse influence on growth in children. Resolving this issue is complicated by the potential for asthma to delay growth and influence bone age, especially if the disease is not well-controlled. This study provides useful data on the subject. This is a prospective, randomized, double-blind study with proper accounting for the patients entering the study. The target enrollment size of 90 patients per treatment group was chosen to provide 80% power of detecting a 1.0 cm per year difference in height velocity. Given the satisfactory safety profile, as noted by the authors, using up to 200 μg of FP per day for 1 year, and the low dropout rate in the treated groups, primary care physicians may well be more inclined to institute such medications in the comprehensive treatment of an asthmatic child.