Assessment of the relation between short and intermediate term growth in children with asthma treated with inhaled glucocorticoids

OBJECTIVE: To assess the relation between short-term growth and intermediate term growth in children with asthma treated with inhaled glucocorticoids. DESIGN: An open 12 months parallel group trial with visits to the clinic on day 1, after 2, 4, 8, 12, 20, 28, 36, 44 and 52 weeks. SETTING: Outpatient clinic in a secondary referral centre. SUBJECTS: Sixteen children with asthma aged 9 (6-13) years; 16 matched healthy subjects. METHODS: Knemometry and stadiometry. INTERVENTIONS: Dry-powder inhaled budesonide 200 microg twice daily. Primary outcome measures: Intra-group comparisons of mean lower leg growth rates. Secondary outcome measures: Inter-group comparisons of mean lower leg growth rates and intra-group comparisons of mean height-standard deviation scores. RESULTS: One year mean lower leg growth rate (0.36 mm/week) did not differ from the rates during the 2 (0.27 mm/week; P = 0.23), 4 (0.33 mm/week; P = 0.54), 8 (0.36 mm/week; P = 0.79) or 12 (0.33 mm/week; P = 0.49) weeks intervals in the asthma group. Similarly, in the healthy children 2 (0.56 mm/week; P = 0.63), 4 (0.46 mm/week; P = 0.36), 8 (0.43 mm/week; P = 0.49) and 12 (0.43 mm/week; P = 0.66) weeks mean growth rates did not vary statistically significantly from the 1 year growth rate (0.42 mm/week). Mean lower leg growth rates, however, were consistently lower during all periods in the children with asthma (P = 0.02-0.03). At completion of the study mean height-standard deviation score in the asthma group (-0.19) was significantly suppressed as compared with the score at study entry (-0.03) (P = 0.02), whereas no statistically significant variation was detected in the control group. CONCLUSIONS: Short-term lower leg growth rates are consistent with intermediate term growth rates in group studies in children with asthma treated with inhaled dry powder budesonide 400 microg/day. Short-term group knemometry should be an integral part of growth evaluations of new inhaled glucocorticoids, doses and inhalation devices in children with asthma.