Background and aims Inhaled corticosteroids (ICS) reduce growth during the first year of treatment, but this growth suppressing effect does not continue during further treatment. Decreasing adherence may play a role in explaining this. The aim of this study was to examine the relationship between cumulative real exposure (with objectively assessed adherence) to ICS and height growth in children with asthma.

Methods We investigated 99 prepubertal children with asthma, 2–13 years of age, who had been using ICS in guideline-recommended dosages for ≥3 months, and continued to do so during 1-year follow-up. ICS adherence was assessed by electronic monitoring devices, allowing calculation of true cumulative exposure to ICS. We analysed the relationship between cumulative ICS dose and height growth velocity (assessed as change in height SD score) over 1 year.

Results Median (IQR) adherence over 1 year was 84 (68–92) %. Mean cumulative fluticasone dose was 64.6 (SD, 27.8) mg, reflecting a daily dose of 167 (SD, 7) µg. The negative correlation between cumulative ICS dose and height growth velocity (r=−0.266; p=0.008) became non-significant after adjustment for age and sex in a multiple regression model (adjusted r=−0.188; p=0.066).

Conclusions One year of ICS treatment in guideline-recommended dosages with high adherence did not result in significant or relevant growth suppression. Unaffected growth can be maintained for at least 1 year in children with asthma during ICS treatment with high adherence.