Impact of inhaled corticosteroids on the risk of early Pseudomonas aeruginosa acquisition in cystic fibrosis

Abstract

Aim: To investigate the role of inhaled corticosteroids (IC) on the risk of Pseudomonas aeruginosa acquisition before the age of 10 y in cystic fibrosis (CF) patients. Methods: For each subject the cumulative dose kg‐1 of IC received for each year of age was calculated until the end of follow‐up. The age at CF diagnosis, the nutritional status (NS) and the number of respiratory exacerbations (RE) were used as surrogate measures for the severity of CF. Results: A total of 83 patients (40 M, 43 F) entered the study. Their median length of follow‐up was 4.4 y, for a total of 386 person‐years at risk. Twenty‐three patients acquired P. aeruginosa at a median age of 4.6 y (range 0.4‐9.9 y). The estimated survival without P. aeruginosa acquisition was 65% at 10 y of age. The effect of different risk factors (IC, NS, RE and age at CF diagnosis) on the probability of P. aeruginosa acquisition was evaluated: none of them was significantly associated with the risk of P. aeruginosa acquisition. In particular, patients receiving very high cumulative doses of IC (4th quartile) had a non‐significantly increased risk of P. aeruginosa acquisition compared with those receiving low doses of IC (1st quartile) (hazard ratio = 1.73, 95% confidence limits 0.40‐7.38). Conclusion: This retrospective study was not able to demonstrate any role of IC in increasing the risk of P. aeruginosa acquisition. This complication seems to occur at a constant pace that is independent of CF severity and age. Prospective multi‐institutional randomized studies are needed to investigate the effects of high‐dose IC in CF patients.