Predictors of deterioration of lung function in Polish children with cystic fibrosis

Introduction: Severity of lung disease varies in patients with the same CFTR genotype. It suggests that other factors affect the severity of cystic fibrosis (CF). The aim of the study was to identify risk factors that determine lung function decline in Polish cystic fibrosis children.

Material and methods: The follow-up time was no less than 5 years of respiratory status observation based on the forced expiratory volume in 1 s value (FEV1). The socio-economic data, perinatal interview, presence of meconium ileus (MI), time of CF diagnosis, initiation of tobramycin inhalation solution (TIS), pancreatic function, sensitization to Aspergillus fumigatus, presence of impaired glucose tolerance (IGT) or diabetes mellitus, chronic bacterial colonization and number of exacerbations and hospitalizations were assessed.

Results: The mean age of 61 included children was 13.3 ±7.6 years. Delta F508 homozygosity was detected in 45.9%, 44.3% were delta F508 heterozygous, and 9.8% had other genotypes. FEV1 decline was observed among 20% of patients; the rest of the patients presented stable values of FEV1 during at least 5 years of observation. The most significant predictors related to the decline of FEV1 were presentation of MI (p = 0.0344), IGT (p = 0.0227), number of exacerbations (p = 0.0288), and early Pseudomonas aeruginosa (PA) chronic colonization (p = 0.0165) followed by late TIS initiation after the first detection of PA (p=0.0071). Neither time of diagnosis nor type of CFTR mutation was statistically significant as a predictor of lung deterioration.

Conclusions: The presence of MI, IGT, chronic PA colonization, and number of exacerbations are risk factors for lung function deterioration.