School-age lung function after preterm birth: early-life determinants in a paediatric pulmonology cohort with comparison with NHANES

INTRODUCTION: Lung-function outcomes among preterm-born children referred for pulmonology care are highly heterogeneous, and early determinants remain incompletely defined. We aimed to identify early-life factors associated with school-age lung function after preterm birth and to examine whether school-age spirometry patterns relate to subsequent lung-function trajectories. METHODS: ) and forced vital capacity (FVC) z-scores at ages 6-8 years using multivariable regression. Spirometry-based phenotypes included prematurity-associated preserved-ratio impaired spirometry (pPRISm), prematurity-associated obstructive lung disease (POLD) and prematurity-associated dysanapsis. Longitudinal mixed-effects models assessed lung-function trajectories from ages 8 to 21 years. Parallel analyses were conducted in the National Health and Nutrition Examination Survey (NHANES). RESULTS: z-score decline (age x pPRISm β -0.08 SD/year, 95% CI -0.15 to -0.02), while POLD was associated with improving FVC z-score (age x POLD β 0.13 SD/year, 95% CI 0.07 to 0.20). DISCUSSION: Early-childhood growth, neonatal respiratory exposures and school-age spirometry patterns help stratify long-term pulmonary risk among preterm-born children referred for pulmonary care.