Airway obstruction in young adults born extremely preterm or extremely low birth weight in the postsurfactant era. Issue 12 (26th September 2019) - Doyle, Lex William
Abstract : Background: It is unknown if adults born <28 weeks or <1000 g since surfactant has been available are reaching their full airway growth potential. Objective: To compare expiratory airflow at 25 years and from 8 to 25 years of participants born <28 weeks or <1000 g with controls, and within the preterm group to compare those who had bronchopulmonary dysplasia with those who did not. Methods: All survivors born <28 weeks or <1000 g in 1991–1992 in Victoria, Australia, were eligible. Controls were born contemporaneously, weighing >2499 g. At 8, 18 and 25 years, expiratory airflows were measured and the results converted to z-scores. Outcomes were compared between groups at age 25 years, and trajectories (change in z-scores per year) from childhood were contrasted between groups. Results: Expiratory airflows were measured at 25 years on 164 of 297 (55%) preterm survivors and 130 of 260 (50%) controls. Preterm participants had substantially reduced airflow compared with controls at age 25 years (eg, zFEV1 ; mean difference −0.97, 95% CI −1.23 to –0.71; p<0.001). Preterm participants had lower airflow trajectories than controls between 8 and 18 years, but not between 18 and 25 years. Within the preterm group, those who had bronchopulmonary dysplasia had worse airflows and trajectories than those who did not. Conclusions: Young adults born <28 weeks or <1000 g in the surfactant era, particularly those who had bronchopulmonary dysplasia, have substantially reduced airway function compared with controls. Some are destined to develop COPD in later adult life.