Lung Function in Very Low Birth Weight Adults.

BACKGROUND AND OBJECTIVES: Lung function attained in young adulthood is 1 of the strongest predictors of obstructive airways disease in later life. Adults born preterm at very low birth weight (VLBW; <1500 g) who have experienced bronchopulmonary dysplasia (BPD) have reduced lung function. We studied the association of lung function in young adulthood with preterm birth at VLBW and with BPD and other prenatal and neonatal conditions.

METHODS: We performed spirometry for 160 VLBW subjects (29 with BPD according to Northway criteria) aged 18 to 27 years and 162 term control subjects group-matched for gender, age, and birth hospital. Lung function was expressed as z scores according to the Global Lung Function Initiative standards.

RESULTS: Forced expiratory volume in 1 second z score was 1.41 units (95% confidence interval [CI]: 0.89 to 1.94) lower in BPD-VLBW subjects and 0.39 units (95% CI: 0.08 to 0.69) in non-BPD VLBW subjects compared with control subjects. Corresponding differences for forced expiratory volume in 1 second/forced vital capacity were 1.52 (95% CI: 0.99 to 2.05) and 0.51 (95% CI: 0.21 to 0.81), respectively. Maternal smoking in pregnancy predicted poorer airflow in all groups; this finding was strongest in the BPD-VLBW group. Lung function was unrelated to fetal or postnatal growth or to neonatal respiratory distress syndrome.

CONCLUSIONS: Young adults born at VLBW have reduced airflow. The outcome is stronger in those who have a history of BPD but is present among those with no such history. This finding suggests an increased risk of later obstructive airways disease in adults born at VLBW.