Pulmonary function and exercise capacity for ELBW survivors in preadolescence: effect of neonatal chronic lung disease.

To assess pulmonary function and exercise capacity of apparently asymptomatic children who were born extremely preterm. Pulmonary function and treadmill testing were performed on 50 children 9 to 15 years old who had birth weight <801 g (extremely low birth weight [ELBW]) and without apparent neurodevelopmental or pulmonary disabilities, compared with 25 children born at term with normal birth weight (NBW). Medical history and physical activity levels were assessed by parent questionnaire. Group differences were determined by two-sample t test. Secondary analysis was performed to assess significant influence of neonatal chronic lung disease (CLD) on outcome measures. Twenty percent of ELBW subjects but no subjects with NBW had clinically abnormal pulmonary function (>2 SD from norms, P=.026). All significant pulmonary function differences except peak expiratory flow rate percentages were accounted for by ELBW subjects who had CLD. Oxygen consumption measurements were significantly lower for subjects with ELBW (30.3+/-6.9 and 38.5+/-5.2 mL/kg/min, P=.000), independent of CLD status. Pulmonary function abnormalities consistent with obstructive lung disease were more frequently detected in ELBW children who had neonatal CLD. Low oxygen consumption measurements suggest a lower level of fitness for ELBW children compared with children with NBW.