Lung function in preterm infants at 3 months corrected age after neonatal LC-PUFA supplementation

Abstract

Objective: To test the hypothesis that long-chain polyunsaturated fatty acid (LC-PUFA) supplementation improves lung function at 3 months corrected age (CA) compared with standard treatment in very preterm infants. We also aimed to investigate the association between bronchopulmonary dysplasia (BPD), longitudinal growth, and lung function at 3 months CA. Methods: A secondary analysis from the ImNuT trial, in which 121 infants with gestational age <29 weeks were randomized to a daily supplement with arachidonic acid (ARA) and docosahexaenoic acid (DHA) (ARA:DHA group) or MCT-oil (control group) from birth up to 36 weeks postmenstrual age (PMA). Lung function was assessed at 3 months CA by tidal flow volume loops and the outcomes were the ratio of time to peak tidal expiratory flow to expiratory time (tPTEF/tE) and tidal volume (VT) per body weight (mL/kg). Results: Thirty-nine infants in the ARA:DHA group versus 51 in the control group had a successful lung function test. There was no mean difference (MD) in tPTEF/tE ratio (MD: 0.01, 95% confidence interval [CI]: −0.04 to 0.05; p =.77) or VT (MD: 0.09 mL/kg, 95% CI: –0.79 to 0.62; p =.81) between the study groups. The multivariable regression model showed that BPD was associated with tPTEF/tE ratio ≤ 0.25 (p =.03) and that an increase in z score for length after 36 weeks PMA correlated positively with VT (mL/kg) (p =.03). Conclusion: Neonatal LC-PUFA supplementation did not improve lung function at 3 months CA in very preterm infants. BPD was independently associated with reduced lung function, while improved linear growth correlated with higher tidal volumes.