Lung function and pulmonary vascular resistance are not associated in 6-year-old children born extremely preterm

Acta Paediatr. 2020 Apr;109(4):746-753. doi: 10.1111/apa.15030. Epub 2019 Oct 10.

Abstract

Aim: Children born preterm are at increased risk of reduced lung function. The aim was to test whether lung function was associated with pulmonary vascular resistance.

Methods: Participants were recruited from a population-based cohort born in 2004-2007. Lung function was assessed with spirometry after administration of a beta2-agonist. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1 ) were determined. Estimations of pulmonary vascular resistance, arterial dimensions, right ventricular wall thickness, sphericity, and systolic (TAPSE) and diastolic functions were performed with echocardiography. Adjusted regression analyses were used to study associations.

Results: Sixty-six children (33 boys) born at 22-26 weeks of gestational age (birthweights 460-1134 g) were assessed at a mean age of 6.7 years. Despite large variations in lung function with FVC z-scores ranging from -4.6 to +2.8, there were no associations between lung function and pulmonary arterial pressure, right ventricular structure or function. Children with higher FVC z-scores (r = .52, β = .55 mm, P = .015) and higher FEV1 z-scores (r = .58, β = .73 mm, P = .001) exhibited larger pulmonary arteries.

Conclusion: In children born extremely preterm, lung function was not associated with pulmonary vascular resistance. Routine echocardiographic evaluation of extremely preterm children may not be indicated at age 6.5 years.

Keywords: echocardiography; extremely preterm; lung function; pulmonary circulation; right heart function.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Child
  • Female
  • Forced Expiratory Volume
  • Humans
  • Infant, Extremely Premature*
  • Infant, Newborn
  • Lung* / diagnostic imaging
  • Male
  • Pregnancy
  • Spirometry
  • Vascular Resistance
  • Vital Capacity