title: Impact of ethnicity and extreme prematurity on infant pulmonary function.
abstract: The impact of birth before 27 completed weeks of gestation on infant pulmonary function (PF) was explored in a multi-ethnic population in comparison to more mature preterm controls (PTC) and healthy fullterm infants. Plethysmographic lung volume (FRCpleth ) and forced expired volume (FEV0.5 ) were obtained at ∼12 months post-term age in 52 extremely preterm (EP) infants (median [range] gestational age [GA]: 26 [23-27] weeks; 40% White mothers; 79% with BPD), 41 PTC (GA:35 [30-36] weeks; 37% White mothers) and 95 fullterm infants (GA:40 [37-42] weeks; 86% White mothers). Using reference equations based on identical equipment and techniques, results were expressed as z-scores to adjust for age, sex and body size. FEV0.5 was significantly lower in EP infants when compared with PTC (mean difference [95% CI]: -1.02[-1.60; -0.44] z-scores, P < 0.001), as was forced vital capacity (FVC) but there were no significant differences in FRCpleth or FEV0.5 /FVC ratio. FEV0.5 , FVC, and FEV0.5 /FVC were significantly lower in both preterm groups when compared with fullterm controls. On multivariable analyses of the combined preterm dataset: FEV0.5 at ∼1 year was 0.11 [0.05; 0.17] z-scores higher/week GA, and 1.28 (0.49; 2.08) z-scores lower in EP infants with prior BPD. Among non-white preterm infants, FEV0.5 was 0.70 (0.17; 1.24) z-scores lower, with similar reductions in FVC, such that there were no ethnic differences in FEV0.5 /FVC. Similar ethnic differences were observed among fullterm infants. These results confirm the negative impact of preterm birth on subsequent lung development, especially following a diagnosis of BPD, and emphasize the importance of taking ethnic background into account when interpreting results during infancy as in older subjects.
authors.affiliation: Portex Respiratory Unit, UCL Institute of Child Health, London, WC1N 1EH, UK; Paediatric Respiratory Medicine Unit, Great Ormond Street Hospital for Children NHS Foundation Trust, London, WC1N 3JH, UK.
authors.forename: Ah-Fong
authors.initials: AF
authors.lastname: Hoo
authors.forename: Amit
authors.initials: A
authors.lastname: Gupta
authors.forename: Sooky
authors.initials: S
authors.lastname: Lum
authors.forename: Kate L
authors.initials: KL
authors.lastname: Costeloe
authors.forename: Angela
authors.initials: A
authors.lastname: Huertas-Ceballos
authors.forename: Neil
authors.initials: N
authors.lastname: Marlow
authors.forename: Janet
authors.initials: J
authors.lastname: Stocks
mesh_terms: D044383:Black People; D001997:Bronchopulmonary Dysplasia / Q000208:ethnology / Q000503:physiopathology; D016022:Case-Control Studies; D005260:Female; D005541:Forced Expiratory Volume; D005865:Gestational Age; D006801:Humans; D007223:Infant; D062071:Infant, Extremely Premature / Q000502:physiology*; D007231:Infant, Newborn; D008131:London; D008168:Lung / Q000503:physiopathology*; D008297:Male; D015999:Multivariate Analysis; D010991:Plethysmography; D014797:Vital Capacity; D044465:White People
keywords: ethnic background; extremely preterm; lung function tests; plethysmography; raised volume technique