Birthweight and Preterm Birth in Relation to Indicators of Childhood Asthma

Kitaw Demissie,Pierre Ernst,Lawrence Joseph,Margaret R Becklake

doi:10.1155/1997/872149

Abstract

BACKGROUND: Early life events may have long term consequences on respiratory health including the risk of developing asthma.OBJECTIVE: To examine the independent roles of birthweight and preterm birth on childhood asthma after accounting for socioeconomic status.METHODS: A total of 989 elementary school children performed spirometry before and after a free-running exercise challenge. A subsample of 327 children underwent methacholine bronchoprovocation and allergy skin prick tests to common inhaled aeroallergens. Information on birthweight and preterm birth was obtained by parental interview. Socioeconomic status was established using parental occupation.RESULTS: After adjusting for the effects of important confounding variables, birthweight was positively associated with forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1); FVC increased 4.5% per kg (95% CI 1.7 to 7.4) and FEV14.4% per kg (95% CI 1.8 to 7.2). Birthweight was not related to exercise-induced bronchospasm or an asthma diagnosis, but airway responsiveness to methacholine increased as birthweight decreased (P=0.01). Preterm birth independent of birthweight was associated with a lower FEV1/FVC (-1.7%; 95% CI -2.8 to -0.5).CONCLUSIONS: Birthweight appears to be related to lung size and methacholine responsiveness while preterm birth appears to diminish airway size.

Highlights

Life events may have long term consequences on respiratory health including the risk of developing asthma
STATISTICAL METHODS The outcome variables in this analysis were lung function, exercise-induced bronchospasm (EIB), a history of asthma, airway responsiveness to methacholine, allergy skin test positivity and EIB or a history of asthma combined
Among children with EIB or a history of asthma (Table 2), nonparticipants were more likely to be Caucasian, have mothers or fathers who smoke or mothers who had smoked during pregnancy

Summary

Introduction

Life events may have long term consequences on respiratory health including the risk of developing asthma. OBJECTIVE: To examine the independent roles of birthweight and preterm birth on childhood asthma after accounting for socioeconomic status. METHODS: A total of 989 elementary school children performed spirometry before and after a free-running exercise challenge. A subsample of 327 children underwent methacholine bronchoprovocation and allergy skin prick tests to common inhaled aeroallergens. Information on birthweight and preterm birth was obtained by parental interview. Socioeconomic status was established using parental occupation. Birthweight was not related to exercise-induced bronchospasm or an asthma diagnosis, but airway responsiveness to methacholine increased as birthweight decreased (P=0.01). Preterm birth independent of birthweight was associated with a lower FEV1/FVC (–1.7%; 95% CI –2.8 to –0.5). CONCLUSIONS: Birthweight appears to be related to lung size and methacholine responsiveness while preterm birth appears to diminish airway size

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Results

Conclusion