Early influences on adult lung function in two national British cohorts

Abstract

OBJECTIVES: To compare adult lung function in two national British cohorts, born in 1946 and 1958, in relation to birth weight, postnatal growth and early air-pollution exposure. DESIGN AND SETTING: Persons born in England, Scotland and Wales during 1 week in March 1946 and in 1958 and followed from childhood into adult life. MAIN OUTCOME MEASURES: Forced expiratory volume in 1 sec (FEV(1)) and forced vital capacity (FVC), measured at age 43 years on subjects born in 1946 (n = 2167) and age 44-45 years on subjects born in 1958 (n = 5947). Spirometric indices were adjusted for gender, adult standing height, smoking history and socioeconomic position in childhood, and analysed in relation to birth weight, growth pattern and area of birth, classified into four groups of differing exposure to domestic coal smoke pollution. RESULTS: Within each cohort, FEV(1) and FVC were positively associated with birth weight and proportional sitting height independent of adult height. Pooling results for both cohorts, the mutually adjusted increment in FEV(1) per 1SD increment was 30 ml (95% CI 16 to 45) for birth weight and 19 ml (95% CI 5 to 33) for proportional sitting height. The proportion of adult height attained by age 7 years and early air-pollution exposure were unrelated to adult lung function. CONCLUSIONS: A small but significant influence of birth weight and trunk size on lung function is confirmed, but neither differences in prenatal and postnatal growth nor differences in childhood air-pollution exposure are likely explanations of the differences in spirometric performance between British adults born in 1946 and 1958.