Predictors of lung function in early adulthood: A population‐based cohort study

Abstract Background and Objective Lung function reaches a peak/plateau in early adulthood before declining with age. Lower early adult lung function may increase the risk for chronic obstructive pulmonary disease (COPD) in mid‐late adult life. Understanding the effects of multiple childhood/adolescent exposures and their potential interactions on plateau lung function would provide insights into the natural history of COPD. Methods Longitudinal spirometry data from 688 participants with complete data from a population‐based birth cohort (original n = 1037) were used to investigate associations between a wide range of childhood/adolescent exposures and repeated measures of FEV 1 , FVC and FEV 1 /FVC during the early‐adult plateau phase. Generalized estimating equations were used to accommodate the multiple timepoints per participant. Results FEV 1 reached a peak/plateau between ages 18 and 26 and FVC from 21 to 32 years, whereas FEV 1 /FVC declined throughout early adulthood. Childhood asthma and airway hyperresponsiveness were associated with lower early adult FEV 1 and FEV 1 /FVC. Smoking by age 18 was associated with lower FEV 1 /FVC. Higher BMI during early adulthood was associated with lower FEV 1 and FVC and lower FEV 1 /FVC. Physical activity during adolescence was positively associated with FEV 1 and FEV 1 /FVC but this was only statistically significant in men. There was no convincing evidence of interactions between exposures. Conclusion Childhood asthma and airway hyperresponsiveness are associated with lower lung function in early adulthood. Interventions targeting these may reduce the risk of COPD in mid‐late adult life. Promotion of physical activity during adolescence, prevention of cigarette smoking and maintenance of a healthy body weight in early adulthood are also priorities.