Association between birth weight and chronic obstructive pulmonary disease in the UK Biobank: a prospective cohort study

Abstract

Background Birth weight has been reported to be associated with chronic obstructive pulmonary disease (COPD) in adulthood, but the results have not yet been determined. This study aims to analyse the potential association of birth weight with COPD risk in UK Biobank.Methods We conducted a prospective analysis for participants without baseline COPD in UK Biobank. The HRs and 95% CIs were calculated by multivariable Cox regression models, and dose-response relationship was evaluated by restricted cubic splines. Besides, we also calculated the interactions for covariates and further analysed the joint effects.Results A total of 251 172 participants with birth weight data were included in this study, and 5602 COPD cases were found during follow-up. According to Cox regression models, participants with the lowest quintile of birth weight (< 2.86 kg) had higher risk for COPD (HR=1.21, 95% CI 1.11 to 1.32). In addition, the dose‒response analysis showed a non-linear relationship between birth weight and COPD risk, which first decreased and then increased, and the interactions for age, passive smoking and maternal smoking were also found by stratified analysis. Furthermore, we also found the joint effects between COPD risk and maternal smoking in the lowest quintile group.Conclusions This study indicated that lower birth weight may increase the risk of COPD. The non-linear associations between birth weight and COPD risk for prospective cohort; as birth weight increased, the risk showed a trend of decreasing first and then increasing. Moreover, maternal smoking had a joint effect with low birth weight for COPD risk.