AUTHOR=Yang Meng , Mei Hong , Du Juan , Yu Linling , Hu Liqin , Xiao Han TITLE=Non-linear association of birth weight with lung function and risk of asthma: A population-based study JOURNAL=Frontiers in Public Health VOLUME=10 YEAR=2022 URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2022.999602 DOI=10.3389/fpubh.2022.999602 ISSN=2296-2565 ABSTRACT=Background

The impact of birth weight on lung function and risk of asthma remains contentious. Our aim was to investigate the specific association of birth weight with lung function and the risk of asthma in children.

Methods

We performed cross-sectional analyses of 3,295 children aged 6–15 years who participated in the 2007–2012 National Health and Nutrition Examination Survey (NHANES). After controlling for potential covariates other than gestational diabetes, maternal asthma and obesity, the linear and non-linear associations of birth weight with lung function metrics and the risk of asthma were evaluated by a generalized linear model and generalized additive model, respectively.

Results

We observed a non-linear association of birth weight with FEV1 %predicted, FEV1/FVC %predicted and FEF25 − 75 %predicted (P for non-linearity was 0.0069, 0.0057, and 0.0027, respectively). Further threshold effect analysis of birth weight on lung function detected the turning point for birth weight was 3.6 kg. When the birth weight was < 3.6 kg, birth weight was significantly positively associated with all pulmonary function metrics. However, negative associations were found in FEV1 %predicted, FEV1/FVC %predicted and FEF25 − 75 %predicted when the birth weight was ≥3.6 kg. These results were consistent in the stratified and sensitivity analyses. Additionally, a possible non-linear relationship was also detected between birth weight and the risk of asthma.

Conclusion

Although not all maternal factors were accounted for, our findings provided new insight into the association of birth weight with lung function. Future studies are warranted to confirm the present findings and understand the clinical significance.