The Influence of Birthweight on Adult Lung Function: Insights from the UK Biobank

Abstract The potential impact of birthweight on adult lung function has been postulated, yet the precise nature of this association in later life remains inconclusive. This study involved extracting data from a total of 201,615 individuals from the UK Biobank dataset. To identify group differences in lung function based on birthweight subgroups, propensity score matching and a pairwise t-test were conducted. The impact of birthweight on lung function was established using a linear regression, gradually adjusting for variables. Additionally, subgroup analyses were conducted to investigate whether the relationship between birthweight and lung function was modified by variations in age-related lung function changes. The modifying effect was examined by adding a multiplicative interaction term. The low birthweight group demonstrated significantly lower forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) in comparison to those in the adequate birthweight group (P < 0.001). Conversely, no statistically significant distinction was observed in macrosomia (P = 0.374 for FEV1; P = 0.911 for FVC). A positive linear correlation between birthweight and lung function was observed within each interval, specifically in the subgroup of individuals with a birthweight ranging from 2.5 to 4 Kg. After accounting for various confounding factors, every 1 Kg increase in birthweight was found to be significantly associated with a mean increase in FEV1 of 70.9 mL (95% CI 63.7 to 78.1, P < 0.001) in males and 56.0 mL (95% CI 52.1 to 59.9, P < 0.001) in females. Additionally, there was a significant increase in FVC of 86.7 mL (95% CI 78.3 to 95.1, P < 0.001) in males and 62.2 mL (95% CI 57.5 to 66.9, P < 0.001) in females. Additionally, macrosomia group demonstrated a more pronounced decrease in lung function over time, in contrast to the low birthweight group which exhibited a similar decline pattern to the adequate birthweight group. The utilization of a rigorous statistical methodology has enabled us to derive reliable results, indicating that attaining an optimal birthweight is of utmost importance in determining respiratory health.