The association between birthweight and adult lung function: insights from the UK Biobank

The potential association between birthweight and adult lung function has been postulated, yet the precise nature of this association in later life remains inconclusive. The analysis included 201,615 individuals from the UK Biobank dataset. To identify birthweight subgroups differences in lung function, propensity score matching and a pairwise t-test were conducted. The association between birthweight and lung function was assessed using a linear regression, gradually adjusting for variables. 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 low birthweight group demonstrated significantly lower forced expiratory volume in 1 s (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. A positive linear correlation between birthweight and lung function was observed within each interval. In the adequate birthweight group, every 1 Kg increase in birthweight was found to be significantly associated with a mean increase in FEV1 of 70.9 mL in males and 56.0 mL in females. Additionally, there was a significant increase in FVC of 86.7 mL in males and 62.2 mL in females. Macrosomia group demonstrated a more pronounced decrease in lung function, in contrast to the adequate birthweight group which exhibited a similar decline pattern to the low birthweight group. Our study suggests an association between optimal birthweight and later-life respiratory health, as observed through stringent statistical analysis.