The impact of birth weight on peak lung function in young adults
Sadasivam Suresh1, Abdullah A Mamun2, Michael O'Callaghan3
1School of Population Health, Queensland; Queensland Children's Medical Research Institute, Queensland; Department of Paediatric Respiratory and Sleep Medicine, Mater Children's Hospital, Brisbane, QLD, Australia.
Insights
Higher birth weight is linked to better adult lung function. This longitudinal study of 2,368 young adults found significant associations between birth weight and lung function (forced vital capacity and forced expiratory volume in 1 second) at age 21.
Area of Science:
- Pulmonary Medicine
- Developmental Pediatrics
- Epidemiology
Background:
- Poor fetal growth, indicated by low birth weight, is linked to reduced childhood respiratory function.
- Existing research on the association between birth weight and adult lung function is inconsistent.
- Longitudinal birth cohorts offer a valuable design to investigate this relationship over time.
Purpose of the Study:
- To examine the long-term association between birth weight and adult lung function.
- To determine if birth weight predicts respiratory function in early adulthood.
Main Methods:
- Utilized data from the Mater-University of Queensland Study of Pregnancy, a longitudinal birth cohort.
- Collected prospective data from 2,368 young adults assessed at 21 years old using standard spirometry.
- Analyzed birth weight and other pregnancy-related variables (placental weight, parental height, maternal lifestyle factors) against adult lung function using univariate and multivariate analyses.
Main Results:
- Each 100g increase in birth weight correlated with a significant increase in forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) at age 21 in both men and women.
- These associations persisted after adjusting for maternal lifestyle factors during pregnancy, current smoking, and parental height.
- Further adjustment for adult height attenuated the association, with FEV1 remaining significant but FVC showing non-significant trends.
Conclusions:
- This longitudinal cohort study confirms robust links between birth weight and adult lung function at age 21.
- The findings suggest that birth weight is a significant determinant of respiratory health in early adulthood.
- Discrepancies in effect size estimates in prior literature may be influenced by the age of assessment in different studies.
Background:
Poor fetal growth rate, as indicated by lower birth weight, is associated with lower respiratory function in childhood; however, findings in adult life remain inconsistent. A birth cohort provides the opportunity to study the association between birth weight and adult respiratory function.
Methods:
The present study data are from a longitudinal birth cohort, the Mater-University of Queensland Study of Pregnancy. Prospective data were available from 2,368 young adults who underwent standard spirometry when 21 years old. Pregnancy and birth-related variables collected were birth weight, placental weight, parental height, maternal educational status, maternal smoking history in pregnancy, and maternal history of alcohol, tea, and coffee consumption during pregnancy. The impact of birth weight on adult lung function was assessed using univariate and multivariate analyses.
Results:
For every 100-g increase in birth weight, FVC (95% CI) at 21 years increased by 24 mL (15-32) in men and 20 mL (13-27) in women, and the increase in FEV1 (CI) was 22 mL (15-30) and 16 mL (11-22), respectively. These associations remain after adjusting for lifestyle factors during pregnancy, current smoking, and parental height. However, further adjustment for adult height reduces the strength of association and remains significant for FEV1: 8 mL (1-14) in men and 5 mL (1-10) in women, but not for FVC: 7 mL (-1-14) in men and 5 mL (-1-11) in women.
Conclusion:
Our longitudinal cohort study provides evidence of robust links between birth weight and adult lung function at the age of 21 years. Various estimates of the effect size in the literature may be related to the age at assessment.
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