Birth Weight and Lung Function in Adulthood: A Systematic Review and Meta-analysis
There is evidence suggesting that birth weight may influence lung function in adulthood, but it is unclear whether it might differentially affect restrictive (FVC) and obstructive (FEV1/FVC) patterns.Objectives:
To summarize evidence available on the association of birth weight, weight at 1 year, and weight gain in the first year of life with FVC and FEV1/FVC in adulthood.Methods:
We performed a systematic review of the literature by searching MEDLINE, EMBASE, and Web of Science through January 2015. Data were combined using inverse-variance weighted meta-analysis with random effects models and between-study heterogeneity evaluated. We conducted a priori subgroup or sensitivity analyses by age, country wealth, ethnicity, sex, and smoking. We evaluated risk of bias using the Newcastle Ottawa Scale and reporting bias using funnel plots.Results:
Eighteen articles were included in the review and 13 in the meta-analyses. Most studies were from high-income countries, and all had a low risk of bias. We found strong evidence of an association of birth weight with adult FVC, a 59.4 ml higher FVC in adulthood per kilogram increase in birth weight (95% confidence interval, 43.3-75.5), with no evidence of heterogeneity. Evidence of an association of birth weight with FEV1/FVC was weaker and showed some inconsistency across studies. Only one study investigated weight at 1 year, and another one reported weight gain in the first year.Conclusions:
Our meta-analyses show strong and consistent evidence of an association of birth weight with adult FVC, a measure of restrictive impairment, with much weaker evidence for airflow obstruction.