Table 1.

Studies addressing the impact of early life insults on development of chronic obstructive pulmonary disease in adulthood

Author(s)	Objective	Design	Subjects	Methods	Results	Conclusion
De Sario et al17	Risk factors for development of different types of wheeze in children	Cross-sectional study	2,107 schoolchildren	Questionnaires on respiratory history and status and allergies Spirometry Skin prick test	Exposure to parental smoking was positively associated to persistent wheezing	Parental smoking predisposes children for wheeze development
Perret et al18	Whether early life exposure to tobacco smoke leads to obstructive lung disease in middle age	Prospective cohort study	8,583 schoolchildren born in 1961	1968: spirometry 2006–2008: spirometry again	Post-BD airflow obstruction detected for 9.3% (n=123)	Heavy parental smoking predisposes to obstructive lung disease
Beyer et al20	Long-term effects of secondhand smoke in children.	Retrospective cohort study	291 COPD patients.	Questionnaires on personal and parental smoking status	COPD patients from smoking mothers had lower FEV1	Maternal smoking leads to decreased lung function
Svanes et al21	Parental smoking in childhood and the association with adult offspring obstructive lung disease	Retrospective cohort study	18,922 subjects aged 20–44	Questionnaires on parental smoking and childhood wheeze Spirometry	Both parents smoking indicated higher risk of wheeze	Early exposure to parental smoking lead to premature respiratory symptoms in adulthood
Jaakkola et al22	The impact of prenatal exposure on childhood respiratory health	Cross-sectional study	5,951 children	Questionnaires on children’s respiratory health and tobacco smoke exposure	In utero smoke exposure was associated with increases in chronic respiratory symptoms in childhood	In utero exposure leads to diminished childhood respiratory health
Tai et al7	Non-reversible airway obstruction in adulthood in subjects with severe asthma in childhood	Prospective cohort study	375 children	Questionnaires on respiratory health Spirometry	Children, who had had severe asthma had 32 times higher risk for COPD in adulthood	Impaired lung function in childhood leads to obstructive lung disease in adulthood
Marossy et al23	Whether childhood chest illness leads to lung function decline from age 35 to 45	Prospective cohort study	1,156 subjects	Age 35: spirometry Age 45: spirometry again	The rate of lung function decline was not significantly associated with pneumonia	Childhood chest illness does not lead to lung function decline from age 35 to 45
Hayden et al24	The correlation between childhood pneumonia and COPD in adult smokers	Case–control study	10,192 exsmokers and smokers	Questionnaires on childhood pneumonia Spirometry	Childhood pneumonia was associated with COPD, chronic bronchitis, increased COPD exacerbations, and lower lung function	Childhood pneumonia is suggested to be some of the cause for COPD
Tagiyeva et al25	Whether childhood wheezy bronchitis increases the risk of COPD development	Prospective cohort study	2,511 children	Spirometry in childhood and adulthood	Childhood wheezy bronchitis and childhood asthma was associated with a reduced ventilator function	Childhood respiratory diseases are connected to an increased risk of COPD development
Shirtcliffe et al9	The potential association between childhood respiratory diseases and COPD	Retrospective cohort study	1,017 subjects	Questionnaires on adult and childhood respiratory health Spirometry	COPD was more likely to develop when childhood asthma had occurred	There is a connection between childhood respiratory diseases and COPD
Berry et al26	Whether failure to reach maximum lung function capacity in early life may predispose subjects for COPD	Prospective cohort study	1,246 subjects followed from the age of 11 until the age of 32 years	Questionnaires on demographics, parental asthma, and parental smoking Radiographic imaging on pneumonia in childhood Spirometry at five survey visits	Subjects with a persistently low lung function (the class with the low trajectory) had more cases of RSV in early life	Respiratory infections in early life decrease lung function later in life. The link to chronic airflow obstruction is uncertain
Lovasi et al27	Impact of ETS on alveolar walls in early life	Retrospective cohort study	396 nonsmokers	Questionnaires on ETS and parental smoking CT scans	Childhood ETS was associated with higher incidence of emphysema	ETS in childhood is suggested as a predisposition for the development of obstructive lung disease in adulthood
Johannessen et al8	The association between COPD and childhood ETS	Case–control study	758 (433 with COPD and 325 controls)	Spirometry Questionnaires on exposure to ETS in childhood	Women with exposure to tobacco smoke in childhood had significantly higher risk for the development of COPD. Family history of COPD was also significantly associated with COPD	Women are more susceptible to ETS
Allinson et al29	Whether personal smoking behaviour across life may contribute to the impact of early life exposures and further decrease lung function	Prospective cohort study	2,172 individuals followed since birth	Interviews by research nurses Prebronchodilator spirometer to assess lung function Questionnaires on early life exposure and smoking behavior	FEV1 deficits were present among ever smokers associated with infant lower respiratory infections, which were not evident among never smokers	Lung function decrease in early life persists into adulthood
Broström et al30	Low birth weight and its connection to obstructive airway disease in adulthood was investigated	Prospective cohort study	6,425 subjects born in 1925 and 1949	Clinical examination to determine weight of subjects Hospital discharge register and cause of death register were used to identify diagnoses on COPD and asthma	Women born <32 weeks of gestation had higher risk for obstructive airways disease development. Low birth weight had no association with obstructive airway disease in men	Low birth weight and preterm birth predisposes to obstructive airways disease development in adulthood
Barker et al31	The association between chronic obstructive airway disease and men born with low birth weight	Prospective cohort study	6,534 men	Information on birth weight was preserved through many years Spirometry	A low birth weight of an individual indicated a low FEV1 at age 59–70	Low birth is most likely associated to chronic obstructive airway disease development in adulthood

Abbreviations: COPD, chronic obstructive pulmonary disease; FEV₁, forced expiratory volume in one second; ETS, environmental tobacco smoke; post-BD, postbronchodilator; RSV, respiratory syncytial virus.