The impact of pre- and post-natal smoke exposure on future asthma and bronchial hyper-responsiveness.
OBJECTIVE
To analyse the impact of pre- and post-natal smoke exposure on asthma presence, bronchial hyper-responsiveness, airway function and active smoking in early adulthood.


METHODS
We have prospectively studied 101 children hospitalized due to wheezing before the age of 2 years. The cohort was re-investigated at age 17-20 years and tested for airway function and bronchial hyper-responsiveness. Data on maternal smoking during pregnancy were obtained from the Swedish Medical Birth Register.


RESULTS
There was a significant, independent correlation between both pre- and post-natal smoke exposure and asthma at age 17-20 years, OR 3.5 (1.1-11.3) and 3.4 (1.2-10.1), respectively. Maternal smoking during pregnancy was an independent risk factor for current bronchial hyper-responsiveness, OR 6.6 (1.2-35.5). Pre-natal smoke exposure seemed to negatively affect small airway function in early adulthood due to structural changes. Post-natal smoke exposure was independently associated with an increased risk of current smoking, OR 7.4 (1.6-35.2).


CONCLUSIONS
In subjects hospitalized due to early wheezing, pre- and post-natal smoke exposure increase the risk of asthma in early adulthood. The connection between pre-natal smoke exposure and asthma appears to be mediated via the development of bronchial hyper-responsiveness. Smoke exposure in infancy is associated with an increased risk of active smoking in early adult age, which is in turn linked to current asthma.
Goksör
Emma
E
Department of Paediatrics, Göteborg University, Queen Silvia Children's Hospital, Göteborg, Sweden.
Amark
Mainor
M
Alm
Bernt
B
Gustafsson
Per M
PM
Wennergren
Göran
G
D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D016535:Bronchial Hyperreactivity / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015999:Multivariate Analysis; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology*; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology*; D013548:Sweden / Q000453:epidemiology; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
D014028:Tobacco Smoke Pollution