Abstract
Rationale: Childhood respiratory illness may impact initiation of smoking in adolescence.
Methods: We determined the prevalences of asthma, wheeze, atopy and airway hyperresponsiveness in an unselected birth cohort of 1037 New Zealand children followed for two decades, and the impact of these characteristics on initiation of smoking.
Results: Current asthma was reported by 7.6%, 11.6%, 12.9%, 14.3%, 14.6%, 16.0%, and 19.0% of the cohort at age 9, 11, 13, 15, 18, 21 and 26 years respectively. The prevalence of airway hyperresponsiveness (PC20 8mg/ml or post-bronchodilator increase in FEV1 10%) decreased from 17.0% at age 9 to 8.4% at age 21 when last measured. Atopy was more common in males than females at age 13 (60% versus 40%; p<0.0001), but not at age 21 (53% versus 47%; p=0.19). At age 26, smoking for at least 1 year was reported by 46% of males and 50% of females; 35% and 37% were current smokers. There were no significant differences in the rates of initiation of smoking related to any marker of childhood respiratory illness or atopy.
Conclusions: A past or present history of asthma or wheezing illness, or evidence of atopy or airway responsiveness did not influence the likelihood of initiation of smoking in this cohort.