Higher risk of wheeze in female than male smokers. Results from the Swedish GA 2 LEN study.

BackgroundWomen who smoke have higher risk of lung function impairment, COPD and lung cancer than smoking men. An influence of sex hormones has been demonstrated, but the mechanisms are unclear and the associations often subject to confounding. This was a study of wheeze in relation to smoking and sex with adjustment for important confounders.MethodsIn 2008 the Global Allergy and Asthma European Network (GA(2)LEN) questionnaire was mailed to 45.000 Swedes (age 16-75 years), and 26.851 (60%) participated. "Any wheeze": any wheeze during the last 12 months. "Asthmatic wheeze": wheeze with breathlessness apart from colds.ResultsAny wheeze and asthmatic wheeze was reported by 17.3% and 7.1% of women, vs. 15.8% and 6.1% of men (both pDiscussionIn addition to the increased risk of COPD and lung cancer female, compared to male, smokers are at greater risk of significant wheezing symptoms in younger age. This became clearer after adjustment for important confounders including cumulative smoke exposure. Estrogen has previously been shown to increase the bioactivation of several compounds in tobacco smoke, which may enhance smoke-induced airway inflammation in fertile women.