ATOPY - A PREDISPOSING FACTOR FOR CHRONIC-BRONCHITIS IN FINLAND

Study objective - To investigate the predictive value of atopy, smokin g, and Living in a farm environment in the development of chronic bron chitis. Design - This was a cross sectional and longitudinal study. Se tting - Postal surveys carried out in Finland in 1975 and 1981. Partic ipants - The study was part of the Finnish twin cohort study, which in cluded adult twin pairs born in Finland before 1958. The cross section al sample consisted of 18 351 subjects, including 1025 prevalent cases , and the follow up sample comprised 17 134 subjects, 553 of whom were incident cases of chronic bronchitis. Main results - According to the cross sectional data, chronic bronchitis was associated with atopy (r elative risk 1.41) and smoking (2.43). In the follow up data, chronic bronchitis was related to atopy (1.28), smoking (2.31), and farming (1 .45). Conclusions - The results confirm the earlier finding in the Fin nish farming population that, in addition to smoking, atopy predispose s the development of chronic bronchitis. A farm environment was also f ound to be a predisposing factor, The results give further support to the ''Dutch hypothesis'' on the aetiology of chronic bronchitis, accor ding to which atopy is a predisposing factor.