Lower prevalence of asthma and atopy in Turkish children living in Germany

Ethnic origin has been reported to affect the prevalence of atopic diseases in several studies in different parts of the world. However, little is kno wn about the prevalence of asthma and atopy in immigrants living in Europe. The objective of this study was to evaluate the prevalence of asthma and a topy in Turkish children living in Germany and to investigate the role of e thnic origin on the development of asthma and atopy in this population. In a cross-sectional survey the prevalence of physician-diagnosed asthma, a topy, skin-prick tests and bronchial hyperresponsiveness (BHR) to cold dry air challenge was assessed in 7,445 school children aged 9-11 yrs, living i n Munich, south Germany. Questionnaires were distributed to the parents for self-completion and children underwent skin prick tests and cold air hyper ventilation challenge. The Turkish children showed a significantly lower prevalence of asthma (5.3 versus 9.4%, p<0.05) than their German peers. Furthermore, atopy, as asses sed by skin prick tests (24.7 vet sus 36.7%, p<0.001) and BHR (3.9 versus 7 .7%, p<0.001), was less common in Turkish children. In multivariate regress ion models controlling for potential explanatory factors, Turkish origin st ill showed a significantly lower risk of developing asthma, atopic sensitiz ation and BHR. The prevalence of childhood asthma was therefore shown to be lower in Turki sh children living in Germany than in Turkey. These findings suggest that t he lower prevalence of asthma and allergy in Turkish children living in Ger many might be attributable to a selection bias affecting the parents of the se children, as healthy individuals may have decided to come to Germany for work.