Prevalence of asthma in a large group of Israeli adolescents: influence of country of birth and age at migration

• Published in: Allergy (Copenhagen) 2008-08, Vol.63 (8), p.1040-1045
• Main Authors: Pereg, D, Tirosh, A, Lishner, M, Goldberg, A, Shochat, T, Confino-Cohen, R
• Format: Article
• Language: English
• Subjects: Adolescent; Age differences; Age Factors; Asthma; Asthma - epidemiology; Asthma - genetics; Biological and medical sciences; Comparative studies; Dermatology; Emigration and Immigration; Environment; environmental effect; Female; Fundamental and applied biological sciences. Psychology; Fundamental immunology; genetic effect; Genetic Predisposition to Disease; Humans; immigrants; immigration; Israel; Male; Medical sciences; native-born Israelis; Noncitizens; Prevalence; Risk Factors; Sarcoidosis. Granulomatous diseases of unproved etiology. Connective tissue diseases. Elastic tissue diseases. Vasculitis; Teenagers
• ISSN: 0105-4538; 1398-9995
• DOI: 10.1111/j.1398-9995.2008.01661.x

The occurrence of asthma has geographic variations and is lower in developing compared with industrialized countries. Both environmental and genetic factors may influence its prevalence. We aimed to evaluate the importance and effect of immigration (country of birth and age at immigration to Israel) on the prevalence of asthma in a large group of Israeli adolescents. Computerized medical records of 17-year-old adolescents, who underwent routine examination before military recruitment, were studied. The sample comprised both native-born Israelis (NBI) and immigrants from Ethiopia, the Former Soviet Union (FSU), and Western countries (WC). Asthma was defined as clinical symptoms and signs compatible with the disease accompanied by abnormal spirometry or documented chronic use of inhaled steroids. Our cohort consisted of 1 466 654 adolescents, including 1 317 556 (89.8%) NBI and 149 098 (10.2%) immigrants. The prevalence of asthma at age 17 was higher in NBI compared with Ethiopian immigrants [4.7% (61 921) vs 2.6% (418), respectively, P < 0.0005], lower compared with immigrants from WC [5.6% (2177), P < 0.0005], and similar to immigrants from the FSU. Further analysis of the association between age at immigration and the risk for developing asthma showed that the younger immigrants from the FSU and Ethiopia arrived to Israel, the higher their prevalence of asthma at the age of 17 was. Both environmental and genetic factors seem to influence the prevalence of asthma in 17-year-old adolescents. However, the higher risk for developing asthma associated with young age of immigration points toward an environmental predominance.