[Prevalence of respiratory and atopic disorders in Chinese school children].

OBJECTIVE: To compare the prevalence of respiratory and atopic disorders, and to assess the role of atopy in the development of asthma in Chinese school children from Beijing, Guangzhou, and Hong Kong.

METHODS: Community-based random samples of school children aged 9 approximately 11 years from three Chinese cities (Beijing, Guangzhou and Hong Kong) were recruited for study using the International Study of Asthma and Allergies in Childhood (ISAAC) Phase II protocol. Subjects were studied by parental questionnaires (n = 10 902), skin-prick tests and skin examination (n = 3 479).

RESULTS: The prevalence rates of current wheeze, speech limiting wheeze, rhinoconjunctivitis and flexural dermatitis were significantly higher in Hong Kong than in Beijing and Guangzhou. The atopy rate was also higher in Hong Kong (41.2%) than in Beijing (23.9%) and Guangzhou (30.8%). Atopy was strongly correlated with current wheeze (OR = 7.74; 95% CI = 5.70 approximately 10.51). Subgroup analyses of children from Hong Kong revealed that children born in mainland China who had subsequently migrated to Hong Kong had a significantly lower rate of allergic symptoms and atopy than those born in Hong Kong.

CONCLUSION: The prevalence of asthma, allergic diseases and atopy was highest in school children from Hong Kong. Atopic sensitizations is an important factor associated with asthma in Chinese children.