Asthma and asthma-related symptoms in 16 789 Chinese children in relation to pet keeping and parental atopy.

■ Abstract Background: The relationship between exposure to animals and allergic respiratory diseases in childhood is controversial, and there is little information about how exposure to pets affects the respiratory health of Chinese children, who have lower rates of asthma. Objective: To study the association between exposure to pets and doctor-diagnosed asthma and asthma-related symptoms in Chinese children. We also investigated whether genetic propensity as a result of parental atopy modifi es these relations. Methods: A cross-sectional study of 16 789 children was conducted at 24 randomly selected kindergartens and 12 elementary schools in Liaoning province, China. Information on respiratory health and exposure to indoor allergens was obtained by a standard questionnaire from the American Thoracic Society. Results: In children, exposure to animals was associated with a diagnosis of asthma (adjusted odds ratio [OR], 1.49; 95% confi dence interval [CI], 1.30-1.70), wheezing (adjusted OR, 1.37; 95% CI, 1.18-1.60), persistent cough (adjusted OR, 1.71; 95% CI, 1.52-1.91), and persistent phlegm (adjusted OR, 2.26; 95% CI, 1.94-2.64). Parental atopy increased the risk of a diagnosis of asthma (adjusted OR, 3.12; 95% CI, 2.61-3.73) and asthma-related symptoms. There was an interaction between parental atopy and pet exposure in persistent cough and persistent phlegm, but not in doctor-diagnosed asthma. Conclusions: Pet keeping and parental atopy increased the risk of asthma and allergic respiratory diseases in children. Parental atopy modifi ed the effect of pet exposure in persistent cough and persistent phlegm but not in doctor-diagnosed asthma.