The risk factors for chronic obstructive pulmonary disease in Li and Han ethnic groups in Hainan, China

Objective: To investigate the risk factors of chronic obstructive pulmonary disease(COPD) in Li and Han ethnic group in Hainan, China. Methods: All subjects were randomly selected from various regions in Hainan. General characteristics were compared between COPD cases and healthy control cases in both Li and Han ethnic groups. The odds ratio(OR), the corresponding 95% confidence interval(CI) of COPD were calculated by logistic regression.Results: A total of 277 Li COPD cases, 307 Li healthy control subjects, 290 Han COPD cases and 301 Han healthy control were included in this study. In both the Li and Han groups, the average age exceeded 65 years, and the cigarette number smoked per day and the smoking duration were correlated with risk of COPD. In the Li COPD subjects, low weight, smoking, and recurrent infection of respiratory tract were mainly risk factors; while the mainly risk factor of Han COPD subjects was family history of respiratory disease. Conclusions: The risk factors are different in COPD subjects of Han and Li nationalities in Hainan of China. The age and smoking are strongly correlated with COPD risk.