The risk factors for chronic obstructive pulmonary disease in Xinjiang rural areas

Objective To evaluate the risk factors for chronic obstructive pulmonary disease (COPD) in Xinjiang rural areas. Methods This was a population-based and cross-sectional survey on prevalence of COPD in Xinjiang from December 2007 to December 2010. The clusterrandomsampling method was performed to collect the data from 3575 people in rural areas in southern (mainly with the Uygur nationality and Han nationality) and northern (mainly with Hazakh nationality and Han nationality) parts of Xinjiang. The subjects were interviewed with questionnaires and tested with spirometry. A post-bronchodilator FEV1/FVC <70% was defined as diagnostic of COPD. Results Completed data were obtained from 3489 participants. The average prevalence of COPD was 4.0% (138/3489). Of the 138 COPD patients, only 20 (14.5%, 20/138) had received diagnosis and treatment. The prevalence of COPD in Uygurs was higher (5.1%, 90/1774) than that in Hazakhs (3.3%, 26/784) and that in Hans (2.4%, 22/921). The prevalence of COPD in population older than 50 years increased significantly (>10%, 94/743). Logistic regression model was conducted and statistical association of COPD was found with Uygurs (OR=2.79, 95%CI: 1.71-4.57), older than 30 years (OR=3.41, 95%CI: 1.62-7.18), family history of respiratory diseases (OR=1.68, 95%CI: 1.11-2.53), and cooking behavior (OR=1.47, 95%CI: 1.02-2.12). Conclusions Higher risk for COPD was related with Uygurs, older age, family history of respiratory diseases, and cooking behavior. Whether difference in the prevalence of COPD among different ethnics is related to genetic background, and the relationship between biofuels and other risk factors for COPD need further study. Key words: Pulmonary disease, chronic obstructive; Risk factors; Epidemiology methods