Clinical features, burden, and risk factors for chronic obstructive pulmonary disease in Nonsmokers

Smoking is regarded as a major causative risk factor for COPD. However, increasing evidence showed that a number of nonsmokers could also develop COPD. The COPD patients who never smoke reportedly have a distinct clinical feature from COPD patients who are smokers. Other than smoking, COPD was also shown to be associated with exposure to biomass fuel, environmental tobacco smoke, occupational exposure to dust/gas/fume/vapor, outdoor air pollution, history of pulmonary tuberculosis, chronic asthma, respiratory tract infections during childhood, poor socioeconomic status, individual genetic differences, and so on. Differences in environmental exposure, lifestyle, and behavior may be the underlying causes of the varying prevalence, characteristics, and potential risk factors regarding nonsmoker's COPD across countries and areas. Here we review risk factors and clinical characteristics of nonsmoking COPD patients in China as well as the related burden, aiming to provide more information about COPD among nonsmokers who have never smoked during their lifetime.