Correlates of COPD and chronic bronchitis in nonsmokers: data from a cross-sectional study

PURPOSE Our objective was to assess the prevalence of chronic bronchitis and chronic obstructive pulmonary disease (COPD) and their correlates among a Lebanese nonsmoker group. MATERIAL AND METHODS A cross-sectional study was conducted between October 2009 and September 2010, using a multistage cluster sample throughout Lebanon including Lebanese residents aged 40 years and above with no exclusion criteria. Pre- and postbronchodilator spirometry measurements were performed and carbon monoxide level was measured in exhaled air. COPD was defined and classified according to the Global Initiative for Chronic Obstructive Lung Disease guidelines or according to the lower limit of normal (forced expiratory volume in 1 second/forced vital capacity postbronchodilator < 5th percentile of the healthy population having the same age and sex). Chronic bronchitis was defined by the declaration of morning cough and expectorations for more than 3 months a year over more than 2 years in individuals with normal spirometry. RESULTS Out of 2201 individuals, 732 were never-smokers: 25 (3.4%) of them had COPD, and 86 (11.75%) fulfilled the definition of chronic bronchitis. Correlates of COPD included a childhood respiratory disease, house heated by diesel, and older age. On the other hand, correlates of chronic bronchitis included childhood respiratory diseases, living in southern Lebanon versus other regions, heating home by gas, older age, number of smokers at work, and lower height. CONCLUSION A substantial percentage of the nonsmoking population may exhibit chronic bronchitis or COPD. The significant correlates mentioned above should be taken into consideration in order to reduce the risk of developing such chronic and debilitating respiratory diseases.