Risk factors for chronic bronchitis in indigenous inhabitants of the Arctic zone in Western Siberia, Russia

Nenets (reindeer herders nomads) are indigenous residents of the Arctic zone in Western Siberia. The aim of our study was to assess prevalence of chronic bronchitis and its risk factors in indigenous residents. The 616 indigenous people (26.8% men) aged 24-59 yrs (mean 42.2 yr), 8.0% of the total adult indigenous population in the area, participated in our cross-sectional survey. GARD questionnaire was used to analyze clinical symptoms. Upper airway diseases were excluded by the examination of ENT specialist. Pulmonary function was measured by dry spirometer (SpiroUSB ML 2525 CareFusion, UK) according to ATS/ERS criteria (2005). There were no differences by age (U–27547.0; p=0.3) and by sex (χ2–4.7; p=0.1) between healthy and patients with chronic bronchitis. Third of the respondents smoke and contact with open fire pollutants, 25.0% lived in a traditional dwelling "chum", 44.8% of respondents worked in the cold. Multivariate logistic regression analysis were used to predict risk of chronic bronchitis. The prevalence of chronic bronchitis with normal lung function among the respondents was 19.2%. Fifty percent of active smokers who used stove heating and worked in cold air had symptoms of chronic bronchitis. Combination of smoking and work in open cold air increase risk of developing chronic bronchitis by three times. The use of stove heating increases the risk of respiratory symptoms by two times. Specificity and sensitivity of analysis were 93.8% and 82.7%. We conclude that active smoking, stove heating and unhealthy condition of work are important risk factors of chronic bronchitis in indigenous residents in Arctic zone of Russia. Support from the RFBR grant № 18-010-00875.