PT  - JOURNAL ARTICLE
AU  - Wang, Gang
AU  - Hallberg, Jenny
AU  - Um Bergström, Petra
AU  - Janson, Christer
AU  - Pershagen, Göran
AU  - Gruzieva, Olena
AU  - van Hage, Marianne
AU  - Georgelis, Antonios
AU  - Bergström, Anna
AU  - Kull, Inger
AU  - Lindén, Anders
AU  - Melén, Erik
TI  - Assessment of chronic bronchitis and risk factors in young adults: results from BAMSE
AID  - 10.1183/13993003.02120-2020
DP  - 2021 Mar 01
TA  - European Respiratory Journal
PG  - 2002120
VI  - 57
IP  - 3
4099  - https://publications.ersnet.org//content/57/3/2002120.short
4100  - https://publications.ersnet.org//content/57/3/2002120.full
SO  - Eur Respir J2021 Mar 01; 57
AB  - Background Chronic bronchitis is associated with substantial morbidity among elderly adults, but little is known about its prevalence and risk factors in young adults. Our aim was to assess the prevalence and early-life risk factors for chronic bronchitis in young adults.Methods Questionnaire data and clinical measures from the 24-year follow-up of the Swedish BAMSE (Child (Barn), Allergy, Milieu, Stockholm, Epidemiological) cohort were used. We assessed chronic bronchitis (CB) as the combination of cough and mucus production in the morning during winter. Environmental and clinical data from birth and onwards were used for analyses of risk factors.Results At the 24-year follow-up, 75% (n=3064) participants completed the questionnaire and 2030 performed spirometry. The overall prevalence of CB was 5.5% (n=158) with similar estimates in males and females. 49% of CB cases experienced more than three self-reported respiratory infections in the past year compared to 18% in non-CB subjects (p<0.001), and 37% of cases were current smokers (versus 19% of non-CB cases). Statistically significant lower post-bronchodilator forced expiratory volume in 1 s/forced vital capacity were observed in CB compared to non-CB subjects (mean z-score −0.06 versus 0.13, p=0.027). Daily smoking (adjusted (a)OR 3.85, p<0.001), air pollution exposure (black carbon at ages 1–4 years aOR 1.71 per 1 μg·m−3 increase, p=0.009) and exclusive breastfeeding for ≤4 months (aOR 0.66, p=0.044) were associated with CB.Conclusion Chronic bronchitis in young adults is associated with recurrent respiratory infections. Besides smoking, our results support the role of early-life exposures, such as air pollution and exclusive breastfeeding, for respiratory health later in life.Chronic bronchitis in young adults is strongly associated with recurrent respiratory infections. Besides smoking, our results support the role of early-life environmental exposures for respiratory health in this age group. https://bit.ly/2RNsv5z