Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Apr;10(1):e001449.
doi: 10.1136/bmjresp-2022-001449.

Clinical features and 1-year outcomes of chronic bronchitis in participants with normal spirometry: results from the ECOPD study in China

Fan Wu  1   2 , Youlan Zheng  1 , Ningning Zhao  1 , Jieqi Peng  1   2 , Zhishan Deng  1 , Huajing Yang  1 , Heshen Tian  1 , Shan Xiao  1 , Xiang Wen  1 , Peiyu Huang  1 , Cuiqiong Dai  1 , Lifei Lu  1 , Kunning Zhou  1 , Xiaohui Wu  1 , Huanhuan Fan  1 , Haiqing Li  1 , Ruiting Sun  1 , Changli Yang  3 , Shengtang Chen  4 , Jianhui Huang  5 , Shuqing Yu  6 , Yumin Zhou  7   2 , Pixin Ran  7   2
Affiliations

Clinical features and 1-year outcomes of chronic bronchitis in participants with normal spirometry: results from the ECOPD study in China

Fan Wu et al. BMJ Open Respir Res. 2023 Apr.

Abstract

Background: Evidence regarding clinical features and outcomes of individuals with non-obstructive chronic bronchitis (NOCB) remains scarce, especially in never-smokers. We aimed to investigate the clinical features and 1-year outcomes of individuals with NOCB in the Chinese population.

Methods: We obtained data on participants in the Early Chronic Obstructive Pulmonary Disease Study who had normal spirometry (post-bronchodilator forced expiratory volume in 1 s/forced vital capacity ≥0.70). NOCB was defined as chronic cough and sputum production for at least 3 months for two consecutive years or more at baseline in participants with normal spirometry. We assessed the differences in demographics, risk factors, lung function, impulse oscillometry, CT imaging and frequency of acute respiratory events between participants with and without NOCB.

Results: NOCB was present in 13.1% (149/1140) of participants with normal spirometry at baseline. Compared with participants without NOCB, those with NOCB had a higher proportion of men and participants with smoke exposure, occupational exposure, family history of respiratory diseases and worse respiratory symptoms (all p<0.05), but there was no significant difference in lung function. Never-smokers with NOCB had higher rates of emphysema than those without NOCB, but airway resistance was similar. Ever-smokers with NOCB had greater airway resistance than those without NOCB, but emphysema rates were similar. During 1-year follow-up, participants with NOCB had a significantly increased risk of acute respiratory events compared with participants who did not have NOCB, after adjustment for confounders (risk ratio 2.10, 95% CI 1.32 to 3.33; p=0.002). These results were robust in never-smokers and ever-smokers.

Conclusions: Never-smokers and ever-smokers with NOCB had more chronic obstructive pulmonary disease-related risk factors, evidence of airway disease and greater risk of acute respiratory events than those without NOCB. Our findings support expanding the criteria defining pre-COPD to include NOCB.

Keywords: COPD epidemiology; Emphysema.

PubMed Disclaimer

Conflict of interest statement

Competing interests: None declared.

Figures

Figure 1
Figure 1
Study flow chart. COPD, chronic obstructive pulmonary disease; ECOPD, Early Chronic Obstructive Pulmonary Disease.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. GBD Chronic Respiratory Disease Collaborators . Prevalence and attributable health burden of chronic respiratory diseases, 1990-2017: a systematic analysis for the global burden of disease study 2017. Lancet Respir Med 2020;8:585–96. 10.1016/S2213-2600(20)30105-3 - DOI - PMC - PubMed
    1. Adeloye D, Song P, Zhu Y, et al. . Global, regional, and national prevalence of, and risk factors for, chronic obstructive pulmonary disease (COPD) in 2019: a systematic review and modelling analysis. Lancet Respir Med 2022;10:447–58. 10.1016/S2213-2600(21)00511-7 - DOI - PMC - PubMed
    1. Martinez FJ, Han MK, Allinson JP, et al. . At the root: defining and halting progression of early chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2018;197:1540–51. 10.1164/rccm.201710-2028PP - DOI - PMC - PubMed
    1. Han MK, Agusti A, Celli BR, et al. . From gold 0 to pre-COPD. Am J Respir Crit Care Med 2021;203:414–23. 10.1164/rccm.202008-3328PP - DOI - PMC - PubMed
    1. Martinez FJ, Agusti A, Celli BR, et al. . Treatment trials in young patients with chronic obstructive pulmonary disease and pre-chronic obstructive pulmonary disease patients: time to move forward. Am J Respir Crit Care Med 2022;205:275–87. 10.1164/rccm.202107-1663SO - DOI - PMC - PubMed

Publication types