Effects of smoking cessation on individuals with COPD: a systematic review and meta-analysis

Zihan Wang; Yifan Qiu; Xiang Ji; Liang Dong

doi:10.3389/fpubh.2024.1433269

Effects of smoking cessation on individuals with COPD: a systematic review and meta-analysis

Front Public Health. 2024 Dec 11:12:1433269. doi: 10.3389/fpubh.2024.1433269. eCollection 2024.

Authors

Zihan Wang^#^{1

2}, Yifan Qiu^#¹, Xiang Ji³, Liang Dong^{1

3}

Affiliations

¹ Department of Respiratory, Shandong Qianfoshan Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.
² Department of Respiratory and Critical Care Medicine, Research Center for Chronic Airway Diseases, Peking University Health Science Center, Peking University Third Hospital, Beijing, China.
³ Department of Respiratory, Shandong Provincial Qianfoshan Hospital, The First Affiliated Hospital of Shandong First Medical University, Shandong Institute of Respiratory Diseases, Shandong University, Jinan, China.

^# Contributed equally.

Abstract

Objective: Despite smoking being a significant risk factor in the occurrence and progression of chronic obstructive pulmonary disease (COPD), no comprehensive analysis has been conducted to determine the potential benefits of smoking cessation for patients with established COPD or identify specific indicators that may be improved. The aim of our meta-analysis was to elucidate the positive impact of smoking cessation on COPD.

Methods: We conducted a comprehensive search of PubMed, EMBASE, Web of Science, Cochrane Library, CNKI, Wan Fang and VIP databases to identify studies that met our eligibility criteria from inception up to 1, May 2024. Data were extracted independently by two authors and pooled using a random-effects model. Study quality was evaluated using the Newcastle-Ottawa Scale (NOS).

Results: Preliminary screening of publications gave a total of 13,460 documents after which the repetitive and non-compliant studies were removed. Eventually, 11 studies were included for follow-up analysis. The pooled results showed that cessation of smoking produced significant improvements in forced expiratory volume in one second (FEV1)% predicted (MD = 6.72, 95% CI, 4.55-8.89, P < 0.001; I² = 53%), FEV1/forced vital capacity (FVC) (MD = 6.82, 95% CI, 5.09-8.54, P < 0.001; I² = 0%), modified Medical Research Council (mMRC) (MD = -0.49, 95% CI, -0.95--0.02, P = 0.040; I² = 73%), 6-minute walk test (6-MWT) (MD = 64.46, 95% CI 14.60-114.32, P = 0.010; I² = 94%), partial oxygen pressure (MD = 1.96, 95% CI, 1.03-2.89, P < 0.001; I² = 0%), mortality (RR = 0.75, 95% CI, 0.56-1.00, P = 0.05; I² = 44%).

Conclusion: Our meta-analysis presented suggestive evidence that smoking cessation offered significant benefits to COPD patients, notably in the improvement of specific key indicators of pulmonary function (FEV1% predicted, FEV1/FVC), alleviating symptoms, enhancing exercise tolerance, and could reduce mortality.

Prospero registration: https://www.crd.york.ac.uk/prospero/, identifier: CRD42022384123.

Keywords: 6-MWT; COPD; mMRC scale; mortality; partial oxygen pressure; pulmonary function; smoking cessation.

Publication types

Meta-Analysis
Systematic Review

MeSH terms

Forced Expiratory Volume
Humans
Pulmonary Disease, Chronic Obstructive*
Smoking Cessation*

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by grants from the National Natural Science Foundation of China (82270032), the Key Research and Development Program of Shandong Province (2021SFGC0504), Shandong Provincial Natural Science Foundation (ZR2021LSW015), and Jinan Clinical Medicine Research Program for Respiratory Disease (No. 202132002).