Smoking patterns and outcomes of severe sars-CoV-2 infection: a retrospective cohort study
Abstract
The purpose of this study was to analyze the association between the number of cigarettes smoked and the length of smoking with mortality among patients who were hospitalized in the intensive care unit (ICU) due to SARS-CoV-2 infection. This retrospective cohort study was conducted at the General Hospital in Sombor (Serbia). Patients who were hospitalized because of severe SARS-CoV-2 infection between March 2021 and March 2023 were included in this study. Data were retrieved from electronic medical records, including those on smoking status, duration of smoking, and the number of cigarettes smoked per day. Of 307 patients whose medical records were analyzed, 40.7% were current smokers. Current smokers more often required treatment in the ICU, where they also had a higher mortality rate compared to current non-smokers. Longer duration of smoking was independently associated with dying of SARS-CoV-2 infection in the ICU. The Kaplan-Meier survival curve showed that hospitalized patients with SARS-CoV-2 infection who smoked had poorer survival compared to current non-smokers. According to the receiver operating characteristic curve, patients who smoked for more than 40 years had a 73.9% chance of dying from SARS-CoV-2 infection. Current smokers who smoked 22.5 cigarettes per day had a 75.4% chance of dying from SARS-CoV-2 infection in the ICU. Smokers with severe SARS-CoV-2 infection had a higher likelihood of having poor outcomes. Longer duration of smoking was an independent predictor of SARS-CoV-2 mortality. Smoking prevention and smoking cessation are of paramount importance in the prevention of SARS-CoV-2-related mortality.
Ethics Approval
This study was approved by the Ethics Committee of the General Hospital "Dr Radivoj Simonovic" Sombor (approval no. 23-2171-2023-2).
References
- Vardavas CI, Nikitara K. COVID-19 and smoking: a systematic review of the evidence. Tob Induc Dis 2020;18:20. DOI: https://doi.org/10.18332/tid/119324
- Jacobs M, Van Eeckhoutte H P, Wijnant SR, et al. Increased expression of ACE2, the SARS-CoV-2 entry receptor, in alveolar and bronchial epithelium of smokers and COPD subjects. Eur Resp J 2020;56:2002378. DOI: https://doi.org/10.1183/13993003.02378-2020
- Edmiston JB, Cohn EG, Teruya SL, et al. Clinical and social determinants of health features of SARS-CoV-2 infection among Black and Caribbean Hispanic patients with heart failure: the SCAN-MP Study. PLoS One 2023;18:e0283730. DOI: https://doi.org/10.1371/journal.pone.0283730
- Oakes JM, Fuchs RM, Gardner JD, et al. Nicotine and the renin-angiotensin system. Am J Physiol Regul Integr Comp Physiol 2018;315:895-906. DOI: https://doi.org/10.1152/ajpregu.00099.2018
- Miyara M, Tubach F, Pourcher V, et al. Lower rate of daily smokers with symptomatic COVID-19: a monocentric self-report of smoking habit study. Front Med 2022;8:668995. DOI: https://doi.org/10.3389/fmed.2021.668995
- Leung JM, Yang CX, Tam A, et al. ACE-2 expression in the small airway epithelia of smokers and COPD patients: implications for COVID-19. Eur Respir J 2020;55:2000688. DOI: https://doi.org/10.1183/13993003.00688-2020
- Gao M, Aveyard P, Lindson N, et al. Association between smoking, e-cigarette use and severe COVID-19: a cohort study. Int J Epidemiol 2022;51:1062-72. DOI: https://doi.org/10.1093/ije/dyac028
- Patanavanich R, Siripoon T, Amponnavarat S, Glantz SA. active smokers are at higher risk of COVID-19 death: a systematic review and meta-analysis. Nicotine Tob Res 2023;25:177-84. DOI: https://doi.org/10.1093/ntr/ntac085
- Patanavanich R, Glantz SA. Smoking is associated with worse outcomes of COVID-19 particularly among younger adults: a systematic review and meta-analysis. BMC Public Health 2021;21:1554. DOI: https://doi.org/10.1186/s12889-021-11579-x
- Serbian Medical Chamber. Therapeutic protocol for COVID-19. Available from: https://www.lks.org.rs/images/Documents/Obavestenja/Protokol%20za%20le%C4%8Denje%20pacijenata%20sa%20%20COVID%2019%20%D0%B0%D0%BF%D1%80%D0%B8%D0%BB%2021.pdf. Accessed on: 31/10/2023. [Material in Serbian].
- Menachemi N, Dixon BE, Wools-Kaloustian KK, et al. How many SARS-CoV-2-infected people require hospitalization? Using random sample testing to better inform preparedness efforts. J Public Health Manag Pract 2021;27:246-50. DOI: https://doi.org/10.1097/PHH.0000000000001331
- Mohsin FM, Tonmon TT, Nahrin R, et al. Association Between Smoking and COVID-19 Severity: Evidence from Bangladesh. J Multidiscip Healthc 2021;14:1923-33. DOI: https://doi.org/10.2147/JMDH.S317603
- Le Guen CL, Muir KC, Simons M, et al. The impact of smoking status and smoking-related comorbidities on coronavirus disease 2019 patient outcomes: a causal mediation analysis. Nicotine Tob Res 2023;25:331-8. DOI: https://doi.org/10.1093/ntr/ntac193
- WHO. WHO report on the global tobacco epidemic 2021. Country profile. Serbia. Available from: https://cdn.who.int/media/docs/default-source/country-profiles/tobacco/who_rgte_2021_serbia.pdf?sfvrsn=50e60c0a_5&download=true.
- Guan WJ, Liang WH, Zhao Y, et al. Comorbidity and its impact on 1590 patients with COVID-19 in China: a nationwide analysis. Eur Respir J 2020;55:2000547. DOI: https://doi.org/10.1183/13993003.01227-2020
- Grzywa-Celińska A, Krusiński A, Milanowski J. 'Smoging kills' - Effects of air pollution on human respiratory system. Ann Agric Environ Med 2020;27:1-5. DOI: https://doi.org/10.26444/aaem/110477
- Ganesan S, Comstock AT, Sajjan US. Barrier function of airway tract epithelium. Tissue Barriers 2013;1:e24997. DOI: https://doi.org/10.4161/tisb.24997
- Wistuba II, Gazdar AF. Lung cancer preneoplasia. Annu Rev Pathol 2006;1:331-48. DOI: https://doi.org/10.1146/annurev.pathol.1.110304.100103
- Samara K, Zervou M, Siafakas NM, Tzortzaki EG. Microsatellite DNA instability in benign lung diseases. Respir Med 2006;100:202-11. DOI: https://doi.org/10.1016/j.rmed.2005.05.015
- Lippi G, Henry BM. Active smoking is not associated with severity of coronavirus disease 2019 (COVID-19). Eur J Intern Med 2020;75:107-8. DOI: https://doi.org/10.1016/j.ejim.2020.03.014
- Patanavanich R, Glantz SA. Smoking is associated with COVID-19 progression: a meta-analysis. Nicotine Tob Res 2020;22:1653-6. DOI: https://doi.org/10.1093/ntr/ntaa082
- Rohleder N, Kirschbaum C. The hypothalamic-pituitary-adrenal (HPA) axis in habitual smokers. Int J Psychophysiol 2006;59:236-43. DOI: https://doi.org/10.1016/j.ijpsycho.2005.10.012
- Jiang C, Chen Q, Xie M. Smoking increases the risk of infectious diseases: a narrative review. Tob Induc Dis 2020;18:60. DOI: https://doi.org/10.18332/tid/123845
- Almirall J, Serra-Prat M, Bolibar I, Balasso V. Risk factors for community-acquired pneumonia in adults: a systematic review of observational studies. Respiration 2017;94:299-311. DOI: https://doi.org/10.1159/000479089
- Nuorti JP, Butler JC, Farley MM, et al. Cigarette smoking and invasive pneumococcal disease. Active Bacterial Core Surveillance Team. N Engl J Med 2000;342:681-9. DOI: https://doi.org/10.1056/NEJM200003093421002
- Almirall J, Bolibar I, Serra-Prat M, et al. New evidence of risk factors for community-acquired pneumonia: a population-based study. Eur Respir J 2008;31:1274-84. DOI: https://doi.org/10.1183/09031936.00095807
- Kihara T, Yamagishi K, Iso H, Tamakoshi A. The association of smoking cessation with mortality from pneumonia among middle-aged and elderly community residents: the Japan Collaborative Cohort (JACC) study. Prev Med 2022;163:107188. DOI: https://doi.org/10.1016/j.ypmed.2022.107188
- Xu L, Chen B, Wang F, et al. A higher rate of pulmonary fungal infection in chronic obstructive pulmonary disease patients with influenza in a large tertiary hospital. Respiration 2019;98:391-400. DOI: https://doi.org/10.1159/000501410
- Musellim B, Erturan S, Sonmez Duman E, Ongen G. Comparison of extra-pulmonary and pulmonary tuberculosis cases: factors influencing the site of reactivation. Int J Tuberc Lung Dis 2005;9:1220-3.
- Ahrenfeldt LJ, Otavova M, Christensen K, Lindahl-Jacobsen R. Sex and age differences in COVID-19 mortality in Europe. Wien Klin Wochenschr 2021;133:393-8. DOI: https://doi.org/10.1007/s00508-020-01793-9
- Aleksanyan Y, Weinman JP. Women, men and COVID-19. Soc Sci Med 2022;294:114698. DOI: https://doi.org/10.1016/j.socscimed.2022.114698
- Marinković I, Tramošljanin A. Mortality in Serbia due to the COVID-19 pandemic: Overview of basic mortality data for 2020 and 2021. Stanovnistvo 2022;60:165-9. DOI: https://doi.org/10.59954/stnv.501
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