Cattaruzza Maria Sofia, Zagà Vincenzo, Gallus Silvano, D'Argenio Paolo, Gorini Giuseppe
Department of Public Health and Infectious Diseases, Sapienza University, Rome, Italy.
Italian Society of Tobaccology (SITAB), Italy.
Acta Biomed. 2020 May 11;91(2):106-112. doi: 10.23750/abm.v91i2.9698.
COVID-19 pandemic burst onto the international scene as a new disease not affecting patients uniformly; hence it has risen many questions yet to be clarified. The aim of this study was to outline the main issues that led tobacco smoking being discussed as a potential risk factor associated with COVID-19.
articles from MEDLINE and pre-prints published from January to April 2020 were identified.
data from China showed that men had more severe outcomes of COVID-19 than women. Since smoking prevalence is very high among Chinese men in comparison to women, it was hypothesized that smoking could be a risk factor for poor prognosis. This was also supported by the higher prevalence of comorbidities, many of which are tobacco-related diseases, in patients with severe COVID-19, who were also more likely to have a smoking history. A meta-analysis confirmed these results reporting an OR=2.25 (95% CI: 1.49-3.39) for developing severe Covid-19 among patients with a smoking history. Some authors, noticing that reported smoking prevalence among hospitalized patients was substantially below smoking prevalence in the corresponding populations, speculated a protective role of nicotine. However, it is likely that low prevalence among hospitalized patients are partially due to many smokers misclassified as nonsmokers. Tobacco smoking seems to cause a dose-dependent upregulation of the angiotensin-converting- enzyme-2 (ACE2), the virus cellular entry receptor, which could explain the higher risk of severe COVID-19 in smokers.
There is need for further independent studies to clarify the role of smoking on COVID-19 incidence, progression and mortality.
新冠疫情作为一种新出现的疾病，在国际上突然爆发，对患者的影响并不一致；因此引发了许多尚待澄清的问题。本研究的目的是概述导致吸烟被作为与新冠病毒相关的潜在风险因素进行讨论的主要问题。
检索了2020年1月至4月发表在MEDLINE上的文章和预印本。
来自中国的数据显示，男性新冠患者的病情比女性更严重。由于中国男性的吸烟率相比女性非常高，因此推测吸烟可能是预后不良的一个风险因素。重症新冠患者中合并症的患病率更高，其中许多是与烟草相关的疾病，这些患者也更有可能有吸烟史，这也支持了上述推测。一项荟萃分析证实了这些结果，报告有吸烟史的患者患重症新冠的比值比（OR）为2.25（95%置信区间：1.49 - 3.39）。一些作者注意到，住院患者报告的吸烟率大幅低于相应人群的吸烟率，推测尼古丁有保护作用。然而，住院患者中吸烟率低可能部分是由于许多吸烟者被误分类为非吸烟者。吸烟似乎会导致病毒细胞进入受体血管紧张素转换酶2（ACE2）呈剂量依赖性上调，这可以解释吸烟者患重症新冠的风险更高。
需要进一步开展独立研究，以阐明吸烟在新冠发病率、病情进展和死亡率方面的作用。
