Dear Editor,

Coronavirus disease 2019 (COVID-19) is an infectious disease provoked by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)1. The virus typically spreads from person to person via respiratory droplets produced during coughing, and common symptoms include fever, cough, and shortness of breath2. The COVID-19 outbreak was initially identified in Wuhan, capital of Hubei Province, China, in December 2019, and has since spread rapidly globally. It was declared a pandemic on 11 March 2020 by the World Health Organization (WHO)3. As of 26 March 2020, a total number of 480446 cumulative cases of COVID-19 have been reported in 175 countries and regions, including 22030 confirmed deaths, the majority of which have been reported in Italy (7503), Spain (4089) and China (3169)4. In Spain, as of 25 March 2020, most of those who have died were elderly, about 96% of deaths were in those over 60 years old, and 45% had pre-existing health conditions including cardiovascular disease (31%)5.

With 120859 deaths in 2018, cardiovascular disease (CVD) is the leading cause of death in Spain (28.3%)6. Sex-disaggregated data for CVD in Spain show differences in mortality between men (46.3%) and women (53.7%)6. Surprisingly, although men (51%) and women (49%) are getting infected by COVID-19 at similar rates, men have been dying from COVID-19 at a significantly higher rate (4.4%) than women (2.5%), and the sex differences regarding vulnerability in those with COVID-19 and preexisting CVD seem to be again reflected in men (35%) and women (26%)5.

Emerging evidence suggests that these discrepancies could potentially be due to gendered differences such as patterns and prevalence of smoking. In this regard, approximately 10% of cardiovascular disease is globally attributed to smoking7, with smoking prevalence in 2017 among men in Spain being approximately 25.6% but only 18.8% in women8.

Could smoking influence the gender-based impact of the outbreak? And the impact itself?

These hypotheses could be coupled with new available evidence from the WHO on COVID-19, warning that a weaker cardiovascular system among COVID-19 patients with a history of tobacco use could make such patients susceptible to severe symptoms, thereby increasing the chance of death9. According to the recent (18 March 2020) systematic review of Vardavas and Nikitara10, smoking is most likely associated with the negative progression and adverse outcomes of COVID-19.

Accordingly, we recommend that public health messages and behavioural interventions coming from the Spanish government that focus on how to spread and flatten the COVID-19 infection curve should also consider available evidence-based high-quality smoking cessation advice.