The team from the University of Utah, Mexican clinicians and researchers from Greece looked at 236,439 patients, of which 89,756 (38.0%) had been diagnosed with COVID-19.
Their motivation was that “it is important to understand the pathophysiology and the mechanisms of disease progression,” and that “the rapid transmission of the disease and the increased pressure across healthcare systems have led to emergency measures resulting in substantial social and economic disruption.”
“Smoking was also recorded, with participants classified as smokers (who were considered current smokers) or non-smokers. No data on former smokers was available.”
Only patients diagnosed with COVID-19 were included and those with results pending were excluded from the study.
“Adverse outcome was defined as the primary composite end-point of intensive care unit admission, mechanical ventilation or death.”
“There's something weird going on with smoking and coronavirus” - Linda Bauld, professor of public health at the University of Edinburgh
The authors believe this work constitutes “a case series with the highest number of laboratory-confirmed COVID-19 patients”, and made reference to similar studies from Chinese, British and New York patients.
They concluded that age was the largest factor in patients contracting COVID-19 and developing severe symptoms. Patients presenting with hypertension, obesity and diabetes were also more at risk.
“Notably, smoking was not associated with a higher risk for adverse outcomes and hospitalization. Smokers were also less likely to be diagnosed with COVID-19 compared to non- smokers. The latter is in agreement with a recent observational population study from Israel.”
They added: “It is still not clear whether nicotine exerts any positive effect or not. However, there is no doubt that smoking cannot be used as a protective measure and smoking cessation should be encouraged during the COVID-19 pandemic. The potential value of nicotine or other nicotinic agonists in COVID-19 is expected to be determined through clinical trials.”
Corresponding author Doctor Konstantinos Farsalinos wrote in Internal and Emergency Medicine: “'Up-regulation of ACE2, though seemingly paradoxical, may in fact protect patients from severe disease and lung injury. Nicotine has effects on the immune system that could be beneficial in reducing the intensity of the cytokine storm. The potential benefits of nicotine.... could explain, at least in part, the increased severity or adverse outcome among smokers hospitalized for COVID-19 since these patients inevitably experience abrupt cessation of nicotine intake during hospitalization. This may be feasible through repurposing already approved pharmaceutical nicotine products such as nicotine patches.”
- “Characteristics and risk factors for COVID-19 diagnosis and adverse outcomes in Mexico: an analysis of 89,756 laboratory-confirmed COVID-19 cases” by Giannouchos, Sussman, Mier, Poulas, and Farsalinos – [link]