Increased Risk of COVID-19 Symptoms Associated with Smoking

Tobacco smokers are at a significant risk for both viral and bacterial infections of the respiratory system.

In a recent study that was published in the journal Thorax, investigators from King’s College London found that smokers are more likely to be admitted to a hospital for the coronavirus disease 2019 (COVID-19), and are also at an increased risk to experience symptoms.

“Some reports have suggested a protective effect of smoking on COVID-19 risk. However, studies in this area can easily be affected by biases in sampling, participation and response," Mario Falchi, an author on the study said. “Our results clearly show that smokers are at increased risk of suffering from a wider range of COVID-19 symptoms than non-smokers.”

The investigators used data from the ZOE COVID Symptom App, a phone application that is used to study the symptoms of COVID-19 and track the spread of the virus, to analyze information of smokers. 11% of participants using the app smoked, which is lower than the 14.7% in the general UK population. However, the difference reflects the demographics of the self-selected sample.

The findings showed that current smokers were 14% more likely in comparison to non-smokers to develop three usual COVID-19 symptoms, fever, shortness of breath and persistent cough, which suggests a diagnosis of the disease. They also found that smokers have a higher chance of symptom burden, with 29% reporting more than 5 symptoms and 50% reporting more than 10 symptoms associated with COVID-19.

Common symptoms reported were loss of smell, fatigue, diarrhea, muscle pain, confusion and fatigue. Investigators discovered that the greater the number of symptoms a participant experienced, the more likely they were to experience a more severe form of the disease.

The team behind the study recommended that a smoking cessation strategy should be included to address COVID-19, as a reduction in smoking rates could have the potential to reduce the burden on the healthcare systems.

"As rates of COVID-19 continue to rise and the NHS edges towards capacity, it's important to do all we can to reduce its effects and find ways to reduce hospital admissions,” Claire Steves, lead research on the study said. “Our analysis shows that smoking increases a person's likelihood to attend hospitals, so stopping smoking is one of the things we can do to reduce the health consequences of the disease."