Smoking increases the risk of catching a coronavirus, according to a study of 2.4 million British people

Smoking increases the risk of getting Coronavirus, According to a major British study that challenges the growing evidence that the practice is protective.

Imperial College Team London We surveyed 2.4 million British people, 11% of whom reported smoking.

All participants were users of the COVID Symptom Survey app. This app will help you regularly report your health, ask if you have any symptoms of coronavirus and build a clearer situation of an outbreak in the UK.

Current smokers are 14% more likely to develop overt symptoms such as persistent cough and high temperatures, suggesting a diagnosis of COVID-19.

They are also 50% more likely to have other symptoms such as diarrhea, loss of appetite, and delirium.

In addition, current smokers who tested positive were more than twice as likely to need to go to hospital because of COVID-19.

Smokers are known to be more at mouth and powerful chemicals damage the respiratory tract and are known to be at higher risk of getting other viruses.

Increasing evidence suggests that smokers have a lower risk of COVID-19, but if they catch it, they are more likely to be severely ill.

Researchers around the world have found very few smokers among hospitalized COVID-19 patients, suggesting that they are protected.

However, there are many holes in the data because doctors cannot always know if a seriously ill person is a smoker.

Scientists are controversial on this topic and believe that some smokers are protective against COVID-19, so they plan to test the nicotine patch as a preventative tool.

Smoking increases the risk of catching coronaviruses and throws away the theory that habits are protective, according to a British study

This comes after a series of studies showed a surprisingly low prevalence of COVID-19 inpatient smokers. The graph shows smoking rates by country for the percentage of smokers with COVID-19 patients. This is reported in a study review by University College London. The lowest numbers in each country have been selected to show the tough comparisons found in several studies

A review of 28 studies conducted at the University of London in April found that smoking prevalence in COVID-19 patients was “lower than expected.”

One study found that in the UK, the percentage of smokers with COVID-19 patients was only 5%, a third of the national 14.4%.

Another found in France The rate was four times lower. To ChinaA study found that 3.8% of patients were smokers, even though more than half of the population smoked regularly.

However, researchers often point out that smokers have a lower prevalence either because doctors are too busy to accurately record everyone’s smoking habits, or because patients are sick to speak. doing.

Given that older people are more likely to be hospitalized for COVID-19, lower smoking rates may be explained by differences in smoking rates between age groups, with older people having more habits. Is more likely to be.

These studies also often lack data and can distort the results.

The team at Imperial College London, led by Dr. Nicholas Hopkinson, has taken a different approach to most research to date using hospital data.

They used information from the COVID-19 Symptom app developed by King’s College London to help track the crisis.

Since March, more than 3.6 million people have downloaded the app in the UK.

On first use, the app records key health risk factors such as self-reported location, age, height, weight, smoking and common illnesses.

Users are regularly instructed to report their health and whether they have developed coronavirus symptoms (up to 14), and if so, test results.

The study obtained data from 2.4 million people who entered the data through the app between March 24 and April 23, 2020.

About 11% of the group were smokers. Researchers say this may be lower than the national average (14%), because wealthier people are less likely to smoke and more likely to have a smartphone.

The main finding was that current smoking was associated with a “significant increase in risk of developing symptoms suggesting COVID-19.”

Among’standard users’ who have never actually been tested, current smokers are 14% more likely to develop the triple COVID-19 classic symptoms than non-smokers. It was.

These were fever, persistent cough and shortness of breath.

It is also 29% more likely to have 5 or more symptoms and 50% more likely to have 10 or more symptoms.

Doctors at Royal Glamorgan Hospital are currently awaiting funding and ethical approval to proceed with the nicotine patch trial to prevent COVID-19.

These included abdominal pain, chest pain, delirium, diarrhea, fatigue, headache, hoarse voice, loss of smell, skipped meals, sore throat, and unusual muscle aches.

Researchers said this showed their illness was more severe.

Next, we investigated people who actually received the COVID-19 test results, but the results were slightly different.

They first noted that smoking rates were 2% lower in the tested group compared to the untested group.

This is because health workers are more likely to be tested, but less likely to be smokers, they said.

Due to testing restrictions in the UK, only health care workers or hospitalized people were available at that time.

Fewer smokers in the negative-to-positive group (7.4% vs. 9.3%), suggesting that smoking is protective.

But the researchers said the effects of smokers were more serious.

People with positive results are 42% more likely to have more than 10% of the symptoms, suggesting they are suffering more than nonsmokers.

In addition, current smokers who tested positive were more than twice as likely to need to go to hospital because of COVID-19.

This risk was only slightly reduced if existing health conditions were considered.

The findings so far are in stark contrast to previous smaller and less accurate papers because of the lower risk of smokers being hospitalized.

The author concluded with a preprint paperNot peer-reviewed by other scientists: “Our results are compelling evidence of an association between current smoking and personal risk from COVID-19, including burden of symptoms and risk of going to the hospital. Will be provided. “

In the light of new evidence that smokers make up a small number of hospitalized patients, scientists discussed how nicotine affects ACE-2 receptor expression.

ACE-2 is a protein in the body that the virus binds to infect cells.

When nicotine reduces the expression of ACE-2, viral particles are less likely to enter the cell and cause infection.

However, theoretically, increasing the ACE-2 receptor increases the risk of smokers becoming infected with coronaviruses.

To achieve this, the Imperial team measured ACE2 expression in adipose tissue, which is composed of adipocytes.

The sample was from 541 women, including 54 smokers, 196 former smokers, and 291 nonsmokers.

Smokers were found to have reduced ACE2 expression in adipose tissue compared to non-smokers.

This suggests that smokers are less likely to catch the coronavirus. However, research in this area is very vague and it is difficult to say if this is the case.

Even Hopkinson and his colleagues wrote that the problem was “complex.”

More clearly, a lower number of ACE-2 receptors appears to exacerbate the disease by preventing lung damage.

The virus itself is known to cause lung damage by reducing the number of ACE-2 receptors. Therefore, the problem is exacerbated when nicotine reduces the ACE-2 receptor.

But on the other hand, if nicotine potentiates the ACE-2 receptor as suggested in other studies, withdrawal from nicotine during hospitalization may also worsen the results.

Studies show that nicotine may prevent a severe overreaction of the immune system called the cytokine storm. This phenomenon has killed many COVID-19 patients.

NHS doctor in Wales wants to do a COVID-19 test with a nicotine patch based on the theory that addictive chemicals are somehow protected.

Doctors at Royal Glamorgan Hospital are currently awaiting funding and ethical approval for any clinical trials.

French researchers are also planning a trial after finding low-level smokers in a Paris hospital.

This move will be controversial, as studies such as those by Imperial warn that it is a risk factor for COVID-19.