- One in three young adults has at least one risk factor that could lead to serious COVID-19 infections, according to a new study.
- The researchers determined that smoking was the most frequent risk factor for people in their teens and early 20s.
- Other factors such as underlying diseases or genetic differences could also put young people at risk for serious infection.
- Visit the Business Insider home page for more stories.
It is almost common knowledge that young people are less vulnerable to severe coronavirus infections.
Adults 18 to 49 accounted for about 25% of patients hospitalized with coronavirus in March, while those over 65 accounted for about 43%, according to the Centers for Disease Control and Prevention. Adults 18 to 44 years old accounted for only 2% of coronavirus deaths from February to May, while people aged 65 and older accounted for almost 80%.
But certain factors can put anyone at risk of serious illness, regardless of age. A new study by researchers at the University of California, San Francisco determined that one in three young adults ages 18-25 is vulnerable to severe cases of COVID-19.
Patients were considered vulnerable if they had at least one risk factor, including smoking or chronic diseases such as heart disease, diabetes, asthma, obesity, autoimmune diseases, or liver problems.
The researchers found that smoking was by far the most common risk factor for people in their teens and early 20s. Of the approximately 8,400 young adults in the study, about 25% said they had smoked tobacco, e-cigarettes, or cigars in the past 30 days.
In contrast, only about 16% reported having a chronic illness. Asthma was by far the most common: about 9% of young adults reported that they were asthmatic. That compares with about 12% who said they had smoked tobacco in the past 30 days and about 7% who said they had used e-cigarettes.
“The risk of being medically vulnerable is halved when smokers, including e-cigarette users, are removed from the sample,” the researchers wrote. According to the study, only one in six young adults who did not smoke was vulnerable to severe COVID-19 disease.
The findings came just days after the World Health Organization warned of the link between smoking and severe cases of coronavirus.
“Smoking kills 8 million people a year, but if users need more motivation to quit, the pandemic offers the right incentive,” WHO Director-General Tedros Adhanom Ghebreyesus said at a press conference on Friday. . “The evidence reveals that smokers are more vulnerable than nonsmokers to developing a severe case of COVID-19.”
Smoking habits differ between men and women.
A business displays a sign that sells masks, e-cigarettes, and CBD during the coronavirus pandemic on May 27, 2020 in New York City.
Cindy Ord / Getty Images
The UCSF study found that the risk of serious coronavirus infections from smoking or using e-cigarettes was higher among younger, lower-income white men who were uninsured for at least part of the year.
Research has shown that white people are more likely to be daily smokers compared to other racial groups, although people of color face other coronavirus risk factors that were not included in the study. Black and Hispanic people, for example, are more likely to have jobs in the service industry that increase their risk of exposure to coronavirus. The results may also be biased by the fact that the study examined many more white adults (55%) than Hispanic adults (22%) or black adults (13%).
About 16% of young adults who reported smoking in the study were men. Only 9% were young women.
But the women in the study had higher rates of asthma and autoimmune conditions like lupus or rheumatoid arthritis. Overall, that mainly made up for the fact that fewer women smoke: 30% of young women in the study were vulnerable to severe COVID-19 infections compared to 33% of young men.
Genetic factors may also increase the risk of serious infection.
Physician Lauren Bernese administers a coronavirus test in Seattle, Washington, on April 29, 2020.
David Ryder / Reuters
Since the coronavirus attacks the respiratory system first, patients who already suffer from smoking-related lung damage or inflammation may develop more serious respiratory problems as a result of COVID-19.
The research also suggests that smokers have higher expressions of ACE-2 receptors, the cellular receptors that the coronavirus uses to invade the body, in its airways. People with more ACE2 receptors also appear to be at increased risk of serious COVID-19 infection.
But even young patients with no smoking or underlying health conditions may still be at risk for a serious case of COVID-19. People ages 18 to 29 account for more than four times as many coronavirus hospitalizations as they did a few months ago: about 38 hospitalizations for every 100,000 people as of July 4, compared to nine hospitalizations for every 100,000 people on April 18.
Some young and healthy patients have also reported feeling ill for several months, with long-lasting symptoms such as chest pain and difficulty breathing. That could be the result of genetic differences that result in increased ACE2 receptor expression or that trigger a more aggressive immune response.
But unlike many risk factors, smoking can be avoided.
“Efforts to reduce smoking and e-cigarette use among young adults would likely reduce their medical vulnerability to serious illness,” the UCSF researchers wrote. Their findings, they added, underscore “the importance of tobacco prevention and mitigation.”
