It's also hitting youth - 33% of young adults at risk of serious COVID-19 infection

It's also hitting youth - 33% of young adults at risk of serious COVID-19 infection

As the number of young adults infected with the coronavirus soars, a new study from researchers at UCSF Benioff Children's Hospitals shows that young people may not be protected from serious illness.

The study examined data from a representative sample of approximately 8,400 men and women aged 18 to 25

The study examined data from a representative sample of approximately 8,400 men and women ages 18 to 25 and concluded that overall "medical vulnerability" was 33 percent for men and 30 percent for women. The effects of smoking exceeded other less common risks, the UCSF researchers reported in their study, published July 13 in the Journal of Adolescent Health.

Data from the U.S. Centers for Disease Control and Prevention (CDC), not included in the UCSF study, shows that while patients over 65 are hospitalized more often than younger people, the gap is narrowing. In the week ending April 18, there were 8.7 hospitalizations per 100,000 residents in the 18-29 age group, compared with 128.3 per 100,000 residents for patients 65 and older. For the week ending June 27, the numbers were 34.7 and 306.7, respectively, representing a nearly 300% increase in hospitalizations for young adults versus a 139% increase in hospitalizations for older adults.

The researchers, from UCSF's Division of Adolescent Medicine, determined vulnerability using indicators identified by the CDC. These included heart disease, diabetes, asthma, immune disorders (such as lupus, gout, rheumatoid arthritis), liver disease, obesity and smoking within the last 30 days. Additionally, researchers added e-cigarettes to the tobacco and cigar consumption the CDC included and found that all three were associated with adverse effects on respiratory and immune function.

No data are available on the relative impact of each CDC risk factor

Because there was no data on the relative impact of each CDC risk factor, the researchers used a medical vulnerability estimate using at least one of the indicators as the outcome variable, rather than a cumulative assessment of the indicators. Susceptibility was assessed based on each indicator, so that, for example, 100 percent of smokers were susceptible to severe COVID-19.

Most notable among their findings was that medical vulnerability was 16.1 percent among 6,741 nonsmokers, compared with 31.5 percent among the full sample of 8,405 young adults, which included smokers.

Smoking linked to COVID-19 progression

“Recent evidence suggests that smoking is associated with a higher likelihood of COVID-19 progression, including increased disease severity, intensive care unit admission, or death,” Adams said. “Smoking can have a significant impact on young adults, who typically have low rates of most chronic diseases.”

Recent research also shows that young adults are more likely to smoke than teens, a reversal of previous trends.

The study, which used data from the National Health Interview Survey, found that in the past 30 days, 10.9 percent had smoked a cigarette, 4.5 percent had smoked a cigar product and 7.2 percent had smoked an e-cigarette. The number of smokers - 1,664 or 19.8 percent - was higher than the number of people with asthma (8.6 percent), obesity (3 percent) and immune disorders (2.4 percent). Additionally, 1.2 percent had diabetes, 0.6 percent had liver disease and 0.5 percent had heart disease.

“The risk of being medically vulnerable to serious illness is halved when smokers are removed from the sample,” said senior author Charles Irwin Jr., MD, of the UCSF Department of Adolescent and Adolescent Medicine. “Efforts to reduce smoking and e-cigarette use among young adults would likely reduce their susceptibility to serious disease.”

Gender differences in five vulnerability indicators

Gender differences were found in five vulnerability indicators. Women were more likely to have asthma (10 percent versus 7.3 percent), be obese (3.3 percent versus 2.6 percent) and have immune disorders (3.2 percent versus 1.6 percent). But significantly fewer young women smoked, resulting in a medical vulnerability of 29.7 percent compared to 33.3 percent for young men.