Being obese can increase the risks of death or complications and hospitalization in people who contract COVID-19, according to three recent studies and updated guidance on risk factors from the Centers for Disease Control (CDC). In addition, one of the studies noted that being physically active can lower the risk of COVID-19 contraction.
Underlying health conditions that put people at higher risk of more severe outcomes, such as hospitalization or even death, when they contract COVID-19 include a BMI of more than 30, cardiovascular disease and type 2 diabetes among other conditions, Dr. Jay Butler, COVID-19 incident manager for the CDC, shared in a June 25 press briefing.
Previously, the CDC noted that severe obesity (BMI of more than 40) was a risk factor, but now the CDC has said that a BMI of 30 or more may also increase risk.
“I think we have to recognize the reality: Our nation isn’t as healthy as some other nations, particularly as you look at the issue of obesity or at some of these chronic medical conditions,” CDC Director Dr. Robert Redfield said in the press briefing.
This update on risk factors for COVID-19 severity comes around the time that several studies on COVID-19 were released.
A study in the United Kingdom concluded that “adopting simple lifestyle changes could lower the risk of severe COVID-19 infection.”
Data from Public Health England was collected from March 16-April 26 of patients testing positive for COVID-19 who had been admitted to the hospital. The study found that physical activity had a protective factor against COVID-19, even if activity levels were below the suggested 150 minutes of moderate to vigorous activity per week. The authors noted the protective effects of physical activity could be due to exercising decreasing inflammation and improving immunity.
The study also noted that being overweight and obese increased the chance of more severe COVID-19, perhaps due to immune hyper-reactivity, impaired metabolic responses or the effects that obesity has on the ability of lungs to work effectively.
In another study, this one by the University of Chicago Medicine, obesity was determined to be a significant predictor for mortality among patients with COVID‐19. The study looked at the records of COVID-19-positive patients admitted to the University of Chicago Medical Center from March 1-April 18. The sample size was 238 people, which the authors noted was a small sample size.
“For every increase from one BMI category to the next, there was a 70 percent increased odds of mortality in the multivariable model,” the study’s authors wrote. “This finding provides further evidence that obesity is a key comorbidity in COVID-19 that may not only predict severe disease requiring hospital admission, oxygen supplementation, or mechanical ventilation, but may also predict increased mortality.”
This finding is consistent with findings of higher risk factors obesity offers for other severe viral infections, including H1N1, the authors wrote.
Another study looked at obesity in people under 60 and found that obesity in people in this younger age group who test positive for COVID-19 can lead to a greater chance of hospitalization. The study of patients admitted to a large academic hospital system in New York City looked at the records of 3,615 people admitted to the hospitals who tested positive for COVID-19 and were younger than 60. Thirty-seven percent of the patients had a BMI of 30 or more.
Patients in this age group with a BMI between 30 and 34 were two times more likely to need acute and critical care compared to individuals with lower BMIs. Patients with BMIs of 35 or higher were 2.2 and 3.6 times more likely to be admitted for acute and critical care.
Although people under 60 are considered lower risk for severe COVID-19, the study’s authors found that “obesity appears to be a previously unrecognized risk factor for hospital admission and need for critical care” for this group.
“This has important and practical implications, where nearly 40 percent of adults in the United States are obese with a BMI of greater than 30,” the authors wrote.