COVID-19 Positivity Increases with Age, BMI and Waist Circumference
February 4/2021
by Françoise Makanda, Communications Officer at DLSPH
If you’re over the age of 65 and have a high waist circumference, you are more likely to test positive for COVID-19 regardless of your BMI, U of T researchers have observed.
It’s the first study to include waist circumference and BMI together to assess the likelihood of testing positive to COVID-19.
PhD Student Rebecca Christensen
“Research has already shown that as BMI increases, individuals have a greater risk for testing positive for COVID-19 but once you include waist circumference, we saw that waist circumference is an independent predictor of risk,” says research lead and PhD student Rebecca Christensen of the Dalla Lana School of Public Health.
High waist circumference was a significant predictor for testing positive for COVID-19 for those aged 65 or older only. “Obesity was always part of the conversation in a way, but researchers weren’t considering the BMI and waist circumference together,” adds Christensen.
DLSPH Prof. Jennifer Brooks, student Shelby Sturrock, alumnus Jasleen Arneja and Christensen used data from UK Biobank with age 40 or older and included more than 9,000 adult participants.
People under the age of 65 still had an increased risk of testing positive for COVID-19 as their BMI increased but there was no significant association for high waist circumference.
Researchers suggest that lifestyle changes may be a protective measure to reduce test positivity among those under 65. Christensen also argues that another protective measure against the risk of catching COVID-19 have been public health guidelines. Social distancing has proven to be a great deterrent for test positivity in a traditionally high-risk group.
“We weren’t sure why those over the age of 65 with obesity class III were not at an increased risk of positive, but they have around 10 comorbidities on average. Because of this, they are likely not interacting with majority of the population. They’re likely staying home.”
Nonetheless, researchers have confidence in the dataset. The UK has been severely affected by the virus.
“We saw that the population tested was sicker on average, letting us know that they are prioritizing testing those at greatest risk.”