A BMI that is too high is associated with greater risks of Covid-19 infection and long Covid unlike the blood sugar level, according to a British meta-analysis.
- For adults, there is overweight when the BMI is equal to or greater than 25 and there is obesity when the BMI is equal to or greater than 30, according to the WHO.
- More than 47% of Covid patients entering intensive care are obese (Ministry of Health).
- Nearly one in two French people (47%) is either overweight (30%) or obese (17%), according to the League Against Obesity.
“Early in the pandemic, research identified diabetes and obesity as risk factors for becoming seriously ill with Covid-19. And we know that many people with type 2 diabetes also have excess Our early findings support the idea that obesity-related mechanisms may be responsible for the excess Covid-19 risks associated with diabetes, rather than hyperglycemia per se.”, said Dr Knuppel, at the annual meeting of the European Association for the Study of Diabetes (EASD) in Stockholm. She and her colleagues at University College London carried out a meta-analysis of nine UK studies. Their findings reveal that too high a BMI is associated with a greater risk of Covid-19 infection and a longer Covid.
Being overweight increases the risk of Covid infection by 10%
Analysis of data from 31,252 participants from nine studies found that higher BMI was associated with a greater likelihood of Covid-19 infection, with a 7% higher risk for each 5 kg/m2 increase of BMI. People who were overweight (BMI 25 to 29.9 kg/m2) and obese (30 kg/m2 or more) had a 10% and 16% higher risk of Covid-19 infection, respectively, than people who were not overweight (less of 25 kg/m2).
Similar results were seen for long Covid (4,243 participants from six studies) — with a 20% higher risk for each 5 kg/m2 increase in BMI. Overweight and obese people had a 20% and 36% higher chance of developing long Covid, respectively.
In parallel, studies on average blood sugar (HbA1c) and diabetes have not revealed any association with Covid-19 or long Covid.
Severe Covid: why does being overweight increase the risks?
The researchers stress the need for further research to explore the mechanisms underlying these associations and the possibilities of reducing the risk associated with high BMI. “We need to explore more what makes overweight and obese people at risk and how this relates to severe cases”emphasized Dr. Knuppel.
The authors acknowledge that their study was observational and cannot prove that a higher BMI definitely increases the risk of Covid-19 infection. They also cannot rule out the possibility that other unmeasured factors or missing data may have affected the results. They also point out that the data on Covid-19 infections was based on participant reports rather than positive tests and that clinical measures taken before the pandemic may be outdated for some of the nine studies. Finally, they note that study participants were healthier than the general population, which may limit the conclusions drawn.