As the COVID-19 pandemic sweeps over the world, much is still unknown about the virus.
New studies have indicated that outside of age and co-morbidities, obesity may be a risk factor. Other experts have pointed out that the evidence to back this up is scarce. In fact, this could increase the stigma against treating obese patients - which is what truly makes obesity a risk factor.
So what’s the truth? Fact-checking site Politico gave this news a ‘half-truth’ verdict; FIT investigates.
Looking at Obesity As a Risk Factor for COVID-19
The US’s Center for Disease Control and Prevention advised that “severe obesity” or a body mass index (BMI) of 40 or above puts people at risk of COVID-19 complications.
Obesity is often a risk factor for serious underlying conditions like hypertension, heart disease, diabetes and even certain cancers, according to Mayo Clinic. The CDC adds that severely obese people could also get serious breathing problems like acute respiratory distress syndrome (ARDS), which makes them even more vulnerable to COVID-19 (which is a respiratory disease.)
However, a meta-analysis found that “obesity and morbid obesity are associated with lower mortality in patients with ARDS.”
Another preliminary study from NYU Langone Health of over 4,000 COVID-19 patients found that most patients who were admitted had two factors: they were “older than 65 years and obese.” NYU School of Medicine’s researchers wrote a letter to the editor of the journal Clinical Infectious Diseases which provided anecdotal evidence by doctors that pointed to a link between COVID and obesity - especially among younger patients. A small French study of 124 people found that obesity was present in patients admitted for COVID-19 and those admitted to the ICU.
Furthermore, obesity was shown in the 2009 H1N1 influenza pandemic to cause poor prognosis and death. However, a 2016 study disproved any link and actually proved something startling: thinner people got faster anti-viral treatments. So actually, healthcare stigma and not actual obesity was the real issue.
With all these studies come many caveats: from the research’s limited scope to there not being enough data as yet in the pandemic and more.
Lack of Evidence
The problem is that the evidence, so far, to link obesity to COVID-19 is weak. Many of the studies are not peer-reviewed which means it has not been scrutinized by other scientists for accuracy. That’s a pretty big step to take before assuming causal links!
Dr Leora Horwitz, associate professor and Langone, said that COVID-19 cases often see significant inflammation and obesity increases inflammation so a link may be possible. But without peer reviewing and making clear the link, the results are fallible.
Evidence from most studies across the world has proven that those at risk are the elderly and people with underlying conditions. Obesity has not featured prominently on any list.
Take this Chinese study titled the ‘Clinical Characteristics of Coronavirus Disease’ or in India, the Ministry of Health and Family Welfare’s report on those at risk also included the elderly and people with “comorbidities like diabetes, hypertension, chronic kidney disease and chronic obstructive pulmonary disease,”- but no obesity.
Over-reliance on BMI and Stigma
According to Harvard Medical School, BMI may not be the best indicator of obesity or subsequent health risks. This is because it can only tell you your body fat percentage based on your height and weight but not exactly where the fat is stored - which is vital to “determine cardiovascular risks.” They suggest using a waist-to-hip ratio to get a better sense of the situation.
Another problem with BMI and obesity is often the stigma attached to both that colour doctors and physician's perspectives. Many studies have found that doctor’s biases cloud their judgement, and obese people receive poorer health. Very often, a patient’s weight is blamed for their ill health without further investigation into the real causes. This leads to severe underdiagnoses or misdiagnoses - worsening their health.
According to Joy Cox, a researcher at Rutgers New Jersey Medical School, this stigma is leading to worse treatment for COVID-19 as well, reports Wired.
Of course, this can work both ways, with obese people refusing to seek treatment because of “perceived bias,” as this US study says, which also worsens their health.Of course, this can work both ways, with obese people refusing to seek treatment because of “perceived bias,” as this US study says, which also worsens their health.
On the other hand, weight is assumed to be such a direct indicator of health that obese people are weighed more - leading to an overrepresentation of BMI data.
No Control of Co-Morbidities
The studies linking BMI to COVID-19 don’t control for co-morbidities - making it almost a chicken and egg game. What causes mortality? Co-morbidities like diabetes, asthma and more or obesity or both? Or medications used for either?
These are important answers that are just not there. Both the CDC report and the NYU letter don’t control for diabetes or cardiovascular diseases, reports Wired.
Even the French study does not control these risk factors (though it does control for diabetes and hypertension) so the link remains fuzzy.
To be clear, being obese does put one at risk of developing serious conditions like hypertension, diabetes, CVD and more that are linked with COVID-19 risk. But does this mean that being obese is a risk factor? That seems to be jumping a few dots.
This is dangerous for two reasons:
- It assumes obese people are more at risk and can put people actually at risk behind the queue.
- BMI as an indictor can often show up the wrong people at risk, again leaving behind vulnerable folk.
COVID-19 Mortality is Due to Many Reasons - Even Socio-Economic Ones
Another main reason to doubt these findings?
COVID-19 deaths are largely, so far, linked to age, diabetes, co-morbidities, smokers and immunocompromised patients. But also because of delayed healthcare access often due to poor public health systems, systemic inequalities (trans people in India are often denied healthcare), and financial restraints.
Furthermore, in pure BMI terms, women have higher BMI’s and yet studies suggest they are at lower risk of COVID-19. So a study of obesity needs to make clear the link - while controlling for other associated factors.
The Obesity Paradox
There are several studies which actually provide evidence of obesity protecting against pneumonia, heart failure and more.
This study in the BMC Journal says there is an “obesity survival paradox’ for pneumonia,” but admits more studies are needed to confirm the results. Similarly, a study in the Journal Science Direct questions the link between diabetes and obesity. It observed better survival rates and less hospitalization for diabetes in severely obese people, though it again called for more studies, especially more “randomized controlled trials where obese patients adopted a healthy lifestyle to see if it improves type 2 diabetes patients’ survival.”
What this all basically means is: obesity is a complex issue, with many factors and links to be explored further.
There’s an interesting study that says even reading about anti-obesity news, like its links to COVID-19, can bias healthcare providers and “shift beliefs about weight-related health risks.”
So, the risks of obesity are well-known but linking it to COVID-19 needs more nuance and proof for now - or it can do more harm than good.
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