Risk of severe Covid-19 high for obese people, regardless of other factors

  • Brazilian researchers found a high proportion of severe Covid-19 cases involved obesity.
  • The condition was an independent factor compared to other comorbidities and demographic elements.
  • It highlights the need to pay extra attention to obese Covid-19 patients in hospitals.

As the Covid-19 pandemic continues, obesity has been one of the top triggers for severe cases. Outside of the disease, obesity has always had a detrimental effect on health through chronic inflammation, a higher risk of heart disease and a weakened response to viral infections.

But how much does it matter in relation to other conditions, age, sex and race when it comes to contracting a severe coronavirus infection?

READ | Could interaction between Covid-19 and pre-existing bacteria explain severity in the obese?

Obesity vs other comorbidities

To answer this question, Brazilian researchers conducted a meta-analysis of nine studies from five countries on severe Covid-19, which included more than 6 500 patients. More than half were male and had comorbidities such as hypertension (51.51%), diabetes (30.3%), cardiovascular disease (16.66%), lung disease (15.99%), renal disease (7.49%), cancer (5.07%), and immunosuppression (1.8%). A high proportion of patients were smokers and suffered from dyslipidemia - a condition involving high levels of cholesterol or fat in the blood.

They wanted to investigate the prevalence of obesity as a contributing factor in severe Covid-19 cases that required admission to ICU. They also looked at the best treatments that helped obese patients recover from the virus.

The studies they analysed included case studies and series, clinical trials and randomised controlled trials that mentioned obesity. They found that in more than half of severe cases, people suffered from obesity. In terms of other comorbidities, just less than half had hypertension, while type 2 diabetes, lung disease, smokers, cardiovascular disease were each around the 20% mark.

READ MORE | How to keep your kids trim through quarantine

High risk for infection

Not only is obesity a major factor for severe Covid-19, the condition also indicates that these patients are also more likely to be infected with the coronavirus in the first place.

Obese patients are also three to six times more likely to be put on ventilators which can put heavy strain on pulmonary function - already under strain due to the obesity.

"The highlight of this research is that severely obese individuals presented a high risk for progression to critical illness and require ICU care," write the researchers. 

"There was a high frequency of obesity among patients admitted to intensive care due to Covid-19. Invasive mechanical ventilation was associated with severe obesity and was independent of age, sex, diabetes, and hypertension."

This means that obese patients - especially those with more comorbidities - require intensive attention and care in hospital settings when it comes to coronavirus infection in order to avoid death. 

READ | The immune system's response to Covid-19 may be altered by obesity

More infectious

The researchers also claim that more obese populations may harbour more virulent strains of the disease and be more infectious in general. 

Those with the flu have been previously found to shed the virus for a longer period of time and the internal environment of an obese body can also incubate stronger strains due to the body's delayed response to fight off the virus.  

There are also younger cases in high-obesity populations compared to other populations.


However, the analysis didn't find a difference between non-obese and obese patients with severe Covid-19. More case-controlled studies would be needed to compare the fatality rate between these two groups.

Other gaps in the literature they identified include clinical characterisation, infection prevention, mortality reduction, and efficient therapeutic overlap.

"Providing public information to younger adults, reducing the threshold for virus testing in obese individuals, and maintaining greater vigilance for this at-risk population are necessary to reduce the prevalence of severe Covid-19 disease," advise the researchers.

READ | Don't wait to lose weight: Shedding obesity in youth extends life

Image credit: Getty Images

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