Obese men are more likely to die from Covid than fat women, study finds

  • Study of 3,500 hospital patients in New York showed obese men suffer more 
  • Men were more likely to suffer severe Covid at lower BMI levels than women 
  • Researchers were unable to determine why obesity affects men more 

Obese men are more likely to die from and suffer severe Covid than obese women, research has suggested.

Data from 3,530 infected patients admitted to hospital in New York found men do not need to be as fat as women to have a 'significant association with higher in-hospital mortality'.  

Academics also discovered obesity may be a stronger risk factor for severe Covid pneumonia and the need for a ventilator in men than in women.

In the study, a BMI of 35 to 39.9 was regarded as class II obesity, while 40 and over was regarded as class III.

Obese patients had a higher likelihood of dying in hospital, developing severe pneumonia or needing to be hooked up to a ventilator, compared to adults who had a healthy weight.

The association was stronger the fatter people were, according to results published in the European Journal of Clinical Microbiology and Infectious Diseases.

The authors of the study said men were more likely to suffer severe Covid at lower levels of obesity than women. 

The researchers were unable to determine why obesity had a stronger link to severe Covid in men than in women. 

Obese men are more likely to die from and suffer severe Covid than obese women, research in New York has suggested [stock photo]

Obese men are more likely to die from and suffer severe Covid than obese women, research in New York has suggested [stock photo]

WHY DOES BEING OVERWEIGHT MAKE COVID WORSE? 

People who are overweight or obese are more likely to develop severe Covid and die from it because they are generally less healthy and have worse immune systems.

Covid has been found to prey on people who don't have good health – it causes fluid build-up in the lungs, blood clotting, swelling in the airways and blood vessels, intense fever and can trigger immune over-reaction. All of these can seriously damage vital organs.

Overweight people are more likely to suffer severe versions of these effects because their bodies are already struggling to cope as a result of the strain of carrying excess fat, hormonal and chemical changes triggered by obesity and higher rates of long-term illnesses like diabetes and high blood pressure. 

Fat in the belly pushes up on the diaphragm – the breathing muscle – and compresses the lungs, making them weaker and less able to chuck out the viruses when they get in, Science magazine explains. 

Blood is also more likely to clot because vessels are damaged and don't work properly, partly because of constant swelling and irritation caused by chemicals released by fat. One researcher told Science obese people with Covid had 'the stickiest blood I have ever seen'. These clots then travel to the lungs and other organs and can be deadly.

The immune system is also weaker in overweight people because fat cells intrude on organs that would normally make white blood cells, such as the bone marrow, meaning their capacity to work as normal is reduced. This means it takes longer to fight off the virus, if the body is able to do it at all.

And any organ dysfunction, such as that caused by heart disease, lung disease, diabetes, high blood pressure or dementia, has been found to make Covid-19 worse as it preys on damaged parts of the body and worsens existing problems. All of these are reported to be more common in obese people. 

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They found of the men who died with coronavirus tended to have higher levels of systemic inflation — an immune over-response — than women.

But the team, from the Montefiore Medical Centre in the Bronx, New York, couldn't link that to obesity.

Dr Jamie Hartmann-Boyce, senior research fellow in health behaviours at the University of Oxford, said more work was needed due to the small number of women in the study.

He added: 'Larger studies are needed before we can say with any certainty that class II obesity is less of a risk factor in women than in men.

'What we can say for certain now is that obesity is associated with an increased risk of worse Covid-19 outcomes in and of itself, and is a risk factor for conditions such as type 2 diabetes which also predispose to worse outcomes.

'Obesity is a complex, chronic, and relapsing condition and a major contributor to health inequalities. Structural drivers of obesity urgently need to be tackled.'

Obesity has been linked to more serious reactions to Covid because it causes lung and arterial damage, which make the effects of the virus more dangerous.

Previous studies suggest being overweight can raise the risk of severe Covid by 40 per cent, while obese people are 70 per cent more likely to be hospitalised with the disease. 

The study looked at data from patients admitted between March 10 to May 1 last year.

Out of the 3,530 patients included in the analysis, 1,579 were women, 896 had a BMI below 25, 1,162 had a BMI of 25–29, 809 had a BMI of 30–34 and 663 had a BMI of 35 or above.

The authors also investigated if systemic inflammation was linked to an increased risk of death.

Dr Arcelia Guerson-Gil, one of the authors of the paper, said: 'It is known that a major cause of disease severity and death is an excessive inflammatory response that is associated with high levels of circulating cytokines, such as IL-6.

'Obesity is considered a state of enhanced chronic inflammation, so we suspected there may be an association between body mass index and systemic inflammation as indicated by IL-6 level. However, we found that this wasn't the case.' 

The authors suggested obesity may lead to poor outcomes for Covid due to other factors, such as poorer lung function, increased work of breathing or a higher expression of a receptor called ACE2, which allows Covid to enter cells in fat tissue.