Obesity ups odds for severe Covid-19, but age matters

  • The more obese you are, the higher your risk of dying or requiring ventilation
  • This, however, only applies to people younger than 65 years old
  • Researchers noted several reasons why obesity may increase Covid-19 symptoms

If you're younger than 65 years old and obese, Covid-19 poses a special danger to you.

A new study reports that the more obese you are, the more likely you are to either die from infection with the new coronavirus or require lifesaving mechanical ventilation to survive.

Morbidly obese Covid-19 patients are 60% more likely to die or require intubation, compared with people of normal weight, researchers found.

Patients who were mildly obese were 10% more likely to die or need a breathing machine, while those who were moderately obese were 30% more likely, according to the study.

Bigger risk for younger people

"Increasing obesity was associated with an increased risk of lung failure or death in Covid-19," said lead researcher Dr Michaela Anderson, a pulmonologist at Columbia University Irving Medical Center in New York City.

But obesity only posed a risk for people under 65, researchers added.

Anderson said that's probably because older people are sicker, more frail, and more likely to develop respiratory failure with Covid-19 due to health problems unrelated to their weight.

She and her colleagues reviewed medical records for nearly 2 500 patients hospitalised for Covid-19 in March and April at Columbia University Irving Medical Center. They looked at body mass index (BMI), which is based on height and weight. Obesity begins at a BMI of 30; morbid obesity is 40 or over.

"At the beginning of the pandemic in New York, we noticed there were a lot of young and obese people who required breathing tubes to help them breathe," Anderson said. "We were hoping to figure out if weight or body mass index or obesity were associated with the likelihood of developing lung failure if you got infected with Covid."

About 25% of the patients died and 22% required mechanical ventilation. On average, they were hospitalised for one week, researchers found.

Simple body mechanics

Looking at BMI, researchers found that excess pounds did increase patients' risk of severe Covid-19 – but only if they were young or middle-aged.

Anderson said there are several reasons why obesity might worsen Covid-19 symptoms, starting with simple body mechanics.

"If you have a big, obese belly, does that push up on your lungs and make it harder for you to expand your lungs?" she said.

Fat tissue also produces biochemicals known to promote inflammation and blood clotting – two factors linked to more severe Covid-19 infection, Anderson added.

"Fat tissue doesn't just sit there and store fat," she said. "It also does lots of other things that can influence your health."

It also might be that other illnesses associated with obesity, such as diabetes or high blood pressure, contribute to Covid-19's impact on the body, said Dr Aaron Glatt, chief of infectious diseases at Mount Sinai South Nassau in Hewlett, New York.

Prolonged physical distancing

He said this study basically confirms what experts have suspected. "Clearly every study has shown obesity potentially contributes to more severe illness, more intubations and even death," said Glatt, who wasn't part of the new research.

Based on the evidence, people who are obese might want to hew even more closely to physical distancing and other methods of protecting themselves against infection, Anderson said.

"It's important for doctors and patients to really think about how long they should prolong physical distancing, whether they should continue to try to avoid contact until the pandemic is under better control," she said. "People who are obese and young may want to consider prolonged physical distancing and minimising risks for a little longer than people who are not obese."

Glatt agreed.

"Every person should attempt to minimise their exposure to Covid, regardless if they are obese or not, regardless if they have risk factors or not," Glatt said. "The more risk factors you have, the more risk-averse you should be."

The findings were published on 29 July in the Annals of Internal Medicine.

Image credit: iStock

We live in a world where facts and fiction get blurred
In times of uncertainty you need journalism you can trust. For 14 free days, you can have access to a world of in-depth analyses, investigative journalism, top opinions and a range of features. Journalism strengthens democracy. Invest in the future today. Thereafter you will be billed R75 per month. You can cancel anytime and if you cancel within 14 days you won't be billed. 
Subscribe to News24
Show Comments ()
Editorial feedback and complaints

Contact the public editor with feedback for our journalists, complaints, queries or suggestions about articles on News24.