In Those With Obesity, Will Losing Weight Cut COVID-19 Severity?

Marlene Busko

November 16, 2020

Editor's note: Find the latest COVID-19 news and guidance in Medscape's Coronavirus Resource Center.

As study after study piles up showing that those with obesity who become infected with SARS-CoV-2. are more likely to have severe disease, Medscape Medical News asked experts during the virtual ObesityWeek® Interactive 2020 meeting if they had any advice for clinicians and patients.

Pichamol Jirapinyo, MD, MPH, associate director of bariatric endoscopy at Brigham and Women’s Hospital, Boston, Massachusetts, presented a study on those with obesity from New England hospitals which adds to the evidence that this is "a vulnerable population for COVID-19, like elderly or immunocompromised people," Jirapinyo told Medscape Medical News.

These findings reinforce the need for clinicians to be "more aware of complications of obesity and refer earlier for treatment," she added.

One audience member wanted to know if there are data showing whether people with a BMI above 35 kg/m2 who successfully lose weight subsequently have lower rates of hospitalization, ICU admission, and death if they become infected with SARS-CoV-2.

Jirapinyo said she is not aware of any such studies, but anecdotally, two of her patients who had endoscopic sleeve gastroplasty last fall (whose BMI dropped from about 38 kg/m2 to 30 kg/m2) and later became infected with COVID-19 had mild symptoms.

But David A. Kass, MD, director, Institute of CardioScience, Johns Hopkins University School of Medicine, Baltimore, Maryland, cautioned that the biology of COVID-19 is complex in patients with obesity "and immune system dysfunction is present as are physical factors that could limit breathing."  

"Whether this gets reversed by weight loss is an attractive hypothesis, but at this point, it's still a hypothesis," he stressed to Medscape Medical News.

Changes to Immunity, Inflammatory Signaling in Obesity

"There must be north of 600 or more studies by now with this message that obesity — particularly severe obesity with a BMI of 35 kg/m2 and higher — is a strong independent risk factor for worse COVID-19 outcome," Kass emphasized.

"[COVID-19] revealed to the public in a somewhat dramatic fashion that being very obese does put one at higher risk of this disease being more debilitating and even fatal," he added.

"Before this pandemic, many viewed obesity as only a problem if you have the other associated diseases — hypertension, diabetes, heart disease, atherosclerosis, obstructive sleep apnea, etc."

"What was not as appreciated is that marked obesity changes the body in various ways all by itself — altering metabolism, inflammatory signaling, immune surveillance, and responsiveness (including a less robust response to vaccines that has been written about as well)."  

"This is a bit like having a genetic abnormality that makes you at higher risk for getting, say, cancer," he explained.

"It is there, it is real, it has an impact — but it still does take other stresses to reveal the risk potential. COVID-19 did that with obesity," he said.

Latest Study on Effect of Obesity, Diabetes on COVID-19 Severity

The study presented by Jirapinyo and colleagues identified 1680 patients with COVID-19 at six hospitals in March 2020. Patients were a mean age of 51 and had a mean BMI of 29.4 kg/m2, and 39% had obesity. Patients who required hospitalization were more likely to have obesity (46% vs 35%; P < .0001).

Obesity was a significant risk factor for hospitalization (odds ratio [OR], 1.7), ICU admission (OR, 1.8), and intubation (OR, 1.8; all P < .001), after controlling for age, sex, cardiovascular, pulmonary, liver, and kidney disease, and cancer. 

Compared to having a normal weight, having severe obesity was also associated with roughly threefold higher risks of ICU admission and intubation — after controlling for major comorbidities.

Pandemic Focuses Minds on Obesity Prevention, Treatment 

Naveed Sattar, MD, PhD, told Medscape Medical News that these latest findings are "highly consistent with other studies that point to excess adiposity as a potential modifiable risk factor for more severe COVID-19."

It "also strongly suggests that if people are worried about their risk for COVID-19 and want to improve their chances of a milder outcome, then it is reasonable to encourage them to make sustainable lifestyle changes that may lessen weight and improve their fitness levels," said Sattar, professor metabolic medicine, University of Glasgow, United Kingdom.

"But of course, the big worry," he added, "is that many are putting on weight due to lockdowns, less commuting to work, anxiety, and overeating and drinking, etc, so that many are struggling, and especially those at highest risk, such as those living in more overcrowded housing, etc. By contrast, more advantaged folk may have an easier time to improve lifestyles," he said.

The pandemic highlights that "we need a concerted effort on obesity prevention and treatment," according to Sattar.

"For years we have realized links between obesity and chronic cardiometabolic conditions," he said, "but to think excess weight may also be detrimental to acute effects of a novel virus running amok in the world has focused minds on obesity in a manner not seen before."

"Whether these new painful learnings lead to a more determined effort in countries to improve the obesogenic environment or to place more resources into prevention and management of obesity remains to be seen," he said. 

Increased Enquiries About Bariatric Surgery Following COVID-19

Meanwhile, Matthew M. Hutter, MD, MPH, president, American Society for Metabolic and Bariatric Surgery, told Medscape Medical News that "COVID-19 and studies like this are now making many aware that obesity is not just a lifestyle choice or a cosmetic issue, but "a disease that needs to be taken seriously" and treated.

"Metabolic and bariatric surgery is a very safe and effective treatment for persons with obesity with a BMI > 40 kg/m2 or BMI > 35 kg/m2 and related diseases like diabetes, hypertension, sleep apnea, reflux, back pain, and many others," added Hutter, who is also professor of surgery, Harvard Medical School, Boston, Massachusetts.

"Recently, some metabolic and bariatric centers have seen an increase in patients considering surgery," he said. "Some say that COVID-19 has made them realize they need to do something to be healthier." 

"Currently, less than 1% of those who could benefit from surgery are actually having” it each year, Hutter noted, "and I think there are many who should seriously consider surgery to be healthier, live longer, and live better."

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