Weight loss can lower COVID risks in people with obesity
Obesity is a complex and chronic disease that can affect several organs in the body, and can cause other related conditions such as heart disease, stroke, diabetes and cancer — all known risk factors for severe COVID-19.
Studies have shown people with obesity who develop COVID-19 face higher risks of hospitalization, invasive mechanical ventilation and death, but could weight loss before coronavirus infection reduce their likelihood of progressing to severe disease?
A new study published Wednesday, Dec. 29, in the journal JAMA Surgery “provides reasonably strong evidence” that’s the case.
Among more than 20,000 people with obesity, those who had weight loss surgery years before their coronavirus infection had a 60% lower risk of experiencing severe COVID-19 complications than people without prior weight loss, according to the Cleveland Clinic research.
Prior weight loss was also associated with a 49% and 63% lower risk of COVID-19 hospitalization and need for supplemental oxygen, respectively.
The findings are correlational, meaning people with obesity who have completed weight loss surgery are not guaranteed reduced risks of severe COVID-19. But researchers say their data suggests those who did were healthier at the time of their infection, which could explain their better clinical outcomes and points to obesity as a “modifiable risk factor.”
The study was funded by a research grant from Medtronic — an American-Irish medical device company — but researchers note the company didn’t play a role in the study’s design, data collection, management, interpretation or review.
Patients included in the study underwent weight loss surgery between 2004 and 2017, which gave researchers enough time to see whether health benefits gained over time could have contributed to patients’ reduced risks of severe COVID-19. The study does not say whether devices developed by Medtronic were used in the study participants’ surgeries.
“Striking findings from the current study support the reversibility of the health consequences of obesity in the patients with COVID-19,” senior study author Dr. Steven Nissen, chief academic officer of the Heart, Vascular and Thoracic Institute at Cleveland Clinic, said in a news release. “This study suggests that an emphasis on weight loss as a public health strategy can improve outcomes during the COVID-19 pandemic and future outbreaks or related infectious diseases.”
About 5,000 people with obesity who had weight loss surgery were matched to a control group of more than 15,000 non-surgical patients. Although clinical outcomes were better among those who had surgery, researchers did not find a lower risk of coronavirus infection between the groups.
More than 40% of the U.S. population has obesity, according to the Centers for Disease Control and Prevention. Yet, researchers predict that percentage will grow over the years.
A 2019 Harvard study estimated half of the adult population in the U.S. will have obesity and about a quarter will have severe obesity by 2030.
“We believe this study provides reasonably strong evidence that obesity is a modifiable risk factor for severe COVID-19 infection and that a successful weight loss intervention can play a role in improved COVID-19–related outcomes,” the researchers wrote in the study. “Because conducting clinical trials in this setting is not feasible, the findings of this study represent the best available evidence on the implications of a successful weight loss intervention for COVID-19 outcomes.”