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News From the Centers for Disease Control and Prevention
April 27, 2021

More Severe Obesity Leads to More Severe COVID-19 in Study

JAMA. 2021;325(16):1603. doi:10.1001/jama.2021.4853

The greatest risk of developing severe COVID-19 and being hospitalized with the disease or dying of it was in patients with the highest body mass index (BMI) scores, according to a CDC report.

About 40% of US adults are obese, which some recent reviews suggest puts them at greater risk of severe COVID-19 due to chronic inflammation, reduced immune response, or blunted treatment response.

Using data from nearly 150 000 US adults diagnosed with COVID-19 from March to December 2020, the analysis showed that half of the patients were obese and about 28% were overweight based on BMI—calculated as weight in kilograms divided by height in meters squared. Among them, the risk of hospitalization, admission to the intensive care unit, and death were lowest among patients whose BMI was in the healthy range of 18.5 to 24.9 or just above it. The risks rose sharply as BMIs increased.

The relative risk of mechanical ventilation among individuals with the highest BMIs of 45 or greater was up to double that of patients with a healthy weight. In addition, the highest BMIs were linked with a 61% increased risk of death and a 33% increased risk of hospitalization compared with healthy weight. Patients with a BMI between 30 and 34.9 had a 7% increased risk of hospitalization, an 8% increased risk of dying, and a 35% increased risk of mechanical ventilation compared with patients in the healthy weight category.

“The findings in this report highlight a dose-response relationship between higher BMI and severe COVID-19–associated illness and underscore the need for progressively intensive illness management as obesity severity increases,” the authors wrote. “Preventing COVID-19 in adults with higher BMIs and their close contacts remains important and includes multifaceted protection measures such as masking, as well as continued vaccine prioritization and outreach for this population.”