Obesity was a risk factor for intubation and death from COVID-19 for adults under the age of 65.
For adults under age 65 years, obesity was associated with increased risk for intubation or death from the novel coronavirus 2019 (COVID-19), according to a paper published in Annals of Internal Medicine.
Investigators from Columbia University Irving Medical Center conducted a retrospective study of adults admitted to the hospital from the emergency department with positive COVID-19 test results between March 10 and April 24, 2020 in order to determine the relationship between obesity and intubation or death, inflammation, cardiac injury, or fibrinolysis. The patients were confirmed to have COVID-19 using a PCR test from nasopharyngeal swab. The investigators followed up with patients for in-hospital mortality through June 10, 2020.
The investigators used standard World Health Organization classifications for measures of body mass index, they said, and used the term “overweight” to describe BMI of 25 to 29.9 kg/m2 as the reference group. The study authors also acknowledged that obesity is already known as a risk factor for pneumonia and acute respiratory distress syndrome.
There were 2,466 hospitalized adults with COVID-19 included in the analysis. The patients’ median age was 67 years, 58% were male, and about half were Hispanic, the study authors said. The median BMI of this hospitalized group was 27.9 kg/m2. The study authors said half of the patients had hypertension, 40% had diabetes, and the median number of comorbid conditions was 2.
The patients with class 2 or 3 obesity, which meant a BMI of >35 kg/m2, were younger, less likely to be male, more likely to be black, and less likely to have chronic kidney disease or a history of smoking, the study authors reported. Patients with BMI less than 18.5 kg/m2 or greater than 35 kg/m2 were more likely than class 2 or 3 obesity patients with COVID-19 to have asthma, COPD, or pulmonary heart disease, they added.
During a median hospital stay of 7 days, 22% patients were intubated, a quarter died, half were discharged, and 2% remained hospitalized. Overweight patients with COVID-19 were more likely to be intubated or die compared to those patients who were underweight or who were above the overweight range, the study authors found. This remained true when the study authors analyzed factors such as sex, diabetes, and hypertension; however, it was not the case for adults aged over 65 years. Obesity was only a risk factor for intubation or death for COVID-19 patients under 65 years, the analysis showed.
“Our findings provide evidence to support recommendations from the Centers for Disease Control and Prevention in the United States and the National Health Service in the United Kingdom, which state that patients with a BMI of 40 kg/m2 or greater are at high risk for poor outcomes from COVID-19 and should therefore consider prolonged social distancing,” the study authors wrote. “As the United States and other countries begin to lift stay-at-home orders, these findings might inform discussions between health care providers and patients regarding advanced care planning and benefits of prolonged social distancing, particularly for younger adults with class 2 or 3 obesity.”
While the study authors don’t currently know what mechanisms influence the relationship between obesity and acute respiratory failure and death from COVID-19, they had a few hypotheses, including that more adipose tissue in a body may head to immune activation. They also said that obese patients are more likely to have comorbidities, which may predispose them to greater cardiac dysfunction during acute illness, they wrote.
“Additional investigations should evaluate potential mechanisms linking obesity and respiratory failure in COVID-19, including the role of specific inflammatory cytokines, complement-mediated endothelial cell dysfunction and thrombosis, and chest wall mechanics,” the study authors concluded.