Two big risk factors are emerging over who will develop severe COVID-19 infections that lead to hospitalizations and needing intensive care. A number of studies throughout the world are reporting that the main risk factor in persons under 60 years is being significantly overweight, especially obesity, and the other risk factor is being over 65 years of age.
What is significantly overweight? A body mass index (BMI) of 30 or more is considered obese - probably 40 pounds or more overweight. For example, a 5 ft 5 inch person weighing 181 pounds or more, or a 5 ft 10 inch person 210 pounds or more. [see BMI chart]
Two studies of New York City hospital patients had similar findings. Doctors at NYU Langone Health (Lighter et al) found that overweight patients who were under age 60 were twice as likely to be hospitalized as their thinner peers, while those who were obese were three times as likely to need intensive care, the study found. And this is in patients who didn't have any other diseases or conditions - they were healthy, but overweight. The medical thinking is that this may because obesity is a state of chronic inflammation.
The scary part is that the US has a very high obesity rate - with the NYU researcher Jennifer Lighter pointing out that nearly 40% of adults in the US are obese with a body mass index (BMI) of 30 or more!
A French study found that a key finding was that those with a BMI of greater than 35 had more than sevenfold increased risk of requiring mechanical ventilation (compared to those with a BMI of less than 25). Studies are also finding that disease severity increased with increasing BMI.
Interestingly, obesity wasn't a predictor of severe disease leading to hospital admission or the ICU (intensive care unit) in those over the age of 60 years. But in those younger than 60 years, it was.
Excerpts from Medscape: Obesity Link to Severe COVID-19, Especially in the Under 60s
It is becoming increasingly clear that obesity is one of the biggest risk factors for severe COVID-19 disease, particularly among younger patients.
Newly published data from New York show that among those under 60, obesity was twice as likely to result in hospitalization for COVID-19 and also significantly increased the likelihood that a person would end up in intensive care.
"Obesity [in people < 60 years] appears to be a previously unrecognized risk factor for hospital admission and need for critical care. This has important and practical implications when nearly 40% of adults in the US are obese with a body mass index [BMI] of ≥ 30," write Jennifer Lighter, MD, NYU School of Medicine/NYU Langone Health, and colleagues in their research letter published online April 9 in Clinical Infectious Diseases.
Similar findings in a preprint publication, yet to be peer reviewed, from another New York hospital show that, with the exception of older age, obesity (BMI > 40 kg/m2) had the strongest association with hospitalization for COVID-19, increasing the risk more than sixfold.
Meanwhile, a new French study shows a high frequency of obesity among patients admitted to one intensive care unit for COVID-19; furthermore, disease severity increased with increasing BMI.
One of the authors told Medscape Medical News that many of the presenting patients were younger, with their only risk factor being obesity.
Coauthor of the French article, published online April 9 in Obesity, François Pattou, MD, PhD, told Medscape Medical News that when patients with COVID-19 began to arrive at their intensive care unit in Lille there were young patients who did not have any other comorbidities.
"They were just obese," he observed, adding that they seemed "to have a very specific disease, something different" from that seen before, with patients becoming very sick, very quickly.
A key finding was that those with a BMI > 35 kg/m2 had a more than sevenfold increased risk of requiring mechanical ventilation (odds ratio [OR], 7.36; P = .021), compared to those with a BMI < 25 kg/m2, even after adjusting for age, diabetes, and hypertension.
The studies out of New York, one of which was stratified by age, paint a similar picture.
Obesity wasn't a predictor of admission to hospital or the ICU in those over the age of 60 years, but in those younger than 60 years, it was.
Pattou believes that the culprit behind the increased risk of disease severity seen with obesity in COVID-19 is inflammation, mediated by fibrin deposits in the circulation, which his colleagues have seen on autopsy, and which "block oxygen passage through the blood."