As of September 2020, nearly 30 million worldwide have had COVID-19 and it carries a global mortality rate of 3.7%. The largest obstacle to reining in spread of this virus has been the fact that range of symptoms are unpredictable, from minimal to severe respiratory compromise with diffuse lung damage and death. As COVID-19 initially marched across China and Italy, scientists honed in on factors, such as old age, hypertension, diabetes, and coronary artery disease, which placed specific populations at higher risk. Unfortunately, one risk factor has proven to be fairly catastrophic for the United States: Obesity.
The United States has one of the highest rates of obesity in the world. More than 40% of American adults are obese, which means they have a body mass index (BMI) of 30 or higher. Almost 10% of American adults qualify as severely obese, defined as having a BMI of 40 or more. For example, someone who is 5’4” and weighs 235 pounds has a BMI of 40. For reference, normal adults should have a BMI between 18-24.9. Adults are considered overweight with a BMI between 25-29.9.
While obesity has reached epidemic proportions in the United States, that is not necessarily true for the rest of the developed world. Just 20 percent of the Italian population is obese; 24 percent of the population in Spain; and only 6 percent of the Chinese population qualifies as obese. Even worse, recent research found that the trend in the U.S. trend is getting worse. Obesity rates between 1999-2018 reveal that the proportion of children 6-11 years of age identified as obese has grown from 15% to 19%. The number of obese adolescents aged 12-19 years of age has increased from 16% to 21%. And the same trend holds for those in all age groups who are severely obese.
Facing one “pandemic” already, we were not prepared for that of COVID-19.
A report issued by Public Health England a few months ago concluded that being overweight or obese increased the risk of complications and death from Covid-19. Last spring, it seemed an unusually high proportion of healthcare workers dying of COVID-19 appeared to be overweight in pictures, but at the no one could have predicted how prominently obesity would matter. Since then, nearly 300 scientific articles have reported a clear association between severe obesity and increased morbidity and mortality from COVID-19.
One of the largest studies was published last month in the Annals of Internal Medicine, where researchers examined the records of more than 5000 patients with COVID-19 in the Kaiser Permanente Southern California system. The primary outcome measure of death within 3 weeks of diagnosis. For those with a BMI over 40, the risk of death from COVID-19 was 2.5 times higher and if their BMI was over 45, the risk was 4 times higher.
Those statistics should be somewhat alarming; however, additional findings border on terrifying.
For those patients under 60 years of age, the risk of death increases exponentially with escalating BMI. Compared to their normal weight counterparts, obese patients with a BMI between 35-39.9 are 3 times more likely to die. Of those with extreme obesity — defined as a BMI of 40 or more —the risk of death from COVID-19 is 17 times higher.
As a single risk factor, obesity independently eclipses the mortality risk of other related conditions such as hypertension, diabetes, high cholesterol, or history of a heart attack. Despite the fact that many obese people identify as “healthy,” all bets are off when it comes to fighting COVID-19.
Why are obese patients particularly susceptible to poorer outcomes? We don’t know yet.
Obesity can trigger an excessive immune response to the virus, which may lead to increased lung tissue damage. Abdominal obesity makes it more challenging to breathe while lying down. And while restricted breathing can lead to sleep apnea and even, metabolic dysfunction, the fact that the mortality risk more than doubles makes it unlikely that either of these mechanisms can justify the difference in outcomes.
I have suspected for some time that the elusive ACE 2 Receptor (Angiotensin-Converting Enzyme Receptor 2)—the docking protein required for SARS-CoV-2 to enter the cell and produce viral copies—is the culprit determining disease severity. Research reveals that fat cells have much higher levels of ACE 2 receptors than are found in the lungs. Scientifically, it makes sense that the more receptors binding the virus, the greater number of viral copies made and having a higher viral load could worsen disease severity. For instance, children may fare better because older adults have far more receptor sites in their bodies than children under 10 years of age.
But the real quandary is how to address the obesity epidemic in America before it is too late?
In reality, our nation faces two pandemics simultaneously: Obesity and COVID-19. Despite clear recognition that obesity has a significant negative impact on health status, standard preventive strategies have proven ineffective. Residing in the United States has simply become synonymous with a sedentary lifestyle. Overeating is deeply embedded in our societal fabric. Countless numbers of children in my practice have gained weight, I am calling it the “Coronavirus 15,” since last March. Imagine what those numbers will look for U.S. adults by the end of 2020? It does us no good to survive one pandemic if we succumb to another. Eating healthy and exercising must become as high a priority as the endless search and billions being spent on the search for a miracle COVID-19 cure or vaccine.