If we understand how the disease of obesity compounds COVID-19 severity, how do we put that knowledge to work?
Since the early days of the COVID-19 pandemic, we’ve seen a steady flow of data to suggest that obesity is a risk factor for severe symptoms with COVID-19. Not that obesity increases the risk for infection-but rather, when a person becomes infected with the new coronavirus, the risk of severe symptoms is much higher.
At first, the CDC listed only severe obesity – marked by a BMI >40 – as a risk factor. Later, though, the agency revised its guidance to include any degree of obesity, at a BMI ≥30.
The single most important risk factor is still age. But after age, obesity ranks high on the list of health issues that put a person at risk for severe illness if they develop COVID-19
The physiology behind the risk
Early on, some obesity experts speculated that one reason obesity might increase the risks with COVID-19 might have something to do with respiration. Hypoventilation syndrome can be an issue for people with obesity. Back then, experts were looking at COVID-19 primarily as a pulmonary problem.
However, as the understanding of COVID-19 grew, so did the appreciation that life-threatening complications have much to do with a systemic cascade of inflammation – sometimes referred to as a cytokine storm. It’s this overwhelming inflammation that causes severe damage to lungs and other vital organs.
Likewise, experts in the physiology of obesity have long known that much of the harm of obesity comes from the inflammation that an excess of adipose tissue can promote. This is especially true of visceral fat and ectopic fat. Fatty liver disease is very much an inflammatory condition. ACE2 receptors are plentiful in adipose tissue. Those receptors also serve as a means for the virus to trigger inflammation.
So, researchers suspect that the inflammation that comes with obesity, along with an abundance of ACE2 receptors in adipose tissue, most likely account for the added risk for complications with COVID-19 for individuals with obesity.
The question, then, is what are we supposed to do with this knowledge? One answer is that the knowledge of how obesity and COVID-19 interact gives researchers a clue for finding better ways to treat patients when these conditions overlap.
In addition, though, this insight can be helpful to the patients at risk. Not because they can easily lose weight and reduce their risk. That’s far more easily said than done. However, patients can act to keep themselves in good health and take extra care to avoid exposing themselves to the coronavirus. This is all about good self-care and following public health guidance. Maintaining social distance, staying home as much as possible, hand washing, and using a face mask are all important measures to take. These are measures that are good for all, but they pay extra health dividends to people living with obesity.