Why Having Obesity Can Put You at Greater Risk for COVID-19

Besides the spread of the virus itself, one of the biggest concerns about the ongoing novel coronavirus (COVID-19) pandemic has been tracking what pre-existing conditions increase the risk of grave illness or even death. 

One of the most serious of these conditions is obesity, particularly severe obesity. Multiple studies have shown that having a body mass index (BMI) of 30 or higher increases the risk of severe illness connected with COVID-19, something the CDC has also emphasized. 

Ali Aminian, MD, Director of the Bariatric & Metabolic Institute at Cleveland Clinic, echoes these findings, saying, “In the past six months we have learned that obesity is a risk factor for the severe form of COVID-19 which includes hospital admission, need for intensive care, ventilator support and increased mortality.”  

Possible reasons

The exact reasons why patients with obesity are so adversely affected by COVID-19 is still unknown, but Dr. Aminian has a few suggested explanations. 

• Weakened immunity: Patients with obesity (and the subsequent associated risk factors like diabetes) often suffer from weakened innate and adaptive immunity, making them more susceptible to infections.
• Overactive immune response: Obesity is a chronic inflammatory state that causes the patient’s body to produce excessive amounts of cytokine, molecules that communicate and regulate the immune system. COVID-19 infections also trigger the release of cytokines. When combined with obesity, this can lead to an excess amount of cytokine in the body, called a “cytokine storm,” that can cause damage to multiple body organs. “This,” Dr. Aminian says, “could explain why patients with obesity experience such severe response with COVID-19.” 
• Cardiovascular risks: Patients with obesity frequently have underlying cardiovascular disease and that comes with an array of associated risks such as diabetes and hypertension. These factors can all contribute to difficulties stemming from a COVID-19 infection.
• Increased risk of blood clots: Patients who are overweight or obese are already at a higher risk of blood clots, a condition that’s also been associated with COVID-19. “COVID-19 damages the endothelium (the cellular lining of blood vessels),” says Dr. Aminian. “Autopsies have shown that blood clots and widespread severe endothelial damage are two of the causes of increased mortality in many patients who contract COVID-19.” 
• Damaged pulmonary system: Obesity is known to impact the mechanics of both the chest wall and diaphragm as well as make patients more vulnerable to other lung conditions like sleep apnea, asthma and obesity hypoventilation syndrome. These issues can all become further compounded due to the known pulmonary issues that come with COVID-19 infections.

Protecting patients with obesity

Due to these potential risks, and ones we don’t yet know about, Dr. Aminian stresses the importance of patients with obesity taking precautions to protect themselves from COVID-19. “Because patients with obesity are so vulnerable to infection from COVID-19, it’s extremely important they follow public health guidelines like wearing a mask and social distancing.”

Following these precautions is also important because, as Dr. Aminian points out, patients with obesity may not be protected as well from the virus as other patients even when a vaccine is developed. “We know from previous experience that patients with obesity don’t always show an adequate immunological response even after being vaccinated, a challenge that’s possible with a COVID-19 vaccine.”

There are still many unknowns associated with COVID-19 including a weight measurement at which the extra risks posed by excess weight decrease. One thing that’s for sure, Dr. Aminian says, is that losing weight should absolutely be a goal. “While we don’t know of a particular cutoff point that can decrease that COVID-19 risk, we do know that patients are healthier after losing part of their excess weight.”

He adds, “Generally, patients with obesity who lose at least 5-to-10% of their weight see their risk of cardiovascular disease drop.” 

In the meantime, Dr. Aminian urges patients to stay in touch with their health care providers and dietitians. “If a patient is already on a weight loss plan or other forms of weight loss treatment, including weight loss surgery, that should continue even during this pandemic. And they should make sure to take extra precautions and stay vigilant to lower the risk of their potential exposure to the virus.”