There are many reasons why obesity puts people at risk of becoming critically ill from COVID-19
People living with obesity are emerging as one of the groups most at risk of critical illness if they contract COVID-19.
Data collected by researchers at New York University indicate that, apart from seniors over 65 years of age, obesity is the leading risk factor for hospitalization and need for critical care due to COVID-19.
The researchers wrote in their pre-print: “The chronic condition with the strongest association with critical illness was obesity, with a substantially higher odds ratio than any cardiovascular or pulmonary disease.”
People with obesity (PwO) hospitalized with COVID-19 are almost twice as likely to need a ventilator according to information gathered by 41 hospitals in the southern United States as reported in the New York Times. A hospital in France has confirmed these findings.
Dr. Arya Sharma, scientific director at Obesity Canada and professor of medicine at the University of Alberta, is not surprised. He cites similar findings from earlier virus outbreaks. “From H1N1 and even from SARS, there was evidence showing that people with obesity, once they get into the setting of an ICU and start having respiratory problems, their prognosis is much more difficult,” Sharma says.
These conclusions have far-reaching implications for the healthcare system because more than one in four Canadian adults is living with obesity. This is based on the 2018 Canadian Community Health Survey published by Statistics Canada, which classified obesity by a body mass index of at least 30 (calculated by weight in kilograms divided by the square of height in metres).
Obesity is a chronic medical condition that is already a well-documented risk factor for hypertension, type 2 diabetes, and certain cancers. It is also linked with poor mental health, which has become even more relevant during the current pandemic. To make matters worse, Sharma and others warn that anxiety and stress may contribute to further weight gain while in isolation at home.
Treatment of COVID-19 in PwO raise extra challenges, which can stem from worse overall health or other illnesses such as hypertension.
As Stephanie Hnatiuk, a dietitian working in the intensive care unit at Winnipeg’s Health Sciences Centre puts it: “Weight potentially playing a role with regards to outcomes is not unique to COVID-19.”
She notes, however, that the hospital where she works has asked her not to use metabolic carts in order to limit the use of personal protective equipment. Metabolic carts determine a patient’s calorie requirements, which can be hard to estimate for PwO.
Dr. Mary Forhan, chair of the department of occupational therapy at the University of Alberta, says that bariatric equipment for patients is in high demand in many hospitals.
“People working in the hospitals are finding it difficult to have access to equipment that will support the weight of some patients with bariatric care needs,” she says, citing the example of mechanical lifts with over 200-kilogram capacity.
“The concern when we have a pandemic,” Forhan adds, “is that this equipment is often in limited supply in hospitals and is shared across different units. When you are dealing with infection control, that can limit access.”
Inserting and removing a ventilator also carries increased risks when the patient is of a higher weight. This can be related to physiological factors seen in PwO including lower lung volume and higher airway resistance.
PwO with SARS who required ventilators showed better outcomes, including a shorter hospital stay and lower chance of death, if they laid on their stomach. However, this posture, known as prone positioning, can be physically demanding and possibly unsafe in the absence of bariatric equipment, taking a team of hospital staff to turn the patient over.
Aside from the other resources needed to care for PwO, the risks posed by COVID-19 are exacerbated by the stigma that they face in their everyday lives and when they seek medical care.
“Many people living overweight and with obesity – when they enter the healthcare system, when they meet their doctors or go to a hospital – might actually face weight bias and discrimination,” says Sharma. “This is something that we are very concerned about, especially in times like these.”
Dr. Sara Kirk, a professor of health promotion at Dalhousie University, says that the result may be a lower standard of treatment as part of a vicious cycle for PwO experiencing the healthcare system.
She says that after experiencing stigma, PwO are more likely to seek medical care only once they exhibit more serious symptoms.
From the point of view of health care providers, Kirk also warns, “There will be this idea, why should we bother treating someone who comes in at a higher body weight, needing a ventilator? Their chances are going to be worse.”
The ethical issues around allocating ICU beds and ventilators was raised in 2010 during the H1N1 pandemic by members of the University of Toronto’s Joint Centre for Bioethics.
They were concerned that Indigenous PwO infected with H1N1 would be given a low priority for ventilators, which would “exacerbate the social injustices faced by these groups of people.” In fact, obesity itself can be representative of social inequities, with higher obesity rates in marginalized groups like Indigenous peoples.
Kirk articulates that COVID-19 is already starting to “highlight the terrible injustices in the world that we try and ignore. Once the dust has settled after the COVID-19 pandemic, we may see that people were offered less treatment because of their weight.”