When the first wave of coronavirus hit, people did not know what to expect. The data was inadequate, and it was increasingly hard to study the effect of the virus on different age groups, let alone the calculation of risk factors. In some countries, people were flocking the health centers, displaying typical flu-like symptoms, including fever.
Many tested positive and grew increasingly short of breath. A large number of people were on ventilator support, and many died. The virus is still running havoc, but there are many things that we are sure about now. The data is continuously coming in, and researchers are constantly trying to get the best out of what is available.
Since the very beginning of the pandemic, numerous studies have reported that the sickest of the patients were the ones with obesity. In recent times, the link between obesity and COVID has come into a much sharper focus, and studies have confirmed the association.
People who are slightly overweight are at a higher risk. One of the first meta-analysis of this kind was published in the Obesity Reviews, which tabulated peer-reviewed papers containing data of 399,000 patients.
The study found that people with obesity, who contracted the virus, were 113% more likely to land up in the hospital as compared to healthy people. 74% among the patients likely admitted to the ICU, and 48% patients likely to die. These grim numbers are driven by a wide number of social and physiological factors.
Understanding obesity as a risk factor
Obesity is a root cause of many serious health complications. This pandemic put forth another grave concern associated with the condition. Biology of the obesity includes chronic inflammation, impaired immunity, and all of these make survival with COVID a scary task. Biological risks apart, with obesity being so stigmatized, obese people try to avoid medical care, hence risking their lives.
The devastating impact of COVID on America might have many reasons, but one of the reasons which are now easy to decode is that 40% of adults are already reeling under obesity. People who are obese are more likely to have diseases that are now considered independent risk-factors for COVID, including lung diseases, heart disease, and diabetes. People with obesity also have metabolic syndrome, which means the blood sugar and fat levels are unhealthy, and blood pressure might be persistently high.
A study conducted on 287 hospitalized patients by Tulane University found that the metabolic syndrome itself was substantially responsible for risks of ventilation, ICU admission, and death. One of the largest descriptive studies in this regard was conducted by Genentech researchers, which posted a pre-print of 17000 patients. The researchers found that 77% of the patients, who were hospitalized for COVID-19, were overweight. 29 percent of the 77% were overweight, and 48% of the same 77% were obese.
The Centers for Disease Control and Prevention categorizes people with a BMI of 25-29.9 as overweight and the ones with BMI over 30 as obese. Another study conducted in England was published in the Proceedings of the National Academy of Sciences. The study proceeded with 334,000 people who were hospitalized for COVID-19, and it was found that the admission rate peaked for people with a BMI of 35 and higher.
Body fat and COVID: How matters get worse
Physical pathologies which made obese people more vulnerable to COVID begin with the mechanics. The fat, which is accumulated in the abdomen, starts pushing up on the diaphragm, which in turn causes the large muscle to impinge on the lungs, thereby restricting airflow.
The reduction in the lung volume results in the collapse of the airways in the lower lobes of the lungs, where more oxygenation takes place as compared to the upper lobes. This is just the tip of the iceberg. Some issues add to the risk in obese people. For example, the blood of obese people tends to clot a lot, which poses a grave risk during an infection. These clots at times pepper the small vessels in the lungs.
Immunity is not the strongest suit of obese people. With fat cells infiltrating organs where the immune cells are made and stored, like the spleen, thymus, and bone marrow, the immune tissue loses while adipose tissue takes its place, making the entire immune system less effective. A weaker immune system cannot protect the body from pathogens and does not respond to vaccination as expected. The immune cells, better known as T cells, do not function properly in an obese state. This means even if the immunity cells are present, they are not just very effective. The T cells make fewer molecules which are not enough to destroy the virus-infected cells.
Besides a weaker immunity, people with obesity suffer from chronic low-grade inflammation. The fat cells are responsible for the secretion of various chemicals which trigger inflammation, known as cytokines, and more of such chemicals come from the immune cells, known as macrophages, and both kinds start sweeping in to clean the dying and dead fat cells. All of this together compounds the cytokine activity, which characterizes much severe COVID-19. In simple terms, the process recruits too many cells and causes considerable tissue damage as healthy bystander cells get destroyed.
Obesity and severity of COVID-19 in the US
The pandemic took a disproportionate toll on some of the groups in the United States. The Alaska natives and American Indians lack access to health insurance and healthy food due to poverty. With limited exercise opportunities, the obesity rate is much higher, making the groups more susceptible to COVID-19 related deaths. With obesity so stigmatized, many people delayed seeking medical attention, which increased the likelihood of severe sickness and death.
While obesity has been taking a toll on people even long before the pandemic, recent developments have made it mandatory for people to work harder for overall well-being. Fighting obesity is hard, but if people are capable of making wiser choices, things can get better. At Be Better Bariatrics, new surgery-less techniques are made available to make weight loss easy. The processes are non-invasive, with quick recovery and lower risk. Let us pledge to work towards better health to stay safe from COVID-19 and numerous other health problems stemming from obesity.