September 01, 2020
Fernando Salazar, Gastroenterologist of our clinic, clarifies some key concepts around this issue of vital relevance to our health.
In 2010 obesity was classified by the WHO as a non-infectious pandemic, being the result of how we eat. The food industry does not measure the risks of the ingredients used in its products and, ultimately, the consumer ends up paying the consequences. Fast food is the one with the most harmful effects on our health.
What is obesity?
Obesity is a pathological condition caused by excess fat in the body causing inflammation in the tissues. The consequent increase in body mass (at the cost of fat) can lead us to develop devastating chronic diseases such as high blood pressure, diabetes mellitus, heart disease, and psychiatric diseases. It is also known to increase the risk of acquiring multiple types of malignant tumors.
The WHO has defined the different degrees of overweight based on variables such as weight and height. The Body Mass Index (BMI) is the resulting measure. Thus, a BMI of 24.9 to 30 is considered overweight, from 30 to 35 is moderately obese, from 35 to 40 is severely obese and over 40 is super obese.
And why does it matter in this pandemic?
Up to 70% of people with COVID 19 who end up in ICU, according to British and American reports, have overweight or obesity. Certainly, elderly patients or those suffering from other chronic diseases (with low defenses) are the most vulnerable, but the mere fact of being overweight or obese increases by 6 times the probability of ending up needing a bed in ICU. In New Orleans, for example, 1 out of 4 patients who died from COVID 19 was obese. Herein lies the vulnerability of this population.
What happens in obese patients that makes them so vulnerable to complications in case of contracting COVID 19?
Just as fat accumulates in visibly obvious places, it also tends to settle in, or around, some organs. In the thoracic region, immediately under the skin, there is a layer of fat, the more obese the layer of fat will be thicker. Under normal conditions they are translated into “rolls” appearing in the lateral parts of the thorax so it does not significantly affect people’s breathing; but in conditions of respiratory distress (as in the case of pneumonia), their capacity to accommodate is restricted preventing the lungs from expanding properly during an infection.
There are some receptors called ECA-2 used by the virus, at the microscopic level, to enter the lungs. These entry keys are produced in adipose tissue (fat), consequently, obese patients have more access keys in their pulmonary alveoli.
Viral pneumonia can occur in COVID 19 infection. In the first 10 days, it is caused by the presence of viruses in the lungs. The second phase of COVID 19 viral pneumonia is no longer due to the presence of viruses. It is known that what ends up irreversibly damaging the lungs, leading the patient to need a respirator, is the inflammatory reaction that occurs after the virus has disappeared.
As an inflammatory disease, obesity predisposes to two major and deadly events in this viral infection. First, the body is so busy in its inflammatory environment that it is not aware (low defenses) of the initial viral attack. And second, worse, once it detects the virus, it unleashes an intense response against the affected organ, causing an exaggerated inflammatory response in the virus-infected lungs.
Obesity is closely linked to chronic diseases that lower defenses or predispose to chronic damage to blood vessels. Consequently, patients suffering from hypertension and diabetes mellitus are considered at higher risk for COVID 19 complications. Obese patients with these conditions have the associated disadvantages of poor vascular repair and poor tissue repair.
These four mechanisms make the obese patient so vulnerable to the catastrophic consequences of infection. It does not mean that they are more likely to become infected, but if they do, they are more likely to suffer serious complications. Just as we must obey the rules of social distancing, hygiene, and disinfection, there are also rules that we must follow to fight those bad habits leading to overweight. Let’s be responsible.
Dr. Fernando Salazar
Gastroenterologist at Clínica Ricardo Palma