Metabolic and Endocrine Mechanistic link to COVID-19
At the time of writing, 8,061,550 confirmed cases of coronavirus disease 2020 (COVID-19) caused by severe acute respiratory syndrome coronavirus2 -(SARS-COV-2), have been reported worldwide, resulting in 440,290 deaths. Since the initial cases of pneumonia in Wuhan, China was reported on Dec 31,2019, this localized outbreak rapidly transformed to being declared as a Public Health Emergency of International Concern (PHEIC) by WHO on Jan 30, 2020 and subsequently a global pandemic as of March 11.
In the first case series of hospitalized patients with COVID-19 from Wuhan, basic disorders were reported in 50% patients (diabetes [20%], hypertension [15%], and cardiovascular disease [20%]).
After that, data from 122 653 laboratory-confirmed COVID-19 cases reported to CDC in the USA between February 12 and March 28, showed that approximately one third patients had at least one basic risk factor, of which diabetes was the most frequently reported (in 10-9% of cases). With an estimated 85% of people with type 2 diabetes also having overweight or obesity and obesity a known risk factor for respiratory tract infections such as pneumonia, the impact of BMI on COVID-19 severity and outcomes is of major public health importance.
There is growing evidence that there is an important metabolic and endocrine link to the coronavirus. With COVID-19, we have not just been fighting a communicable disease alone but also a growing backdrop of non-communicable disease (such as diabetes and obesity) that have needlessly raised the death toll.
Type 2 diabetes mellitus and hypertension
Type 2 diabetes mellitus and hypertension are the most common comorbidities in coronavirus patients. There is also evidence that people with type 2 diabetes and metabolic syndrome (i.e. diabetes, high blood pressure and obesity) may have a higher risk of being seriously ill if they develop COVID-19. There are also specific features of coronavirus which could increase this risk. This could be because these patients tend to have metabolic inflammation, which affects the metabolic tissues, such as the liver and the pancreas. This makes these patients more prone to enhanced release of cytokines. During an infection the immune system increases the release of cytokines. A cytokine storm occurring in COVID-19 patients can damage tissues and organs and can also cause multi organ failure.
What are the specific mechanisms in the endocrine system linked to coronavirus infection?
The endocrine system is the collection of glands that secrete hormones that regulate metabolism, growth and development, tissue function, reproduction, sleep and mood etc. The COVID-19 uses a protein on its surface, which binds to a type of receptor called angiotensin-converting enzyme 2 (ACE 2) to enter cells in the body of the infected person.
ACE2s purpose is to break a hormone in the lungs called angiotensin II into another hormone angiotensin 1-7. When ACE2 is blocked and angiotensin II builds up this can cause problems such as increase in blood pressure and hypokalemia (low potassium levels in blood) and increase risk of respiratory distress syndrome (lungs unable to provide enough oxygen).
Angiotensin 1-7 leads to anti-inflammatory and anti-fibrotic (reduce the formation and build-up of scar tissue) responses, both of which are required for the recovery of COVID-19.
What is the metabolic link to coronavirus infection?
There is an association between serious complications from the coronavirus and hypertension and also to type 2 diabetes.
Studies show that patients with the SARS infection with no history of type 2 diabetes became temporarily hyperglycemic during hospitalization for the infection.
As the human endocrine pancreas expresses ACE2 the coronavirus could enter the cells leading to acute hyperglycemia and temporary type 2 diabetes.
Type 2 diabetes also induces expression of angiotensin hormone converting molecule
(such as ACE2) in other tissues such as the lung, liver, and heart, this may help explain why type 2 diabetes could cause higher risk of developing multi-organ failure in coronavirus infections such as SARS.
How could this affect treatment for with COVID-19?
The data suggests that metabolic control of type 2 diabetes and associated metabolic parameters in patients with COVID-19 may be important. This could help reduce the risk of complications in patients with type 2 diabetes and a severe infectious disease.
Everyone needs to be careful to avoid the coronavirus. If you have type 1 or type 2 diabetes, you should be even more cautious. Your risk of catching the virus isn’t higher than anyone else’s. But you could have worse complications if you do get sick. That’s especially true if your diabetes isn’t well-controlled.
To reduce your chance of getting infected:
● Keep your distance from other people.
● Use good hygiene.
● Keep your blood sugar under control.
This article concludes that good metabolic health is more important than ever for us living through the COVID-19 pandemic.
COVID-19 is not primarily a metabolic disease, but metabolic control of glucose, lipid levels and blood pressure are the key in these patients. Effective control of these metabolic parameters might represent a specific and mechanistic approach to prevent and help to improve the acute effects of this virus by reducing the local inflammatory response and blocking its entry into the cells.