A year after the Coronavirus pandemic wreaked havoc on our collective lives, our society has been grappling with fear and insecurity. As a result, we have seen misinformation spread like wildfire, and many resorting to bizarre and incorrect methods of dealing with the virus. With this column, which will be published every Sunday, we aim to address any health or vaccine-related question our readers might have about the coronavirus pandemic.
In this week’s column, Dr. Nikhil Tandon, Professor, and the Head of the Department of Endocrinology and Metabolism, AIIMS, New Delhi has replies to queries related to thyroid, metabolism, and obesity in relation to COVID-19.
Is there any relationship between obesity and COVID-19?
Like diabetes, obesity may also lead to poor disease outcomes in a Covid-19 patient. If a person has both obesity and diabetes, it puts him at a higher risk of developing Covid complications.
Can thyroid disorders directly or indirectly cause/aid the COVID-19 virus?
It is difficult to say that underlying thyroid disorders can make one more susceptible to catching Covid-19 disease but there have been some cases of people getting thyroid abnormalities after Covid-19. For example, thyroiditis, (inflammation in the thyroid gland) can occur in some people after they recover from Covid-19. This condition was observed during the original SARS outbreak also. In fact, several viral infections can be associated with the development of thyroiditis.
What factors, apart from diabetes, facilitates the growth of black fungus?
Mucormycosis or other fungal infections can occur when the body’s immunity is unable to fight the infection. Some diseases and even medications can affect immunity adversely, such as severe uncontrolled diabetes even in non-covid patients. When sugar levels in the blood are high, these could influence the functioning of the blood cells responsible for clearing infections.
Further, extremely high blood glucose levels, especially in those with Type 1 diabetes, could create an imbalance in the acid-base levels of the tissue, which leads to accumulations of iron in a “chemical state" that facilitates fungal growth. Elevated levels of ferritin seen in patients with COVID, also contributes to increased iron availability, thereby encouraging the growth of the fungus.
If a person is on immunosuppressants after an organ transplant, he/she is at a higher risk of catching a fungal infection, the same as cancer patients who are on chemotherapy and people suffering from diseases like HIV, which affect the body’s immunity, are more prone to catching a fungal infection.
Why are people with diabetes more prone to black fungus? What are the chances of a healthy person with no diabetes contracting black fungus?
A study conducted last year showed that in about 90 percent of cases of mucormycosis in Covid-19, patients had high blood glucose levels. What happens is, this fungus is present in the form of spores in the environment. These spores need to convert into the hyphal form to be able to enter the tissue.
In a healthy person, when these fungal spores land in nostrils, the immune cell fights them off. Uncontrolled diabetes adversely impacts the neutrophils, and other immune cells of the body, thereby reducing their ability to fight the infection. Then there are receptors GRP78 which help the fungi invade the blood vessels. It has been seen that these receptors are more in a person with high blood glucose levels. Further, as previously mentioned, change in the acid-base status brought about by the uncontrolled blood sugar, also increases availability of iron in a form that is facilitatory for fungal growth.
Can COVID-19 cause metabolic abnormalities?
These are difficult things to measure. We see the loss of appetite, weakness, exhaustion in many people post Covid, especially in cases of long-Covid but there has not been any dedicated study done to quantitatively evaluate these parameters so far.