- Cortisol is a hormone that regulates various functions in the body.
- With physical stress such as illness, cortisol levels increase.
- Research has found that cortisol levels were abnormally high in some Covid-19 patients on the brink of death.
As the Covid-19 pandemic progresses, there are many factors about SARS-CoV-2 that baffle medical experts. Even though the majority of people recover from the disease, some deteriorate quickly and die.
We now understand that certain comorbidities such as hypertension, diabetes or COPD (chronic obstructive pulmonary disease) increase one's risk for a more severe outcome. Adults over the age of 65 are also more likely to be hospitalised with severe Covid-19.
But now, new research led by National Institute for Health Research research professor Waljit Dhillo, who is affiliated to the Imperial College Healthcare NHS Trust, shows that high levels of cortisol can be linked to the level of severity of the illness, according to a news release.
The new research was published in the journal The Lancet Diabetes & Endocrinology.
What is cortisol?
Cortisol is a hormone produced by the body as a reaction to any type of stress, whether emotional or physical (illness, injury, severe exercise etc.).
This hormone is vital in our bodies as most bodily cells have cortisol receptors, and the hormone affects many different functions such as blood sugar regulation, metabolism, reduction of inflammation, memory formulation and controlling the salt and water levels in our blood responsible for blood pressure.
But, just like with other hormones, when cortisol levels are out of whack, things can go awry. High levels of cortisol due to tumours on the pituitary glands can lead to a condition called Cushing syndrome, which leads to rapid weight gain in the stomach and face, mood swings, extreme fatigue and high blood pressure.
Low cortisol levels, on the other hand, can lead to Addison disease, which is characterised by severe fatigue, weight loss and muscle loss.
Cortisol and Covid-19
When we get ill, cortisol levels often change. When cortisol levels are too low, it can be extremely dangerous, but so can excessive cortisol levels because this can lead to increased risk of infection.
Elevated cortisol levels in the case of an illness like Covid-19 aren't surprising, but the extreme levels in the observational study were significant, stated the authors.
In the study of 535 patients, of whom 403 had Covid-19, the cortisol levels in the Covid-19 patients were significantly higher than those who were not ill. The levels in the Covid-19 group were as high as 3 241 – considerably higher after major surgery, when levels can exceed 1 000.
Out of the patients who had Covid-19, those with a baseline cortisol level of 744 or less survived for an average of 36 days, while those with levels higher than 744 had an average survival rate of just 15 days, according to the research.
Could cortisol levels help determine more urgent cases?
The researchers used this study to suggest that cortisol levels could help determine which Covid-19 patients were at a greater risk of dying, and that it could help establish a triage system.
According to Professor Dhillo, who is also the head of the Division of Diabetes, Endocrinology and Metabolism at Imperial College London, those who are severely ill with Covid-19 will naturally have higher cortisol levels, but these extreme levels are reason for concern.
"Three months ago when we started seeing this wave of Covid-19 patients here in London hospitals, we had very little information about how to best triage people. Now, when people arrive at hospital, we potentially have another simple marker to use alongside oxygen saturation levels to help us identify which patients need to be admitted immediately, and which may not.
"Having an early indicator of which patients may deteriorate more quickly will help us with providing the best level of care as quickly as possible, as well as helping to manage the pressure on the NHS. In addition, we can also take cortisol levels into account when we are working out how best to treat our patients," Professor Dhillo stated in the news release.
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