In medicine, too much or too little of something is usually a problem. Excess hormones, excess knees, hospital excess – all of these things can be a genuine pain in the butt.
For ages, doctors thought that excess cortisol only mattered if it was over a certain threshold, but it turns out that even a bit of extra cortisol can cause problems over time.
Much of what we understand about mild cortisol excess comes from adrenal incidentalomas – tiny, sneaky tumours in your adrenal glands. These hormonal troublemakers have changed the way doctors have thought about high-but-not-deadly-emergency-high levels of cortisol.
Small tumours, big questions
Sometimes your body just grows random lumps in weird places for no reason.
Because doctors love long words, these lumps are called incidentalomas – ‘incidental’ because they’re usually found by accident when looking for something else, and ‘oma’ because they’re a type of tumour.
Endocrine organs like the adrenal gland, pituitary gland, and thyroid gland are classic places to find incidentalomas. Around 5% of people have one on their adrenal gland and 10-20% have one on their pituitary gland without them even knowing.
Usually, incidentalomas are harmless little blobs that just sit around being blobby. They don’t do much except take up a few centimetres of space and bring a little excitement to a radiologist’s day.
But about a quarter of incidentalomas growing on the adrenal gland have higher ambitions, and start to make hormones of their own – hormones like cortisol.
More cortisol more problems
For years doctors thought that the extra cortisol produced by adrenal incidentalomas wasn’t a huge deal, as it didn’t seem to be causing too many problems in the short term.
But now the long-term studies are in, and the evidence suggests that a lifetime of exposure to extra cortisol actually has some serious effects.
While researchers are still looking into how it all works, it’s clear that higher cortisol levels raises the chances of heart disease, metabolic issues like type 2 diabetes and obesity, and dying too early. However, since most adrenal incidentalomas are found in older people who are getting scans for other problems, it’s difficult to tease apart the relationships between all the different conditions and say definitively that one thing directly causes another.
“We know that there are some associations, but at this stage they are just associations” advises Dr Angela Xun-Nan Chen, Staff Specialist at Westmead Hospital and .
“In that grey zone, the science is just not good enough for us to be able to tell if it is directly related or not. Although, looking at the very big and very long term studies, we do know that there is an association with increased cardiovascular disease and cardiovascular death.”
People with adrenal incidentalomas might face a higher risk of disease and death for the same reason as people who are chronically stressed – cortisol makes changes in the body that are useful for short-term emergencies but harmful if kept up for a long time.
Dr Chen hypothesises that “If you’ve had this low level [of excess cortisol secretion] for a very long time, cumulatively you’ve probably had a higher life-long exposure and you’re probably at higher risk. These are the sorts of things that we can infer, but we don’t know for sure.”
So how much cortisol is too much?
Compared to the professional adrenal gland that pumps out hormones for a living, the adrenal incidentaloma can only produce an amateur amount of cortisol. This means that people with incidentalomas find themselves in a medical grey zone – having a bit more cortisol than the average person, but not enough for it to be classified as an endocrine emergency.
“There’s a clear cutoff when people have a very high level of cortisol,” explains Dr Chen, “That’s pretty easy in terms of diagnosis.”
“Then there’s this subgroup of patients who fall into this category of Mild Autonomous Cortisol Secretion (MACS). They are the people who we’d describe as biochemically having cortisol excess, but not clinically having cortisol excess.”
This means that adrenal incidentalomas can produce enough cortisol to make the numbers on your test results look a bit strange, but not enough to cause any symptoms in day-to-day life.
However, it’s now clear that excess cortisol can still do damage over time – if very high cortisol levels was a wrecking ball, MACS would be English ivy – not as dramatic or quick, but still able to bring down a wall given enough time.
What to do if you have an incidentaloma
“I would say, if a patient were to have something like this diagnosed: not to panic” advises Dr Chen. “It’s very treatable in terms of the individual factors, and we look at you as an individual person before we consider ways of treating it.”
“They don’t tend to progress. You’re not going to suddenly go from a small tumour to a huge tumour. You’re also not suddenly going to go from just a little bit of excess cortisol to a lot of excessive cortisol.”
“It kind of gives us time to have a think about what would be the best treatment for you. Have your co-morbidities progressed, what’s your general health like? And then, how should we think about treatment in that sort of context?”
The most important thing to do as a patient is keep an eye on yourself and pop to the doctor if you suspect something might not be quite right. Catching things like high blood pressure or insulin resistance early means you can get them patched up without much fuss before they turn into bigger problems. It’s always best to avoid surgery, but if things do progress, then it also might be an option.
Current guidelines for treatment
Current guidelines advise that if the tumour is less than four centimetres across and the cortisol level isn’t too high, doctors should treat any conditions that arise rather than focusing on the adrenal incidentaloma itself.
However, this is an active area of research and this advice may change in the future.
“At this stage, our recommendations would be to treat each of the individual co-morbidities” Dr Chen says, but notes that “this is an evolving space. Even in five years time, the recommendations might differ and things might be quite different and we may be performing more surgery to remove these adrenal incidentalomas.”
Managing risks and staying healthy
While a higher cortisol level is generally associated with a greater chance of illness, it doesn’t mean that you’re definitely going to get sick, just that you need to keep an eye on your ticker.
If you have a hormonally active adrenal incidentaloma or a higher than average cortisol level, take it as an opportunity to focus on your health and develop a low-stress lifestyle. Damage from cortisol isn’t the only thing that accumulates slowly over time – good habits do too.
In the meantime check in with yourself and your doctor regularly, and you’ll be doing better than people who can’t even pronounce incidentaloma.
