What is Cushing Syndrome?
Cushing syndrome happens when the body is exposed to high levels of a hormone called cortisol for a long time. The most common reason people show signs of Cushing syndrome is due to the use of a type of medication called corticosteroids. Certain herbal remedies can also increase levels of this hormone, leading to Cushing syndrome. Another term for Cushing syndrome is hypercortisolism. If the body produces too much cortisol because of a noncancerous tumor in the pituitary gland, it’s specifically known as Cushing disease. This accounts for 80% of cases where Cushing syndrome develops naturally in the body.
What Causes Cushing Syndrome?
Cushing syndrome can come from two main sources: too much cortisol (a hormone) in the body that is either created internally (endogenous hypercortisolism) or introduced from an external source (exogenous hypercortisolism). Exogenous hypercortisolism, which is the main cause of Cushing syndrome, usually happens as a side effect of taking certain medications for a long time, such as glucocorticoids.
On the other hand, endogenous Cushing syndrome occurs when the body’s adrenal glands produce too much cortisol. There are two types namely, ACTH-dependent and ACTH-independent. The ACTH-dependent type is typically caused by a growth in the pituitary gland (Cushing disease) or a tumor elsewhere in the body that produces ACTH, a hormone that signals the adrenal glands to release cortisol.
The ACTH-independent type, however, is typically caused by problems with the adrenal glands themselves, such as overgrowth, benign tumors, or cancers. No matter the source, an excess of cortisol in the body can lead to serious medical complications.
Risk Factors and Frequency for Cushing Syndrome
The exact number of people suffering from Cushing syndrome is hard to determine. How common this disease is can vary greatly among different ethnic and cultural groups. This is due to the varying need for steroid-based treatment often used for many medical conditions. However, when we look at the known cases, most cases of extra cortisol (a hormone) in the body are caused by medical treatment (iatrogenic hypercortisolism) rather than the body producing too much on its own (endogenous causes).
- Within the endogenously caused cases, 80% are due to the pituitary gland making too much of the hormone ACTH.
- Other causes include problems with the adrenal glands, unknown sources, and ACTH production caused by cancers.
Signs and Symptoms of Cushing Syndrome
Patients with certain medical conditions could report having various experiences. These might include:
- Weight gain and fatigue
- Feeling weak or experiencing a slow healing process after a wound
- Easily bruising, back pain, and bone pain
- The loss of height over time
- Depression, mood swings, and emotional reactivity
- Low sex drive, erectile dysfunction in men, and irregular menstrual cycles in women
- Infertility and excessive sweating
- Excessive hair growth known as hirsutism
- Loss of peripheral vision if they have a large pituitary tumor
- Frequent fungal and bacterial infections due to weakened immunity
- Difficulty in combing hair or rising from a sitting position due to muscle weakness
It’s not uncommon for patients to experience psychological issues, like cognitive dysfunction and depression. Some might develop bone thinning (severe osteopenia) and bone fractures. Patients may also have a history of conditions like high blood pressure, stomach ulcers, and diabetes.
When a physical examination is conducted, there might be signs of:
- Increased fat deposits in the upper body that create a “Buffalo torso”
- A moon-like face shape where earlobes aren’t visible from the front
- Thin arms and legs
- Acne and excessive hair growth
- Weakness in the shoulder and hip muscles
- Paper-thin skin
- Abdominal pain, possibly due to a rare case of a ruptured gut
- Wide, purplish stretch marks on the abdomen
Testing for Cushing Syndrome
If your doctor suspects you might have Cushing’s syndrome, a condition caused by an overproduction of the hormone cortisol, they will likely run a few tests. One is a late-night saliva test, which checks the level of cortisol in your saliva at night when it should be at its lowest. Another is a 24-hour urine test, in which you collect all urine passed in a 24-hour period to test for cortisol.
In normal circumstances your body should suppress cortisol production. However, in Cushing’s syndrome, this suppression doesn’t happen properly. To test this, your doctor might use a one-milligram overnight dexamethasone suppression test, or a two-day low-dose dexamethasone suppression test. Dexamethasone is a medication that normally reduces cortisol production.
However, it’s crucial to know that certain factors can affect the results of these tests. If the volume of urine collected in the 24-hour urine test is unusually low or high, it can lead to incorrect results. Additionally, having a very low kidney function rate (less than 60 ml/min) can artificially lower the cortisol level in the urine test. Furthermore, substances like licorice and chewing tobacco, as well as smoking, can falsely increase the cortisol level in the saliva test, so they should be avoided on the day of the test.
If your cortisol level is higher than expected after taking dexamethasone, it’s a sign of Cushing’s syndrome. A particular type of this test, the 48-hour low-dose dexamethasone suppression test, can help rule out conditions that mimic Cushing’s syndrome, such as anxiety, depression, heavy alcohol use, diabetes, and obesity.
Your doctor can also measure your blood’s ACTH levels, another hormone that controls cortisol production, to better understand the cause of your symptoms. Other tests, like an MRI of the pituitary gland (which controls hormone production), a CT scan of the adrenal glands (which produce cortisol), or X-rays and CT scans of the chest, may also be done to help identify the source of the problem.
It’s important to remember that certain conditions like anxiety, depression, uncontrolled diabetes, alcoholism, and obsessive-compulsive syndrome can lead to false-positive results, making it seem like you have Cushing’s syndrome when you don’t.
Treatment Options for Cushing Syndrome
The best treatment for Cushing syndrome caused by long-term use of steroid medication involves gradually decreasing the dosage of these drugs. Regular use of steroids can affect how the adrenal glands work and it can take a few months for them to function normally again. Therefore, the steroid dosage should be reduced slowly to give the adrenal glands time to recover.
For Cushing syndrome caused by a disease or tumor in the adrenal glands, surgery to remove the tumor is normally the preferred treatment. It’s important to closely monitor the patient even after surgery, using specialized imaging techniques and hormone tests, to check the success of the treatment and identify any possible recurrence.
For certain cases where the first surgery wasn’t successful or the disease has affected surrounding structures, radiotherapy is recommended. There are also certain medications available such as pasireotide, cabergoline, and mifepristone.
Effective management of Cushing syndrome also involves taking care of related health issues, like diabetes, high blood pressure, bone thinning (osteoporosis), mental health problems, and disorders related to body salt levels.
For cases where a tumor causing Cushing syndrome cannot be entirely removed, a surgery to remove both adrenal glands (bilateral adrenalectomy) might be necessary. This will lead to the need for lifelong replacement therapy with adrenal hormones (like hydrocortisone and fludrocortisone).
What else can Cushing Syndrome be?
Obesity, alcohol use disorder, bulimia, and depression are all health conditions that could significantly impact a person’s life.
Obesity is a condition where a person has accumulated so much body fat that it might negatively influence their health. It’s usually determined by using the body mass index (BMI), a measure that considers your weight and height.
Alcohol use disorder, often known as ‘alcoholism’, is an issue characterized by an uncontrollable need for alcohol. It’s a chronic disease that can lead to severe health complications if not addressed.
Bulimia is an eating disorder where individuals binge eat large amounts of food in a short period and then try to prevent weight gain by purging, exercising excessively, or fasting.
Depression is a mental health disorder characterized by persistently low mood and a strong sense of sadness and loss of interest. It greatly influences a person’s ability to function at work and home.
What to expect with Cushing Syndrome
Earlier studies suggested that people with Cushing syndrome had a median survival of around 4.6 years and that only half survived for five years. However, thanks to recent treatment advancements, the survival rate is now similar to that of the general population of the same age.
The health issues and risk of death associated with Cushing syndrome mainly arise from related conditions, such as diabetes, high blood pressure, heart disease, obesity, and osteoporosis leading to fractures. If the patient has a hormone-producing tumor that can’t be removed surgically, this worsens their overall health outlook.
Possible Complications When Diagnosed with Cushing Syndrome
- Excessive hair growth
- Osteoporosis or weak bones
- Increased likelihood of catching infections
- Type 2 diabetes
- Peptic ulcer disease which can cause stomach or abdominal pain
- High blood pressure, also known as hypertension
Preventing Cushing Syndrome
Treatment for Cushing syndrome should be managed by a team of healthcare professionals, led by an endocrinologist, which is a doctor who specializes in hormone-related conditions. It’s also important for individuals diagnosed with Cushing syndrome to understand its potential complications. This condition can negatively affect quality of life, so it’s crucial to be aware and informed about the effects and the ongoing management of the syndrome.
