Brief overview
- Symptoms: Altered fat distribution, truncal obesity, “moon face”, on the other hand relatively thin limbs, muscle weakness, bone atrophy, increased susceptibility to infections, in women: impure skin, signs of masculinization (e.g. strong facial hair)
- Course of disease and prognosis: Depends on cause, treatability and duration of the disease; often successful treatment possible, risk of secondary diseases such as diabetes mellitus, high blood pressure, cardiovascular diseases
- Examinations and diagnosis: Various laboratory tests, imaging procedures (MRI) if necessary, ultrasound examination.
- Treatment: Depending on the cause, removal of the triggering tumor by surgery, radiation, medication, rarely removal of the adrenal glands
- Prevention:No specific prevention, regular control examination if taking glucocorticoids, no abusive use of steroids
What is Cushing’s disease?
For cortisol to be produced in the adrenal cortex, it must be stimulated to do so by another hormone: adrenocorticotropic hormone (ACTH or corticotropin). ACTH is produced in the pituitary gland. In Cushing’s disease, there is often too much ACTH circulating in the bloodstream, resulting in what is called ACTH-dependent hypercortisolism.
If Cushing’s disease arises in the body on its own, it is counted among the so-called endogenous forms of hypercortisolism (endogenous = from within). This means that the body itself produces too much ACTH and thus cortisol. In contrast, exogenous Cushing’s syndrome (caused externally) occurs when people take glucocorticoids or ACTH over a long period of time.
What are the symptoms of Cushing’s disease?
The following symptoms are typical in Cushing’s disease:
- Redistribution of fat deposits: Fat is stored especially on the trunk (“truncal obesity”) and in the face. Therefore, patients have a so-called “full moon face” and a “bull neck”, but comparatively thin arms and legs.
- Loss of strength: Muscle mass decreases (myopathy) and bones become brittle (osteoporosis).
- High blood pressure
- Elevated blood sugar levels
- Streaky, reddish discolorations of the skin (stretch marks, striae rubrae), especially on the upper arms and thighs and on the flanks
- Thin, parchment-paper-like skin where open sores (ulcers) sometimes appear
In addition, women with Cushing’s disease experience symptoms such as the following, which are due to an excess of male hormones:
- Cycle disturbances
- Masculinization (virilization): Women get a deeper voice, male body proportions or their clitoris grows.
In addition, some patients with Cushing’s disease develop psychological symptoms, for example depression. Children with Cushing’s disease are more likely to have stunted growth.
What is the life expectancy in Cushing’s disease?
Because of the many different effects of cortisol on the body, in some cases various complications occur during the course of Cushing’s disease. These include bone fractures, heart attacks and strokes.
What are the causes of Cushing’s disease?
The main cause of Cushing’s disease in 80 percent of cases is a microadenoma of the pituitary gland. A microadenoma is a small, in most cases benign tumor. In the healthy body, there are regulatory circuits that control the amounts of hormones produced. A microadenoma is not subject to this regulatory circuit. Therefore, the amount of hormones in the body exceeds the required amounts.
In addition to a microadenoma, there are other causes of Cushing’s disease.
In some cases, there is a dysfunction of the hypothalamus. Corticoliberin (CRH) is produced in this brain area. This hormone stimulates the production of ACTH in the pituitary gland. Excessive amounts of corticoliberin from the hypothalamus cause increased production of ACTH in the pituitary gland, which eventually leads to overproduction of cortisol in the adrenal cortex.
If Cushing’s disease is suspected, your family doctor will refer you to a specialist in endocrinology. This is a specialist in disorders of the metabolism and hormone balance. First, he will ask you in detail about your medical history. Among other things, he will ask the following questions:
- Have you gained weight?
- Have your body proportions changed?
- Do you have muscle or bone pain?
- Do you catch colds more often?
Cushing’s disease: laboratory tests
Your blood will be tested in the laboratory for various values that are indicative of Cushing’s disease. These include the amount of cortisol in your blood, blood glucose levels, concentration of cholesterol, number of immune cells, and concentration of electrolytes (especially the blood salts sodium and potassium).
Cushing’s disease: specific tests
Furthermore, a so-called dexamethasone inhibition test is performed. The patient is given dexamethasone (a glucocorticoid like cortisol) in the evening before going to bed. The next morning, the endogenous cortisol level in the blood should have fallen. This is how the doctor proves that there is no hypercortisolism.
To distinguish between the different forms of hypercortisolism, the amount of ACTH in the blood is now determined. If it is high, there is ACTH-dependent hypercortisolism, as is the case in Cushing’s disease.
Cushing’s disease: Imaging diagnostics
A magnetic resonance imaging (MRI) of the head is performed by the radiologist. Tumors of the anterior pituitary can be detected on the MRI image. This is not always successful because the tumors are sometimes very small.
Cushing’s disease: Other diseases with similar symptoms.
Your doctor will need to differentiate Cushing’s disease from other conditions and triggers that cause similar symptoms and findings. These include:
- Taking hormonal contraceptives (“birth control pills”).
- Taking steroids such as cortisone or sex hormones (without a doctor’s order)
- Metabolic syndrome (clinical picture consisting of obesity, high blood pressure and elevated blood lipid levels)
- Tumors of the adrenal cortex
- Osteoporosis (bone loss)
How can Cushing’s disease be treated?
If a microadenoma in the pituitary gland is the cause of Cushing’s disease, it is surgically removed. To do this, neurosurgeons gain access to the pituitary gland through the nose or through the sphenoid bone (a bone at the base of the skull). After surgery, cortisol must be administered artificially for a short time.
In addition, irradiation of the pituitary gland is a possibility to treat Cushing’s disease. In this way, the microadenoma is destroyed. Rarely, it is necessary to surgically remove both adrenal glands (adrenalectomy). This option is not a causative therapy and is rarely chosen when other treatment options have failed.
Patients must then artificially replace cortisol and mineral corticoids, which are also produced in the adrenal cortex, with drugs for the rest of their lives.
Since there is no prevention for most causes of Cushing’s disease, such as pituitary tumors, the disease cannot be prevented by any particular measure.
In general, you should not take glucocorticoids or steroids (such as abused for muscle building) on your own without a medical reason or without a doctor’s prescription.
