Cushing Syndrome – An Overview
When there is a high level of the hormone cortisol in the body for long periods of time, one can develop a metabolic disorder known as Cushing syndrome.
Cushing Syndrome Causes
Cushing syndrome can advance due to a cause outside of your body (exogenous Cushing syndrome). One example is taking oral corticosteroid medications in high doses over an extended period of time. These medications, such as prednisone, have the equivalent influence on the body as does the cortisol produced by the body.
Oral corticosteroids may be essential to treat inflammatory diseases, such as rheumatoid arthritis, lupus and asthma, or to avoid the body from declining a transplanted organ. Since the dosages required to treat these disorders are often higher than the amount of cortisol the body normally needs each day, side effects from excess cortisol can arise.
There is also a possibility to develop Cushing syndrome from injectable corticosteroids such as frequent injections for joint pain, bursitis and back pain. Inhaled steroid medications (taken for asthma) and steroid skin creams (used for skin disorders such as eczema) are usually less likely to cause Cushing syndrome than oral corticosteroids. But, in some people, these medications could lead to Cushing syndrome, especially if taken in higher quantities.
The body’s own overproduction
The condition may also be because of the body’s own increased production of cortisol (endogenous Cushing syndrome). This may occur from excess production by one or both adrenal glands, or increased production of the adrenocorticotropic hormone (ACTH), which generally regulates cortisol production. In these cases, Cushing syndrome may be related to:
- A pituitary gland tumour (pituitary adenoma): A benign tumour of the pituitary gland, located at the base of the brain, secretes an excess amount of ACTH, which in turn stimulates the adrenal glands to create more cortisol. When this form of the syndrome progresses, it’s called Cushing disease. It occurs much more often in women and is the most common form of endogenous Cushing syndrome.
- An ectopic ACTH-secreting tumour: Seldom, when a tumour develops in an organ that generally does not produce ACTH, the tumour will begin to secrete this hormone in excess, resulting in Cushing syndrome. These tumors, which can be benign or malignant, are usually found in the lungs, pancreas, and thyroid or thymus gland.
- A primary adrenal gland disease: In some individuals, the cause of Cushing syndrome is surplus cortisol secretion that does not depend on stimulation from ACTH and is associated with disorders of the adrenal glands. The utmost common of these conditions is a noncancerous tumour of the adrenal cortex, called an adrenal adenoma.
Cancerous tumors of the adrenal cortex (adrenocortical carcinomas) are sporadic, but they can cause Cushing syndrome as well. Seldom, benign, nodular enlargement of both adrenal glands can lead to Cushing syndrome.
- Familial Cushing syndrome: Seldom, people inherit a propensity to develop tumors on one or more of their endocrine glands, distressing the cortisol levels and leading to Cushing syndrome.
Cushing Syndrome Symptoms
Symptoms of Cushing syndrome vary depending on the levels of cortisol in the body. The most common signs and symptoms include:
- Thinning and fragile skin
- Weight gain
- Fatty tissue deposits in the midsection, upper back, face and between the shoulders
- Stretchmarks on the skin of the abdomen, thighs breasts and arms
- Slow healing of cuts, insect bites, etc.
- Muscle weakness
- Depression and anxiety
- Increased blood pressure
- Cognitive difficulties
- Impaired growth in children
- Bone loss
Additional symptoms of Cushing syndrome in women may include:
- Absence of menstrual periods
- Thicker and more visible facial and body hair
Additional symptoms of Cushing syndrome in men may include:
- Erectile dysfunction
- Decreased libido
- Decreased fertility
Cushing Syndrome Risk Factors
The following factors may increase the chances of develop Cushing syndrome:
- Type 2 diabetes
- Poorly controlled blood sugar levels
- High blood pressure
- Women are more prone to this syndrome
Cushing Syndrome Diagnosis
In order to check if you have Cushing syndrome, your doctor may first run a physical exam to rule out any other possibilities as many of symptoms can be associated with other conditions. The doctor may then suggest the following diagnostic tests:
- Urine and blood tests: These tests quantify hormone levels in the urine and blood and show whether the body is producing excessive cortisol. For the urine test, you may be asked to collect the urine over a 24-hour period. Both the urine and blood samples will be sent to a laboratory to be examined for cortisol levels.
The doctor might also recommend other specialized tests that involve determining cortisol levels before and after stimulation or suppression with other hormone medications.
- Saliva test: Cortisol levels typically rise and fall through the day. In people without Cushing syndrome, levels of cortisol drop considerably in the evening. By analysing cortisol levels from a small amount of saliva collected late at night, doctors can see if cortisol levels are too high, suggesting a diagnosis of Cushing syndrome.
- Imaging tests: Computerized tomography scans or magnetic resonance imaging scans can enable viewing of images of the pituitary and adrenal glands to identify abnormalities, such as tumors.
- Petrosal sinus sampling: This test can help decide whether the cause of endogenous Cushing syndrome is imbedded in the pituitary or somewhere else. For the test, blood samples are taken from the petrosal sinuses Ã¢â‚¬â€ veins that drain the pituitary glands.
Cushing Syndrome Treatment
Treatment for Cushing syndrome depends on the level of cortisol in your body. Treatment ranges from making lifestyle adjustments to medication to surgery.
Reducing the intake of corticosteroid can help reduce the effects of Cushing syndrome to a great extent.
Medications for Cushing syndrome include ketoconazole, mitotane and metyrapone, mifepristone, pasireotide.
While these drugs are effective, they do come with side effects. Consult your doctor and thoroughly understand these before consumption.
If a tumour has caused Cushing syndrome to develop, then your doctor may recommend surgical removal.
If surgery proves futile in the removal of the tumour, radiation therapy may be used in small doses over a few weeks time.