Cushing's and Cortisol
There is strong evidence linking cortisol and Cushing's -- namely, Cushing's syndrome can develop when the body produces excessive levels of cortisol for an extended period. The connection between the two is most common when glucocorticoid hormones are taken, or when tumors are present in the adrenal or pituitary glands.
Cushing's syndrome is a hormonal condition that occurs when a person's tissues are exposed to an excess of the hormone cortisol for extended periods. The disorder is sometimes called "hypercortisolism."
Normally, cortisol is produced through a precise chain of events. First, the hypothalamus, a part of the brain that is about the size of a small sugar cube, sends corticotropin-releasing hormone (CRH) to the pituitary gland. CRH causes the pituitary to secrete adrenocorticotropin (ACTH), a hormone that stimulates the adrenal glands. When the adrenals, which are located just above the kidneys, receive ACTH, they respond by releasing cortisol into the bloodstream.
Cortisol performs several vital tasks in the body. It helps:
- Maintain blood pressure and cardiovascular function
- Balance the effects of insulin in breaking down sugar for energy
- Reduce the immune system's inflammatory response
- Regulate the metabolism of proteins, carbohydrates, and fats.
One of the most important jobs of cortisol is to help the body respond to stress. For this reason, women in their last three months of pregnancy and highly trained athletes normally have high levels of the hormone. People suffering from depression, alcoholism, malnutrition, and panic disorders may also have increased cortisol levels.
When the amount of cortisol in the blood is adequate, the hypothalamus and pituitary release less CRH and ACTH. This ensures that the amount of cortisol released by the adrenal glands is precisely balanced to meet the body's daily needs. However, if something goes wrong with the adrenals or with their regulating switches in the pituitary gland or the hypothalamus, cortisol production can be increased, resulting in the symptoms of Cushing's syndrome.