Hypercortisolemia Health Article

Definition

Cortisol is an essential glucocorticoid hormone, a subgroup of steroid hormones, the major hormone secreted by the adrenal glands. Hormones are messenger substances, substances produced in one gland or area of the body that move through the blood and stimulate activity in other glands or areas. Glucocorticoid hormones affect carbohydrate and protein metabolism. Steroid hormones are hormones related to cholesterol. Hypercortisolemia refers to high amounts of circulating cortisol and may be a pathological or non-pathological condition.

Description

Pathological hypercortisolemia, or Cushing's syndrome, named after the United States surgeon, Harvey Cushing (1869–1939), may result from a lung cancer, tumor of the pituitary or adrenal glands, or from kidney failure. Nonpathological hypercortisolemia is a normal response of pregnancy, and to such traumas, as accidents or surgery (including circumcision, studies show), some forms of depression and stress. Over time, continued exposure to trauma and stress may produce chronic hypercortisolemia and result in serious long-term debilitating illness.

Causes & symptoms

The natural regulation of cortisol is governed by a circular feedback response system. Output is initiated when pituitary gland secretions of adrenocorticotropin hormone (ACTH) travel to and stimulate the adrenal glands located atop the kidneys near the middle of the upper back. From the adrenals, cortisol travels to its target tissues, initiating a series of reactions known as the "flight-or-fight" response. Information from these target tissues is monitored by the brain. If the messages received tell the brain that more help is needed, the pituitary gland is stimulated to secrete more ACTH, which stimulates increased secretion of cortisol. The most significant feedback factor is stress. When stress levels are reported to the brain as high, high levels of cortisol are released in response. When stress remains high indefinitely, cortisol levels may also remain high indefinitely, producing a series of biochemical, physiological and even anatomical reactions.

Normally, cortisol output has a diurnal and circadian rhythm, rising in the morning, falling at night, and changing with the seasons. Changes related to work-sleep cycles affect this rhythm, and changes in the rhythm affect night time sleep patterns. Changes in the length of daylight hours, blindness, and loss of consciousness also affects the rhythm.

Cortisol target tissues include:

• liver
• bone
• blood vessels
• kidney
• muscle
• brain
• immune system

Long-term exposure to cortisol, whether natural or synthetic—from such steroid drugs as prednisone, dexamethasone (Decadron), and Methylprednisone (Medrol)—may eventually result in such changes as osteoporosis, muscle weakening and wasting, high blood pressure, increased abdominal fat deposition, immune dysfunction, steroid-induced diabetes, and cardiovascular disease. Another serious consequence may be the eventual fatigue and failure of the adrenal glands. Cushing's syndrome classic symptoms include, in addition to "normal" long-term symptoms, a "moon face" (rounded), thinning of the skin accompanied by purple or pink stretch marks and easy bruising, acne, increased facial and body hair and decreased scalp hair in women, and fatigue.

Diagnosis

Initial diagnosis may be made through the office of a family practice physician or internist on the basis of signs and symptoms, physical examination, and lab work including testing levels of circulating cortisol. Three types of testing are available to check cortisol levels: 24-hour urine collection; blood testing; and, saliva sampling. The 24-hour urine collection test is done at home beginning after the first urination of the morning and finishing after the first urination of the following day. This test can be done on infants. No special preparation is necessary. The test is described as not uncomfortable. Special considerations were reported to include emotional or physical stress and medications: lithium, diuretics, estrogen, tricyclic antidepressants, ketoconazole, and glucocorticoids. Blood testing requires a visit to a lab, where blood is drawn and then analyzed. This test can be performed on infants, children and adults. Preparation for the test may include discontinuation of medications similar to those medications listed above, as advised by one's healthcare provider. Some people experience pain or trauma with blood drawing, which may affect test results. Results may also be affected by the timing of the blood draw, since cortisol normally varies rhythmically. Risks of a blood test include bruising, pain, excessive bleeding, infection, fainting or the need for multiple punctures. Saliva sampling is done at home by collecting four samples at specific times of day. Unlike the urine collection method that produces a daily average, or the blood test that produces a single-spot sampling, saliva sampling produces a time-wave pattern for a more amplified diagnosis. Preparation includes discontinuation of medications listed with the other two methods, as well as a short list of foods and drinks, antacids, tooth brushing, and smoking prior to sampling. Cost comparisons were not reported. Test results may suggest followup care with an endocrinologist, who is a specialist in glandular and hormonally related disease, for further testing and diagnosis.