Oscar T. a 45-year-old male from the Midwest presented with the following sympto

Question

Oscar T. a 45-year-old male from the Midwest presented with the following symptoms during February: weakness, fatigue, orthostatic hypotension, weight loss, dehydration, and decreased cold tolerance. His blood chemistry values follow:

Serum sodium 128 mEq/L

Serum potassium 6.3 mEq/L

Fasting blood glucose 65 mg/dL

Serum creatinine 0.5 mg/dL

Hematology tests resulted in the following values: Hematocrit 50%; Leukocytes 5000/cu mm

Oscar also noticed increased pigmentation (tanning) of both exposed and nonexposed portions of the body and back. A plasma cortisol determination indicated a low cortisol level. Following administration of ACTH, plasma cortisol did not rise significantly after sixty and ninety minutes. Endogenous circulating levels of ACTH were later determined to be significantly elevated.

1. What endocrine organ is the site of the malfunction? . Is this a primary or secondary disturbance?

2. What is the name of this disorder?

3. Discuss the electrolyte (Na+ and K+) disturbances resulting from this disorder.

4. Which hormone is involved and are the levels of this hormone abnormally high or abnormally low?

5. Discuss the metabolic disturbances resulting from this disorder. Which hormone is responsible?

6. What is the cause of Oscar's tanning?

7. What type of replacement therapy would be required for Oscar?

8. What is the long-term outlook for Oscar? Might one expect Oscar's abnormal pigmentation to resolve? Explain.

Explanation / Answer

Administration of ACTH and no result in the plasma cortisol level indicate that the patient is suffering from adrenal gland disorder-Addision's disease.

Cortisol is normally produced by the adrenal glands, located just above the kidneys. It belongs to a class of hormones called glucocorticoids, which affect almost every organ and tissue in the body. Cortisol has hundreds of effect in our body. Some of the functions of cortisol are:

Because cortisol is so vital to health, the amount of cortisol produced by the adrenal's is balanced. Like many other hormones, cortisol is regulated by the hypothalamus and the pituitary gland situated in the brain. First, the hypothalamus sends "releasing hormones" to the pituitary gland under stress conditions. The pituitary responds by secreting ACTH (adrenocorticotropin), a hormone that stimulates the adrenal glands. When the adrenals receive the pituitary's signal in the form of ACTH, they respond by producing cortisol. Completing the cycle, cortisol then signals the pituitary to lower secretion of ACTH(feedback effect).

Failure to produce adequate levels of cortisol, or adrenal insufficiency, can occur for different reasons. The problem may be due to a disorder of the adrenal glands themselves (primary adrenal insufficiency) or to inadequate secretion of ACTH by the pituitary gland (secondary adrenal insufficiency).

Since here administration of ACTH results in no increase in cortisol, it denote that the person is suffering from adrenal gland nonfunctioning, pituitary is normal.

Addision Disease:-

Addisons disease is a rare endocrine, or hormonal disorder that affects about 1 in 100,000 people. It occurs in all age groups and afflicts men and women equally. The disease is characterized by weight loss, muscle weakness, fatigue, low blood pressure, and sometimes darkening of the skin in both exposed and non-exposed parts of the body.

Addisons disease occurs when the adrenal glands do not produce enough of the hormone cortisol and in some cases, the hormone aldosterone.

The given case indicate that the gland is not functioning and production of both harmones is affected.

Most cases of Addisons disease are caused by the gradual destruction of the adrenal cortex, the outer layer of the adrenal glands, by the body's own immune system.

The symptoms of adrenal insufficiency usually begin gradually. Chronic, worsening fatigue and muscle weakness, loss of appetite, and weight loss are characteristic of the disease. Nausea, vomiting, and diarrhea occur in about 50 percent of cases. Blood pressure is low and falls further when standing, causing dizziness or fainting. Skin changes also are common in Addisons disease, with areas of hyperpigmentation, or dark tanning, covering exposed and nonexposed parts of the body. This darkening of the skin is most visible on scars; skin folds; pressure points such as the elbows, knees, knuckles, and toes; lips; and mucous membranes.

Addisons disease can cause irritability and depression. Because of salt loss, craving of salty foods also is common.

TREATMENT

Treatment of Addisons disease involves replacing, or substituting, the hormones that the adrenal glands are not making. Cortisol is replaced orally with hydrocortisone tablets, a synthetic glucocorticoid, taken once or twice a day.

During an addisonian crisis, low blood pressure, low blood sugar, and high levels of potassium can be life threatening. Standard therapy involves intravenous injections of hydrocortisone, saline (salt water), and dextrose (sugar). This treatment usually brings rapid improvement.

The hyperpigmentation is caused by high levels of circulating ACTH that bind to the melanocortin 1 receptor on the surface of dermal melanocytes. Other melanocyte-stimulating hormones produced by the pituitary and other tissues include alpha-MSH (contained within the ACTH molecule), beta-MSH, and gamma-MSH. When stimulated, the melanocyte changes the color of pigment to a dark brown or black.

A deficiency of aldosterone in particular causes the body to excrete large amounts of sodium and retain potassium, leading to low levels of sodium and high levels of potassium in the blood. The kidneys are not able to retain sodium easily, so when a person with Addison disease drinks too much water or loses too much sodium, the level of sodium in the blood falls, and the person becomes dehydrated. Severe dehydration and a low sodium level reduce blood volume and can lead to shock.

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