Conn's Syndrome (Primary Hyperaldosteronism)
Primary hyperaldosteronism is a rare disorder that occurs when your body produces too much aldosterone, a hormone that controls sodium and potassium levels in the blood. But what are its symptoms? How should it be treated? The following information should help you talk to a urologist about this condition.
What happens under normal conditions?
The adrenal glands are endocrine glands that are located on the top of both kidneys. The adrenal glands are triangular shaped and measure about one-half inch in height and three inches in length. Each gland consists of a medulla that is surrounded by the cortex. The medulla is responsible for producing epinephrine also known as adrenaline. The adrenal cortex produces other hormones necessary for fluid and salt balance in the body such as cortisone and aldosterone. Disorders of either the cortex or the medulla can result in hypertension.
What is primary hyperaldosteronism?
Also known as Conn's syndrome, this disorder occurs when the adrenal overproduces aldosterone, a hormone that controls sodium and potassium levels in the blood. Its overproduction leads to retention of salt (sodium) and loss of potassium, which leads to hypertension. It is due to either a benign cortical adenoma, or bilateral adrenal hyperplasia. Both diseases cause an over secretion of the salt retaining hormone aldosterone.
Primary hyperaldosteronism accounts for less than one percent of all cases of hypertension. It is more common in females than males (3:1 ratio). It can occur at any age, but most commonly when a person is in their 30s and 40s. The majority of cases are sporadic, but hereditary causes have been identified: one type is glucocorticoid remediable aldosteronism (GRA). GRA is caused by a rare gene where aldosterone production is controlled by the pituitary gland rather than by the kidney. Other causes of hyperaldosteronism include any condition that decreases blood flow to the kidney, including dehydration, kidney artery constriction, cardiac failure, shock, liver disease, pregnancy and renin-secreting kidney tumors. In this setting the term secondary hyperaldosteronism is used because the cause of the hypersecretion is not primarily a problem with the adrenal gland.
What are the symptoms of primary hyperaldosteronism?
In hyperaldosteronism, excess aldosterone leads to an inappropriate salt re-absorption, which increases the extracellular fluid volume until the kidneys can respond appropriately. Patients typically have mild to moderate hypertension. Primary hyperaldosteronism can be distinguished from basic hypertension through blood tests. In general, hyperaldosteronism is unresponsive to standard medical therapy used to prevent or reduce high blood pressure.
Mild hypernatremia (high blood sodium), hypokalemia (low blood potassium), hyperkaluria (high urine potassium) and high levels of alkalinity are the electrolyte abnormalities commonly seen with excess aldosterone. These contribute the following symptoms: muscle weakness, frequent urination, nighttime urination, headache, excessive thirst, pins and needles sensation, visual disturbances, temporary paralysis, muscle twitching and cramps. The severity of these symptoms may be highly variable depending on the degree of electrolyte abnormality.
How is primary hyperaldosteronism diagnosed?
A screening test may be conducted to pinpoint a diagnosis. Blood and urine tests can check for high aldosterone, and low potassium and renin activity. A CT scan or MRI may be ordered to detect tumors.
How is primary hyperaldosteronism treated?
Secondary hyperaldosteronism that is caused by kidney enlargement or heart disease is usually treated with medical therapy. Primary hyperaldosteronism resulting from a tumor is usually treated by removing an adrenal gland (unilateral adrenalectomy). This surgery is almost always performed with a laparoscopic approach. Bilateral hyperplasia is treated with potassium sparing diuretics such as spironolactone.
What can be expected after treatment for primary hyperaldosteronism?
In general, patients experience rapid and uneventful postoperative recovery. Of the patients who undergo unilateral adrenalectomy for primary hyperaldosteronism, hypertension is completely resolved or significantly improved in 80 to 90 percent. The preoperative plasma renin activity (PRA) level is the best predictor of postoperative blood pressure outcome. As a result, the cured patients have lower pre-surgical PRA levels than those who are not cured. Even after surgery, some patients have high blood pressure and require medication for hours or weeks until their blood pressure returns to normal. Blood pressure and serum electrolytes should be monitored after surgery and/or after the start of medical therapy.
Up to 5 percent of patients may suffer from ongoing high blood pressure. The reason for this is not fully understood, but some experts believe this may be a result of chronic, irreversible kidney damage from the primary hyperaldosteronism.
Frequently asked questions:
Can a woman with primary hyperaldosteronism safely become pregnant?
Yes, pregnancy is perfectly feasible. Ironically, in pregnancy the high blood pressure of hyperaldosteronism settles without spironalactone due to the aldosterone effect being blocked by the naturally rising sex hormone produced by the pregnancy.
What is the prognosis for primary hyperaldosteronism?
The outcome is good with treatment.
Reviewed: January 2011
Last updated: April 2013
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