endocrine and metabolic disorders
Primary Aldosteronism
Introduction
Primary aldosteronism is aldosteronism caused by autonomous production of aldosterone by the adrenal cortex (due to hyperplasia, adenoma, or carcinoma). Symptoms and signs include episodic weakness, elevated blood pressure, and hypokalemia. Diagnosis includes measurement of plasma aldosterone levels and plasma renin activity. Treatment depends on cause. A tumor is removed if possible; in hyperplasia,spironolactoneor related drugs may normalize blood pressure and eliminate other clinical features. (See also Overview of Adrenal Function .) Aldosterone is the most potent mineralocorticoid produced by the adrenals. It causes sodium retention and potassium loss. In the kidneys, aldosterone causes transfer of sodium from the lumen of the distal tubule into the tubular cells in exchange for potassium and hydrogen. The same effect occurs in salivary glands, sweat glands, cells of the intestinal mucosa, and in exchanges between intracellular fluid (ICF) and extracellular fluid (ECF). Aldosterone secretion is regulated by the Primary Aldosteronism and, to a lesser extent, by adrenocorticotropic hormone (ACTH). Renin, a proteolytic enzyme, is stored in the juxtaglomerular cells of the kidneys. Reduction in blood volume and flow in the afferent renal arterioles or Primary aldosteronism is caused by an Adrenal adenoma, usually unilateral, of the glomerulosa cells of the adrenal cortex Adrenal carcinoma or hyperplasia (rare) Adenomas are extremely rare in children, but primary aldosteronism sometimes occurs in childhood adrenal carcinoma or hyperplasia. In adrenal hyperplasia, which is more common among older men, both adrenals are overactive, and no adenoma is present. The clinical picture can also occur with certain forms of congenital adrenal hyperplasia (in which other mineralocorticoids are elevated) and the dominantly inheriteddexamethasone-suppressible hyperaldosteronism. Small aldosterone-secreting adenomas are increasingly recognized as a cause of primary hypertension even when serum potassium levels are normal. 