Primary aldosteronism
Overview
Primary aldosteronism, also known as primary hyperaldosteronism and Conn syndrome, is characterized by the overproduction of the mineralocorticoid hormone aldosterone by the adrenal glands. Aldosterone causes increase in sodium and water retention and potassium excretion in the kidneys, leading to arterial hypertension (high blood pressure). Also increase production of mineralocorticoid from the adrenal gland is evident. It is a rare but recognised cause of hypertension.
Symptoms
Primary hyperaldosteronism, aside from high blood pressure, may manifest with muscle cramps (due to hyperexcitability of neurons), muscle weakness (due to hypoexcitability of skeletal muscles), headaches (due to the low potassium or high blood pressure), and metabolic alkalosis (due to increased secretion of H+ ions by the kidney). The high pH of the blood makes calcium less available to the tissues and causes symptoms of hypocalcemia (low calcium levels). It can be mimicked by liquorice ingestion (glycyrrhizin) and Liddle syndrome.
Causes
The syndrome is due to: * aldosterone-secreting adrenal adenoma (benign tumor, 50-60%) * hyperplasia of the adrenal gland (40-50%) * rare forms
Diagnosis
Measuring aldosterone alone is not considered adequate to diagnose primary hyperaldosteronism. Rather, both renin and aldosterone are measured, and the ratio is diagnostic. Usually, renin levels are suppressed, leading to a very low renin-aldosterone ratio (