In primary aldosteronism, what is the expected level of renin?

In primary aldosteronism, the expected level of renin is low. This condition is characterized by the excessive production of aldosterone from the adrenal glands, usually due to an adenoma or hyperplasia. High levels of aldosterone lead to increased sodium retention and potassium excretion, which results in higher blood volume and blood pressure.

In response to the elevated blood pressure and sodium levels, the kidneys reduce the secretion of renin. Renin is an enzyme released by the juxtaglomerular cells of the kidneys in response to low blood volume or blood pressure, and its role is primarily to activate the renin-angiotensin-aldosterone system (RAAS). In primary aldosteronism, since aldosterone secretion is inappropriate and high, the body's feedback mechanism detects this excess and decreases renin production as a counter-regulatory response, resulting in low levels of renin.