Which is NOT a feature of primary hyperaldosteronism –
**Core Concept**
Primary hyperaldosteronism is a condition characterized by the excessive production of aldosterone, a hormone produced by the adrenal glands that regulates sodium and potassium levels in the body. This leads to hypertension, hypokalemia, and metabolic alkalosis. The underlying pathophysiology involves the overactivation of the renin-angiotensin-aldosterone system (RAAS).
**Why the Correct Answer is Right**
The features of primary hyperaldosteronism include hypertension, hypokalemia, metabolic alkalosis, and suppressed plasma renin activity. This is because the excess aldosterone leads to increased sodium reabsorption and potassium excretion in the kidneys, resulting in high blood pressure and low potassium levels. The RAAS is suppressed due to the negative feedback from the high levels of aldosterone.
**Why Each Wrong Option is Incorrect**
**Option A:** This feature is characteristic of primary hyperaldosteronism, as the excess aldosterone leads to increased sodium reabsorption and water retention, resulting in hypertension.
**Option B:** Hypokalemia is a common feature of primary hyperaldosteronism, as the excess aldosterone leads to increased potassium excretion in the kidneys.
**Option C:** Metabolic alkalosis is a feature of primary hyperaldosteronism, as the excess aldosterone leads to increased sodium reabsorption and hydrogen ion excretion in the kidneys.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that primary hyperaldosteronism can be caused by either an aldosterone-producing adenoma or bilateral adrenal hyperplasia, which are often differentiated by imaging studies and biochemical tests.
**Correct Answer: D.**