A primary hyperaldosteronemic state is characterized by which of the following?

A primary hyperaldosteronemic state is characterized by which of the following?

• A. A urine potassium of 35 mmol/d
• B. A urine potassium of 21 mmol/d
• C. A spot urine test where the sodium levels are greater than potassium levels
• D. Within 3 hours of taking 50 mg of captopril, plasma aldosterone was low

Answer: (A)

In primary hyperaldosteronism, aldosterone is produced autonomously, which drives more sodium reabsorption and increases potassium secretion in the distal nephron. That enhanced potassium loss into the urine shows up as elevated urinary potassium excretion. A 24-hour urine potassium of 35 mmol/day reflects this increased kaliuresis and aligns with the excess aldosterone driving renal potassium loss, making it the best indicator among the choices. By contrast, a lower urine potassium like 21 mmol/day would not demonstrate this excess kaliuresis; a spot urine pattern where sodium exceeds potassium isn’t a specific hallmark of aldosterone excess, and a rapid drop in plasma aldosterone after captopril would argue against autonomous production, since primary hyperaldosteronism is not suppressed by ACE inhibition.

In primary hyperaldosteronism, aldosterone is produced autonomously, which drives more sodium reabsorption and increases potassium secretion in the distal nephron. That enhanced potassium loss into the urine shows up as elevated urinary potassium excretion. A 24-hour urine potassium of 35 mmol/day reflects this increased kaliuresis and aligns with the excess aldosterone driving renal potassium loss, making it the best indicator among the choices. By contrast, a lower urine potassium like 21 mmol/day would not demonstrate this excess kaliuresis; a spot urine pattern where sodium exceeds potassium isn’t a specific hallmark of aldosterone excess, and a rapid drop in plasma aldosterone after captopril would argue against autonomous production, since primary hyperaldosteronism is not suppressed by ACE inhibition.