American Board of Surgery Qualifying Exam (ABS QE) Practice Test

What most characterizes Conn's syndrome?

1. Hypokalemia, metabolic acidosis

2. Hyperkalemia, metabolic alkalosis

3. Hypertension, low aldosterone

4. Hypotension, hypernatremia

The correct answer is: Hypokalemia, metabolic acidosis

Conn's syndrome, also known as primary hyperaldosteronism, is characterized primarily by the presence of hypertension and hypokalemia due to increased levels of aldosterone. In this condition, the adrenal glands produce excess aldosterone, which leads to sodium retention, potassium excretion, and increased water retention, resulting in hypertension. Hypokalemia occurs because aldosterone acts on the renal tubules to promote the excretion of potassium. Individuals with Conn's syndrome typically present with metabolic alkalosis rather than acidosis, stemming from the excretion of protons that occurs due to the effects of excess aldosterone. The other options do not accurately represent Conn's syndrome. For instance, hyperkalemia would imply a lack of aldosterone function, which is not the case in this syndrome. Additionally, low aldosterone levels contradict the very pathology of Conn's syndrome, where aldosterone is elevated. Hypotension is also inconsistent with the usual presentation of this condition, as hypertension is a hallmark.