A 24 year-old man presents for his annual check-up and his blood pressure is found to be 152/78. The measurement is repeated and the same result is obtained. His primary care physician suspects secondary hypertension. In which of the following scenarios would this patient have suppression of the renin-angiotensin system?
Aortic coarctation
Carcinoid syndrome
Primary hyperaldosteronism
Unilateral renal artery stenosis
Volume depletion
Correct answer
Primary hyperaldosteronism
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correct answer: C
Although unilateral renal artery stenosis, primary hyperaldosteronism, and aortic coarctation are all causes of secondary hypertension, only in primary hyperaldosteronism (or Conn syndrome) would there be suppression of the renin-angiotensin system. In unilateral renal artery stenosis and aortic coarctation, it would be activated due to relative renal hypoperfusion. Volume depletion would not cause hypertension, and the renin-angiotensin system would be stimulated. In carcinoid syndrome (flushing, hypotension, tachycardia, diarrhea), the renin-angiotensin system would be stimulated to increase vascular tone.