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Difficulty: HardEndocrinology and Metabolism

Match each clinical and laboratory profile of a patient presenting with secondary hypertension to the most likely underlying pathophysiologic diagnosis.

  • Hypertension, hypokalemia, suppressed plasma renin activity, and elevated plasma aldosterone concentration.Primary hyperaldosteronism
  • Hypertension, hypokalemia, abdominal bruit, elevated plasma renin activity, and elevated plasma aldosterone concentration.Renovascular hypertension
  • Hypertension, hypokalemia, primary amenorrhea, delayed puberty, suppressed renin, and suppressed aldosterone.17-alpha-hydroxylase deficiency
  • Hypertension, hypokalemia, severe virilization in a female, suppressed renin, and suppressed aldosterone.11-beta-hydroxylase deficiency
  • Hypertension, paroxysmal headaches, tachycardia, diaphoresis, and elevated plasma free metanephrines.Pheochromocytoma

Answer

The correct pairings match Primary hyperaldosteronism with low renin/high aldosterone; Renovascular hypertension with high renin/high aldosterone; 17-alpha-hydroxylase deficiency with absent puberty/low renin/low aldosterone; 11-beta-hydroxylase deficiency with virilization/low renin/low aldosterone; and Pheochromocytoma with metanephrines.
Each profile describes a distinct etiology of secondary hypertension. Primary hyperaldosteronism is characterized by autonomous aldosterone secretion, suppressing renin. Renovascular hypertension involves reduced renal perfusion, activating the RAAS axis to increase both renin and aldosterone. Both 11-beta and 17-alpha hydroxylase deficiencies lead to the accumulation of 11-deoxycorticosterone (a weak mineralocorticoid), which causes hypertension and hypokalemia, suppressing both renin and aldosterone. They are distinguished phenotypically: 11-beta causes virilization (shunting to androgens), while 17-alpha causes absent sexual development (impaired androgen synthesis). Pheochromocytoma is identified by catecholamine excess.

Step-by-Step Solution

1
Evaluate the plasma renin and aldosterone levels.
These levels categorize patients into primary mineralocorticoid excess (low renin, high aldosterone), secondary hyperaldosteronism (high renin, high aldosterone), or other non-aldosterone mineralocorticoid excess (low renin, low aldosterone).
This is the essential first branch point in the diagnostic algorithm for endocrine hypertension.
2
Differentiate causes of low renin and low aldosterone hypertension.
Evaluate for other mineralocorticoids (e.g., 11-deoxycorticosterone) by assessing sex steroid production: virilization indicates 11-beta-hydroxylase deficiency, while absent puberty indicates 17-alpha-hydroxylase deficiency.
Congenital adrenal hyperplasias have distinct phenotypic presentations based on the specific enzyme block and subsequent hormone shunting pathways.
3
Identify non-mineralocorticoid causes of secondary hypertension.
Recognize the pathognomonic episodic symptoms and elevated metanephrines associated with pheochromocytoma.
Catecholamine excess causes unique sympathetic activation distinct from RAAS-mediated or steroid-mediated hypertension.

Key Concept

Diagnostic interpretation of the renin-angiotensin-aldosterone system and adrenal steroidogenesis pathways in the evaluation of secondary hypertension.
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Topics

Endocrinology and Metabolism

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