Primary aldosteronism: current knowledge and controversies in Conn's syndrome


Primary aldosteronism has been recognized as a common cause of secondary hypertension, accounting for approximately 10% of the hypertensive population. Screening should be applied in hypertensive patients presenting with one of the following: hypokalemia, refractory hypertension, suggestive family history, or an incidentally detected adrenal mass. The most advocated screening test at present is the aldosterone-to-renin ratio, which has a high sensitivity but low specificity. The specificity increases if patients with low aldosterone concentrations are excluded. Published cut-off values vary depending on the hormone assay and the investigated population. Before screening, antihypertensive treatment, especially aldosterone antagonists and β-blockers, should be discontinued. A pathologic result requires additional work up to prove mineralocorticoid excess. Subtype differentiation is performed by adrenal venous sampling combined with imaging (CT or MRI). One-third of cases are due to aldosterone-producing adenomas, for which the preferred treatment is laparoscopic adrenalectomy. Bilateral adrenal hyperplasia (idiopathic aldosteronism) underlies two-thirds of cases and requires treatment with aldosterone antagonists. Treatment is started with low doses of spironolactone (25–50 mg once daily), which often results in substantial improvements in hypertension.

Key Points

  • Primary aldosteronism most frequently presents as normokalemic hypertension

  • In suspected cases, screening involves the aldosterone-to-renin ratio

  • Confirmatory testing (e.g. the saline suppression test) should follow a pathologic screening test result

  • After a confirmed diagnosis, patients undergo MRI or CT scan followed by adrenal venous sampling

  • Therapy consists of spironolactone treatment (25–100 mg) in patients with bilateral adrenal hyperplasia and unilateral adrenalectomy in those with aldosterone-producing adenomas

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Figure 1: Diagnostic algorithm for primary aldosteronism in specialized centers


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The authors are grateful to Kathy Muller-Schertler for language editing.

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Correspondence to Martin Reincke.

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Schirpenbach, C., Reincke, M. Primary aldosteronism: current knowledge and controversies in Conn's syndrome. Nat Rev Endocrinol 3, 220–227 (2007).

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