What would you see in Conn's syndrome?

From the Guidelines

In patients with Conn's syndrome, you would typically see hypertension, hypokalemia, metabolic alkalosis, and sometimes muscle weakness or cramping, as a result of excessive aldosterone production from the adrenal glands. According to the most recent guidelines, specifically the 2024 ESC guidelines for the management of elevated blood pressure and hypertension 1, primary aldosteronism (Conn syndrome) is the most common form of secondary hypertension. The management of primary aldosteronism depends on its subtype, particularly on adrenal lesions being unilateral or bilateral. Some key features of Conn's syndrome include:

• Hypertension (often resistant to standard treatments)
• Hypokalemia (low potassium levels)
• Metabolic alkalosis
• Muscle weakness or cramping
• Increased thirst and frequent urination
• Headaches and fatigue Laboratory findings would show elevated aldosterone levels with suppressed renin activity, resulting in a high aldosterone-to-renin ratio, as noted in the British Hypertension Society guidelines for hypertension management 2004 (BHS-IV) 1. Imaging studies like CT scans or MRI might reveal an adrenal adenoma (benign tumor) in unilateral cases, while bilateral adrenal hyperplasia may be seen in other cases. Treatment depends on the cause, with surgical removal (adrenalectomy) recommended for adenomas, while mineralocorticoid receptor antagonists like spironolactone (50-100 mg daily) or eplerenone (25-100 mg daily) are used for bilateral disease or when surgery isn't possible, as recommended by the 2024 ESC guidelines 1. These medications block aldosterone's effects, helping normalize blood pressure and potassium levels. Conn's syndrome is important to identify as it's a potentially curable cause of hypertension when caused by an adenoma.

From the Research

Conn's Syndrome Diagnosis and Treatment

In patients with Conn's syndrome, the following may be observed:

• Elevated aldosterone levels and low renin levels, resulting in an increased aldosterone-renin ratio 2, 3, 4, 5, 6
• Hypertension, which may be resistant to treatment 2, 3, 4, 5, 6
• Hypokalemia, or low potassium levels 3, 4, 6
• Cardiovascular risk and comorbidities, such as type 2 diabetes mellitus 2

Diagnostic Tests

The following diagnostic tests may be used to diagnose Conn's syndrome:

• Measurement of the aldosterone-renin ratio, which is used as a first screening test for primary aldosteronism 2, 3, 4, 5
• Confirmatory testing, such as adrenal venous sampling, to validate the diagnosis of primary hyperaldosteronism 2, 3, 4, 5
• Imaging of the adrenal glands, such as CT or MRI scans, to identify any adrenal adenomas or hyperplasia 2, 3, 4, 5, 6

Treatment Options

The following treatment options may be considered for patients with Conn's syndrome:

• Unilateral laparoscopic adrenalectomy for patients with unilateral adrenal disease 2, 3, 5
• Lifelong treatment with mineralocorticoid receptor antagonists, such as spironolactone, for patients with bilateral adrenal disease or contraindications for adrenalectomy 2, 3, 4, 5, 6
• A low-sodium diet and lifelong treatment with a mineralocorticoid receptor antagonist for patients with bilateral aldosterone hypersecretion 5