From the Guidelines
The standard workup for diagnosing hyperaldosteronism begins with screening tests, specifically measuring the aldosterone-to-renin ratio (ARR), followed by confirmatory testing and subtype classification, as recommended by the most recent guidelines 1. The initial screening involves measuring the ARR after ensuring the patient has adequate potassium levels and has discontinued interfering medications (such as spironolactone, eplerenone, ACE inhibitors, ARBs, and diuretics) for at least 2-4 weeks.
- Blood samples should be collected in the morning with the patient in a seated position.
- An elevated ARR (typically >20-30 ng/dL per ng/mL/hr) suggests hyperaldosteronism. Confirmatory testing follows positive screening and may include:
- The oral sodium loading test
- Saline infusion test
- Fludrocortisone suppression test
- Captopril challenge test These tests evaluate whether aldosterone production can be suppressed, which doesn't occur in primary hyperaldosteronism. Once confirmed, subtype classification involves:
- Adrenal imaging (CT or MRI) to identify adenomas
- Adrenal vein sampling to determine if aldosterone production is unilateral or bilateral This distinction is crucial as unilateral disease may be surgically curable, while bilateral disease typically requires medical management with mineralocorticoid receptor antagonists like spironolactone (25-100 mg daily) or eplerenone (50-100 mg daily) 1. Throughout the workup, monitoring of blood pressure, serum potassium, and renal function is essential for proper diagnosis and management. The most recent guidelines emphasize the importance of a multidisciplinary approach and consideration of the patient's overall clinical context in the diagnosis and management of hyperaldosteronism 1.
From the Research
Standard Workup to Diagnose Hyperaldosteronism
The standard workup to diagnose hyperaldosteronism involves several steps, including:
- Case detection: identifying patients at risk, such as those with resistant hypertension, well-controlled hypertension with a first-degree relative with primary aldosteronism, hypokalemia, an adrenal nodule, atrial fibrillation, obstructive sleep apnea, or a family history of an early stroke 2
- Initial testing: measuring plasma aldosterone concentration and plasma renin activity to calculate the aldosterone-renin ratio (ARR) 2, 3
- Confirmatory testing: performing tests such as the captopril challenge, oral or intravenous salt loading, or fludrocortisone suppression to confirm the diagnosis of primary aldosteronism 2, 4
- Imaging studies: using adrenal computed tomography (CT) and adrenal vein sampling to differentiate between unilateral and bilateral adrenal production of aldosterone 2, 5
Diagnostic Criteria
The diagnostic criteria for hyperaldosteronism include:
- An elevated aldosterone-renin ratio (ARR) greater than 30 2
- Failure to suppress aldosterone levels after confirmatory testing 2, 4
- Presence of hypokalemia, hypertension, and suppressed plasma renin activity 3, 4
Treatment
Treatment of hyperaldosteronism depends on the underlying cause and may include: