From the Guidelines
Conn's syndrome, also known as primary aldosteronism, is a condition where the adrenal glands produce too much aldosterone hormone, leading to high blood pressure and low potassium levels, and is the most common form of secondary hypertension, as stated in the 2024 ESC guidelines for the management of elevated blood pressure and hypertension 1.
Definition and Causes
Conn's syndrome is characterized by the excessive production of aldosterone, a hormone that regulates sodium and potassium levels in the body. This excess aldosterone causes increased sodium retention and potassium excretion, leading to high blood pressure and low potassium levels. The most common cause is an aldosterone-producing adenoma (benign tumor) in one adrenal gland, though bilateral adrenal hyperplasia can also cause it.
Diagnosis
Diagnosis typically involves blood tests measuring aldosterone and renin levels, followed by confirmatory tests and imaging studies like CT scans or MRI to locate any tumors. The aldosterone:renin activity ratio is currently the most accurate and reliable means of screening for primary aldosteronism, as stated in the 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults 2, 3, 4.
Treatment
Treatment depends on the cause, with surgical removal of the affected adrenal gland (adrenalectomy) recommended for patients with unilateral adenomas, while medication management is used for bilateral disease, as stated in the 2024 ESC guidelines for the management of elevated blood pressure and hypertension 1. The main medications include mineralocorticoid receptor antagonists like spironolactone (50-100 mg once daily, titrated up to 300-400 mg once daily if necessary) or eplerenone, which block aldosterone's effects. Potassium supplements may be needed initially to correct hypokalemia. After successful treatment, blood pressure often improves significantly, though some patients may still require additional antihypertensive medications.
Importance of Early Diagnosis and Treatment
Early diagnosis and treatment are important to prevent complications like cardiovascular disease and kidney damage that can result from prolonged uncontrolled hypertension. Primary aldosteronism is associated with a higher risk of cardiovascular and kidney damage compared to primary hypertension, as stated in the 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults 3.
From the FDA Drug Label
Spironolactone tablets are indicated in the following settings: Short-term preoperative treatment of patients with primary hyperaldosteronism. Long-term maintenance therapy for patients with discrete aldosterone-producing adrenal adenomas who are not candidates for surgery Long-term maintenance therapy for patients with bilateral micro or macronodular adrenal hyperplasia (idiopathic hyperaldosteronism).
Primary Hyperaldosteronism, also known as Conn's syndrome, is a condition characterized by the excess production of aldosterone, a hormone that regulates sodium and potassium balance in the body. It can be caused by a variety of factors, including:
- Aldosterone-producing adrenal adenomas: benign tumors on the adrenal glands that produce excess aldosterone
- Bilateral micro or macronodular adrenal hyperplasia: a condition where the adrenal glands become overactive and produce excess aldosterone This condition can lead to hypertension, edema, and other complications. Spironolactone is used to treat primary hyperaldosteronism by blocking the effects of aldosterone and helping to regulate sodium and potassium balance in the body 5.
From the Research
Definition and Causes of Conn's Syndrome
- Conn's syndrome, also known as Primary Aldosteronism, is a condition characterized by excessive production of aldosterone, leading to hypertension and hypokalaemia 6, 7, 8, 9, 10.
- The syndrome is usually caused by either a unilateral aldosterone-producing adenoma or bilateral adrenal hyperplasia 6, 8, 10.
- Primary aldosteronism is the most common cause of endocrine hypertension and is associated with an increased cardiovascular risk and comorbidities such as type 2 diabetes mellitus 7.
Diagnosis of Conn's Syndrome
- The diagnostic workup of primary aldosteronism involves a sequence of three phases: screening tests, confirmatory tests, and differentiation of unilateral from bilateral forms 6, 8.
- Screening can be accomplished by measuring the plasma aldosterone to plasma renin activity ratio, followed by aldosterone suppression confirmatory testing 6.
- Patients with suspected primary aldosteronism should undergo screening if they have hypertension and hypokalaemia, treatment-resistant hypertension, severe hypertension, or an incidental adrenal mass 6.
- The aldosterone-renin ratio is used as a first screening test for primary aldosteronism, and should be evaluated under optimized conditions 7.
Treatment and Outcomes of Conn's Syndrome
- Unilateral adrenalectomy is the treatment of choice for patients with unilateral aldosterone-producing adenoma or unilateral adrenal hyperplasia 6, 7, 9.
- Patients with bilateral adrenal disease or those who are contraindicated for surgery should receive lifelong treatment with mineralocorticoid receptor antagonists 6, 7, 9.
- Treatment can mitigate or reverse the increased risks associated with primary aldosteronism, including cardiovascular and cerebrovascular events, and adverse effects on the heart and kidney 10.
- The prevalence of primary aldosteronism is estimated to be around 5-13% of all patients with hypertension, and it is considered the most common potentially curable form of hypertension 6, 10.