Primary Aldosteronism (Conn’s Syndrome): Symptoms, Causes, Treatment

What are the symptoms of primary aldosteronism?

Primary aldosteronism, also known as Conn’s syndrome, is a condition characterized by excessive production of aldosterone by the adrenal glands. This hormone regulates sodium and potassium levels in the blood. Symptoms of primary aldosteronism include:

1. High Blood Pressure (Hypertension): Often severe and resistant to treatment.
2. Low Blood Potassium Levels (Hypokalemia): This can lead to muscle weakness, muscle cramps, fatigue, and abnormal heart rhythms.
3. Muscle Symptoms: Muscle spasms, muscle cramps, or weakness due to low potassium levels.
4. Increased Urination (Polyuria): Frequent urination, especially at night (nocturia).
5. Thirst (Polydipsia): Excessive thirst due to increased urination.
6. Fatigue: General feeling of tiredness and weakness.
7. Headaches: Frequent or severe headaches.
8. Tingling or Numbness: Sensations of tingling or numbness, often due to electrolyte imbalances.

Some individuals with primary aldosteronism may not exhibit any noticeable symptoms and are only diagnosed during evaluations for hypertension or low potassium levels.

What are the causes of primary aldosteronism?

Primary aldosteronism is typically caused by issues within the adrenal glands that lead to excessive production of aldosterone. The main causes include:

1. Aldosterone-producing Adenoma (APA): A benign tumor in one of the adrenal glands that produces too much aldosterone. This is also known as Conn’s syndrome.
2. Bilateral Adrenal Hyperplasia (BAH): Enlargement of both adrenal glands, leading to increased aldosterone production. This condition is sometimes called idiopathic hyperaldosteronism.
3. Unilateral Adrenal Hyperplasia: Enlargement of one adrenal gland, resulting in excessive aldosterone production.
4. Adrenal Carcinoma: A rare cause, where a malignant tumor in the adrenal gland produces aldosterone.
5. Familial Hyperaldosteronism: A genetic condition that leads to excessive aldosterone production. There are several types, with type I and type II being the most common.

These conditions disrupt the normal regulation of aldosterone, causing it to be overproduced, which in turn affects sodium and potassium balance in the body, leading to hypertension and other symptoms associated with primary aldosteronism.

How is the diagnosis of primary aldosteronism made?

The diagnosis of primary aldosteronism involves several steps. Initially, doctors perform screening tests, including measuring plasma aldosterone concentration (PAC) and plasma renin activity (PRA), and calculating the aldosterone-to-renin ratio (ARR). A high ARR suggests primary aldosteronism.

If the screening tests are positive, confirmatory tests follow. These include the saline infusion test, which measures aldosterone levels after saline infusion, and the oral sodium loading test, where aldosterone levels are measured after increasing dietary sodium intake. In both tests, aldosterone levels remain high in cases of primary aldosteronism. Another confirmatory test is the fludrocortisone suppression test (FST), which uses fludrocortisone to suppress aldosterone production.

Imaging studies, such as CT scans or MRIs of the adrenal glands, are used to identify structural abnormalities like adenomas or hyperplasia. Additionally, adrenal vein sampling (AVS) can differentiate between unilateral and bilateral sources of excess aldosterone by measuring aldosterone levels from both adrenal veins and comparing them to peripheral blood levels.

In cases where there is a family history or other indicators, genetic testing may be performed to identify mutations associated with familial hyperaldosteronism. Combining these tests allows clinicians to accurately diagnose primary aldosteronism, determine its cause, and guide appropriate treatment.

What is the treatment for primary aldosteronism?

The treatment for primary aldosteronism varies based on the underlying cause and the patient’s overall health. Surgical treatment, specifically adrenalectomy, is typically recommended for patients with an aldosterone-producing adenoma (unilateral adrenal hyperplasia). This surgery can often cure the condition and significantly improve blood pressure and potassium levels.

For patients with bilateral adrenal hyperplasia or those who are not candidates for surgery, medical treatment is the primary approach. Medications such as spironolactone or eplerenone, which are mineralocorticoid receptor antagonists, are prescribed to block the action of aldosterone, helping to control blood pressure and correct potassium levels. Additionally, other blood pressure-lowering medications may be needed to manage hypertension.

Lifestyle changes are also important. Reducing sodium intake can help control blood pressure, and increasing potassium intake through diet may be beneficial, though this should be done under medical supervision to avoid complications. Regular follow-up appointments are necessary to monitor blood pressure, potassium levels, and overall health.

In cases where there is a genetic component, such as familial hyperaldosteronism, genetic counseling and testing may be recommended. Treatment plans may be adjusted based on specific genetic findings. The choice of treatment is tailored to each patient, and regular monitoring and follow-up are essential to ensure effective management and to make any necessary adjustments to the treatment plan.