What is Conn Syndrome?
Conn Syndrome, medically known as primary hyperaldosteronism, is a disorder of the small, pyramid-shaped adrenal glands, which are located in the abdomen directly above the kidneys. These glands produce vital hormones. The main problem in Conn’s Syndrome is the excessive secretion of the hormone aldosterone by the adrenal glands.
Normally, aldosterone regulates blood pressure and the body’s salt and water balance. However, when aldosterone is produced in excess, this delicate balance is disrupted, typically leading to persistently high blood pressure (arterial hypertension) and sometimes low potassium levels (hypokalemia).
Primary hyperaldosteronism is diagnosed in 5-29% of patients with hypertension. The incidence is even higher in cases of resistant hypertension. These rates are increasingly being identified due to heightened awareness and screening methods, and they are of great significance for patient prognosis. Primary hyperaldosteronism is associated with serious cardiovascular diseases such as stroke, myocardial infarction, and atrial fibrillation.
What Are the Causes of Conn's Syndrome?
The primary cause of Conn’s Syndrome is excessive aldosterone production in the adrenal glands. The most common reasons for this overproduction are:
- Bilateral adrenal hyperplasia (enlargement of both adrenal glands): This is the most common cause, accounting for about 60-70% of all cases. Both adrenal glands enlarge and produce too much aldosterone.
- Aldosterone-producing adenoma (unilateral benign tumor): This is the second most common cause, affecting about 30-40% of cases. It’s a benign tumor (adenoma) that typically develops in only one adrenal gland and produces excessive amounts of aldosterone. This condition is relatively frequently associated with low potassium levels in the blood.
- Unilateral adrenal hyperplasia: This is a very rare, one-sided enlargement of only one adrenal gland.
- Aldosterone-producing malignant tumor: This is a very rare malignant (cancerous) tumor that forms in the adrenal gland.
- Familial hyperaldosteronism: This is a very rare hereditary form caused by a genetic defect.
- Ectopic aldosterone production: These are aldosterone-producing tumors that originate in the ovaries and kidneys.
What Are the Symptoms of Conn Syndrome?
The most noticeable symptom of Conn Syndrome, occurring in almost all cases, is persistently high blood pressure. This high blood pressure can be difficult to distinguish from other forms of hypertension. However, the high blood pressure caused by Conn’s Syndrome is often resistant and difficult to control, even with multiple antihypertensive medications. Very high blood pressure values can trigger the following symptoms:
- Fatigue
- Headaches
- Dizziness
- Tinnitus (ringing in the ears)
- Nosebleeds
- Palpitations
- Chest pressure
If Conn’s Syndrome also leads to low potassium levels (hypokalemia) (this can occur in up to a third of all cases), additional symptoms may appear:
- Muscle weakness or cramps
- Constipation
- Cardiac arrhythmias (irregular heartbeat)
In many cases, Conn’s Syndrome can remain asymptomatic and undetected for long periods. However, as Uzm. Dr. Burcu Meryem Atak Sançmış emphasizes, this condition is by no means harmless; it can silently lead to serious cardiovascular complications. Therefore, especially in cases of uncontrolled resistant hypertension, distinguishing triggers are of great importance for early diagnosis.
How Is Conn Syndrome Diagnosed?
The diagnosis of Conn’s Syndrome is a multi-stage process that requires a comprehensive and multidisciplinary approach. This process should be carefully followed under the supervision of endocrinology specialists like Uzm. Dr. Burcu Meryem Atak Sançmış.
Persistently high blood pressure, chronically low potassium levels in the blood, or an incidentally discovered adrenal nodule often lead to suspicion of Conn’s Syndrome.
The diagnostic process includes the following steps:
- Blood Tests (Screening Test): The initial screening involves measuring the blood concentrations of the hormones aldosterone and renin. This uses the plasma aldosterone concentration (PAC) and plasma renin activity (PRA) or direct renin concentration (DRC). For screening tests, blood samples should be drawn in the morning between 8:00 AM and 9:30 AM, after the patient has been seated for 15 minutes, in a sitting position. The patient should have been out of bed for at least 2 hours before the test. Ideally, sodium intake in the patient’s diet should not be restricted, and serum potassium levels should be normalized before the test. Medications that could influence the tests should also be reviewed. In this case, Uzm. Dr. Burcu Meryem Atak Sançmış will guide her patients accordingly.
- Confirmatory Tests: If the screening test is positive, confirmatory tests are performed to confirm or rule out the diagnosis.
- Saline Infusion Test: This is the most commonly used confirmatory test. Two liters of saline solution are administered intravenously over four hours. In healthy individuals, this overload lowers aldosterone levels, while in Conn’s Syndrome, they remain high.
- Other confirmatory tests include the captopril challenge test and the fludrocortisone suppression test.
- Important Note: Some blood pressure medications can affect measurements and may need to be temporarily discontinued or replaced before the test.
- Imaging (CT and MRI): After the diagnosis of primary hyperaldosteronism is confirmed, computed tomography (CT) or magnetic resonance imaging (MRI) scans of the abdomen are performed to obtain detailed images of the adrenal glands. These images help to detect tumors or other abnormalities.
- However, the discovery of a tumor does not always reveal the source of aldosterone, as hormonally inactive benign tumors are also common. Furthermore, tumors small enough to cause the disease may be missed on imaging.
- Adrenal Venous Sampling (AVS): Adrenal venous sampling is the gold standard for distinguishing between unilateral and bilateral aldosterone hypersecretion. Discrepancies may occur between imaging findings and adrenal venous sampling findings. Even if an adenoma is found by imaging, adrenal venous sampling is recommended before a definitive treatment decision is made. This advanced examination is typically used to confirm imaging findings and definitively determine the aldosterone source (unilateral or bilateral).
- Under local anesthesia, an interventional radiologist accesses the veins coming from the adrenal glands via a catheter inserted through the femoral vein. Bilateral blood samples are drawn to measure aldosterone concentrations. This examination is particularly important for deciding on surgical treatment.
How Is Conn Syndrome Treated?
Treatment depends on the subtype of the disease and the patient’s general condition. Essentially, there are two main treatment approaches: surgical therapy and medical therapy. Uzm. Dr. Burcu Meryem Atak Sançmış optimally adapts these treatment options for her patients.
- Surgical Intervention (Adrenalectomy): If Conn’s Syndrome is caused by a unilateral aldosterone-producing adenoma, surgical removal of this tumor (adrenalectomy) is the most effective treatment method. In patients with confirmed unilateral cause and who desire surgery, unilateral adrenalectomy is the preferred treatment method. However, if there are contraindications to surgery or the patient does not wish to undergo surgery, medical treatment with mineralocorticoid receptor antagonists (MRA) is recommended. It is also reported that in patients under 35 years of age with severe hyperaldosteronism, hypokalemia, and an adrenal lesion consistent with a unilateral cortical adenoma greater than 1 cm on adrenal CT, unilateral adrenalectomy can be performed without the need for adrenal venous sampling. Laparoscopic adrenalectomy is the preferred surgical method, as it has been shown to result in fewer complications and shorter hospital stays. In patients with unilateral primary hyperaldosteronism, adrenalectomy treats hyperaldosteronism and hypokalemia. In these patients, it leads to an improvement or better course of hypertension or a reduction in medication.
- This operation is usually performed laparoscopically (minimally invasive), and tumor removal leads to blood pressure normalization or a significant reduction in medication requirements for most patients. Potassium levels also normalize.
- Medical Therapy: If Conn’s Syndrome is caused by bilateral adrenal hyperplasia or if surgical intervention is not an option, medical therapy is preferred.
- The main treatment involves medications called mineralocorticoid receptor antagonists (e.g., spironolactone, eplerenone). These medications block the effect of aldosterone in the body, lowering blood pressure and normalizing potassium levels.
- Regular monitoring of blood pressure and electrolytes is important during treatment.
In the post-treatment course, patients’ blood pressure, potassium, and other hormone levels are regularly monitored. Uzm. Dr. Burcu Meryem Atak Sançmış creates individualized follow-up programs to improve her patients’ quality of life after treatment and prevent possible complications.
Frequently Asked Questions
Does Conn's Syndrome Always Cause High Blood Pressure?
Is Conn Syndrome Permanent?
Is Conn Syndrome Genetic?
What Happens If Conn's Syndrome Is Left Untreated?
Why Is the Diagnosis of Conn Syndrome Often Delayed?
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