Hyperaldosterosnism

Hyperaldosteronism is the clinical disorder caused by excess secretion of the hormone aldosterone by the adrenal glands.

How is it produced?

Aldosterone is a hormone that basically performs its function in the kidney where it retains sodium and eliminates potassium, while increasing the circulating volume of fluid in the blood (hypervolemia).

The kidney, in the face of stimuli such as a small amount of blood or a decrease in sodium in the blood, releases renin, which acts on a protein in the blood released by the liver, angiotensinogen. Due to the action of renin on angiotensinogen, angiotensin I is produced, which, due to the effect of ACE (a protein found in the pulmonary arteries), produces angiotensin II. Angiotensin II stimulates the production of aldosterone by the adrenal glands.

The mechanism by which an increase in aldosterone occurs depends on different causes. The causes that are due to alterations of the gland itself are primary hyperaldosteronism: benign tumors (adenomas) and malignant of the adrenal glands, hyperplasia of the adrenal glands, or unknown causes. The most common form is usually cortical adenoma (Conn's syndrome).

Other causes of the increase in aldosterone are due to stimuli originating outside the gland; constitute secondary hyperaldosteronism. They include Bartter syndrome, renal artery stenosis (narrowing), kidney tumors, heart failure.

Symptoms

In primary hyperaldosteronism, most symptoms are due to the effect that excess aldosterone has on the regulation of sodium and potassium levels. As aldosterone produces sodium and fluid retention in the kidney, when more of the hormone is produced, high blood pressure, low potassium in the blood (hypokalemia) will appear. Hypokalemia causes symptoms such as muscle weakness, fatigue, and cramps, and can be the cause of serious cardiac arrhythmias. Other paradoxical symptoms that may appear are increased urine volume (polyuria) and excessive water intake (polydipsia). In the case of a patient without other concomitant diseases, the increase in the volume of blood fluid can be well tolerated. However, if there are other diseases such as kidney disease or heart failure, there may be significant fluid retention and cause edematous disorders that manifest as swelling of declining regions such as the feet and legs.

In secondary hyperaldosteronism, the symptoms may vary from that referred to for primary hyperaldosteronism. For example, in Bartter syndrome the blood pressure figures are usually lower and it is not usually associated with edema.

Diagnosis

Diagnosis begins with clinical suspicion, in a patient with hypertension and the detection of low potassium in the blood (hypokalemia) and high sodium (hypernatremia). In mild forms of primary hyperaldosteronism, potassium levels may be normal. If the hypokalemia is severe, the magnesium levels in the blood also fall.

Faced with these alterations, the levels of aldosterone and renin in the blood will be requested. There will be decreased renin and hypersecretion of aldosterone.

Imaging techniques, especially magnetic resonance imaging and CT, can detect tumors (adenomas and other adrenal tumors).

Treatment

Treatment can be based on drugs, or by surgical intervention in selected cases. In general, the aim is to correct arterial hypertension and ionic (sodium and potassium) and metabolic (hyperglycemia) alterations. Potassium-sparing diuretics such as spironolactone and amiloride are used to treat high blood pressure.

In the case of an adrenal tumor, blood pressure and hypokalemia must be normalized before surgery with a low-sodium diet, spironolactone, and potassium supplements.

In Bartter syndrome, symptoms are controlled with spironolactone, propanolol, enalapril, potassium and magnesium supplementation, adequate diet, and glucocorticoids (such as dexamethasone).

Regarding surgical treatment, a surgical removal of the adenoma can be performed. Other tumors may require more aggressive surgery and radiation therapy plus chemotherapy.

Precautionary measures

The best prevention is the control of blood pressure values ​​and, in the presence of arterial hypertension, look for data that may suggest the existence of an adrenal alteration.