Primary Hyperaldosteronism (Conn’s Syndrome)

What is Primary Hyperaldosteronism (Conn’s Syndrome)?

In 1955, Conn described the syndrome, accompanied by arterial hypertension and a decrease in the level of potassium in the blood, the development of which is associated with a tumor (adenoma) of the adrenal cortex, which produces the hormone aldosterone. This pathology is called Conn syndrome.

Primary hyper aldosteronism (Conn’s syndrome) is a disease characterized by an increase in aldosterone secretion by the adrenal glands, manifested in a decrease in the activity of a specific substance, plasma renin, which plays an important role in regulating the body’s work, arterial hypertension and a decrease in the potassium content in the blood. Many other cases of hyperplasia (excessive tissue proliferation and its changes) of the adrenal cortex with an increase in aldosterone secretion were later described, and now the term “primary hyperaldosteronism” is used to describe both Conn’s syndrome itself and another pathology accompanied by hypersecretion of aldosterone, for example, hyperplasia of the cortex adrenal glands. Currently, primary hyper aldosteronism (PHA), and in particular Conn’s syndrome, is the most common cause of secondary arterial hypertension.

Causes of Primary Hyperaldosteronism (Conn Syndrome)

Currently, there are two main causes of PHA, accompanied by an increase in aldosterone secretion:

  • unilateral aldosterone-producing tumor – adenoma or Conn’s syndrome (50-60% of cases);
  • bilateral hyperplasia of the adrenal cortex or idiopathic hyper aldosteronism (40-50% of cases).

There are rare diseases and tumors that are similar in symptoms, including a hereditary disease, accompanied by an increase in aldosterone concentration.

Even less often, aldosterone-secreting adrenal cortex or ovarian tumors are found.

The most common cause of PHA is Conn syndrome, and the adenoma usually does not exceed 3 cm in diameter, is unilateral and renin-independent. This means that the secretion of aldosterone does not depend on a change in body position. Less commonly, an adenoma can be renin-dependent (that is, aldosterone levels increase in an upright position). Conn syndrome occurs in 50-60% of cases.

The remaining 40-50% of cases occur in bilateral hyperplasia of the adrenal cortex, when the level of aldosterone increases in an upright position. Less common is primary adrenal hyperplasia, in which the level of aldosterone does not depend on the position of the body, as in renin-independent adenoma.

Aldosterone can secrete tumors of extra-adrenal localization – in the kidneys or ovaries.

Symptoms of Hyperaldosteronism Primary (Conn’s Syndrome)

Complaints of patients with severe hypokalemia: fatigue, muscle weakness, muscle cramps, headaches and heart attack. Such patients may also experience increased thirst: as a result, they drink a lot, and polyuria (a lot of urine is released) due to so-called diabetes insipidus, developed as a result of hypokalemia and corresponding changes in the kidneys, due to the effect of aldosterone on them.

Relative hypocalcemia develops (a decrease in calcium in the blood) with the development of numbness in the extremities and around the mouth, muscle spasms in the hands and feet and, to an extreme degree, laryngeal spasm with the appearance of a feeling of suffocation and cramps. In this case, calcium preparations are not prescribed, since the total calcium content in the blood is normal, but due to hormonal imbalance, the balance of calcium in the body changes.

Long-existing arterial hypertension can lead to complications of the cardiovascular and nervous systems with all the accompanying symptoms.