Conn Syndrome

Definition-What is Conn syndrome?

Conn syndrome, also known as primary hyperaldosteronism, is caused by a pathological change in the adrenal cortex, which leads to an overproduction of the messenger substance aldosterone. Aldosterone is a hormone which has an important function in the regulation of the human salt and water balance. It sometimes plays a decisive role in the absorption of sodium and water and the release of potassium.

Causes of Conn syndrome

The cause for a Conn syndrome is in about 2/3 of the cases a so-called hyperplasia. Hyperplasia refers to an increase in the size of a tissue due to the proliferation of the cells located there. The adrenal cortex is divided into zones that have different functions or produce different hormones.

The part responsible for aldosterone production is called the zona glomerulosa. In addition, there are two other zones in which mainly other hormones are produced. Hormone production is generally subject to complex control and feedback mechanisms in order to dose the amount of hormones in the body as needed.

In the context of a Conn syndrome, cell proliferation occurs in the zona glomerulosa, as well as disturbances in the regulatory mechanism. As a result, the cells produce unhindered large amounts of aldosterone. Furthermore, a so-called adenoma of the adrenal cortex can lead to hyperaldosteronism. An adenoma is a benign tumour that is composed of glandular cells. In about 1/3 of the cases such a change in the tissue is responsible for the increased production of aldosterone.

Diagnosis

If Conn syndrome is suspected, which is usually caused by therapy-resistant high blood pressure, various diagnostic measures are used. One important method is the determination of the aldosterone-renin quotient. Renin is another hormone that can affect blood pressure and is produced in the kidney.

If blood pressure is too low, the kidney releases the hormone, which then naturally boosts aldosterone production in the adrenal cortex. If there is an increased amount of aldosterone or high blood pressure, the kidney lowers its renin production and the concentration of renin in the blood is reduced. The high blood pressure in Conn syndrome, which is caused by the high concentration of aldosterone, leads to such a decrease in the renin content of the blood.

If we now consider the quotient of renin and aldosterone, this is increased in a Conn- Syndrome. A high renin-aldosterone quotient therefore speaks for a primary hyperaldosteronism. Furthermore, the blood is checked for the concentration of potassium, which in this case is lowered. It is important to stop taking certain antihypertensive drugs before the blood test or to determine the values of aldosterone, renin, etc., as these can influence various messenger substances and thus lead to falsified values.