The clinical picture of primary hyperaldosteronism is also known as Conn syndrome. It is characterized by elevated levels of the hormone aldosterone, which increases blood pressure.
What is primary hyperaldosteronism?
Underlying primary hyperaldosteronism in most cases is either hyperplasia of the adrenal cortex or adrenocortical adenoma. The result is increased production of the hormone aldosterone. This raises blood pressure, so that primary hyperaldosteronism often manifests as hypertension, i.e. high blood pressure. This type of hypertension is called secondary because it is caused by a hormonal disorder. It used to be assumed that primary hyperaldosteronism was the underlying cause in only less than one percent of all patients with hypertension. Nowadays, however, the prevailing assumption is that the condition is even one of the most common causes of hypertension. Nevertheless, it is usually recognized late, namely when hypertension cannot be successfully controlled even after therapy with three or more drugs. A lowered potassium level in the blood can also be measured. Although the symptoms do not differ from those of classic hypertension, the likelihood of secondary diseases such as stroke and myocardial infarction is significantly higher.
Causes
The cause of primary hyperaldosteronism is a change in the adrenal cortex. This change affects a very specific zone, namely the zona glomerulosa. In the zona glomerulosa of the adrenal cortex, the steroid hormone aldosterone is produced, which causes decreased sodium excretion and thus raises blood pressure because water is retained along with sodium. At the same time, it increases potassium excretion. With normal function of the adrenal cortex as well as the higher-level glands, blood pressure is thus regulated and adjusted to current needs. In primary hyperaldosteronism, this control loop no longer functions, and the adrenal cortex produces too much aldosterone. This is why high blood pressure occurs. The above-mentioned changes can basically involve three pathologies, either bilateral adrenocortical hyperplasia, an aldosterone-producing adrenocortical adenoma or a familial change in the adrenal cortex. At present, 70 percent of cases of primary hyperaldosteronism are due to bilateral adrenocortical hyperplasia, and less than 30 percent are due to adenoma. Only in less than 1 percent of cases is the condition genetic.
Symptoms, complaints, and signs
Primary hyperaldosteronism often becomes symptomatic with arterial hypertension. Hypokalemia and metabolic alkalosis may also be signs of the disease. Only rarely, however, do all three of these classic symptoms manifest at once. Frequently, serum potassium is also in the low normal range. The shift in potassium levels leads to, among other things, lassitude, adynamia, constipation, and a mild form of diabetes insipidus characterized by increased urination and thirst. The reason for this is that hypokalemia also affects the regulatory circuits of other hormones, thus upsetting them. Metabolic alkalosis, i.e. a shift of the blood pH to the alkaline range, is also caused by the lowered potassium level. The potassium deficiency causes an increased transfer of potassium ions from the cell interior to the cell exterior. This occurs in exchange with hydrogen ions. The kidney also releases hydrogen ions so that it can reabsorb more potassium. Overall, therefore, there is a decrease in hydrogen ions in the outer space of the cells. As a result, the metabolic state becomes alkalotic.
Diagnosis and course of the disease
Diagnosis is based on the clinical symptom picture and on characteristic blood values. In hypertension, secondary hypertension such as primary hyperkalemia is likely, especially if the patient is very young, i.e., has not yet exceeded 30 years of age, or if the onset of hypertension is very sudden in patients older than 55 years. A secondary cause of hypertension must also be reckoned with if there is an abrupt onset of a marked rise in blood pressure while the patient is demonstrably taking medication on a regular basis.Furthermore, patients with primary hyperaldosteronism often lack the physiological nocturnal drop in blood pressure because the hormonal control circuit is disturbed by aldosterone overproduction. A possible secondary cause of hypertension should always be investigated if there is no significant improvement even after the use of three antihypertensive drugs. Blood is taken to confirm the diagnosis. High aldosterone levels, decreased renin concentration and activity, and an increased aldosterone-renin quotient are conspicuous. Hypokalemia and metabolic alkalosis may also be present. Sodium is typically in the high-normal range because hypernatremia is avoided by hormonal counterregulation.
Complications
The three features of hypertension, hypokalemia, and metabolic alkalosis are responsible for the high risk of complications in primary hyperaldosteronism. For example, chronic hypertension (high blood pressure) causes long-term damage to the cardiovascular system and may lead to atherosclerosis, angina pectoris, and myocardial infarction in the long term. Hypokalemia leads to muscle weakness, smooth muscle paralysis, cardiac arrhythmias up to ventricular fibrillation, and sometimes even rapid breakdown of transverse striated muscle (rhabdomyolysis). The paralysis of the smooth muscles can block vital functions of the body. For example, bowel or bladder muscles may be paralyzed, resulting in bladder paralysis with urinary retention or paralytic bowel obstruction. Rhabdomyolysis leads to severe muscle weakness, muscle pain, nausea, vomiting and fever due to the breakdown of the muscles. In very severe cases, extensive muscle breakdown may occur due to ischemia. This represents an emergency that requires rapid medical attention. In metabolic alkalosis, the PH of the blood rises above 7.43. This is also a medical emergency that manifests as convulsions to the point of tetany, paresthesias, impaired consciousness, and confusion. Without rapid establishment of normal PH, death can occur here as well. Furthermore, primary hyperaldosteronism is characterized by symptoms such as polydipsia (unquenchable thirst) and polyuria (excretion of large amounts of urine). Polyuria can lead to exsiccosis (dehydration) of the organism despite large amounts of drinking.
When should you go to the doctor?
Disorders and peculiarities of the cardiovascular system should always be clarified by a doctor. As a cause, there may be serious diseases in which action is required. High blood pressure, palpitations, an internal heat or a persistent restlessness should be presented to a doctor. Interruptions of night sleep, discoloration of the skin and hectic behavioral traits indicate a health impairment. A visit to the doctor is necessary as soon as the complaints are persistent or increase. Disturbances of the digestive tract are also considered unusual. If constipation or a feeling of pressure in the intestines occurs, a visit to the doctor is necessary. If the affected person refuses food intake due to the complaints, a doctor must be consulted. A feeling of pressure in the abdomen, pain or general malaise should be presented to a doctor. Changes in weight, a feeling of illness, apathy, or a loss of well-being should be investigated more thoroughly by a physician. A sudden increase in the feeling of thirst should be understood as a warning signal from the organism. If the affected person consumes significantly more fluid than usual for no apparent reason, the observation should be discussed with a physician. An increased urge to urinate is just as unusual. This should also be investigated. Disturbances of the metabolism or irregularities of the hormone balance indicate a disease. If mood swings, changes in libido or behavioral abnormalities are evident, a doctor is needed.
Treatment and therapy
If the suspicion of primary hyperaldosteronism is confirmed, confirmatory tests are performed. One is the saline load test and the other is the fludrocortisone inhibition test. In the saline load test, aldosterone secretion is increased by administration of water with sodium. In healthy individuals, this decreases aldosterone secretion. Fludrocortisone acts similarly to aldosterone. When administered, it also decreases aldosterone levels in healthy patients. In people with primary hyperaldosteronism, however, it remains elevated.For the final confirmation of the diagnosis, imaging procedures such as sonography and computer tomography are used to detect the enlarged adrenal cortex. Therapeutically, the drug spironolactone is given, which acts like an antagonist to aldosterone and thus lowers the excessively high aldosterone level in the blood. If adrenocortical adenomas are present, they should be surgically removed.
Prevention
Effective prevention of primary hyperaldosteronism is not possible. However, if typical symptoms of the disease occur, then these should be clarified as soon as possible to avoid secondary damage.
Follow-up
In primary hyperaldosteronism, follow-up depends on the therapy with which a patient has been treated. If the therapy consists of treatment with aldosterone blockers, then regular follow-up visits to the physician are sufficient for follow-up. This involves checking whether the patient’s blood pressure is within a normal range and what the tolerance is to the prescribed preparations. If a patient has had minimally invasive surgery, follow-up visits check for healing of the surgical scar and changes in blood pressure. If the physician determines that the patient’s blood pressure has decreased significantly without medication, no further addition of medication is necessary. The occurrence of new hyperlesions is comparatively low, so a patient can lead a normal life. However, if an adrenal gland had to be completely removed in the course of therapy, a patient may have to take medication for the rest of his or her life. The drugs are not intended to affect blood pressure as much. Instead, the patient receives cortisol preparations to normalize his or her hormone levels. During the follow-up examination, it can be determined whether new ulcers have formed so that they can be removed at an early stage. Such recurrences are very rare, so most patients can live almost normally after adrenalectomy.
What you can do yourself
For patients with this diagnosis, it is first necessary to determine whether surgical intervention makes sense. It is possible that aldosterone levels will normalize once the adrenal gland from which the disease originated is removed. If primary hyperaldosteronism has another cause, it is usually treated with medication. Patients should be careful to take the prescribed drugs regularly according to the instructions of the treating physicians, otherwise they may not have the desired effect. In patients with primary hyperaldosteronism, commercially available ACE inhibitors do not work, so other painkillers are indicated for them. In this case, physicians advise which medications can exert their effect despite an elevated aldosterone level and for which pain they are advisable. Depending on how long it took for the diagnosis to be made, the patient may already have suffered damage from long-term elevated blood pressure or from other symptoms of the disease. This damage can be offset by emphasizing a healthy lifestyle. This includes the patient maintaining a normal weight, not smoking and drinking very little alcohol. A healthy diet that includes plenty of fresh fruits, vegetables, sea fish and lean meats is also advised. It is also important to get regular exercise in the fresh air, precisely to normalize blood pressure permanently.
