Diseases associated with excessive production of aldosterone ( aldosteronism )
Endocrinology / / May 21, 2016
There are two main forms of aldosteronism: primary and secondary.
Primary aldosteronism (conn's syndrome)
In 1955 Conn described the syndrome, occurring with increased production of aldosterone tumor of the adrenal cortex, and called his primary aldosteronism.Subsequently, this syndrome was named after him.
Etiology The etiology of the disease is unknown.
Primary aldosteronism - a partial hypercortisolism, the disease caused by the primary organic lesion of the adrenal cortex (adenomas, carcinomas rarely, hyperplasia of the cortex).This independent endocrine disorder in which the main pathogenetic importance has increased production of aldosterone, resulting in a delay in the body of sodium and water, and increased excretion of potassium ions.The main manifestations of the disease are caused by these violations of water-salt balance.Delay
sodium organism appears to be a factor leading to development of hypertension.
hypokalemia, along with other violations, causing degen
hypertension and renal injury, including in the pathogenetic chain can lead to irreversible vascular changes do not disappear after the removal of hyperaldosteronism.
most often with primary aldosteronism there is a tumor of the adrenal cortex, mostly benign adenoma.There are, though rarely, malignant tumors - cancer of the adrenal cortex.When a second tumor of the adrenal gland adrenal gland is usually somewhat atrophied.Among the 31 observed patients with Conn's syndrome 23 had benign adenoma of the adrenal cortex, 2 - adrenal cortex cancer, 3 - bilateral adrenal hyperplasia and adrenal glands in 3 patients had a normal structure.
adenomas with primary aldosteronism may be single or multiple and occasionally bilateral.Usually they small size (1-4 cm in diameter, weighing 3.1 g), but there are large tumors (87 g).In the context of tumor yellow or orange.Sometimes adenoma cells similar to the cells of the glomerular zone, sometimes the beam, they are often mixed with a predominance of cell structure of the beam zone.The cells are usually large, bright, rich in lipids.The tumor tissue was found a large amount of aldosterone, but cases where the tumor tissue is contained and corticosterone were also described.
Primary aldosteronism 9% proceeded with bilateral adrenal hyperplasia.In such cases, the most pronounced feature of the structure of the adrenal cortex is thickened glomerular area.
other organs, which in the primary aldosteronism usually found marked morphological changes were the kidneys.
In the kidneys there hydropic and fatty degeneration of tubular cells, thickening of the basement membrane.In more severe cases are found to expand the tubular epithelium atrophy, necrosis and calcification of them.These degenerative changes that occur mainly in the proximal tubule, but sometimes extends to the distal, the Conn relates to kidney damage, which he called «kaliopenic nephropathy».In the initial stages of these changes are reversible.Hyalinization glomeruli with foci of interstitial scarring usually expressed to a lesser degree.Often marked sclerosis of the renal arterioles.Some patients found pyelonephritis.
Besides kidney damage, there are focal necrosis of cardiac muscle and skeletal muscle, as well as the partial loss of their cross-striations.
Primary aldosteronism is more common in middle age - from 30 to 50 years, although cases have been observed in younger and older age.Women suffer 2.5 times more often than men.
main complaints of patients with primary aldosteronism: severe headache, polydipsia, polyuria, often nocturia, paresthesia, tetany attacks occur periodically sudden muscle weakness, sometimes accompanied by ascending paralysis of muscles.
Headaches with primary aldosteronism may be explained by increased hydration of the brain.
polyuria more often mild.This symptom is usually associated with the presence of degenerative changes in the renal tubules, leading to a decrease in water reabsorption.Urine output in patients with primary aldosteronism is not reduced when administered vasopressin or Restrictions on fluid intake.
Polydipsia may be due to an increased urine output.It is suggested that the reason is polydipsia intracellular dehydration and hypernatremia.
Two-thirds of patients complain of paresthesia associated with hypokalemia.
attacks of tetany, which are developed on the basis of a sharp gipokaliemicheskogo alkalosis with normal blood calcium, manifested convulsions of the upper and lower extremities are sometimes accompanied by positive symptoms chvostek and Trousseau and increased tendon reflexes.Tetany may be generalized or local.It expressed the view that tetany is caused not so much by extracellular alkalosis, as a violation of intracellular ionic equilibrium, ie. E. The rapid movement of potassium into the cell or out of it.
Muscle weakness in primary aldosteronism is due to hypokalemia.According to the Conn, 39% of patients have lingering paralysis of the muscles, especially of the lower extremities.Paralysis develops quickly, sometimes occur suddenly and disappear, too, after a few hours, but can be kept for days and even weeks.It is believed that muscle weakness develops in the large extent of depletion of the body potassium, reaching no less than 10-30% of its stock.The reason for the intermittent nature of tetanic muscle weakness and seizures are not verified.From
objective symptoms of primary aldosteronism is the most permanent hypertension.
hypertension in some patients with primary aldosteronism moderate, but often there are significant increases in blood pressure, and then the diastolic pressure can reach high numbers - 140 to 150 mm Hg.v., typically with a small pulse pressure.These attacks are sometimes accompanied by sudden headache, paresthesia, disturbance of cerebral circulation (the latter is uncommon).Occasionally there come changes in the fundus, which are expressed in the swelling of the optic nerve papilla, retinopathy development.Sometimes there comes a sudden amblyopia.These abnormalities are observed predominantly in patients younger than 20 years.It is noted that serious complications of hypertension in primary aldosteronism are more common in patients with adrenocortical hyperplasia than the tumor.
noteworthy rarity of edema - according Conn edema observed in less than 10% of patients.
When electrocardiographic investigations often show signs of hypokalemia - reducing the interval ST, elongation QRST, negative T-wave
low urine specific gravity, alkaline reaction.Urine specific gravity did not increase after the administration of vasopressin or fluid restriction.Reaction urine under a load is not changed with ammonium chloride.Often it is a constant or intermittent mild albuminuria.
Simultaneously with lowering water reabsorption in the tubules also impaired glomerular filtration, reduced renal blood flow.
Allocation of potassium in the urine and its contents in the saliva increased.sodium excretion is reduced.
One of the permanent symptoms of primary aldosteronism is hypokalemia.Reducing the level of potassium in the blood serum of less than 15 mg% (3 mEq / L), detectable again, is a hallmark of the disease.However, recently obtained evidence that hypokalemia is a measure of far-gone a long process and may be absent in the early stages of the disease.
often observed increase of sodium in the blood.
often gipohloremichesky alkalosis.
There are observations indicating a decrease in carbohydrate tolerance of patients with primary aldosteronism, until the development of diabetes.Lowering carbohydrate tolerance associated with potassium deficiency.
characteristic feature of primary aldosteronism is an increased release of aldosterone excretion.Sometimes the amount of free aldosterone in the urine is normal, but found high levels of a metabolite - tёtragidroaldosterona.Conn saw large fluctuations in the allocation of free urine aldosterone from the same patient, and aldosterone excretion periodically reduced to normal.Therefore it is necessary to investigate the urinary aldosterone repeatedly.
Contents 17 gidroksikortikosteroidov in the blood and release of 17-gidroksikortikosteroidov and 17-keto steroids in urine is usually normal.
D iagnoz and differential diagnosis
diagnosis of primary aldosteronism in an advanced stage is based on the presence of characteristic clinical signs and, in particular, the three main symptoms: hypertension, hypokalemia, detectable in repeated studies, polyuria with a fixed low specific weighturine does not increase with the introduction of vasopressin or Restrictions on fluid intake.
diagnostic importance is the determination of the sodium / potassium ratio in the blood serum.Increasing this ratio above 32 speaks in favor of primary aldosteronism.The presence of primary aldosteronism indicates a reduction ratio of sodium / potassium in saliva is lower than 0.6.If there
hypokalemia additional diagnostic data can be obtained by spirolaktonovogo test.Spirolactone possess the ability to block the action of aldosterone on renal tubules.Use of spironolactone 300 mg four times a day for three days leads to normalization of potassium levels in the blood of patients with primary aldosteronism.
most reliable sign of aldosteronism is aldosterone increased excretion of urine.This study should be performed after the patient for five days with food gets at least 5 g of sodium chloride per day, since the restriction of sodium in the diet can lead to increased release of aldosterone.In 5-10% of patients with primary aldosteronism aldosterone excretion in urine is not increased, but there are indications that these patients aldosterone secretion rate is increased.
Conn and others point out that in the early stages of the disease may be absent hypokalemia, and in this period is particularly important definition of aldosterone excretion and plasma renin activity, which in patients with primary aldosteronism lowered.
differential diagnosis with malignant hypertension can present significant challenges.In this form of hypertension is often secondary aldosteronism - increase aldosterone production.However, the serum potassium level is not reduced or reduced a little.In primary aldosteronism, except his congenital forms rarely swelling of the optic nerve papilla, normally observed in malignant hypertension.
In renal hypertension associated with renal ischemia, release of aldosterone excretion is increased, however, in contrast to primary aldosteronism there is no significant hypokalemia.In some cases, it is necessary for the diagnosis of renal disease to resort to intravenous pyelography or aortography.
rare diseases, which is necessary to differentiate primary aldosteronism is nephritis with sodium loss, in which due to the increased sodium excretion increases production of aldosterone.When the loss of sodium nephritis, unlike primary aldosteronism, sodium in food deprivation does not lead to a decrease of its discharge urine.
Jade with the loss of potassium is being considered as a late stage of primary aldosteronism.
differential diagnosis of primary aldosteronism with forms of secondary aldosteronism (liver cirrhosis, nephrosis, heart defects) is usually not difficult.
Due to the presence of polyuria, low urine specific gravity may be necessary in the differential diagnosis of primary aldosteronism with diabetes insipidus and hyperparathyroidism.When diabetes insipidus urine specific gravity lower than aldosteronism, usually rises after administration of vasopressin;hypertension and hypokalemia absent.When hyperparathyroidism is not hypokalemia, increased content of calcium in the blood, reduced levels of phosphorus.
- Diagnosis and differential diagnosis of congenital adrenal hyperplasia
- Treatment of chronic adrenal insufficiency
- apoplexy adrenal cortex.Syndrome Waterhouse-Friderichsen (waterhouse- friderichsen)
- virilizing congenital adrenal hyperplasia
- Treatment of congenital adrenal hyperplasia
- Acute adrenocortical insufficiency
flow forecast, disabled
Becausenow usually diagnosed only advanced stages of primary aldosteronism, to judge the course of the disease in the early stages is difficult.Conn and others indicate that patients with tumors of the adrenal cortex aldosteronprodutsiruyuschimi may have high blood pressure for many years before they will emerge hypokalemia and other typical signs of the disease.
Untreated primary aldosteronism leads to progressive renal and vascular lesions, which are the cause of death of patients.If removal
bilateral adrenalectomy or adrenal tumors (in the presence of adrenal hyperplasia) produced before irreversible changes will develop kidney and cardiovascular system, there is complete recovery.Kaliopenicheskaya nephropathy can undergo reverse development.
When malignant aldosteroma poor prognosis.
Patients with primary aldosteronism in an advanced stage of the disease inefficient.Disabled after surgical treatment depends on the degree of reversibility of renal and vascular disorders.After bilateral adrenalectomy patients need constant replacement therapy and corticosteroids are inoperative or disabilities.
only radical treatment of primary aldosteronism is the surgical removal of the tumor or removal of the adrenal glands when hyperplasia.In the preoperative period it is recommended to normalize the level of potassium in the blood serum.For this patient for at least one week allowed between 4 and 12 g of potassium chloride per day while limiting sodium in the diet.Prolonged potassium intake is not shown, because it causes an increase in aldosterone production.To normalize the potassium level in blood preoperatively spironolactone can be used as spirolaktonovogo during the test.
During operation should take into account the possibility that the second adrenal may be in a state of atrophy.Therefore, it is advisable to carry out surgery on the background of glucocorticoid, as in surgery for Cushing's syndrome - Cushing.