Aldosterone deficiency

Introduction to aldosterone deficiency Aldosterone deficiency, also known as hypoaldosteronism, is an endocrine disorder caused by reduced aldosterone (ALD) secretion or defects in peripheral action. Clinically, hyperkalemia, hyponatremia, hypovolemia, orthostatic hypotension and urinary salt loss are the main manifestations. Aldosterone deficiency may be one of the manifestations of total adrenal insufficiency, or it may be simple selectivity. Lack of aldosterone. The former includes Addison disease, congenital adrenal hyperplasia, chronic hypopituitarism, infection, hemorrhage or metastasis to destroy the adrenal gland, surgical removal of the adrenal gland, etc.; the latter refers to the selective secretion of aldosterone, other hormones of the adrenal gland (such as glucocorticoids) ) normal, or due to defects in peripheral effects of ALD. basic knowledge Sickness ratio: 0.0004%-0.0008% Susceptible people: no specific population Mode of infection: non-infectious Complications: Adrenal insufficiency

Causes of aldosterone deficiency

Causes

According to the etiology and pathogenesis, aldosterone deficiency can be divided into four categories: congenital primary aldosterone deficiency, acquired primary aldosterone deficiency, acquired secondary aldosterone deficiency, and pseudo aldosterone deficiency. Symptoms, primary and secondary are based on the ratio of plasma renin activity (PRA) to aldosterone, the ratio of primary aldosterone deficiency is lower than normal (high renin low aldosteronism), and secondary The sex ratio is normal (low renin low aldosteronism).

Acquired secondary aldosterone deficiency (20%):

Is the most common type of this disease, the main causes are various kidney diseases, such as chronic glomerulonephritis, interstitial nephritis, chronic glomerulonephritis, renal amyloidosis, kidney stones, renal cysts, etc.; systemic diseases Kidney damage such as diabetic nephropathy, lupus nephritis, multiple myeloma, gout kidney, etc.; other diseases such as cirrhosis, sickle cell anemia, hemochromatosis, acute respiratory distress syndrome, etc.; long-term use of beta blockers, Prostaglandin inhibitors (such as indomethacin) can also cause this disease. The aldosterone deficiency secondary to the decrease in renin levels is a pathophysiological feature of this type, so it is called hyporenin hypoaldosteronism.

Acquired primary aldosterone deficiency (20%):

The lesions in the adrenal gland destroy cortical tissue for a variety of reasons, leading to adrenal insufficiency, so most patients may have a lack of glucocorticoids, selective primary acquired aldosterone deficiency is rare, autoimmune adrenal insufficiency, Infection (common tuberculosis), sepsis, metastatic tumors, etc. can cause destruction of adrenal tissue structure; heparin can directly inhibit aldosterone biosynthesis.

Congenital primary aldosterone deficiency (10%):

It is related to heredity, which is caused by the deficiency of aldosterone in the enzyme deficiency. The lack of cholesterol carbon chain enzyme causes the conversion of cholesterol to 5 pregnenolone, so it cannot produce any kind of steroid hormone.

Pseudoaldosterone (PHA) deficiency (10%):

It is not the true deficiency of aldosterone, but the biological activity of aldosterone is reduced or disappeared due to aldosterone receptor or post-receptor factors. The clinical manifestations are similar to those of aldosterone deficiency, so it is called pseudoaldosterone deficiency, also known as aldosterone resistance. Syndrome, the pathogenesis of this disease is not fully understood, according to the genetic basis can be divided into congenital and acquired.

Aldosterone plays an important role in the metabolism of water and salt, mainly to promote the absorption of sodium and excretion of potassium by renal tubules. The reduction of aldosterone inevitably leads to the loss of renal sodium, resulting in hyponatremia, decreased blood volume and hypotension; renal tubules Epithelial cells secrete K and H disorders, causing hyperkalemia and metabolic acidosis. Aldosterone deficiency can also cause a unique acidosis called type IV renal tubular acidosis, which is due to a decrease in ammonia production in the kidneys, distal tubules. Caused by low hydrogen-discharging capacity, renal tubular obstruction is not caused directly by aldosterone deficiency, but secondary to hyperkalemia caused by aldosterone deficiency; in the absence of aldosterone, improved high potassium status can make renal tubular ammonia production capacity Get a certain recovery, sometimes to alleviate or correct acidosis.

Aldosterone deficiency prevention

In the case of a large number of fluid replacements, especially those who are given glucocorticoids at the same time, be alert to hypokalemia.

Acetone deficiency complication Complications Adrenal insufficiency

Acquired primary aldosterone deficiency lesions in the adrenal gland, a variety of causes of cortical tissue damage, leading to adrenal insufficiency, so most patients may have a lack of glucocorticoids, selective primary acquired aldosterone deficiency is rare.

Symptoms of aldosterone deficiency Common symptoms Leukocytosis Loss of appetite, weakness, weakness, lack of drinking, fatigue, nausea, intestinal pressure, blood pressure, thrombocytosis

Aldosterone deficiency mainly manifests as thirst, polydipsia, nausea, vomiting, loss of appetite, weakness, blood pressure, arrhythmia and other manifestations of hyperkalemia and hyponatremia. Laboratory tests can find elevated blood potassium. Reduced blood sodium and metabolic acidosis, the symptoms vary according to different types of clinical manifestations, such as acquired secondary aldosterone deficiency is more common in the 50 to 70 years old, clinically more unexplained, chronic asymptomatic Hyperkalemia; congenital primary aldosterone deficiency in the onset of neonatal or infant disease, can have severe dehydration, hyponatremia, vomiting, hyperkalemia and metabolic acidosis.

1. Hyperkalemia: The blood potassium level caused by this syndrome is mostly between 5.5 and 6.5 mmol/L. There is no obvious clinical manifestation of mild hyperkalemia. The blood potassium is obviously increased: 1 cardiovascular Systemic symptoms: manifested as slow heart rate, arrhythmia, mainly ventricular premature contraction, severe cases of fatal ventricular fibrillation or cardiac arrest during diastole; typical electrocardiogram showed hyperkalemia above 7mmol / L The "T" wave is often high and the base is narrowed, the sinus or indoor conduction block, the R wave becomes smaller, the S wave becomes deeper, the ST segment decreases and the ventricular fibrillation; 2 The neuromuscular system symptoms: the early main performance is Abnormal feelings, extreme fatigue, muscle cramps, paralysis reflexes; vasoconstriction can cause pale and dampness of the skin; respiratory muscle spasm can cause difficulty in speaking, hoarseness and difficulty breathing; a small number of patients show nausea due to gastrointestinal fistula , diarrhea and colic.

2. Hyponatremia and metabolic acidosis: hyponatremia in patients with aldosterone deficiency is mostly slow development, mainly characterized by fatigue, weakness, thirst, postural vertigo, sensation, etc.; but congenital Children with aldosteronism deficiency can also have obvious neurological symptoms such as nausea, severe vomiting, headache, and even convulsions and coma due to a sharp drop in blood sodium. Metabolic acidosis is mainly caused by accelerated breathing.

3. The performance of the primary disease: such as renal insufficiency, diabetes and other clinical manifestations.

4. Laboratory examination: renal function often has moderate to severe abnormalities, plasma urea nitrogen and creatinine increased, creatinine clearance decreased, high chloride metabolic acidosis; blood renin activity, 24h urine aldosterone concentration decreased (false) Except for aldosterone deficiency); decreased carbon dioxide binding and pH, elevated blood potassium, decreased or normal blood sodium, and abnormal laboratory tests for primary disease.

Examination of aldosterone deficiency

Renal function often has moderate to severe abnormalities, plasma urea nitrogen and creatinine increased, creatinine clearance decreased, high chloride metabolic acidosis; blood renin activity, 24h urine aldosterone concentration decreased (except pseudo-aldosterone deficiency); Carbon dioxide binding and pH decreased, blood potassium increased, blood sodium decreased or normal, and laboratory tests for primary disease were abnormal.

Abdominal B ultrasound, electrocardiogram, EMG, etc.

Diagnosis and identification of aldosterone deficiency

Diagnostic criteria

1. The diagnosis of aldosterone deficiency

(1) Blood potassium increased by more than 5.5 mmol/L.

(2) High chloride metabolic acidosis.

(3) Reduced blood sodium or normal low limit.

(4) Blood and urine aldosterone levels are reduced (except for pseudoaldosterone deficiency).

(5) The level of renin in patients with secondary aldosteron deficiency is decreased, and the level of renin in primary aldosterone deficiency is elevated.

2. Pay special attention to the following points when diagnosing

(1) Any hyperkalemia that cannot be explained clinically for a long time should consider the possibility of aldosterone deficiency.

(2) Patients with renal failure should consider the possibility of this disease if the degree of hyperkalemia is not consistent with the degree of renal failure.

(3) Diabetes patients, especially those with a disease duration of more than 10 years, have a high probability of having this disease, and should be given special attention.

(4) In the judgment of whether or not hyperkalemia occurs, care must be taken not only by electrocardiogram, because the blood potassium concentration exceeds 5.5mmol/L to make a diagnosis, and the typical potassium onset of electrocardiogram is more than 7mmol/L.

(5) Due to the presence of hyponatremia and metabolic acidosis in this disease, care must be taken to avoid causing severe hyponatremia and aggravating acid-base balance disorders when using furosemide or low-sodium reaction tests.

(6) Pay attention to the identification of other diseases that cause hyperkalemia. There are many diseases that cause hyperkalemia in the clinic, such as acute, chronic renal failure, thrombocytosis, leukocytosis and iatrogenic hyperkalemia, diabetes. Etc. The most obvious difference between this disease and these diseases is plasma renin and blood, and low levels of urinary aldosterone (except for pseudoaldosterone deficiency).

(7) Renin levels are the key to distinguish secondary aldosterone deficiency or primary aldosterone deficiency; the diagnosis of selective secondary aldosterone deficiency, in addition to the aldosterone reduction, must also demonstrate the adrenal gland secretion Both basal secretion of steroid hormones and ACTH stimulation tests are at normal levels.

(8) Pseudo aldosterone deficiency and other types of aldosterone deficiency symptoms are similar, so it is easy to cause misdiagnosis, 24h urine aldosterone concentration is the key to distinguishing from other types of aldosterone deficiency, and it can also be used in combination with mineralocorticoid replacement therapy. As the point of identification.

Differential diagnosis

1. Hyperkalemia caused by other diseases or causes clinically must exclude excessive hyperkalemia and iatrogenic potassium intake caused by hemolysis, thrombocytosis, leukocytosis, etc. (if kidney function is not normal) Caused by persistent hyperkalemia, the effects of renal function and drugs on renal tubular potassium excretion should also be ruled out. There were no significant reductions in plasma renin activity and aldosterone in these diseases and causes.

2. Acquired primary aldosterone deficiency and congenital primary aldosterone deficiency such as chronic adrenal insufficiency, long-term use of heparin, corticosterone methyl oxidase deficiency, etc., but cause the two types of aldosterone deficiency diseases No renal dysfunction, plasma renin activity increased or normal, and responded to the aforementioned stimuli.

3. Pseudo aldosterone deficiency has similar clinical manifestations and intrinsic symptoms, but the disease is due to the mineralocorticoid receptor or receptor post-deficiency, the target cell is resistant to aldosterone deficiency or its action, the renal function of the disease Normally, elevated levels of PRA and aldosterone can be identified.

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