What is typical for diabetes insipidus tests. Diabetes insipidus. According to severity

Diabetes insipidus – a disease caused by an absolute or relative deficiency of the hypothalamic hormone vasopressin (ADH-antidiuretic hormone).

The frequency of the disease is unknown; it occurs in 0.5-0.7% of endocrine patients.

Regulation of vasopressin release and its effects

Vasopressin and oxytocin are synthesized in the supraoptic and paraventicular nuclei of the hypothalamus, packaged into granules with the corresponding neurophysins and transported along axons to the posterior lobe of the pituitary gland (neurohypophysis), where they are stored until released. The reserves of vasopressin in the neurohypophysis with chronic stimulation of its secretion, for example, with prolonged abstinence from drinking, are sharply reduced.

Vasopressin secretion is caused by many factors. The most important of them is blood osmotic pressure, i.e. osmolality (or otherwise osmolarity) of plasma. In the anterior hypothalamus, close to, but separate from the supraoptic and paraventicular nuclei, is located osmoreceptor . When plasma osmolality is at a certain normal minimum, or threshold value, the concentration of vasopressin in it is very low. If plasma osmolality exceeds this set threshold, the osmocenter perceives this, and the concentration of vasopressin rises sharply. The osmoregulation system reacts very sensitively and very accurately. Some increase osmoreceptor sensitivity is associated with age.

The osmoreceptor is unequally sensitive to different plasma substances. Sodium(Na +) and its anions are the most powerful stimulators of the osmoreceptor and vasopressin secretion. Na and its anions normally determine 95% of plasma osmolality.

Very effectively stimulate the secretion of vasopressin through the osmoreceptor sucrose and mannitol. Glucose practically does not stimulate the osmoreceptor, just like urea.

The most reliable evaluative factor in stimulating vasopressin secretion is to determineNa + and plasma osmolality.

The secretion of vasopressin is influenced by blood volume and blood pressure level. These influences are exerted through baroreceptors located in the atria and aortic arch. Stimuli from the baroreceptor travel through afferent fibers to the brainstem as part of the vagus and glossopharyngeal nerves. From the brain stem, signals are transmitted to the neurohypophysis. A decrease in blood pressure or a decrease in blood volume (eg, blood loss) significantly stimulates the secretion of vasopressin. But this system is much less sensitive than osmotic stimuli at the osmoreceptor.

One of the effective factors stimulating the release of vasopressin is nausea, spontaneous, or caused by procedures (vomiting, alcohol, nicotine, apomorphine). Even with incoming nausea, without vomiting, the level of vasopressin in plasma increases 100-1000 times!

Less effective than nausea, but an equally constant stimulus for vasopressin secretion is hypoglycemia, especially spicy. A decrease in the level of glucose in the blood by 50% of the initial level increases the content of vasopressin by 2-4 times in humans, and in rats by 10 times!

Increases vasopressin secretion renin-angiotensin system. The level of renin and/or angiotensin required to stimulate vasopressin is not yet known.

It is also believed that nonspecific stress, caused by factors such as pain, emotions, physical activity, increases the secretion of vasopressin. However, it remains unknown how stress stimulates the secretion of vasopressin - in some specific way, or through a decrease in blood pressure and nausea.

Inhibits the secretion of vasopressin vasoactive substances such as norepinephrine, haloperidol, glucocorticoids, opiates, morphine. But it is not yet clear whether all these substances act centrally, or by increasing blood pressure and volume.

Once in the systemic circulation, vasopressin is quickly distributed throughout the extracellular fluid. Equilibrium between the intra- and extravascular space is achieved within 10-15 minutes. Inactivation of vasopressin occurs mainly in the liver and kidneys. A small part is not destroyed and is excreted intact in the urine.

Effects. The most important biological effect of vasopressin is retaining water in the body by reducing urine output. The point of application of its action is the epithelium of the distal and/or collecting tubules of the kidneys. In the absence of vasopressin, the cell membranes lining this part of the nephron form an insurmountable obstacle to the diffusion of water and soluble substances. Under such conditions, the hypotonic filtrate formed in the more proximal parts of the nephron passes unchanged through the distal tubule and collecting ducts. The specific gravity (relative density) of such urine is low.

Vasopressin increases the permeability of the distal and collecting ducts to water. Since water is reabsorbed without osmotic substances, the concentration of osmotic substances in it increases, and its volume, i.e. quantity decreases.

There is evidence that a local tissue hormone, prostaglandin E, inhibits the action of vasopressin in the kidneys. In turn, non-steroidal anti-inflammatory drugs (for example, Indomethacin), which inhibit the synthesis of prostaglandins in the kidneys, increase the effect of vasopressin.

Vasopressin also acts on various extrarenal systems, such as blood vessels, gastrointestinal tract, and central nervous system.

Thirst serves as an indispensable complement to the antidiuretic activity of vasopressin . Thirst is a conscious sensation of the need for water. Thirst is stimulated by many factors that cause the secretion of vasopressin. The most effective of them is hypertensive environment. The absolute level of plasma osmolality at which the feeling of thirst appears is 295 mOsmol/kg. At this osmolality, the blood normally produces urine with maximum concentration. Thirst is a kind of brake, the main function of which is to prevent a degree of dehydration that exceeds the compensatory capabilities of the antidiuretic system.

The feeling of thirst increases rapidly in direct proportion to plasma osmolality and becomes unbearable when the osmolality is only 10-15 mOsmol/kg above the threshold level. Water consumption is proportional to the feeling of thirst. A decrease in blood volume or blood pressure also causes thirst.

Etiology

The development of central forms of diabetes insipidus is based on damage to various parts of the hypothalamus or posterior pituitary gland, i.e. neurohypophysis. The following factors may be the reasons:

infections acute or chronic: influenza, meningoencephalitis, scarlet fever, whooping cough, typhus, sepsis, tonsillitis, tuberculosis, syphilis, rheumatism, brucellosis, malaria;

traumatic brain injuries : accidental or surgical; electric shock; birth trauma during childbirth;

mental trauma ;

pregnancy;

hypothermia ;

tumor of the hypothalamus or pituitary gland : metastatic or primary. Cancer of the breast, thyroid glands, and bronchi most often metastasizes to the pituitary gland. Infiltration with tumor elements in lymphogranulomatosis, lymphosarcoma, leukemia, generalized xanthomatosis (Hand-Schüller-Crispen disease). Primary tumors: adenoma, glioma, teratoma, craniopharyngioma (especially common), sarcoidosis;

endocrine diseases : Simmonds, Sheehan, Lawrence-Moon-Biedl syndromes, pituitary dwarfism, acromegaly, gigantism, adinosogenital dystrophy;

idiopathic: in 60-70% of patients the cause of the disease remains unclear. Among idiopathic forms, hereditary diabetes mellitus, which lasts for several generations, has a noticeable representation. The type of inheritance is autosomal dominant and recessive;

autoimmune : destruction of the hypothalamic nuclei as a result of an autoimmune process. This form is thought to occur among idiopathic diabetes insipidus, in which autoantibodies to vasopressin-secreting cells appear.

For peripheral In diabetes insipidus, vasopressin production is preserved, but the sensitivity of renal tubular receptors to the hormone is reduced or absent, or the hormone is intensively destroyed in the liver, kidneys, and placenta.

Nephrogenic diabetes insipidus is more often observed in children, and is caused by anatomical inferiority of the renal tubules (congenital deformities, cystic degenerative processes), or damage to the nephron (amyloidosis, sarcoidosis, lithium poisoning, methoxyfluramine). or decreased sensitivity of renal tubular epithelial receptors to vasopressin.

Diabetes insipidus clinic

Complaints

for thirst from moderate to painful, not letting go of patients day or night. Sometimes patients drink 20-40 liters of water per day. At the same time, there is a desire to drink ice water;

polyuria and frequent urination. The urine produced is light, without urochromes;

physical and mentalweakness;

loss of appetite,weight loss; possible development obesity if diabetes insipidus develops as one of the symptoms of primary hypothalamic disorders.

dyspeptic disorders from the stomach - a feeling of fullness, belching, pain in the epigastrium; intestines - constipation; gallbladder - heaviness, pain in the right hypochondrium;

mental and emotional disorders: headaches, emotional imbalance, insomnia, decreased mental activity, irritability, tearfulness; sometimes psychosis develops.

menstruation disorders, in men - potency.

Anamnesis

The onset of the disease can be acute and sudden; less often - gradual, and symptoms increase as the disease becomes more severe. The cause may be traumatic brain or mental injuries, infections, or surgical interventions on the brain. Most often, the cause cannot be identified. Sometimes a family history of diabetes insipidus is established.

Flow chronic diseases.

Inspection

emotional lability;

the skin is dry, salivation and sweating are reduced;

body weight can be reduced, normal or increased;

the tongue is often dry due to thirst, the borders of the stomach are lowered due to constant fluid overload. With the development of gastritis or biliary dyskinesia, increased sensitivity and pain on palpation of the epigastrium and right hypochondrium is possible;

the cardiovascular and respiratory systems, the liver are usually not affected;

urinary system: frequent urination, polyuria, nocturia are noted;

signsdehydration of the body, if the fluid lost in the urine is not replenished for some reason - lack of water, conducting a test with “dry eating”, or the sensitivity of the “thirst” center decreases:

severe general weakness, headaches, nausea, repeated vomiting, aggravating dehydration;

hyperthermia, convulsions, psychomotor agitation;

CVS disorder: tachycardia, hypotension up to collapse and coma;

blood thickening: increase in the number of Hb, red blood cells, Na + (N136-145 mmol/l, or mEq/l) creatinine (N60-132 μmol/l, or 0.7-1.5 mg%);

the specific gravity of urine is low - 1000-1010, polyuria persists.

These phenomena of hyperosmolar dehydration are especially characteristic of congenital nephrogenic diabetes insipidus in children.

The diagnosis is made based on classic signs of diabetes insipidus and laboratory and instrumental studies:

polydipsia, polyuria

low specific gravity of urine – 1000-1005

plasma hyperosmolarity, > 290 mOsm/kg (N280-296 mOsm/kg water, or mmol/kg water);

hypoosmolarity of urine,< 100-200 мосм/кг;

hypernatremia, > 155 mEq/L (N136-145 mEq/L, mmol/L).

If necessary, carried out samples :

Test with dry eating. This test is carried out in a hospital setting, its duration is usually 6-8 hours, if well tolerated - 14 hours. No fluid is given. Food should be protein. Urine is collected every hour, and the volume and specific gravity of each hourly portion are measured. Body weight is measured after every 1 liter of urine excreted.

Grade: the absence of significant dynamics in the specific gravity of urine in two subsequent portions with a loss of 2% of body weight indicates a lack of stimulation of endogenous vasopressin.

Test with intravenous administration of 50 ml of 2.5% solutionNaCl within 45 min. In diabetes insipidus, the volume and density of urine do not change significantly. In psychogenic polydipsia, an increase in plasma osmotic concentration quickly stimulates the release of endogenous vasopressin and the amount of urine excreted decreases and its specific gravity increases.

A test with the administration of vasopressin drugs - 5 units IV or IM. With true diabetes insipidus, health improves, polydipsia and polyuria decrease, plasma osmolarity decreases, and urine osmolarity increases.

Differential diagnosis of diabetes insipidus

Based on the main signs of diabetes insipidus - polydipsia and polyuria, this disease is differentiated from a number of diseases that occur with these symptoms: psychogenic polydipsia, diabetes mellitus, compensatory polyuria in chronic renal failure (chronic renal failure).

Nephrogenic vasopressin-resistant diabetes insipidus (congenital or acquired) is differentiated on the basis of polyuria with primary aldosteronism, hyperparathyroidism with nephrocalcinosis, malabsorption syndrome in chronic enterocolitis.

With diabetes

Table 22

With psychogenic polydipsia

Table 23

Sign	Diabetes insipidus	Psychogenic polydipsia
common reason	Infections, traumatic brain injuries (including surgical)	Gradual Psychotrauma, psychogenic stress
Presence of a tumor	Pituitary tumors, sarcoma, lymphogranulomatosis, etc.	Absent
Osmolarity:
Test with dry eating (no more than 6-8 hours)	No dynamics	The amount of urine decreases, specific gravity and osmolality normalize
How you feel during this test	Worsens, thirst becomes painful	Condition and well-being are not affected
Test with i.v. injection 50 ml 2.5% NaCl	The amount of urine and its density without dynamics	The amount of urine decreases and the specific gravity 
	Feeling better, polydipsia and polyuria decrease	Feeling worse (headaches)

Central (hypothalamic pituitary) with nephrogenic diabetes insipidus

Table 24

Sign	Central diabetes insipidus	Nephrogenic diabetes insipidus
	Traumatic brain injuries, infections, tumors.	Family; hyperparathyroidism; taking medications - lithium carbonate, demeclocycline, methoxyflurane
Test with intravenous administration of 5 units of vasopressin	The state of health improves, polydipsia and polyuria decrease. Plasma osmolality , and urine osmolality	No dynamics
Changes are detected in the urine	None	Albuminuria, cylindruria
Blood creatine
Arterial hypertension		BP often 

Treatment of diabetes insipidus

Etiological : for tumors of the hypothalamus or pituitary gland - surgery, or radiation therapy, cryodestruction, administration of radioactive ytrium.

For infectious processes - antibacterial therapy.

For hemoblastoses – cytostatic therapy.

Replacement therapy – drugs that replace vasopressin:

Adiuretin(synthetic analogue of vasopressin) intranasally, 1-4 drops in each nostril 2-3 times a day; Available in bottles of 5 ml, 1 ml - 0.1 mg of active substance;

Adiurecrin(extract of the posterior lobe of the pituitary gland of cattle). Available in powder form. Inhale 0.03-0.05 2-3 times a day. The duration of action of one inhalation is 6-8 hours. During inflammatory processes in the nasal cavity, the absorption of adiurecrine is disrupted and its effectiveness is sharply reduced;

RP:adiurecrini0.05Dsd№30.S. inhale through the nose, ampoules 1 ml;

Pituitrin. Release form 5 units of activity. Water-soluble extract of the posterior lobe of the pituitary gland of cattle. 5 units (1 ml) are administered 2-3 times a day intramuscularly. Often causes symptoms water intoxication(headaches, abdominal pain, diarrhea, fluid retention) and allergies;

DDAVP(1 deamino-8D-arginine-vasopressin) – a synthetic analogue of vasopressin;

diuretics of the thiazide group(Hypothiazide, etc.). Hypothiazide 100 mg per day reduces glomerular filtration, Na + excretion with a decrease in the amount of urine. The effect of thiazide diuretics is not detected in all patients with diabetes insipidus and weakens over time;

Chlorpropamide(oral glucose-lowering drug) is effective in some patients with diabetes insipidus. Tablets of 0.1 and 0.25. Prescribed in a daily dose of 0.25 in 2-3 doses. The mechanism of antidiuretic action is not fully understood; it is assumed that it potentiates vasopressin, at least with minimal amounts in the body.

To avoid hypoglycemia and hyponatremia, it is necessary to control the level of glucose and Na + in the blood.

Two completely different diseases - diabetes mellitus and diabetes insipidus - are united by one symptom: patients suffer from abnormally high urination or polyuria. Diseases differ in treatment methods and have different etymologies. Both diseases have serious consequences for the body, so at the first signs you should consult a doctor.

How is diabetes mellitus different from diabetes insipidus?

Medicine distinguishes 2 types of diabetes. In the first case, insulin is not produced by the pancreas and glucose is not absorbed. The disease is treated with lifelong insulin injections. In the second type, the mechanism of insulin absorption is disrupted, so drug treatment is indicated. In both cases, it increases in the blood. High sugar destroys the body, and to compensate for its level, polyuria develops.

Diabetes insipidus is different in that it is associated with a malfunction of the hypothalamic-pituitary system. As a result of the disease, the production of the hormone vasopressin decreases or stops. This hormone affects the distribution of fluids, maintains hemostasis at a normal level and regulates fluid drainage.

Reasons for the development of the disease

For sweet disease, the causes are also classified depending on the type of disease. Risk factors for type 1 disease are:

heredity;
patient's Caucasian race;
beta cell antibodies in the blood.

Type 2 of the disease depends on many factors:

Symptoms of the disease

Comparative table of diabetes mellitus and diabetes insipidus

Manifestations in patients	Diseases
Manifestations in patients	Sugar	Non-sugar
Thirst	Strong	Strong, disturbing even at night
Polyuria	Frequent night urination	Progressive (up to 20 liters)
Leather	Itching, poor healing of wounds and cuts	Dry skin
Bodily discomfort	Numb feet	Headache
Specific symptoms	Decline in visual function	Weight loss due to increased appetite
	Intractable candidiasis in women	Lower blood pressure
	Fatigue, memory problems	Lower blood pressure

Treatment of the disease

The doctor selects a treatment regimen for the disease individually for each patient.

Both types of diabetes are often the result of changes occurring in the body. Therefore, the doctor first treats the cause of the disease. An appropriate diet must be prescribed: in severe forms of disease, a violation of the diet can lead to death. Therapy is prescribed on an individual basis based on the patient’s medical history and health status.

In the initial stages, drug-free treatment of the disease is possible. If, with diabetes insipidus, the daily volume of urine is less than 4 liters, a gentle diet and timely replenishment of fluid levels are recommended. The same applies to the second disease - sugar control and a carbohydrate-free diet are necessary. Doctors know cases of cure of insulin-dependent type of disease thanks to a strict diet. Only a specialist should prescribe medications. Severe forms of diseases are treated throughout life.

Not many people know that in addition to the usual diabetes mellitus types 1 and 2, there is also diabetes insipidus. This is a disease of the endocrine glands, it is a syndrome of the hypothalamic-pituitary system. Therefore, such a disease actually has nothing in common with diabetes, except for the name and constant thirst.

In diabetes insipidus, there is a partial or complete deficiency of the antidiuretic hormone vasopressin. It overcomes osmotic pressure and stores and then distributes fluid throughout the body.

Thus, the hormone provides the necessary amount of water, allowing the kidneys to function normally. Consequently, vasopressin is necessary for natural homeostasis, because it ensures its normal functioning even with a lack of moisture in the body.

In critical situations, for example, during dehydration, the brain receives a signal that regulates the functioning of organs. This helps to reduce fluid loss by reducing the flow of saliva and urine.

Thus, diabetes insipidus differs from diabetes mellitus in that during its course the blood glucose level remains normal, but both diseases have a common symptom - polydipsia (extreme thirst). Therefore, diabetes insipidus, which is characterized by the reabsorption of fluid from the kidney tubules, received this name.

The course of ND is often acute. It is considered a disease of the young, so the age category of patients is up to 25 years. Moreover, disruption of the endocrine glands can occur in both women and men.

Diabetes insipidus: types

There is central and nephrogenic diabetes insipidus. CND, in turn, is divided into 2 types:

functional;
organic.

The functional type is classified as the idiopathic form. The factors influencing the appearance of this type have not been fully established, but many doctors believe that heredity plays a significant role in the development of the disease. Also, the reasons lie in a partial disruption of the synthesis of the hormone neurophysin or vasopressin.

The organic type of the disease appears after various injuries, surgery and other damage.

Nephrogenic diabetes insipidus develops when the natural functioning of the kidneys is disrupted. In some cases, there is a failure in the osmotic pressure of the renal tubules; in other situations, the susceptibility of the tubules to vasopressin decreases.

There is also a form called psychogenic polydipsia. It can be triggered by drug abuse or PP is one of the types of manifestations of schizophrenia.

There are also such rare types of ND as the gestagenic type and transient polyuria. In the first case, the placental enzyme is very active, which has a negative effect on the antidiuretic hormone.

The transient form of diabetes develops before the age of 1 year.

This occurs when the kidneys are underdeveloped, when enzymes involved in metabolic processes begin to behave more actively.

Causes and symptoms of the disease

Sugar level

There are many factors leading to the development of diabetes insipidus:

tumor-like formations;
chronic and acute infections (postpartum sepsis, influenza, syphilis, typhoid, scarlet fever, etc.);
radiation therapy;
nephritis;
damage to blood vessels and parts of the brain;
brain injury or surgery;
amyloidosis;
granulomatosis;
hemoblastoses.

Autoimmune diseases and psychogenic disorders also contribute to the appearance of ND. And in the idiopathic form of the disease, the cause is the sudden appearance of antibodies against hormone-producing cells.

The clinical picture of diabetes insipidus is varied, ranging from headaches to dehydration in the absence of adequate fluid intake. Therefore, in addition to screening, various tests are performed for diabetes insipidus.

The main signs of the disease include:

disruptions in the gastrointestinal tract - constipation, gastritis, colitis, poor appetite;
strong thirst;
sexual dysfunction;
mental disorders – poor sleep, irritability, headache, fatigue;
frequent urination with copious amounts of fluid (6-15 liters);
drying of mucous membranes and skin;
blurred vision due to diabetes;
weight loss;
anorexia;
asthenic syndrome.

Diabetes insipidus is often accompanied by increased internal pressure and decreased sweating. Moreover, if the patient does not drink enough water, his condition will worsen greatly. As a result, the patient may develop symptoms such as blood thickening, vomiting, nausea, tachycardia, increased temperature, and collapse appears against the background of dehydration. In women with ND, the menstrual cycle is disrupted, and men have poor potency.

In children, the course of the disease can lead to a slowdown in sexual and physical development.

Diagnostics

To detect the presence of ND, a three-stage diagnostic examination is performed:

detection of hypotonic polyuria (urinalysis, Zimnitsky test, biochemical blood test);
functional tests (desmopressin test, dry eating);
detection of the causes that provoked the development of the disease (MRI).

First stage

Initially, if diabetes insipidus is suspected, a study is performed to determine the density of urine. Indeed, with the disease, the functioning of the kidneys deteriorates, as a result, urine density indicators are less than 1005 g/l.

To find out the level of density during the day, a study according to Zimnitsky is being carried out. This analysis is done every three hours for 24 hours. During this period, 8 urine samples are taken.

Normally, the results are deciphered as follows: the amount of daily urine should not exceed 3 liters, its density is 1003-1030, while the ratio of night and daytime diuresis is 1:2, and excreted and drunk - 50-80-100%. Urine osmolarity is 300 mOsm/kg.

A biochemical blood test is also performed to diagnose ND. In this case, the osmolarity of the blood is calculated. If there is a high concentration of salts in the plasma of more than 292 mOsm/L and excessive sodium content (from 145 nmol/L), diabetes insipidus is diagnosed.

Blood is taken from a vein on an empty stomach. Before the procedure (6-12 hours), you can only drink water. As a rule, test results need to wait one day.

In addition, during a biochemical blood test, the following values are examined:

glucose;
potassium and sodium;
total protein, including hemoglobin;
ionized calcium;
creatinine;
parathyroid hormone;
aldosterone.

The normal blood sugar level is up to 5.5 mmol/l. However, with ND, glucose concentrations often do not increase. But its fluctuations can be observed with strong emotional or physical stress, pancreatic diseases, pheochromocytoma and chronic liver and kidney failure. A decrease in sugar concentration occurs when there are disturbances in the functioning of the endocrine glands, fasting, tumors, and in case of severe intoxication.

Potassium and sodium are chemical elements that give cell membranes electrical properties. The normal potassium level is 3.5 – 5.5 mmol/l. If its value is too high, this indicates liver and adrenal failure, cell damage and dehydration. Low potassium levels occur with fasting, kidney problems, excess of certain hormones, dehydration and cystic fibrosis.

The norm of sodium in the bloodstream is from 136 to 145 mmol/l. Hypernatremia occurs with excessive salt intake, disruptions in water-salt balance, and hyperfunction of the adrenal cortex. And hyponatremia occurs when consuming a large volume of liquid and in the case of pathologies of the kidneys and adrenal glands.

Total protein analysis reveals the level of albumin and globulin. The normal level of total blood protein for adults is 64-83 g/l.

Glycosylated hemoglobin is of no small importance in the diagnosis of diabetes insipidus. Ac1 shows the average blood glucose level over 12 weeks.

Hemoglobin is a substance present in red blood cells that delivers oxygen to all organs and systems. In people who do not suffer from diabetes, glycosylated hemoglobin in the blood does not exceed 4-6%, which is also typical for diabetes insipidus. Thus, elevated Ac1 values make it possible to differentiate these diseases.

However, fluctuations in hemoglobin levels can occur with anemia, the use of nutritional supplements, taking vitamins E, C, and excess cholesterol. Moreover, glycosylated hemoglobin may have different levels in liver and kidney diseases.

The level of ionized calcium is an indicator responsible for mineral metabolism. Its average values range from 1.05 to 1.37 mmol/l.

Tests for diabetes insipidus also include blood tests for aldosterone levels. A deficiency of this hormone often indicates the presence of diabetes insipidus.

An increased level of creatinine and parathyroid hormone may also indicate the presence of the disease.

Second phase

At this stage, it is necessary to draw up a test protocol with dry eating. The dehydration phase includes:

drawing blood to check osmolality and sodium levels;
taking urine to determine its quantity and osmolality;
weighing the patient;
measurement of pulse and blood pressure levels.

However, in hypernatremia, such tests are contraindicated.

It is worth noting that during the test you cannot eat fast-carbohydrate foods with. Preference should be given to fish, lean meat, boiled eggs and grain bread.

The dry eating test is stopped if: osmolality and sodium levels exceed the norm, unbearable thirst occurs, and weight loss occurs by more than 5%.

The desmopressin test is performed to distinguish between central and nephrogenic diabetes insipidus. It is based on testing the patient's sensitivity to desmopressin. In other words, the functional activity of V2 receptors is tested. The study is done after a test with dry eating at the highest impact of endogenous AVP.

The patient must urinate before the test. He is then given desmopressin, and he can drink and eat, but in moderation. After 2-4 hours, urine is collected to determine its osmolality and volume.

Normal research results are 750 mOsm/kg.

With NND, the values increase to 300 mOsm/kg, and in the case of CND after dehydration they are 300, and for desmopressin - 750 mOsm/kg.

Third stage

An MRI is often performed to detect diabetes insipidus. In a healthy person, the pituitary gland shows clear differences between the anterior and posterior lobes. Moreover, the latter on the T1 image has a hyperintense signal. This is due to the presence of secretory granules containing phospholipids and AVP.

In the presence of CND, the signal emitted by the neurohypophysis is absent. This occurs due to a failure in the synthesis and transport and storage of neurosecretory granules.

Also, for diabetes insipidus, neuropsychiatric, ophthalmological and x-ray examinations can be performed. And in the case of the renal form of the disease, ultrasound and CT scans of the kidneys are performed.

The leading method of therapy for NND is the use of synthetic analogues of vasopressin (Desmopressin, Chlorpropamide, Adiuretin, Minirin). In the renal form, diuretics and NSAIDs are prescribed.

Any type involves infusion treatment based on the administration of saline solution. This is necessary to correct water-salt metabolism.

It is of no small importance to adhere to a certain diet, including limited consumption of salt (4-5 g) and protein (up to 70 g). Diets No. 15, 10 and 7 meet these requirements.

What tests should be taken if diabetes insipidus is suspected is described in the video in this article.

Diabetes insipidus or diabetes insipidus- a disease in which, due to a lack of vasopressin (antidiuretic hormone), severe thirst appears, and the kidneys excrete a large amount of low-concentrated urine.

This rare disease occurs equally often in women, men and children. However, young people aged 18 to 25 are most prone to it.

Anatomy and physiology of the kidneys

Bud- a paired bean-shaped organ, which is located behind the abdominal cavity in the lumbar region on both sides of the spine at the level of the twelfth thoracic and first and second lumbar vertebrae. The weight of one kidney is about 150 grams.

Kidney structure

The kidney is covered with membranes - a fibrous and fatty capsule, as well as renal fascia.

In the kidney, a distinction is made between the renal tissue itself and the pyelocaliceal system.

Kidney tissue responsible for filtering blood to form urine, and pyelocalyceal system- for the accumulation and excretion of formed urine.

Kidney tissue has two substances (layers): cortical (located closer to the surface of the kidney) and medulla (located inward from the cortex). They contain a large number of closely interconnected tiny blood vessels and urinary tubules. These are the structural functional units of the kidney - nephrons(there are about one million of them in each kidney).

Each nephron begins from the renal corpuscle(Malpighi-Shumlyansky), which is a vascular glomerulus (an intertwined cluster of tiny capillaries), surrounded by a spherical hollow structure (Shumlyansky-Bowman capsule).

The structure of the glomerulus

The glomerular vessels originate from the renal artery. Initially, upon reaching the kidney tissue, it decreases in diameter and branches, forming bringing vessel(afferent arteriole). Next, the afferent vessel flows into the capsule and branches into the smallest vessels (the glomerulus itself), from which the efferent vessel(efferent arteriole).

It is noteworthy that the walls of the glomerular vessels are semi-permeable (have “windows”). This ensures the filtration of water and some solutes in the blood (toxins, bilirubin, glucose and others).

In addition, in the walls of the afferent and efferent vessels there is juxtaglomerular apparatus of the kidney, in which renin is produced.

The structure of the Shumlyansky-Bowman capsule

It consists of two leaves (outer and inner). Between them there is a slit-like space (cavity), into which the liquid part of the blood from the glomerulus penetrates, along with some substances dissolved in it.

In addition, a system of convoluted tubes originates from the capsule. First, the urinary tubules of the nephron are formed from the inner layer of the capsule, then they flow into the collecting tubules, which connect with each other and open into the renal calyces.

This is the structure of the nephron in which urine is formed.

Physiology of the kidney

Basic functions of the kidney- removal from the body of excess water and metabolic end products of certain substances (creatinine, urea, bilirubin, uric acid), as well as allergens, toxins, medications and others.

In addition, the kidney is involved in the exchange of potassium and sodium ions, the synthesis of red blood cells and blood clotting, regulation of blood pressure and acid-base balance, metabolism of fats, proteins and carbohydrates.

However, in order to understand how all these processes are carried out, it is necessary to “arm yourself” with some knowledge about the functioning of the kidney and the formation of urine.

The process of urine formation consists of three stages:

Glomerular filtration(ultrafiltration) occurs in the glomeruli of the renal corpuscles: through the “windows” in their wall, the liquid part of the blood (plasma) with some substances dissolved in it is filtered. Then it enters the lumen of the Shumlyansky-Bowman capsule

Reverse suction(resorption) occurs in the urinary tubules of the nephron. During this process, water and nutrients that should not be removed from the body are reabsorbed. While substances to be excreted, on the contrary, accumulate.

Secretion. Some substances that must be excreted from the body enter the urine already in the renal tubules.

How does urine formation occur?

This process begins with the fact that arterial blood enters the vascular glomerulus, in which its flow slows down somewhat. This occurs due to high pressure in the renal artery and an increase in the capacity of the vascular bed, as well as the difference in the diameter of the vessels: the afferent vessel is slightly wider (20-30%) than the efferent vessel.

Thanks to this, the liquid part of the blood, together with the substances dissolved in it, begins to exit through the “windows” into the lumen of the capsule. At the same time, normally the walls of the glomerular capillaries retain formed elements and some blood proteins, as well as large molecules whose size is more than 65 kDa. However, toxins, glucose, amino acids and some other substances, including useful ones, pass through. This is how primary urine is formed.

Next, primary urine enters the urinary canaliculi, where water and useful substances are reabsorbed from it: amino acids, glucose, fats, vitamins, electrolytes and others. In this case, substances to be excreted (creatinine, uric acid, medications, potassium and hydrogen ions), on the contrary, accumulate. Thus, primary urine turns into secondary urine, which enters the collecting ducts, then into the pyelocaliceal system of the kidney, then into the ureter and bladder.

It is noteworthy that about 150-180 liters of primary urine are formed within 24 hours, while secondary urine is from 0.5 to 2.0 liters.

How is kidney function regulated?

This is a rather complex process in which vasopressin (antidiuretic hormone), as well as the renin-angiotensin system (RAS), take the most active part.

Renin-angiotensin system

Main functions

regulation of vascular tone and blood pressure
increased sodium reabsorption
stimulation of vasopressin production
increased blood flow to the kidneys

Activation mechanism

In response to the stimulating effect of the nervous system, a decrease in blood supply to the renal tissue, or a decrease in the level of sodium in the blood, renin begins to be produced in the juxtaglomerular apparatus of the kidney. In turn, renin promotes the conversion of one of the blood plasma proteins into angiotensin II. And, in fact, angiotensin II determines all the functions of the renin-angiotensin system.

Vasopressin

This is a hormone that is synthesized (produced) in the hypothalamus (located in front of the cerebral peduncles), then enters the pituitary gland (located at the bottom of the sella turcica), from where it is released into the blood.

The synthesis of vasopressin is mainly regulated by sodium: when its concentration in the blood increases, the production of the hormone increases, and when it decreases, it decreases.

The synthesis of the hormone also increases during stressful situations, a decrease in fluid in the body, or nicotine entering the body.

In addition, the production of vasopressin decreases with increased blood pressure, inhibition of the renin-angiotensin system, decreased body temperature, intake of alcohol and certain medications (for example, clonidine, haloperidol, glucocorticoids).

How does vasopressin affect kidney function?

The main task of vasopressin- promote the reabsorption of water (resorption) in the kidneys, reducing the amount of urine formation.

Mechanism of action

With the blood flow, the hormone reaches the renal tubules, where it attaches to special areas (receptors), leading to an increase in their permeability (the appearance of “windows”) for water molecules. Thanks to this, water is absorbed back and urine is concentrated.

In addition to urine resorption, vasopressin regulates several other processes occurring in the body.

Functions of vasopressin:

Promotes contraction of capillaries in the circulatory system, including glomerular capillaries.
Supports blood pressure.
Affects the secretion of adrenocorticotropic hormone(synthesized in the pituitary gland), which regulates the production of hormones from the adrenal cortex.
Enhances the release of thyroid-stimulating hormone(synthesized in the pituitary gland), which stimulates the production of thyroxine by the thyroid gland.
Improves blood clotting due to the fact that it causes aggregation (sticking together) of platelets and increases the release of certain blood clotting factors.
Reduces the volume of intracellular and intravascular fluid.
Regulates the osmolarity of body fluids(total concentration of dissolved particles in 1 l): blood, urine.
Stimulates the renin-angiotensin system.

With a lack of vasopressin, a rare disease develops - diabetes insipidus.

Types of diabetes insipidus

Considering the mechanisms of development of diabetes insipidus, it can be divided into two main types:

Central diabetes insipidus. It is formed when there is insufficient production of vasopressin in the hypothalamus or a violation of its release from the pituitary gland into the blood.

Renal (nephrogenic) diabetes insipidus. In this form, vasopressin levels are normal, but the kidney tissue does not respond to it.

In addition, sometimes the so-called psychogenic polydipsia(increased thirst) in response to stress.

Also diabetes insipidus can develop during pregnancy. The reason is the destruction of vasopressin by placental enzymes. As a rule, symptoms of the disease appear in the third trimester of pregnancy, but disappear on their own after childbirth.

Causes of diabetes insipidus

Depending on the development of what type of diabetes insipidus they can lead to, they are divided into two groups.

Causes of central diabetes insipidus

Brain lesions:

tumors of the pituitary gland or hypothalamus
complications after brain surgery
sometimes develops after previous infections: ARVI, influenza and others
encephalitis (inflammation of the brain)
skull and brain injuries
disruption of the blood supply to the hypothalamus or pituitary gland
metastases of malignant neoplasms in the brain that affect the functioning of the pituitary gland or hypothalamus
the disease may be congenital

Causes of renal diabetes insipidus

the disease may be congenital(most common reason)
the disease is sometimes caused by certain conditions or diseases, in which the medulla of the kidney or the urinary tubules of the nephron are damaged.
rare form of anemia(sickle cell)
polycystic disease(multiple cysts) or amyloidosis (deposition of amyloid in the tissue) of the kidneys
chronic renal failure
increased potassium or decreased calcium in the blood
taking medications that have a toxic effect on kidney tissue (for example, Lithium, Amphotericin B, Demeclocillin)
sometimes occurs in debilitated patients or in old age

Symptoms of diabetes insipidus

Despite the various causes that lead to the development of diabetes insipidus, the signs of the disease are almost the same for all variants of its course.

However, the severity of the manifestations of the disease depends on two points:

How resistant are nephron tubule receptors to vasopressin?
degree of antidiuretic hormone deficiency or absence

As a rule, the onset of the disease is sudden, but it can develop gradually.

The most first signs of illness- severe, painful thirst (polydipsia) and frequent excessive urination (polyuria), which bother patients even at night.

From 3 to 15 liters of urine can be released per day, and sometimes its amount reaches up to 20 liters per day. Therefore, the patient is tormented by severe thirst.

Later, as the disease progresses, the following symptoms appear:

Signs of dehydration (lack of water in the body) appear: dry skin and mucous membranes (dry mouth), decreased body weight.
Due to the consumption of large amounts of liquid, the stomach stretches and sometimes even drops.
Due to lack of water in the body, the production of digestive enzymes in the stomach and intestines is disrupted. Therefore, the patient’s appetite decreases, gastritis or colitis develops, and there is a tendency to constipation.
Due to the release of urine in large volumes, the bladder is stretched.
Since there is not enough water in the body, sweating decreases.
Blood pressure often drops and heart rate increases.
Sometimes there is unexplained nausea and vomiting.
The patient gets tired quickly.
Body temperature may increase.
Sometimes bedwetting (enuresis) occurs.

Since thirst and excessive urination continue at night, the patient develops mental and emotional disorders:

insomnia and headaches
emotional lability (sometimes even psychosis develops) and irritability
decreased mental activity

These are the signs of diabetes insipidus in typical cases. However, the manifestations of the disease may differ slightly in men and women, as well as children.

Symptoms of diabetes insipidus in men

The symptoms described above will be accompanied by a decrease in libido (attraction to the opposite sex) and potency (male impotence).

Symptoms of diabetes insipidus in women

The disease occurs with normal symptoms. However, in women, the menstrual cycle is sometimes disrupted, infertility develops, and pregnancy ends in spontaneous miscarriage.

Diabetes insipidus in children

In adolescents and children over three years of age, the symptoms of the disease are practically no different from those in adults.

However, sometimes the signs of the disease are not clearly expressed: the child eats poorly and gains weight, suffers from frequent vomiting when eating, has constipation and bedwetting, and complains of pain in the joints. In this case, the diagnosis is made late, when the child is already lagging behind in physical and mental development.

Whereas in newborns and infants (especially with the renal type), the manifestations of the disease are striking and differ from those in adults.

Symptoms of diabetes insipidus in children under one year of age:

The baby prefers water to mother's milk, but sometimes there is no thirst
baby urinates frequently and in large quantities
anxiety appears
body weight is quickly lost (the child literally loses weight before our eyes)
tissue turgor decreases (if the skin is folded and released, it slowly returns to its normal position)
no or few tears
frequent vomiting occurs
heart rate increases
Body temperature can either rise or fall quickly

A baby under one year old cannot express in words his desire to drink water, so his condition quickly worsens: he loses consciousness and may develop convulsions. Unfortunately, sometimes even death.

Diagnosis of diabetes insipidus

First, the doctor clarifies several points:

What is the amount of fluid drunk and urine excreted by patients? If its volume is more than 3 liters, this indicates diabetes insipidus.

Is there bedwetting and frequent excessive urination at night (nocturia), and does the patient drink water at night? If yes, then the volume of liquid drunk and urine excreted must be specified.

Isn’t increased thirst also associated with a psychological reason? If it is absent when the patient is doing what he loves, walking or visiting, then most likely he has psychogenic polydipsia.

Are there any diseases?(tumors, endocrine disorders and others), which can give impetus to the development of diabetes insipidus.

If all symptoms and complaints indicate that the patient probably has diabetes insipidus, then The following studies are carried out on an outpatient basis:

the osmolarity and relative density of urine are determined (characterizes the filtering function of the kidneys), as well as the osmolarity of blood serum
computed tomography or nuclear magnetic resonance of the brain
radiography of the sella turcica and skull
echoencephalography
excretory urography
Kidney ultrasound
the level of sodium, calcium, potassium, nitrogen, urea, glucose (sugar) is determined in the blood serum
Zimnitsky's test

In addition, the patient is examined by a neurologist, ophthalmologist and neurosurgeon.

Based on laboratory data Diagnostic criteria for diabetes insipidus are the following indicators:

increased blood sodium (more than 155 mEq/L)
increase in blood plasma osmolarity (more than 290 mOsm/kg)
decreased urine osmolarity (less than 100-200 mOsm/kg)
low relative density of urine (less than 1010)

When the osmolarity of urine and blood is within normal limits, but the patient’s complaints and symptoms indicate diabetes insipidus, a test is performed with fluid restriction (dry eating). The meaning of the test is that insufficient intake of fluid into the body after a certain time (usually after 6-9 hours) stimulates the production of vasopressin.

It is noteworthy that this test allows not only to make a diagnosis, but also to determine the type of diabetes insipidus.

Test procedure with liquid restriction

After a night's sleep, the patient is weighed on an empty stomach, and blood pressure and pulse are measured. In addition, the level of sodium in the blood and the osmolarity of the blood plasma, as well as the osmolarity and relative density of urine (specific gravity) are determined.

The patient then stops taking liquids (water, juices, tea) for as long as possible.

The test is stopped if the patient:

weight loss is 3-5%
there is an unbearable thirst
the general condition sharply worsens (nausea, vomiting, headache appears, heart rate increases)
blood sodium and osmolarity levels are higher than normal

An increase in blood osmolarity and sodium in the blood, as well as a decrease in body weight by 3-5% indicates in favor of central diabetes insipidus.

While a decrease in the amount of urine excreted and the absence of weight loss, as well as normal serum sodium levels, indicate renal diabetes insipidus.

If this test confirms diabetes insipidus, a minirhin test is performed for further diagnosis.

Methodology for conducting the minirin test

The patient is prescribed Minirin tablets and urine is collected according to Zimnitsky before and while taking it.

What do the test results say?

With central diabetes insipidus, the amount of urine excreted decreases, and its relative density increases. Whereas in renal diabetes insipidus these indicators practically do not change.

It is noteworthy that to diagnose the disease, the level of vasopressin in the blood is not determined, since the technique is too expensive and difficult to perform.

Diabetes insipidus: differential diagnosis

Most often it is necessary to distinguish diabetes insipidus from diabetes mellitus and psychogenic polydipsia.

Sign	Diabetes insipidus	Diabetes	Psychogenic polydipsia
Thirst	strongly expressed	expressed	strongly expressed
Amount of urine excreted per day	from 3 to 15 liters	up to two or three liters	from 3 to 15 liters
Onset of the disease	usually spicy	gradual	usually spicy
Bed-wetting	sometimes present	absent	sometimes present
Increased blood glucose	No	Yes	No
Presence of glucose in urine	No	Yes	No
Relative density of urine	downgraded	increased	downgraded
General condition during dry eating test	getting worse	does not change	does not change
Volume of urine excreted during dry eating test	does not change or decreases slightly	does not change	decreases to normal numbers, while its density increases
Blood uric acid level	more than 5 mmol/l	increases in severe disease	less than 5 mmol/l

Treatment of diabetes insipidus

First, if possible, the cause of the disease is eliminated. Then medications are prescribed depending on the type of diabetes insipidus.

Treatment of central diabetes insipidus

It is carried out taking into account how much fluid the patient loses in the urine:

If your urine volume is less than four liters per day, no medications are prescribed. It is only recommended to replenish lost fluid and follow a diet.

When the amount of urine is more than four liters per day, substances are prescribed that act like vasopressin (replacement therapy) or stimulate its production (if hormone synthesis is partially preserved).

Treatment with medications

For more than 30 years, intranasal Desmopressin (Adiuretin) (injection of medication into the nasal passages) has been used as replacement therapy. However, its production has now been discontinued.

Therefore, currently the only drug that is prescribed as a replacement for vasopressin - Minirin(tablet form of Desmopressin).

The dose of Minirin, which suppresses the symptoms of the disease, is not affected by the patient’s age or weight. Since everything depends on the degree of deficiency of antidiuretic hormone or its complete absence. Therefore, the dosage of Minirin is always selected individually during the first three to four days of taking it. Treatment begins with minimal doses, which are increased if necessary. The drug is taken three times a day.

To medicinal substances that stimulate the production of vasopressin, include Chlorpropamide (especially effective in the combination of diabetes mellitus and diabetes insipidus), Carbamazepine and Miscleron.

Treatment of renal diabetes insipidus.

First of all, a sufficient supply of fluid to the body is ensured, then, if necessary, medications are prescribed.

Treatment with medications

It is practiced to prescribe medications that, paradoxically, reduce the amount of urine - thiazide diuretics (diuretics): Hydrochlorothiazide, Indapamide, Triampur. Their use is based on the fact that they prevent the reabsorption of chlorine in the urinary tubules of the nephron. As a result, the sodium content in the blood decreases slightly, and the reabsorption of water increases.

Anti-inflammatory drugs (Ibuprofen, Indomethacin and Aspirin) are sometimes prescribed as an adjunct to treatment. Their use is based on the fact that they reduce the flow of certain substances into the urinary tubules of the nephron, thereby reducing the volume of urine and increasing its osmolality.

However, successful treatment of diabetes insipidus is impossible without following certain nutritional rules.

Diabetes insipidus: diet

Nutrition for diabetes insipidus has goals - reducing urine output in large volumes and thirst, as well as replenishing nutrients which are lost in urine.

Therefore, first of all salt intake is limited(no more than 5-6 grams per day), and it is handed out, and food is prepared without adding it.

Useful dried fruits, since they contain potassium, which enhances the production of endogenous (internal) vasopressin.

Besides, you need to give up sweets, so as not to increase thirst. It is also recommended to refrain from drinking alcoholic beverages.

The diet includes a sufficient amount of fresh vegetables, berries and fruits, milk and lactic acid products. In addition, juices, compotes, and fruit drinks are useful.

It is very important that phosphorus enters the body(it is necessary for normal brain function), so it is recommended to consume low-fat fish, seafood and fish oil.

Besides, lean meats and eggs are healthy(yolk). However, it must be remembered that in case of diabetes insipidus you should still limit proteins, so as not to increase the load on the kidneys. While fats (for example, butter and vegetable oil), as well as carbohydrates (potatoes, pasta and others) must be present in the diet in sufficient quantities.

It is advisable to eat meals in fractions: 5-6 times a day.

Diabetes insipidus: treatment with folk remedies

To improve the condition of patients with this disease, Mother Nature has prepared several wonderful recipes.

To reduce thirst:

Take 60 grams of crushed burdock root, place it in a thermos and pour one liter of boiling water. Leave it overnight and express in the morning. Take two-thirds of a glass three times a day.

Take 20 grams of elderberry flowers, pour a glass of boiling water and leave for an hour. Then strain and add honey to taste. Take one glass three times a day.

Take 5 grams (one teaspoon) of crushed young walnut leaves and pour a glass of boiling water. Let it brew and take it like tea.

To improve nutrition of brain cells

Consume one teaspoon of pea flour per day, which is rich in glutamic acid.

To improve sleep and reduce irritability sedative fees apply:

Take equal parts of crushed valerian roots, hop cones, motherwort herbs, rose hips, mint leaves and mix everything thoroughly. From the resulting mixture, take one tablespoon of raw material and pour a glass of boiling water. Let it sit for an hour and then express. Take 1/3 glass at night for insomnia or increased nervous agitation.

Take equal parts of crushed valerian roots, fennel and caraway fruits, motherwort herbs and mix everything thoroughly. Then, from the resulting mixture, take two tablespoons of the raw material and pour 400 ml of boiling water, let it brew until cool and decant. Take half a glass if you feel irritable or nervous.