Diabetes insipidus is a disease that develops when there is insufficient release of antidiuretic hormone (ADH) or a decrease in the sensitivity of the renal tissue to its action. As a result, there is a significant increase in the amount of fluid released from the urine, there is an unquenchable feeling of thirst. If fluid losses are not fully compensated, then dehydration of the body develops – dehydration, a distinctive feature of which is concomitant polyuria. Diagnosis is based on the clinical picture and determination of the level of ADH in the blood. To find out the cause of disease, a comprehensive examination of the patient is carried out.
ICD 10
E23.2 Diabetes insipidus
Classification
Modern endocrinology classifies this pathology depending on the level at which the disorders occur. There are central (neurogenic, hypothalamic-pituitary) and renal (nephrogenic) forms. In the central form, disorders develop at the level of secretion of antidiuretic hormone by the hypothalamus or at the level of its release into the blood. In the renal form, there is a violation of the perception of ADH by the cells of the distal tubules of the nephrons.
Central form is divided into idiopathic (a hereditary disease characterized by a decrease in the synthesis of ADH) and symptomatic (occurs against the background of other pathologies). Symptomatic diabetes insipidus can develop during life (acquired) after traumatic brain injuries, tumors and infiltrative processes of the brain, meningoencephalitis or be diagnosed from birth (congenital) with a mutation of the ADH gene.
The renal form of diabetes insipidus is relatively rare with anatomical inferiority of the nephron or impaired receptor sensitivity to antidiuretic hormone. These disorders may be congenital in nature or develop as a result of drug or metabolic damage to the nephrons.
Causes
The central form of diabetes insipidus associated with hypothalamic-pituitary destruction as a result of primary or metastatic tumors, neurosurgical interventions, vascular, tuberculosis, malaria, syphilitic lesions, etc. is more often detected. In idiopathic form, there is no organic lesion of the hypothalamic-pituitary system, and the cause is the spontaneous appearance of antibodies to hormone-producing cells.
The renal form of diabetes insipidus can be caused by congenital or acquired kidney diseases (renal insufficiency, amyloidosis, hypercalcemia) or poisoning with lithium preparations. Congenital forms most often develop with autosomal recessive inheritance of Wolfram syndrome, which in its manifestations can be complete (with the presence of diabetes insipidus and diabetes mellitus, optic atrophy, deafness) or partial (combining diabetes mellitus and diabetes insipidus).
Symptoms
Typical manifestations of diabetes insipidus are polyuria and polydipsia. Polyuria is manifested by an increase in the volume of excreted daily urine (more often up to 4-10 liters, sometimes up to 20-30 liters). Urine is colorless, with a small amount of salts and other elements and a low specific gravity (1000-1003) in all portions. The feeling of unquenchable thirst in diabetes insipidus leads to polydipsia – the consumption of a large amount of fluid, sometimes equal to that lost with urine. The severity of diabetes insipidus is determined by the degree of antidiuretic hormone deficiency.
Idiopathic diabetes insipidus usually develops acutely, suddenly, less often – gradually increasing. Pregnancy can provoke the manifestation of the disease. Frequent urge to urinate (pollakiuria) leads to sleep disorders, neurosis, fatigue, emotional instability. In children, enuresis is an early manifestation of diabetes insipidus, later growth retardation and puberty are added.
Late manifestations of diabetes insipidus are the expansion of the renal pelvis, ureters, and bladder. As a result of water overload, overstretching and lowering of the stomach occurs, biliary dyskinesia develops, chronic intestinal irritation.
The skin of patients with diabetes insipidus is dry, the secretion of sweat, saliva and appetite are reduced. Later, dehydration, weight loss, vomiting, headache, and a decrease in blood pressure are added. With diabetes insipidus, caused by damage to the brain, neurological disorders and symptoms of pituitary insufficiency (panhypopituitarism) develop. Men develop a weakening of potency, women – menstrual function disorders.
Complications
Disease is dangerous by the development of dehydration of the body, in cases when the loss of fluid in the urine is not adequately replenished. Dehydration is manifested by sharp general weakness, tachycardia, vomiting, mental disorders, blood thickening, hypotension up to collapse, neurological disorders. Even with severe dehydration, polyuria persists.
Diagnostics
Typical cases make it possible to suspect diabetes insipidus by insatiable thirst and excretion of more than 3 liters of urine per day. To assess the daily amount of urine, a Zimnitsky test is carried out. When examining urine, its low relative density (< 1005), hyponatryuria (hypoosmolarity of urine – 100-200 mosm / kg) are determined. Hyperosmolarity (hypernatremia) of plasma (> 290 mosm/kg), hypercalcemia and hypokalemia are detected in the blood. Diabetes mellitus is excluded by the determination of fasting blood glucose. In the central form of this disease, a low content of ADH is determined in the blood.
The results of the dry-eating test are indicative: abstinence from taking liquids for 10-12 hours. With this disease, weight loss of more than 5% occurs, while maintaining a low specific gravity and hypoosmolarity of urine. The causes are clarified during X-ray, neuropsychiatric, ophthalmological studies. Volumetric formations of the brain are excluded by conducting an MRI of the brain. To diagnose the renal form, ultrasound and CT of the kidneys are performed. A nephrologist’s consultation is required. Sometimes a kidney biopsy is required to differentiate renal pathology.
Treatment
Treatment of symptomatic diabetes insipidus begins with the elimination of the cause (for example, a tumor). In all forms of diabetes insipidus, substitution therapy with a synthetic analog of ADH – desmopressin is prescribed. The drug is administered orally or intranasally (by instillation into the nose). A prolonged preparation from an oil solution of pituitrin is also prescribed. In the central form, chlorpropamide, carbamazepine are prescribed, stimulating the secretion of antidiuretic hormone.
Correction of the water-salt balance is carried out by infusion of saline solutions in large volumes. Sulfonamide diuretics (hypochlorothiazide) significantly reduce diuresis in diabetes insipidus. Nutrition for diabetes insipidus is based on protein restriction (to reduce the load on the kidneys) and sufficient intake of carbohydrates and fats, frequent meals, increasing the number of vegetable and fruit dishes. From drinks, it is recommended to quench thirst with juices, fruit drinks, compotes.
Forecast
Diabetes insipidus, which develops in the postoperative period or during pregnancy, is more often transient (transient) in nature, idiopathic – on the contrary, persistent. With appropriate treatment, there is no danger to life, although recovery is rarely recorded.
Recovery of patients is observed in cases of successful removal of tumors, specific treatment of diabetes insipidus tuberculosis, malaria, syphilitic genesis. With the correct appointment of hormone replacement therapy, the ability to work is often preserved. The least favorable course of the nephrogenic form in children.