Hyperstenuria is an increase in the relative density (specific gravity) of urine more than 1.030 g / ml. Most often, this condition occurs with dehydration, but can also occur with diabetes mellitus, increased production of antidiuretic hormone, and heart disease. There are no clear clinical signs of hyperstenuria. Relative density indicators are measured with a general urine test. To eliminate hyperstenuria, it is necessary to treat the underlying disease.
In healthy people, the relative density of urine can fluctuate during the day. In adults, in the morning, it can reach 104g / ml. Very often, short-term minor hyperstenuria is observed with insufficient water intake or intense sweating.
The most common pathological cause of hyperstenuria is dehydration. Due to the lack of fluid in the body, the volume of diuresis decreases, the urine becomes "concentrated" due to the high content of electrolytes with a small volume. The degree of hyperstenuria is directly proportional to the severity of dehydration. Replenishment of the fluid deficit quickly normalizes the relative density. Diseases and pathological conditions often accompanied by dehydration:
Glucose is an osmotically active substance, therefore, getting into the urine, it increases the specific gravity. Hyperstenuria is more typical for patients with decompensated diabetes mellitus, when the blood glucose content is so high that its "renal threshold" is exceeded, and it passes into the urine. Each g/dL of glucose increases urine density by 0.004 g/mL.
In addition to hyperstenuria, other urinary syndromes are observed in diabetes, such as glucosuria, ketonuria, proteinuria, and in the early stages of diabetic nephropathy, microalbuminuria. Normalization of blood glucose levels with the help of diet, insulin injections and the intake of hypoglycemic agents quickly leads to the disappearance of hyperstenuria.
The main hormone that regulates water balance in the human body is antidiuretic hormone (vasopressin). With its increased secretion, water reabsorption in the tubules of the kidneys increases, fluid retention and an increase in urine concentration occur.
For this reason, hyperstenuria is considered one of the characteristic signs of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH, or Parhon's syndrome) or non-compliance with the dosage of desmopressin in replacement therapy for diabetes insipidus. The degree of hyperstenuria correlates with the severity of plasma hypoosmolarity and hyponatremia. The normalization of the specific gravity occurs after the restriction of fluid intake, the intake of diuretics, and the elimination of the etiology of SIADH. The causes of Parkon's syndrome are as follows:
Aldosterone, a mineralocorticoid hormone produced in the adrenal cortex, is involved in the regulation of water-salt balance, namely, it stimulates the reabsorption of sodium ions in the distal tubules of the nephron. With insufficient production of aldosterone (which is observed in primary or secondary adrenal insufficiency), sodium begins to be intensively excreted in the urine, which increases its relative density. With the appointment of hormone replacement therapy, hyperstenuria regresses.
Atrial natriuretic peptide is synthesized in the wall of the right atrium and is a functional aldosterone antagonist - it increases the excretion of sodium in the urine (natriuresis). Its long-term hypersecretion is observed in chronic heart failure, when, due to the weakening of the contractility of the ventricles, the preload on the heart increases (i.e., the stretching of the atrial wall increases).
In some cases, incorrect results may be obtained when measuring relative density. Overestimation of indicators is observed when:
A single detection of hyperstenuria is possible in any person and should not cause serious concern. However, if repeated urine tests show an increase in its relative density, it is worth contacting a general practitioner or nephrologist to find out the cause. At the appointment, the doctor asks about other patient complaints that can help conduct a diagnostic search - constant thirst, increased urination, shortness of breath, general or muscle weakness.
Anamnestic data are important - it is necessary to clarify whether the patient is registered with other specialists (mainly an endocrinologist), what medications and in what dosage he takes, whether he underwent surgery, etc.
On examination, attention is drawn to the skin: signs of dehydration (dryness, reduced turgor) or vice versa, the presence of peripheral edema. Hyperpigmentation of the skin, especially in places of natural folds, is characteristic of adrenal insufficiency. Blood pressure is measured, auscultation of the heart is performed. For the differential diagnosis of the etiological factor, the following examination is prescribed:
Previously, to assess the dynamics of changes in relative density, various tests were carried out - for concentration, for dilution. However, due to the complexity of the technique, low information content, danger to the health and life of the patient, they are practically not carried out at present.
With short-term hyperstenuria caused by dehydration, it is enough to eliminate the fluid deficiency. If this deviation is caused by any disease, then its treatment is necessary. Since hyperstenuria itself does not pose any threat to the life and health of the patient, if it develops while taking the drug, its cancellation is not required (with the exception of drug-induced SIADH and an overdose of desmopressin).
Patients with diabetes mellitus are prescribed a diet with a restriction of easily digestible carbohydrates and animal fats. With Parkhon's syndrome, the volume of fluid consumed should be reduced to 100 ml per day and the content of table salt in the diet should be increased to 4-6 g per day. People with CHF, on the contrary, are strongly recommended to reduce the amount of table salt to 1-2 g per day. The following medications are also used:
In severe clinical situations, for example, with prolonged decompensation of diabetes, the presence of morbid obesity, it is not possible to achieve normalization of blood glucose levels by conservative methods. In such cases resort to bariatric surgical interventions: gastric bypass, gastric banding. With SIADH induced by a tumor (cancer of the lung, colon), it is removed.
In the vast majority of cases, hyperstenuria indicates insufficient fluid intake. However, prolonged persistent hyperstenuria may be a sign of an endocrine disorder or cardiac disease. The prognosis for timely diagnosis and treatment of the underlying pathology is most often favorable.