Microalbumin in urine (single serving)
Why this test?
- For early diagnosis of diabetic nephropathy.
- For the diagnosis of nephropathy in systemic diseases (secondary nephropathy), which occurs in long-term hypertension, congestive heart failure.
- To monitor kidney function in the treatment of various types of secondary nephropathy (primarily DN).
- For the diagnosis of nephropathy during pregnancy.
- To identify the early stages of nephropathy, which arose due to glomerulonephritis, inflammatory and cystic diseases of the kidneys (primary nephropathy).
- To detect renal dysfunction in autoimmune diseases, such as systemic lupus erythematosus, amyloidosis.
In what cases is it prescribed?
- For newly diagnosed type II diabetes (and then every 6 months).
- With type I diabetes lasting more than 5 years (once every 6 months - mandatory).
- With diabetes in children at an early age, with a labile course of diabetes (frequent decompensations: ketosis, diabetic ketoacidosis, hypoglycemia), 1 year after the onset of the disease.
- With long-term, especially uncompensated arterial hypertension, congestive heart failure accompanied by specific swellings.
- During pregnancy with symptoms of nephropathy (if the general analysis of urine showed the absence of proteinuria).
- In the differential diagnosis of early stages of glomerulonephritis.
- In case of systemic lupus erythematosus, amyloidosis for early diagnosis of specific kidney damage accompanying these diseases.
Albumins are water-soluble proteins. They are synthesized in the liver and make up the majority of serum proteins. In the body of a healthy person, normally, only a small amount of albumin, which has the smallest size, is excreted in the urine - microalbumin, since the glomeruli of an unaffected kidney are impermeable to larger albumin molecules. At the initial stages of damage to the cell membranes of the kidney glomerulus, more and more microalbumin is excreted in the urine, as the damage progresses, larger albumins also begin to be released. This process is divided into stages by the amount of excreted proteins (from 30 to 300 mg / day, or from 20 to 200 mg / ml in the morning portion of urine, it is considered microalbuminuria (MAU), and more than 300 mg / day - proteinuria). UIA always precedes proteinuria. However, as a rule, when proteinuria is detected in a patient, the changes in the kidneys are already irreversible, and treatment can only be aimed at stabilizing the process. At the stage of UIA, changes in the renal glomeruli can still be stopped with the help of correctly selected therapy. Thus, microalbuminuria is defined as the excretion of albumin in the urine in such an amount that it exceeds the physiological level of its excretion, but precedes proteinuria.
In the development of nephropathy (both diabetic and caused by hypertension, glomerulonephritis), two periods are distinguished. The first is preclinical, during which it is practically impossible to detect any changes in the kidneys using traditional clinical and laboratory research methods. The second - clinically expressed nephropathy - advanced nephropathy with proteinuria and chronic renal failure. During this period, kidney dysfunction can already be diagnosed. It turns out that the initial stage of nephropathy can only be detected by determining microalbumin in urine. In some kidney diseases, UAS very quickly turns into proteinuria, but this does not apply to dysmetabolic nephropathies (DN). UIA can precede the manifestation of DN for several years.
Since DN and, as a result, chronic renal failure (CKD) are the most common kidney diseases today, the determination of UAS in patients with diabetes mellitus (DM) type I and II is most significant.
Early detection of DN is extremely important, as the possibility of slowing down the development of DN and kidney failure has been proven. The only laboratory criterion that allows detecting the preclinical stage of DN with a high degree of reliability is UIA.
It is advisable to prescribe urine microalbumin analysis at the initial signs of nephropathy in pregnant women, but in the absence of proteinuria (for differential diagnosis).