Albumin/creatinine ratio in a single portion of urine

Albumin/Creatinine Ratio (ACR) - a screening method for patients with diabetes mellitus and arterial hypertension, which are risk factors for kidney disease.

Analysis have shown that early detection of kidney disease improves the prognosis of the disease and the effectiveness of treatment. The control of glycemia in patients with diabetes mellitus and blood pressure in hypertensive patients slows down and sometimes suspends the development of kidney diseases.

Albumin is a protein that is present in the blood in large quantities. During normal kidneys function, albumin is practically absent in the urine; therefore, the determination of urinary albumin excretion is important in the diagnosis, assessment of progression, and monitoring of kidneys disease treatment.

An increase in albumin in urine is a risk factor for the development of cardiovascular diseases and one of the early signs of kidney tissue damage. Urinary albumin excretion is subject to significant variation throughout the day, which is related to physical activity, diet, circadian rhythm and other factors, for this reason, if albumin is detected in the morning urine, the analysis should be repeated or confirmed by daily urine test.

To date, the "gold standard" for the diagnosis of proteinuria is test for the determination of protein in daily urine. However, the execution of this analysis is difficult due to the need to collect urine within 24 hours. To simplify the diagnosis of albuminuria, it has been proposed to measure the albumin concentration in a single urine sample and correct this value for creatinine, also measured in this urine sample. This is how the albumin-creatinine ratio (Albumin-to-Creatinineratio, ACR) was obtained.

This is necessary to more accurately determine the amount of albumin entering the urine. Urine concentration varies throughout the day and is related to the amount of fluid consumed per day, which leads to a change in the concentration of albumin in urine. Creatinine, on the other hand, a product of muscle metabolism, has a fairly constant rate of excretion.

ACR results have been shown to be in almost perfect agreement with the results of daily urine test. Given the high informative value and ease of performing the ACR test, the American Diabetes Association has recommended ACR as a screening test for albuminuria for early detection of kidney disease. Because the amount of albumin in the urine can vary considerably, an elevated ACR should be repeated twice within 3-6 months to confirm the diagnosis.