urine albumin to creatinine ratio
UACR; urine microalbumin
To be screened for a possible risk of developing a kidney or cardiovascular disorder
Annually after a diagnosis of diabetes or hypertension (high blood pressure)
A urine sample
Albumin is a protein that is present in large amounts in the blood. When kidneys are functioning properly, only tiny amounts of albumin leaks through into the urine. In kidney failure (the last stage of a slow process of decline in kidney function), large amounts of protein are spilled into the urine. A long time before this amount of damage happens, small changes in the kidney allow very small but abnormal amounts of albumin to leak through, usually as a result of having diabetes. This condition is called microalbuminuria and the test that measures this very small amount of albumin is called urine albumin/creatinine ratio (UACR).
You will be asked to collect an early morning sample of urine.
Diabetes is a very common cause of kidney failure. Studies have shown that identifying diabetics in the very early stages of kidney disease by demonstrating microalbuminuria helps patients and doctors adjust treatment. With better diabetic control and better control of other complications, such as high blood pressure, the progression of diabetic kidney disease can be slowed or prevented.
UACR should be requested when a person is first diagnosed with diabetes. After that, all are usually screened annually using the UACR test. When significant levels of albumin have been found, the test may be done more frequently.
Moderately increased UACR levels in urine indicate that a person is in one of the very early phases of developing kidney disease. Recently, studies have shown that an abnormal UACR result indicates an increased risk of developing heart and blood vessel (cardiovascular) complications, especially in people with diabetes. Low levels are an indication that kidney function is normal.
UACR should be performed on the first specimen of urine passed after getting up in the morning. If this is not possible a random urine specimen is acceptable.
The serum prealbumin test is only used infrequently and measures a protein that reflects your nutritional status. It is sometimes done before and after surgery, or if you are taking nutritional supplements. Albumin testing is used more frequently, often to test for liver or kidney disease. Albumin can also be used to monitor nutritional status. However, prealbumin changes more quickly, making it more useful for detecting changes in short-term nutritional status than albumin. The UACR test measures very small levels of albumin in your urine and may indicate whether you are at risk for developing kidney disease.
UACR tests for a small amount of albumin, not smaller molecules. If you are diabetic, each year your doctor will test a sample of your urine to see if your kidneys are leaking albumin, even in small amounts. It is good news if your kidneys are not leaking even small amounts of albumin. This means your kidneys are working well.
Yes, albuminuria is not specific for diabetes. It may also be associated with hypertension (high blood pressure), some lipid abnormalities and several immune disorders. Elevated results may also be caused by vigorous exercise, blood in the urine, urinary tract infection, dehydration and some drugs.
Albumin; creatinine; glucose; haemoglobin A1c
Conditions: Diabetes, kidney disease, proteinuria, liver disease, cardiovascular disease
RCPA Manual: Albumin - urine
Australasian proteinuria consensus working group
Diabetes UK: Long term complications-Kidney
Last Review Date: September 26, 2012