Urine Albumin to Creatinine Ratio or ACR
Note: this site is for informational purposes only. To view test results or book a test, use the NHS app in England or contact your GP.
The urine albumin-to-creatinine ratio (ACR) test is a urine test in which a single urine sample is collected and analysed to compare the amount of albumin with creatinine. It is used to screen for and detect early kidney damage, particularly in people with diabetes or high blood pressure.
Why get tested?
To be screened for the early detection of kidney disease occurring as a complication of diabetes or hypertension (high blood pressure)
When to get tested?
Annually after a diagnosis of diabetes or hypertension
Sample required?
A urine sample. You will be asked to collect either an early morning or random sample of urine in which albumin and creatinine will be measured. The results are expressed as an albumin/creatinine ratio or ACR for short. The use of this ratio allows the albumin concentration to be related to the dilution of urine (as indicated by the creatinine concentration) which can depend on how much fluid you have consumed that day. ACR measurement in random urine samples has been shown to be just as good as the measurement of albumin alone in 24 hour urine samples and is much more convenient for the person being tested.
Test preparation needed?
None
Common questions
Diabetes is a very common cause of kidney failure. Studies have shown that identifying the very early stage of kidney disease in diabetes , by demonstrating an abnormal ACR, helps treatment to be appropriately adjusted. Good control of diabetes and other conditions, such as high blood pressure, can slow down or prevent the progression of kidney disease.
ACR should be requested when diabetes is first diagnosed. It is then usually measured annually or more frequently if significantly raised ACR values are found.
A moderately increased ACR indicates an early phase of developing kidney disease. Very high values show that kidney disease is present in a more severe form. Very low values generally indicate that kidney function is normal if other tests of kidney function, e.g. the glomerular filtration rate, also show no abnormality.
Recent studies have shown that in patients with Type II diabetes, an abnormal ACR result indicates an increased risk of developing heart and blood vessel disease.
Yes, an increased ACR is not confined to diabetes and hypertension (high blood pressure). It may also be seen with a fever, urinary tract infection, several immune disorders, dehydration, certain drugs and other conditions causing blood in the urine. Temporarily elevated results may also be caused by vigorous exercise.