Kidney Function: Albuminuria Test Fact Sheet
Albuminuria, also called microalbuminuria and proteinuria is a condition affecting around eight percent of adults and around one in six people aged 60 and older. Having albuminuria means that excess protein is present in the urine. A very high level of urine protein is known as macroalbuminuria.
An albumin test measures the amount of the protein albumin in the urine to discover if someone has too much or too little, and is a screening tool for early kidney disease. Albuminuria may also occur in people who have congestive heart failure, hypertension, a metabolic syndrome, or a nephrotic syndrome that has damaged their kidneys. The condition is linked to increased progression of chronic kidney disease and an elevated risk of kidney failure.
Detecting problems with the kidneys or heart early increases chances of survival and offers faster treatment options that can have a positive impact on quality of life.
Overview of the Test
When there is kidney damage, albumin and other proteins may spill out into the urine. A significant amount of albumin in the urine is linked to premature mortality. By testing the urine for the presence of albumin, particularly more than once to look for a persistent condition, it gives doctors an indication whether someone has kidney damage or another serious condition. The higher the albumin levels in the urine, the more serious the prognosis.
The test itself is for screening, not diagnosis, but it is useful for catching issues early while they are still treatable.
Evidence and Science behind the Test
The Framingham Health Study found that people who did not have metabolic or nephrotic syndromes, or other diseases linked to albuminuria, had an elevated risk for heart disease when their albumin tests showed high levels of the protein. There is also a link with diabetes, with one in three people with diabetes having albuminuria. One in seven people with hypertension are affected as well.
If an individual’s albumin test comes back positive in two consecutive tests spaced a few weeks apart, it is considered the first indication of kidney disease related to diabetes. Results need to show that someone excretes between 30 and 300 milligrams of albumin in 24 hours to be considered albuminuria. A score above 300 milligrams is called macroalbuminuria.
How is it done?
Random urine sample tests screen for kidney disease. The test for albumin is very simple. A nurse typically collects a urine sample. A dipstick designed to reveal the presence of albumin goes into the sample. This test may be followed by a closer analysis of the urine in order to determine levels of albumin.
Doctors may ask for more samples over the course of four, 12 or 24 hours. Each sample is tested for albumin. A urine test that measures the amount of albumin to createnine may be ordered as well as a blood test if kidney function impairment is suspected due to the presence of albumin.
Who does it?
Any doctor might ask for this test.
When and How Often
Yearly albumin tests are recommended for people with type 1 or type 2 diabetes who do not already have albuminuria.
People over the age of 60 should also have yearly albumin tests. Older adults are at a higher risk for chronic kidney disease. People with a family history, hypertension and systematic illnesses should also receive yearly tests because of their increased risk.
Certain populations have an elevated risk for albuminuria, and these people should be tested regularly. At-risk populations include Native Americans, Latinos, African Americans, Pacific Islanders, and people who are overweight.
Cost
Most insurance companies will cover the cost of this inexpensive test.
Issues
Certain factors can cause false positives for albuminuria, at least in terms of indicating a serious health condition. People who engage in vigorous exercise, smoke cigarettes, have a urinary tract infection, or are sick may have a positive test without kidney issues. Standing upright while collecting a urine sample can cause a positive albumin test.
References
Last reviewed 26/Feb/2014
