The glomerular filtration rate is a test to determine how well your kidneys are functioning. This test is especially important for people with diabetes because kidney disease is one of the most common complications that occurs with long-term diabetes.
What does the test measure?
The glomerular filtration rate estimates the amount of blood per minute that passes through the small filters in the kidneys. These filters are called glomeruli. The glomeruli are critical for filtering out many bodily waste products, including one produced by the muscles called creatinine, which is only eliminated from the body by the kidneys. When the glomeruli are not functioning properly, creatinine is not adequately eliminated from the body and builds up in the blood. Because creatinine is only removed from the body by the kidneys, this is an indication that the kidneys are not functioning as they should.
What do the GFR test results mean?
A GFR test result that is:
- 60-120 mL/minute is considered normal
- 15-59 mL/minute is considered abnormal and might indicate the presence of chronic kidney disease
- Below 15 mL/minute indicates kidney failure
If the GFR test comes back in the abnormal range, your doctor may test you again. If the test result is less than 60 mL/minute for three or more months, it usually indicates a decrease in kidney function.
American Kidney Fund. "Blood Test: eGFR."
National Library of Medicine. "Glomerular filtration rate."