A low estimated glomerular filtration rate suggests the presence of kidney disease, according to the American Kidney Fund. A person's eGFR is based on the results of a creatinine blood test.
Laboratories distinguish the eGFR results of African-Americans from non-African-Americans because African-Americans tend to have higher concentrations of creatinine in their blood, according to researchers from the University of California and Stanford University School of Medicine. These elevated creatinine levels are attributed to differences in body mass.
Laboratories often report eGFR results for both African-American and non-African-American patients, states the National Kidney Disease Education Program. This makes it easier to report accurate results when the race of a patient is unknown. Using the MDRD Study equation for calculating eGFR, a 63-year-old woman with a creatinine level of 1.82 milligrams per deciliter has an eGFR of 36 milliliters per minute if she is African-American and an eGFR of 20 milliliters per minute if she is non-African-American.
A normal eGFR level is anything above 60 milliliters per minute, states the National Kidney Fund. A patient with a persistently low eGFR may need additional blood and urine tests to assess kidney function. Although eGFR is a useful tool, it is not always accurate. This test is less accurate in pregnant women, children, muscular people and very overweight people.