eGFR is considered a mostly reliable test for doctors to know how well your kidneys are working. However, the eGFR may not be accurate if you are younger than 18, pregnant, very overweight or very muscular.
"Near the border of 60 mL/min/1.73 m2 creatinine-based eGFR can be inaccurate. More than half of patients with eGFR less than 60 have an eGFR of 45 to 60, and in that group there are a lot of false positives, meaning the eGFR based on creatinine says they have CKD, but their kidney function may be normal.
This formula does not require any body measurements, thus can be easily calculated in the laboratory. However, there may be falsely high eGFRs for patients with very low body muscle mass, or falsely low eGFRs if you have a large muscle mass. When the eGFR approaches the near normal GFR range, it is less accurate.
In adults, the normal eGFR number is usually more than 90. eGFR declines with age, even in people without kidney disease.
The use of a single eGFR measurement to categorize CKD stage 3 can result in a “false positive” assignment to CKD stage 3 in as many as 30% of subjects (12).
eGFR is considered a mostly reliable test for doctors to know how well your kidneys are working. However, the eGFR may not be accurate if you are younger than 18, pregnant, very overweight or very muscular.
The estimated glomerular filtration rate (eGFR) is variable and it relies on a blood test, which may have day to day variations and it is an "estimation". Hence, the more times you do the test, the more accurate will be the estimate.
If the decrease in the estimated glomerular filtration rate (eGFR) is due to acute kidney injury with a sudden decrease in kidney function, this can commonly be reversed. If the kidney disease is due to chronic kidney disease (CKD), the recovery of eGFR is usually not possible.
gFR declines with age, even in people without kidney disease. If your GFR is between 60 and 89... People with mildly low gFR (between 60 and 89) may not have kidney disease if there is no sign of kidney damage, such as protein in their urine. these people should have their gFR checked more often.
GFR generally declines at a rate of 1 mL/min/year.
Barasch. “But because the course of creatinine cannot be known when first seeing a patient, it is possible to deliver the wrong diagnosis. An initial misdiagnosis can lead to mistreatment, with potentially dangerous consequences.” Failure to treat dehydration can quickly lead to irreversible kidney damage.
You're more tired, have less energy or are having trouble concentrating. A severe decrease in kidney function can lead to a buildup of toxins and impurities in the blood. This can cause people to feel tired, weak and can make it hard to concentrate.
It may. Eating well and regular exercise are good habits for overall health and kidney health and are a great way to take control of your health.
Dehydration does cause the serum creatinine to rise and the estimated glomerular filtration rate (eGFR) will, accordingly, fall. The degree of change is generally proportional to the degree of dehydration.
Volume of water intake positively correlated to estimated glomerular filtration rate (eGFR), and negatively correlated to urinary albumin to creatinine ratio (UACR), as well as plasma osmolality and urine osmolality, although the correlations were weak.
Acute kidney injury (AKI), formerly called acute kidney failure, is a sudden decline in glomerular filtration rate (GFR). This results in elevations in serum creatinine (SCr), blood urea nitrogen (BUN) and electrolyte levels (Okusa and Rosner, 2019).
A GFR of 60 or higher is in the normal range. A GFR below 60 may mean kidney disease. A GFR of 15 or lower may mean kidney failure.
Blood test: eGFR
eGFR (estimated glomerular filtration rate) is a measure of how well your kidneys are working. Your eGFR is an estimated number based on a blood test and your age, sex, body type and race. eGFR is considered a mostly reliable test for doctors to know how well your kidneys are working.
People over age 60 may have an apparently normal creatinine blood level but still have a low GFR. This opposite can also be true, where GFR may be mildly low but there is no real kidney disease.
Normal Results
Older people will have lower than normal GFR levels, because GFR decreases with age. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.
Estimated GFR
eGFR is more accurate than serum creatinine alone. Serum creatinine is affected by muscle mass, and related factors of age, sex, and race. eGFR is not reliable for patients with rapidly changing creatinine levels, extremes in muscle mass and body size, or altered diet patterns.
The standard way to estimate GFR has been to measure blood levels of creatinine. Creatinine is a waste product from the digestion of dietary protein and the normal breakdown of muscle tissue.
Inulin has historically been considered the best exogenous compound, since it fulfils all the requirements of an ideal GFR marker and is considered the first 'gold standard'. However, even for inulin, extrarenal clearance has been documented at least in patients with reduced GFR (<30 mL/min/1.73 m2) (61).