Estimated GFR

Estimated GFR, also called eGFR, is a kidney biomarker. It is expressed in mL/min/1.73m², a standardized unit for reporting the measurement.

Estimated GFR requires a serum sample. Fasting is not required, so the test does not require fasting preparation before collection.

When arranging testing, check that the requested measurement is Estimated GFR and that a serum sample will be collected. Results may be reviewed alongside related markers, including Creatine, Cystatin C, and Bun, because these markers can appear together in assessment of the same clinical picture. Interpretation should use the reference information supplied with the result and take account of the person’s overall health context. Anyone being tested for a medical condition can discuss the appropriate testing approach and result interpretation with a clinician.

Estimated GFR is a serum measurement, and fasting is not required for the sample. In this reference, higher readings are considered better. The reference range and the optimal range are the same, so there is no separate tighter optimal target to interpret.

A result is meaningful only when read with the range and units printed on the laboratory report. Laboratories may use different ranges or units, so results from different reports should not be compared without considering those details. A single value is not a diagnosis and should be interpreted alongside the clinical context. Results outside the reported range belong with a clinician, particularly when there is a medical condition or concern about kidney function.

Estimated GFR is a marker for which higher values are considered better. In studies that measured estimated GFR directly, Sodium Bicarbonate, Vitamin E, Coenzyme Q10, and Drink Enough Water were associated with increases. Milk Thistle (Silymarin), Potassium, L-Leucine, Taurine, BCAA, and Vitamin B3 (Niacin) were associated with no change. Cordyceps and Creatine were associated with decreases, which is an unfavorable direction for this marker.

These findings do not point in one consistent direction across all interventions. Some interventions had mixed results between studies, while others were represented by a single study, so an observed movement should not be treated as a predictable effect for every person or situation. The studies assessed estimated GFR over periods ranging from 12 to 107.3 weeks, meaning that changes were evaluated over both shorter and longer follow-up windows.

All of these interventions belong to the group in which estimated GFR itself was measured. This is different from evidence based only on a related outcome: no interventions in the information presented here are included in that indirect category. Interpretation can depend on the underlying medical condition and the way kidney function is being monitored; consultation with a clinician is appropriate when estimated GFR is relevant to a medical condition.