Is an estimated Glomerular Filtration Rate (eGFR) of 85 normal in an elderly female?

Is an eGFR of 85 mL/min/1.73 m² Good in an Elderly Female?

Yes, an eGFR of 85 mL/min/1.73 m² represents excellent kidney function for an elderly female and is well within the normal range for her age. 1

Age-Specific Context for Kidney Function

An eGFR of 85 mL/min/1.73 m² would be considered excellent kidney function for a 65-year-old woman, as explicitly stated in kidney donor evaluation guidelines. 1 This value falls comfortably above all clinically significant thresholds for kidney disease:

• Normal GFR in young adults is approximately 120-130 mL/min/1.73 m² and declines with age, making age-adjusted interpretation essential. 1
• GFR naturally declines by approximately 0.8-1.75 mL/min/1.73 m²/year with aging, with steeper declines in men than women. 2
• The normal range defined by the National Kidney Foundation is ≥90 mL/min/1.73 m², but this represents young adult values and does not account for physiologic age-related decline. 1

Clinical Staging and Risk Assessment

This eGFR value places your patient in Stage 2 CKD (G2) at most, which is defined as GFR 60-89 mL/min/1.73 m² with evidence of kidney damage, or Stage 1 (normal kidney function) if no markers of kidney damage are present. 3

Key thresholds to understand:

• eGFR ≥60 mL/min/1.73 m²: Represents retention of more than half of normal adult kidney function. 1, 3
• eGFR 45-59 mL/min/1.73 m²: Stage 3a CKD, where complications begin to increase. 3
• eGFR <45 mL/min/1.73 m²: Associated with significantly higher mortality and cardiovascular risk in elderly populations. 2

Prognostic Implications

At an eGFR of 85 mL/min/1.73 m², this elderly female does not have increased mortality or cardiovascular risk compared to those with higher eGFR values. 2 Research demonstrates that:

• Only eGFR <45 mL/min/1.73 m² is associated with significantly higher all-cause and cardiovascular mortality in elderly populations after adjustment for confounders. 2
• Even mildly decreased eGFR (45-59 mL/min/1.73 m²) carries increased risk for kidney failure, cardiovascular disease, and death in older populations. 4
• An eGFR of 85 mL/min/1.73 m² is far above these risk thresholds and represents preserved kidney function. 1

Important Caveats

Do not rely solely on eGFR—check for markers of kidney damage:

• Albuminuria (urine albumin-to-creatinine ratio >30 mg/g) is the principal marker of kidney damage and increases risk even with preserved eGFR. 1
• Serum creatinine alone is unreliable in elderly patients, particularly those who are frail or malnourished, as muscle mass affects creatinine production. 5
• eGFR equations may underestimate true GFR in elderly patients with normal to moderately reduced function, though this would mean actual function is even better than estimated. 1

Monitor eGFR trajectory over time:

• An eGFR decline ≥3 mL/min/year in patients with baseline eGFR >60 mL/min/1.73 m² predicts increased mortality risk. 6
• Serial measurements are more informative than a single value for risk stratification in elderly patients. 6