Yes, this represents good kidney function for a 62-year-old woman.
For a 62-year-old woman, an eGFR of 87 mL/min/1.73 m² places her in CKD Stage G2 (mildly decreased GFR, 60-89 mL/min/1.73 m²), which is considered normal age-appropriate kidney function without evidence of kidney disease. 1, 2
Understanding the Numbers
Your kidney function parameters show:
- Serum creatinine 77 µmol/L: This falls within the normal range for women (55-90 µmol/L) 1
- eGFR 87 mL/min/1.73 m²: Stage G2 - mildly decreased but age-appropriate 1, 3, 2
- Creatinine clearance 65 mL/min: This appears lower but requires context (see below)
Why This is Normal for Your Age
Kidney function naturally declines by approximately 1% per year after age 30-40, meaning by age 70, renal function may have declined by 40%. 1 At 62 years old, an eGFR of 87 mL/min/1.73 m² is entirely expected and represents well-preserved kidney function.
The internationally standardized CKD staging system classifies kidney function as follows 1, 3, 2:
- Stage G1 (≥90): Normal or increased GFR
- Stage G2 (60-89): Mildly decreased GFR - your category
- Stage G3a (45-59): Mild to moderate decrease
- Stage G3b (30-44): Moderate to severe decrease
- Stage G4 (15-29): Severe decrease
- Stage G5 (<15): Kidney failure
Critical Distinction: eGFR vs Creatinine Clearance
The discrepancy between your eGFR (87) and creatinine clearance (65) is important to address. The Cockcroft-Gault formula used to calculate creatinine clearance was developed in 1970s using only male veterans and tends to underestimate GFR in elderly patients, particularly women. 1 The formula assumes a 15% reduction for females but was never validated in women. 1
Your eGFR of 87 mL/min/1.73 m² is the more reliable measure because:
- Modern eGFR equations (MDRD, CKD-EPI) are specifically validated for diverse populations including elderly women 1, 2
- Serum creatinine alone is unreliable in elderly patients due to decreased muscle mass 1
- The Cockcroft-Gault formula consistently underestimates GFR in older patients, with the discrepancy most pronounced in the oldest patients 1
What Defines Kidney Disease vs Normal Aging
Having an eGFR in the G2 range (60-89) does NOT mean you have chronic kidney disease unless there is other evidence of kidney damage. 2, 4
You would only be classified as having CKD Stage G2 if you also had:
- Albuminuria (urinary albumin ≥30 mg/g creatinine) 2, 5
- Abnormal kidney imaging
- Pathological kidney changes
- Other markers of kidney damage
Without these additional findings, an eGFR of 87 at age 62 represents normal age-related physiological decline, not disease. 4
Clinical Implications
With an eGFR of 87 mL/min/1.73 m²:
- No medication dose adjustments are needed - most drugs don't require adjustment until eGFR falls below 60 2
- Annual monitoring is appropriate - check eGFR and urine albumin once yearly 3, 2
- No dietary restrictions are necessary 3
- No referral to nephrology is indicated 2
Important Caveats
Serum creatinine can underestimate kidney problems in elderly patients because muscle mass decreases with age. 1 A "normal" creatinine doesn't guarantee normal kidney function - which is why eGFR calculation is essential. In one study, 40% of individuals with decreased GFR had serum creatinine in the normal laboratory range. 1
If you have diabetes, hypertension, or cardiovascular disease, ensure urine albumin testing is performed annually even with normal eGFR, as albuminuria is an independent predictor of cardiovascular events and kidney disease progression. 2, 5
Research shows that in healthy adults, eGFR reference ranges naturally decline with age, with lower limits for women aged 60-65 ranging from approximately 58-75 mL/min/1.73 m² depending on the equation used. 6, 7 Your value of 87 exceeds these thresholds comfortably.