Estimated GFR for a 74-Year-Old Hypertensive Male with Creatinine 89
The estimated glomerular filtration rate (eGFR) for a 74-year-old hypertensive male with creatinine of 89 μmol/L is approximately 70-75 mL/min/1.73 m², which places him in Stage 2 Chronic Kidney Disease (mild decrease in GFR).
Calculation of eGFR
The eGFR can be calculated using several formulas:
Cockcroft-Gault Formula 1:
- Formula: [(140 - age) × weight] / [72 × SCr] × (0.85 if female)
- For a 74-year-old male with creatinine of 89 μmol/L (1.01 mg/dL), assuming average weight
- This would yield approximately 70-75 mL/min (varies based on weight)
MDRD Equation 2:
- More accurate than serum creatinine alone
- Takes into account age, gender, race, and serum creatinine
- Would yield similar results for this patient
Interpretation of eGFR Results
According to the National Kidney Foundation classification system 1, 2:
| Stage | Description | GFR (mL/min/1.73 m²) |
|---|---|---|
| 1 | Kidney damage with normal or increased GFR | ≥90 |
| 2 | Mild decrease in GFR | 60-89 |
| 3a | Mild to moderate decrease in GFR | 45-59 |
| 3b | Moderate to severe decrease in GFR | 30-44 |
| 4 | Severe decrease in GFR | 15-29 |
| 5 | Kidney failure | <15 or dialysis |
With an eGFR of approximately 70-75 mL/min/1.73 m², this patient falls into Stage 2 CKD (mild decrease in GFR).
Important Considerations
Age-related decline: Some degree of GFR decline is physiologically normal with aging 3. For a 74-year-old, an eGFR of 70-75 mL/min/1.73 m² represents a relatively well-preserved kidney function.
Hypertension impact: Hypertension is a risk factor for progressive kidney damage 1. This patient should have careful blood pressure management to preserve kidney function.
Diagnosis limitations: Stage 2 CKD diagnosis requires evidence of kidney damage (such as albuminuria) in addition to the GFR value 2. The creatinine level alone is insufficient for complete CKD staging.
Monitoring recommendations: For a hypertensive patient with this eGFR:
- Regular monitoring of kidney function every 3-6 months
- Blood pressure target of <130/80 mmHg 2
- Screening for albuminuria to assess kidney damage
Clinical Implications
Medication adjustments: Most medications do not require dose adjustment at this level of kidney function 1, but careful monitoring is still warranted.
Cardiovascular risk: Even mild reductions in GFR increase cardiovascular risk, especially in the context of hypertension 1.
Progression risk: The combination of age and hypertension puts this patient at risk for progressive decline in kidney function, requiring regular monitoring.
Pitfalls to Avoid
Relying solely on serum creatinine: Serum creatinine alone is a poor indicator of kidney function, especially in elderly patients where muscle mass is reduced 1.
Ignoring age-related changes: Normal GFR values decrease with age, and values below 60 mL/min/1.73 m² may be physiologically normal in adults older than 70 years 3.
Missing albuminuria assessment: Complete kidney function assessment requires evaluation of both GFR and albuminuria 2.