My estimated glomerular filtration rate (eGFR) decreased from 91 to 81 mL/min/1.73 m² over one year; what does this decline mean and how should I manage it?

eGFR Decline from 91 to 81 mL/min/1.73 m²: Assessment and Management

This 10-point decline over one year does not meet criteria for CKD progression and falls within normal measurement variability, requiring only routine annual monitoring without immediate intervention. 1

Understanding Your eGFR Change

Your eGFR decline represents approximately 10 mL/min/1.73 m² per year, which exceeds the threshold for "rapid progression" (>5 mL/min/1.73 m²/year) defined by KDIGO guidelines. 1 However, this must be interpreted carefully:

• Small fluctuations in eGFR are common and not necessarily indicative of true kidney disease progression. 1
• True CKD progression requires either: (1) a drop in GFR category (e.g., from G1 to G2) plus ≥25% decline from baseline, or (2) a sustained decline of >5 mL/min/1.73 m²/year confirmed over multiple measurements. 1
• Your decline from 91 to 81 keeps you in the same GFR category (G2: 60-89 mL/min/1.73 m²) and represents only an 11% decline—well below the 25% threshold. 1
• Confidence in assessing progression increases with more serum creatinine measurements and longer follow-up duration. 1

What This Means Clinically

Both values (91 and 81 mL/min/1.73 m²) place you in CKD Stage G2, which represents mildly decreased kidney function. 2 At this stage:

• You do not have clinically significant chronic kidney disease requiring specialist referral. 1
• The decline rate, while notable, requires confirmation with additional measurements before concluding true rapid progression. 1
• Even declines <25% have been associated with increased risk of mortality and end-stage renal disease in large cohort studies, though the absolute risk remains low at your current eGFR level. 1

Recommended Monitoring Strategy

Repeat eGFR measurement in 3-6 months to confirm whether this represents true progression or measurement variability. 1, 2

• Annual monitoring is appropriate if subsequent values stabilize and you have no diabetes, hypertension, or significant proteinuria. 1, 2
• Increase to twice-yearly monitoring if you have diabetes, urine albumin-to-creatinine ratio (UACR) ≥300 mg/g, or if eGFR continues declining toward <60 mL/min/1.73 m². 1, 2
• Measure urine albumin if not already done—albuminuria is a critical marker for kidney disease risk and progression. 1

Immediate Actions to Take

Review your current medications and clinical status for potentially reversible causes of eGFR decline: 1, 2

• Volume depletion (dehydration, diuretic overuse)
• Nephrotoxic medications (NSAIDs, certain antibiotics, proton pump inhibitors if used chronically)
• Uncontrolled hypertension (target systolic BP <130 mmHg, diastolic <80 mmHg) 1
• Uncontrolled hyperglycemia if diabetic
• Acute kidney injury superimposed on baseline function 1

Optimize nephroprotective strategies: 1, 2

• If hypertensive or diabetic, ensure you are on an ACE inhibitor or ARB (these may cause a transient 10-15% eGFR decline initially, which is hemodynamic and expected). 1
• If diabetic with eGFR >30 mL/min/1.73 m², consider SGLT2 inhibitors (e.g., empagliflozin, dapagliflozin) or GLP-1 receptor agonists—these have proven kidney and cardiovascular benefits. 1
• Maintain blood pressure control, limit sodium intake to <2 g/day if hypertensive. 1
• Avoid NSAIDs and minimize exposure to contrast dye when possible. 2

When to Refer to Nephrology

Nephrology referral is NOT indicated at your current eGFR of 81 mL/min/1.73 m². 1, 2 Consider referral if:

• eGFR declines to <45 mL/min/1.73 m² (Stage G3b or worse) 1, 2
• Sustained decline of >5 mL/min/1.73 m²/year confirmed over multiple measurements 1
• UACR ≥300 mg/g (significant albuminuria) 1, 2
• Drop to a new CKD category with ≥25% decline from baseline 1

Common Pitfalls to Avoid

• Do not assume a single measurement change represents true progression—biological and laboratory variability can account for fluctuations of 10-15%. 1
• Do not stop ACE inhibitors/ARBs if eGFR drops 10-25% after initiation—this is an expected hemodynamic effect and indicates the drug is working. 1
• Do not rely on serum creatinine alone—always calculate eGFR, especially in elderly patients or those with low muscle mass where creatinine may be misleadingly low. 1
• Do not delay measuring albuminuria—it is essential for risk stratification and may change management even at your current eGFR. 1

Prognosis Context

Studies in CKD populations show mean annual eGFR decline rates of 1.03-4.5 mL/min/1.73 m²/year depending on baseline kidney function and comorbidities. 1 Your observed decline of 10 mL/min/1.73 m²/year, if sustained, would be considered rapid. However, a single year of data is insufficient to establish a true slope—you need at least 2-3 years of measurements to reliably assess progression. 1, 3