What is the significance of an elevated albumin (Albumin)/creatinine (Creatinine) ratio of 98 and how should it be managed?

Significance and Management of Elevated Albumin/Creatinine Ratio of 98

An albumin/creatinine ratio (ACR) of 98 mg/g indicates moderately increased albuminuria (category A2) and requires prompt intervention with ACE inhibitors or ARBs, along with optimization of blood pressure and glucose control to reduce the risk of chronic kidney disease progression and cardiovascular events. 1

Understanding the Significance

• ACR of 98 mg/g falls within the moderately increased albuminuria range (30-299 mg/g), formerly called microalbuminuria, and is a marker of kidney damage 1

• This level of albuminuria is associated with increased risk for:

  • Progression of kidney disease 1
  • Cardiovascular disease and mortality 1
  • End-stage renal disease 1

• The term "microalbuminuria" is no longer recommended; instead, use "moderately increased albuminuria" or "category A2" (30-299 mg/g) 1

Confirmation of Results

• Due to high within-individual variability (coefficient of variation of 48.8%), a single elevated ACR reading should be confirmed 2
• Obtain 2-3 samples over a 3-6 month period; at least 2 of 3 tests should be abnormal to confirm the diagnosis 1
• Factors that can cause transient elevation in ACR:
  • Exercise within 24 hours 1
  • Infection or fever 1
  • Congestive heart failure 1
  • Marked hyperglycemia 1
  • Marked hypertension 1

Management Approach

First-line Interventions

• Initiate ACE inhibitor or ARB therapy - strongly recommended for patients with moderately increased albuminuria (30-299 mg/g) 1
• Optimize blood pressure control to target levels (typically <130/80 mmHg) 1
• Optimize glucose control to reduce risk of progression 1
• Dietary protein intake should be approximately 0.8 g/kg body weight per day (recommended daily allowance) 1

Monitoring

• Monitor serum creatinine and potassium levels after starting ACE inhibitors, ARBs, or diuretics 1
• Continue monitoring ACR to assess response to therapy and disease progression 1
• Assess estimated glomerular filtration rate (eGFR) to determine kidney function 1
• Frequency of monitoring should be at least annually, but may need to be more frequent based on severity and risk of progression 1

When to Refer to Nephrology

• If eGFR <60 mL/min/1.73 m² 1
• If difficulties occur in management of hypertension or hyperkalemia 1
• If there is rapid progression of kidney disease 1
• If there is uncertainty about the etiology of kidney disease 1

Risk Assessment and Prognosis

• At any level of GFR, increased ACR is associated with higher risk for adverse outcomes 1
• The risk increases as a continuum as ACR rises 1
• Even values in the high-normal range (>10 mg/g but <30 mg/g) may predict future CKD progression in patients with type 2 diabetes 3
• A 30% reduction in albuminuria is considered a surrogate marker for slowed progression of kidney disease 1

Common Pitfalls to Avoid

• Failing to confirm an elevated ACR with repeat testing 1, 2
• Not accounting for gender differences in creatinine excretion (women have approximately 55% lower creatinine excretion than men, which may affect interpretation) 4
• Neglecting to screen for and address other cardiovascular risk factors in patients with albuminuria 1
• Delaying initiation of ACE inhibitor or ARB therapy in confirmed cases 1
• Overlooking the need for regular monitoring of kidney function and albuminuria after starting treatment 1