What is the treatment for microalbuminuria?

Treatment of Microalbuminuria

The first-line treatment for microalbuminuria is an ACE inhibitor or ARB, which should be initiated as soon as microalbuminuria is confirmed by at least 2 of 3 positive tests over a 3-6 month period. 1, 2

Diagnosis and Confirmation

• Microalbuminuria is defined as urinary albumin excretion of 30-300 mg/g creatinine 2
• Confirmation requires 2 of 3 measurements greater than the reference range (>30 mg albumin/g creatinine) over a 3-6 month period 2, 1
• The preferred screening method is measurement of albumin-to-creatinine ratio in a random spot urine collection 2, 3
• Patients should refrain from vigorous exercise for 24 hours before sample collection 2

Pharmacological Treatment

First-Line Therapy

• ACE inhibitors or ARBs should be initiated and titrated to maximum tolerated dose 2, 1
• These medications should be used even in normotensive patients with microalbuminuria 1, 4
• If one class is not tolerated, the other should be substituted 2
• Monitor serum creatinine and potassium when using these medications 2
• Losartan (an ARB) has been shown to significantly reduce proteinuria by an average of 34% within 3 months of starting therapy 5

Blood Pressure Control

• Target blood pressure should be <130/80 mmHg 1, 3
• If blood pressure goals are not achieved with ACE inhibitors or ARBs alone, additional antihypertensive agents may be added 2, 1
• Avoid dual RAS blockade (combining ACE inhibitor and ARB) as it increases hyperkalemia risk without additional benefit 1

Glycemic Control

• Optimize glucose control with target HbA1c <7.0% 2, 1
• Intensive glycemic control has been shown to delay the onset of microalbuminuria and slow progression to macroalbuminuria 2
• Adjust medication choices based on kidney function as it declines 1

Dietary and Lifestyle Modifications

• Reduce protein intake to 0.8-1.0 g/kg body weight/day 2, 1
• Further protein restriction to 0.6 g/kg/day should be considered when GFR begins to decline 1
• Sodium restriction to less than 2,300 mg/day is recommended 1
• Regular exercise and weight normalization if overweight/obese 1
• Smoking cessation is essential 1, 4

Monitoring and Follow-up

• After initiating treatment, retest for microalbuminuria within 6 months to determine if treatment goals and reduction in microalbuminuria have been achieved 2
• If treatment has resulted in significant reduction of microalbuminuria, continue annual testing 2
• If no reduction occurs, evaluate if:
  1. Blood pressure targets have been achieved
  2. RAS inhibitors are part of the therapy
  3. Treatment regimen needs modification 2
• Monitor serum creatinine and potassium regularly, especially with declining kidney function 2, 1

Cardiovascular Risk Management

• Microalbuminuria is not only a risk for kidney disease progression but also a marker of increased cardiovascular risk 3, 6
• Address all modifiable cardiovascular risk factors:
  • Initiate statin therapy 1
  • Optimize lipid control with target LDL <100 mg/dL for diabetic patients 3
  • Consider aspirin therapy in patients with known cardiovascular disease 2

Special Considerations

• Temporarily discontinue ACE inhibitors/ARBs during periods of volume depletion 1
• Consider nephrology referral when eGFR <60 ml/min/1.73 m² or if difficulties occur in managing hypertension or hyperkalemia 1
• In children with diabetes, ACE inhibitors should be considered for initial treatment of hypertension and microalbuminuria 2

Common Pitfalls to Avoid

• Failing to confirm microalbuminuria with repeat testing before initiating treatment
• Not monitoring potassium and creatinine when using ACE inhibitors or ARBs
• Inadequate blood pressure control despite medication
• Overlooking the cardiovascular risk associated with microalbuminuria
• Using NSAIDs, which may reduce the effectiveness of ACE inhibitors/ARBs and worsen renal function 1