What is the treatment for a patient with a high microalbumin (Microalbuminuria) urine level?

Management of Macroalbuminuria (1,410 mg/g)

Immediate Diagnostic Confirmation

This urine microalbumin level of 1,410 mg/g represents macroalbuminuria (>300 mg/g creatinine), not microalbuminuria, and requires immediate therapeutic intervention with ACE inhibitors or ARBs regardless of blood pressure status. 1

• Confirm the diagnosis by repeating the test, as 2 out of 3 abnormal specimens collected within 3-6 months should show elevation before confirming persistent albuminuria 1
• Rule out transient causes before confirming persistent macroalbuminuria: vigorous exercise within 24 hours, urinary tract infection, fever, congestive heart failure, marked hyperglycemia, marked hypertension, pyuria, or hematuria 1
• Measure serum creatinine and calculate estimated GFR to stage chronic kidney disease 1

Primary Treatment: Renin-Angiotensin System Blockade

Either ACE inhibitors or ARBs must be initiated immediately in all patients with micro- or macroalbuminuria, even if blood pressure is normal. 1

• If one class is not tolerated (e.g., cough with ACE inhibitors), substitute the other class 1
• In type 2 diabetic patients with nephropathy (serum creatinine 1.3-3.0 mg/dL and proteinuria ≥300 mg/g), losartan reduces the rate of progression of nephropathy, including doubling of serum creatinine (25% risk reduction) and end-stage renal disease (29% risk reduction) 2
• Monitor serum creatinine and potassium levels for development of increased creatinine and hyperkalemia when ACE inhibitors, ARBs, or diuretics are used 1

Blood Pressure Management

Target blood pressure should be <130/80 mmHg in patients with diabetes or chronic kidney disease. 1

• Aggressive antihypertensive management decreases the rate of fall of GFR and can reduce mortality from 94% to 45% and need for dialysis/transplantation from 73% to 31% at 16 years in type 1 diabetes 1
• Use drugs that interfere with the renin-angiotensin-aldosterone system as part of the antihypertensive regimen 1
• Additional antihypertensive agents (diuretics, calcium-channel blockers, alpha- or beta-blockers, centrally acting agents) may be added as needed to achieve blood pressure targets 2

Glycemic Control (If Diabetic)

Optimize glucose control with target HbA1c <7% to reduce risk or slow progression of nephropathy. 1

• Metformin may be used in patients with stable congestive heart failure if renal function is normal, but should be avoided in unstable or hospitalized patients with heart failure 1
• Avoid thiazolidinedione (TZD) treatment in patients with symptomatic heart failure 1

Dietary Protein Restriction

Reduce protein intake to 0.8-1.0 g/kg body weight/day in earlier stages of chronic kidney disease, and to 0.8 g/kg body weight/day in later stages. 1

• Protein restriction may improve measures of renal function including urine albumin excretion rate and GFR 1

Cardiovascular Risk Factor Management

All cardiovascular risk factors must be aggressively treated, as macroalbuminuria is a powerful predictor of cardiovascular events and mortality. 1

• Use aspirin and statin therapy (if not contraindicated) in patients with known cardiovascular disease to reduce risk of cardiovascular events 1
• Optimize lipid control with LDL cholesterol targets 1
• Implement smoking cessation interventions 1

Monitoring Strategy

Retest within 6 months to determine if treatment goals and reduction in albuminuria have been achieved. 1

• If significant reduction in albuminuria occurs, continue annual testing 1
• If no reduction occurs, evaluate whether blood pressure and lipid targets have been achieved and whether specific drugs that interfere with the renin-angiotensin-aldosterone system are part of therapy, then modify treatment accordingly 1
• Continue monitoring urine albumin excretion to assess both response to therapy and progression of disease 1
• When estimated GFR is <60 mL/min/1.73 m², evaluate and manage potential complications of chronic kidney disease 1

Nephrology Referral Criteria

Consider referral to a physician experienced in kidney disease for uncertainty about etiology, difficulty achieving treatment targets, or advanced chronic kidney disease. 1

• Refer when estimated GFR <30 mL/min/1.73 m² 1
• Refer when there is uncertainty about the etiology of kidney disease 1
• Refer when active urinary sediment develops or signs of other systemic disease appear 3

Critical Pitfall to Avoid

Do not delay initiation of ACE inhibitor or ARB therapy while waiting for repeat confirmatory testing—the level of 1,410 mg/g is far above the diagnostic threshold and represents established nephropathy requiring immediate treatment. 1, 2