What is the recommended management for an adult with persistent microalbuminuria (urine albumin‑to‑creatinine ratio 30–300 mg/g) who has diabetes mellitus and hypertension?

Management of Microalbuminuria in Adults with Diabetes and Hypertension

For an adult with persistent microalbuminuria (30-300 mg/g), diabetes, and hypertension, initiate an ACE inhibitor or ARB regardless of blood pressure level, target BP <130/80 mmHg, optimize glucose control (HbA1c <7%), and recheck albumin-to-creatinine ratio within 6 months to assess treatment response. 1

Confirmation of Persistent Microalbuminuria

Before initiating treatment, confirm persistence by demonstrating elevated albumin-to-creatinine ratio (>30 mg/g) in 2 out of 3 urine samples collected over 3-6 months 1, 2:

• Use first morning spot urine samples to minimize variability from orthostatic proteinuria and hydration status 1, 2
• Patients should refrain from vigorous exercise for 24 hours before collection 1
• Measure both albumin and creatinine simultaneously as a ratio (not albumin alone) 1
• Calculate estimated glomerular filtration rate (eGFR) from serum creatinine to assess overall kidney function 1

Pharmacologic Management

ACE Inhibitor or ARB Therapy

Initiate an ACE inhibitor or ARB even if blood pressure is normal 1:

• This recommendation applies specifically to nonpregnant patients with confirmed persistent microalbuminuria (30-299 mg/g) 1
• ACE inhibitors and ARBs have proven benefits for reducing progression to macroalbuminuria (>300 mg/g) and cardiovascular events 1
• Do not combine ACE inhibitors with ARBs - this combination increases adverse events (hyperkalemia, acute kidney injury) without additional benefit 1
• Monitor serum creatinine and potassium within 1-2 weeks of starting therapy, then periodically 1, 2
• Do not discontinue therapy for mild-to-moderate creatinine increases (≤30%) in the absence of volume depletion 2

Blood Pressure Targets

Target blood pressure <130/80 mmHg for all patients with confirmed persistent albuminuria 1, 2:

• This lower target is appropriate given the increased cardiovascular and chronic kidney disease progression risk associated with albuminuria 1
• ACE inhibitors or ARBs are the preferred first-line agents for blood pressure control in this population 1

Glycemic Control

Optimize glucose control to HbA1c <7% to reduce risk and slow progression of diabetic kidney disease 1:

• Intensive glucose control is particularly important before the development of microalbuminuria 3
• Consider adding an SGLT2 inhibitor or GLP-1 receptor agonist, as these agents have demonstrated reduction in chronic kidney disease progression and cardiovascular events in patients with type 2 diabetes 1

Dietary Modifications

• Limit dietary protein intake to approximately 0.8 g/kg body weight per day (the recommended daily allowance) 1
• Implement a low-salt diet to support blood pressure control 4
• Counsel on smoking cessation - smoking accelerates kidney damage 1, 2

Monitoring Schedule

Initial Response Assessment

Recheck albumin-to-creatinine ratio within 6 months after starting treatment to determine if treatment goals and reduction in microalbuminuria have been achieved 1, 2:

• If significant reduction in microalbuminuria occurs, proceed to annual testing 1
• If no reduction occurs, evaluate whether: (1) blood pressure targets have been achieved, (2) ACE inhibitor or ARB is part of the regimen, and (3) treatment regimen needs modification 1

Long-term Monitoring

• Annual albumin-to-creatinine ratio if treatment is successful 1, 2
• Annual eGFR if ≥60 mL/min/1.73 m² 2
• Every 6 months eGFR if <60 mL/min/1.73 m² 2
• Annual screening for diabetic retinopathy, as retinopathy often accompanies diabetic kidney disease 1

Referral to Nephrology

Refer to a nephrologist experienced in kidney disease for 1, 2:

• eGFR <30 mL/min/1.73 m² (prompt referral for evaluation for renal replacement therapy) 1
• Rapidly increasing albuminuria despite treatment 2, 5
• Rapidly progressing kidney disease (rapid decline in eGFR) 1, 5
• Uncertainty about etiology of kidney disease 1, 2, 5
• Presence of hematuria or cellular casts suggesting glomerulonephritis 5
• Nephrotic-range proteinuria or nephrotic syndrome 2, 5
• Difficult management issues including resistant hypertension, anemia, or electrolyte disturbances 1

Common Pitfalls to Avoid

• Do not wait for blood pressure elevation before starting ACE inhibitor or ARB therapy - these agents are indicated for microalbuminuria even with normal blood pressure 1
• Do not use ACE inhibitors or ARBs for primary prevention in patients with diabetes who have normal blood pressure, normal albumin excretion (<30 mg/g), and normal eGFR - they are not superior to other antihypertensives in this setting 1
• Avoid orthostatic proteinuria confusion - if microalbuminuria is documented, obtain a first morning void immediately upon arising to exclude benign orthostatic proteinuria, which does not require medication treatment 1
• Do not ignore cardiovascular risk - microalbuminuria is a marker of endothelial dysfunction and significantly increased cardiovascular mortality risk, requiring aggressive management of all cardiovascular risk factors including lipids 4, 6