What is the management of albuminuria (presence of albumin in the urine) in diabetes?

Management of Albuminuria in Diabetes

For diabetic patients with albuminuria, initiate or optimize ACE inhibitor or ARB therapy (but never both together), add an SGLT2 inhibitor for cardiovascular and renal protection, target blood pressure <130/80 mmHg, and optimize glycemic control to HbA1c <7%. 1, 2

Screening and Diagnosis

• Screen annually with spot urine albumin-to-creatinine ratio (ACR) starting at diagnosis in type 2 diabetes and after 5 years duration in type 1 diabetes 1
• Confirm persistent albuminuria by demonstrating elevation in 2 out of 3 specimens collected over 3-6 months, as urinary albumin excretion varies significantly 1, 3
• Avoid testing during acute illness, marked hyperglycemia, uncontrolled hypertension, heart failure, or within 24 hours of exercise, as these transiently elevate albumin excretion 1

Albuminuria categories:

• Normal: <30 mg/g creatinine
• Moderately increased (formerly "microalbuminuria"): 30-299 mg/g creatinine
• Severely increased (formerly "macroalbuminuria"): ≥300 mg/g creatinine 1

Pharmacologic Management

First-Line: RAAS Blockade

ACE inhibitors or ARBs are mandatory for all diabetic patients with albuminuria ≥30 mg/g, regardless of blood pressure. 1

• In type 1 diabetes with any degree of albuminuria: ACE inhibitors delay nephropathy progression 1
• In type 2 diabetes with moderately increased albuminuria (30-299 mg/g): both ACE inhibitors and ARBs delay progression to higher levels 1
• In type 2 diabetes with severely increased albuminuria (≥300 mg/g) and renal insufficiency: ARBs specifically reduce progression to end-stage renal disease by 28.6% 4
• Titrate to maximum approved doses (e.g., lisinopril 40mg daily, losartan 100mg daily) for optimal renoprotection, which may require higher doses than needed for blood pressure control alone 5

Critical monitoring after initiating RAAS blockade:

• Check serum creatinine and potassium within 1-2 weeks of starting therapy 1, 5
• Do not discontinue for creatinine increases ≤30% in absence of volume depletion 3
• Monitor for hyperkalemia, especially with eGFR <60 mL/min/1.73 m² 5
• Never combine ACE inhibitors with ARBs - dual blockade increases adverse events including hyperkalemia and acute kidney injury without additional benefit 5, 2

Add SGLT2 Inhibitors

Initiate an SGLT2 inhibitor (empagliflozin, canagliflozin, or dapagliflozin) in addition to RAAS blockade to reduce cardiovascular events by 30-40% and slow kidney disease progression. 2

• This recommendation represents the most significant advance in diabetic kidney disease management beyond traditional RAAS blockade 2
• Monitor serum creatinine/eGFR and potassium at baseline, 7-14 days after initiation, then at least annually 2

Blood Pressure Management

Target blood pressure <130/80 mmHg in all diabetic patients with albuminuria. 1, 2

• Blood pressure control is equally important as glycemic control for preventing nephropathy progression 1
• Systolic blood pressure control may be more critical than diastolic for preventing kidney disease progression 5
• Use additional antihypertensive agents as needed beyond RAAS blockade to achieve target 1

Glycemic Control

Target HbA1c <7% (53 mmol/mol) to prevent or delay microvascular complications including diabetic kidney disease. 2

• Intensive diabetes management delays onset of moderately increased albuminuria and progression to higher levels in both type 1 and type 2 diabetes 1
• Do not target HbA1c <7% as this increases severe hypoglycemia risk without additional cardiovascular benefit 2

Lifestyle Modifications

• Sodium restriction to <2,300 mg/day using DASH-style eating pattern 2
• At least 150 minutes weekly of moderate-intensity aerobic activity 2
• Smoking cessation is crucial as smoking accelerates kidney damage 3
• Weight loss if BMI >30 kg/m² 6

Monitoring Protocol

Once albuminuria is confirmed and treatment initiated:

• Recheck ACR every 3-6 months initially to assess treatment response 2, 3
• If treatment successful and albuminuria stable, monitor ACR annually 5
• Monitor eGFR at least annually, or every 3-6 months if eGFR <60 mL/min/1.73 m² 1, 2
• The degree of albuminuria reduction predicts long-term renal and cardiovascular protection - greater reduction equals greater protection 7

Nephrology Referral

Refer to nephrology when: 1

• eGFR falls below 60 mL/min/1.73 m² 1
• Difficulties managing hypertension or hyperkalemia 1
• Uncertainty about kidney disease etiology 1
• Rapidly increasing albuminuria or rapid eGFR decline 3
• Presence of hematuria, pyuria, or nephrotic syndrome 3

Early referral reduces costs, improves quality of care, and delays dialysis initiation 1

Common Pitfalls to Avoid

• Never diagnose persistent albuminuria from a single elevated specimen - transient elevations occur with exercise, fever, infection, or poor glycemic control 1
• Never use ACE inhibitor + ARB combination therapy - this increases harm without benefit 5, 2
• Do not withhold RAAS blockade in normotensive patients with albuminuria - renoprotection occurs independent of blood pressure effects 1
• Do not stop monitoring albuminuria after starting treatment - continued surveillance assesses response and progression 1