What is the diagnosis and management for an adult patient with impaired renal function, eGFR 56, creatinine 1.4 mg/dL, and BUN 31 mg/dL, possibly with hypertension or diabetes?

Diagnosis: Stage 3a Chronic Kidney Disease (CKD)

Your patient has Stage 3a CKD with an eGFR of 56 mL/min/1.73m², which represents mild-to-moderate renal impairment requiring systematic evaluation and management. 1

Initial Assessment Required

Determine the underlying cause and assess for proteinuria immediately:

• Measure urinary albumin-to-creatinine ratio (UACR) in a spot urine sample to quantify albuminuria, as this is essential for risk stratification and treatment decisions 1
• Check for diabetes with fasting glucose or HbA1c, as diabetes is a leading cause of CKD 1
• Assess blood pressure to identify hypertension, which both causes and accelerates CKD progression 1, 2
• Review medication history including NSAIDs, supplements (especially creatine), and other nephrotoxic agents that can falsely elevate creatinine or worsen renal function 3, 4

The combination of reduced eGFR and proteinuria indicates substantially greater cardiovascular and renal risk than either abnormality alone, making UACR measurement critical 1, 2

Management Strategy

Blood Pressure Control

Target blood pressure <130/80 mmHg in all patients with CKD 2

If albuminuria is present (UACR ≥30 mg/g):

• Start an ACE inhibitor or ARB immediately as first-line therapy, as these agents reduce proteinuria, slow CKD progression, and decrease cardiovascular events independent of blood pressure lowering 1, 2, 5
• Expect and tolerate up to 30% increase in serum creatinine after initiating ACE inhibitor/ARB therapy—this reflects beneficial hemodynamic changes from reduced intraglomerular pressure, not kidney damage 2, 5
• Monitor serum creatinine and potassium within 7-14 days after starting therapy 1

If blood pressure remains elevated despite ACE inhibitor/ARB:

• Add a thiazide-like diuretic (chlorthalidone or indapamide preferred) or a dihydropyridine calcium channel blocker 1, 2
• Consider initial dual therapy if blood pressure is ≥150/90 mmHg 2

Diabetes Management (if present)

For patients with type 2 diabetes and eGFR 56 mL/min/1.73m²:

• Metformin can be continued safely at this eGFR level, but reassess benefits/risks if eGFR falls below 45 mL/min/1.73m² 1
• Do not initiate metformin if eGFR is <45 mL/min/1.73m² 1
• Add an SGLT2 inhibitor (empagliflozin, canagliflozin, or dapagliflozin) as these reduce CKD progression by 30-40% and cardiovascular death/heart failure hospitalization by 31%, independent of glucose control 1, 3
• SGLT2 inhibitors are recommended for eGFR ≥20 mL/min/1.73m² 1
• Consider a GLP-1 receptor agonist (liraglutide or semaglutide) for additional cardiovascular protection and CKD progression reduction 1

Cardiovascular Risk Reduction

Start statin therapy immediately if the patient has diabetes, hypertension, or other cardiovascular risk factors, targeting LDL <70 mg/dL (<1.8 mmol/L) 3

Lifestyle Modifications

• Restrict dietary sodium to <2 g/day to enhance antihypertensive medication effectiveness and reduce proteinuria by 30-50% 2, 3
• Weight loss if BMI >25 kg/m² 2
• Regular physical activity (at least 150 minutes/week of moderate-intensity exercise) 2
• Avoid NSAIDs absolutely as they accelerate kidney function decline 3
• Avoid potassium supplements and potassium-based salt substitutes if on ACE inhibitor/ARB 1, 5

Monitoring Protocol

• Recheck eGFR and electrolytes every 3-6 months to track progression 1, 3
• Repeat UACR annually (or more frequently if initially elevated) to assess treatment response 1
• Monitor blood pressure at each visit 2
• Two of three UACR specimens collected within 3-6 months should be abnormal before confirming persistent albuminuria due to high biological variability 1

Common Pitfalls to Avoid

• Do not discontinue ACE inhibitor/ARB for creatinine increases up to 30% after initiation—this is expected and beneficial 2, 5
• Do not use triple RAAS blockade (ACE inhibitor + ARB + mineralocorticoid receptor antagonist) due to excessive hyperkalemia risk 1
• Do not assume normal renal function based on creatinine alone—eGFR is essential for accurate assessment 1, 6
• Do not overlook medication-induced creatinine elevation from supplements like creatine 4

Specialist Referral Indications

Refer to nephrology if:

• Rapidly declining eGFR (>5 mL/min/1.73m² per year) 1
• Uncertain etiology of kidney disease 1, 3
• Active urinary sediment, nephrotic syndrome, or absence of retinopathy in type 1 diabetes 1
• eGFR approaches 30 mL/min/1.73m² (Stage 3b or worse) 3