What is the significance of an albumin‑to‑creatinine ratio of 137 mg/g with a urine creatinine concentration of 287 mg/dL, and how should it be managed?

Albumin-to-Creatinine Ratio of 137 mg/g: Significance and Management

Your albumin-to-creatinine ratio (ACR) of 137 mg/g indicates moderately increased albuminuria (category A2), representing early kidney damage that requires immediate initiation of ACE inhibitor or ARB therapy regardless of your current blood pressure, along with confirmation testing and aggressive risk-factor modification. 1

Classification and Risk Stratification

• An ACR of 137 mg/g falls within the A2 category (moderately increased albuminuria), defined as 30–299 mg/g, which historically was called "microalbuminuria" but this term is no longer recommended. 1, 2
• This level independently increases your risk of cardiovascular disease, progression to end-stage kidney disease, and all-cause mortality, even before any measurable decline in kidney function occurs. 1
• The risk escalates continuously as ACR rises, including within the moderately increased range, meaning your value of 137 mg/g carries higher risk than an ACR of 50 mg/g. 1
• Your urine creatinine concentration of 287 mg/dL is within the acceptable range for ACR calculation and does not suggest dilute or overly concentrated urine that would invalidate the result. 1

Immediate Confirmation Steps Required

Before confirming chronic kidney disease, you must obtain 2 additional first-morning urine samples over the next 3–6 months; persistent albuminuria is defined as ACR ≥30 mg/g in at least 2 of 3 samples. 1, 3

• First-morning void specimens minimize variability from orthostatic proteinuria and hydration status. 3
• Exclude transient causes that can falsely elevate ACR before confirming chronic elevation: 1, 3
  • Active urinary tract infection or fever
  • Congestive heart failure exacerbation
  • Marked hyperglycemia (high blood glucose)
  • Menstruation
  • Uncontrolled hypertension
  • Vigorous exercise within 24 hours of collection
• Measure serum creatinine and calculate estimated glomerular filtration rate (eGFR) using the CKD-EPI equation to determine your baseline kidney function. 1, 3

Immediate Pharmacologic Management

Start an ACE inhibitor or ARB immediately once persistent albuminuria is confirmed, regardless of your baseline blood pressure, because these agents provide kidney-protective effects beyond simple blood pressure lowering. 1, 3

• Target blood pressure <130/80 mmHg in all patients with confirmed albuminuria. 1, 3
• ACE inhibitors and ARBs are the preferred first-line antihypertensive agents for patients with albuminuria. 1, 3
• Do not combine an ACE inhibitor with an ARB because the combination raises the risk of hyperkalemia and acute kidney injury without added renal benefit. 3
• Monitor serum creatinine and potassium 1–2 weeks after therapy initiation, then at regular intervals. 3
• ACE inhibitors and ARBs are contraindicated in pregnancy and in women of childbearing age not using reliable contraception due to teratogenic effects. 1, 3

Additional Therapeutic Measures

• If you have diabetes, target HbA1c <7% to reduce the risk and slow progression of diabetic kidney disease. 3
• Consider adding an SGLT2 inhibitor (such as empagliflozin) or a GLP-1 receptor agonist if you have type 2 diabetes, as these drug classes reduce chronic kidney disease progression and cardiovascular events. 3, 4
• Lipid management goals: LDL-cholesterol <100 mg/dL if diabetic, <120 mg/dL otherwise; limit saturated fat to <7% of total calories. 1
• Restrict dietary protein to 0.8 g/kg/day (the recommended daily allowance). 1, 3
• Smoking cessation is crucial if you smoke, as smoking accelerates kidney damage approximately four-fold. 3

Monitoring Schedule Based on eGFR

Re-measure ACR at 6 months after therapy initiation to determine whether albuminuria has improved; if significant reduction occurs, transition to annual ACR testing. 1, 3

Baseline eGFR (mL/min/1.73 m²)	Monitoring Frequency for ACR & eGFR
≥60	Annually [1]
45–59	Every 6 months [1]
30–44	Every 3–4 months [1]
<30	Immediate nephrology referral [1]

• The therapeutic goal is to reduce ACR by at least 30–50%, ideally achieving an ACR <30 mg/g. 1
• Sustained reduction in albuminuria is a validated surrogate for slowed progression of chronic kidney disease. 1

Indications for Nephrology Referral

Refer to a nephrologist when any of the following occur: 1, 3

• eGFR <30 mL/min/1.73 m²
• Rapid decline in kidney function or progression to ACR ≥300 mg/g despite optimal therapy
• Rapidly increasing albuminuria
• Active urinary sediment (red blood cells, white blood cells, casts)
• Uncertainty regarding the underlying etiology of kidney disease
• Inadequate response to optimal ACE-inhibitor/ARB therapy
• Refractory hypertension requiring ≥4 antihypertensive agents

Critical Pitfalls to Avoid

• Do not wait for hypertension to develop before initiating ACE inhibitor or ARB therapy; these agents are indicated for moderately increased albuminuria even with normal blood pressure. 1, 3
• Do not rely on a single ACR measurement; day-to-day biological variability can exceed 40–50%, necessitating confirmation with multiple samples. 1, 5
• Do not ignore the continuous nature of risk; even within the "normal" range (<30 mg/g), higher values carry increased cardiovascular and renal risk, so aggressive risk-factor modification is warranted even if subsequent testing shows improvement. 1, 6
• Do not measure albumin concentration alone without creatinine correction, as hydration status can produce false results. 1, 2