Lab

Urine Microalbumin

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Urine Microalbumin, Microalbuminuria, Macroalbuminuria, Urine Microalbumin to Creatinine Ratio, Urine Albumin to Creatinine Ratio

  • Indications
  1. Diabetes Mellitus
  2. Hypertension
    1. Questionable efficacy as prognostic factor in Hypertension (contrast with Diabetes Mellitus)
  • Protocol
  1. Nephropathy diagnosis needs 2 of 3 samples positive
  2. Typically performed as a Urine Albumin to Creatinine Ratio (random spot urine collection)
  3. Consider postural Proteinuria (especially in adolescents)
    1. Obtain overnight timed urine collection
  1. Normal (or mildly increased)
    1. 24h Collection: <30 mg/day
    2. Timed Collection: <20 mcg/min
    3. Urine Albumin to Creatinine Ratio (Spot Collection): <30 mcg/mg Creatinine
  2. Microalbuminuria (moderately increased)
    1. 24h Collection: 30-300 mg/day
    2. Timed Collection: 20-200 mcg/min
    3. Urine Albumin to Creatinine Ratio (Spot Collection): 30-300 mcg/mg Creatinine
  3. Macroalbuminuria (severely increased)
    1. 24h CollecSpot Collectiontion: >300 mg/day
    2. Timed Collection: >200 mcg/min
    3. Urine Albumin to Creatinine Ratio (Spot Collection): >300 mcg/mg Creatinine
  1. Higher Test Sensitivity than Urine Protein to Urine Creatinine Ratio
  2. Normal Ratio (in general <30 mg/g is normal)
    1. Men: < 0.017 (or 17 mg albumin to 1 gram Creatinine)
    2. Women: <0.025 (or 25 mg albumin to 1 gram Creatinine)
  3. Microalbuminuria (moderately increased): 30-300 mg albumin/g Creatinine
  4. Macroalbuminuria (severely increased): >300 mg albumin/g Creatinine
  5. False positive causes
    1. Menstrual Bleeding
    2. Urinary Tract Infection
    3. Exercise