Glomerulus

Orthostatic Proteinuria

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Orthostatic Proteinuria

  • Epidemiology
  1. Patients under age 30 years
  2. Affects 3 to 5% of adults and teenagers
  3. Most common cause of Pediatric Proteinuria (especially in adolescent males)
  • Pathophysiology
  1. Idiopathic
  2. Protein excretion increased only while upright
  3. Protein excretion normalizes when supine
  • Labs
  1. Split spot urine tests (with Urine Dipstick or Urine Protein to Creatinine Ratio)
    1. Normal Urine Protein on spot urine test of first morning void (after supine throughout the night)
    2. Increased Urine Protein after upright for at least 4-6 hours
      1. Urine Dipstick positive for Urine Protein OR
      2. Urine Protein to Creatinine Ratio >0.2
  2. Split 24 Hour Urine Protein collection
    1. Urine Protein decreases to <50 mg for 8 hours supine
  3. Urine Protein 24 Hour collection
    1. Less than 2000 mg protein excretion per day
  4. Other urine and renal tests normal
    1. Renal Function tests (normal Creatinine Clearance, GFR)
    2. Urine microscopy normal (no urine RBC or urine WBC)
  • Differential Diagnosis
  • Monitoring
  1. Blood Pressure yearly
  2. Urinalysis yearly
  • Prognosis
  1. Benign condition with no longterm Renal Function affect