Orthostatic (postural) proteinuria
- Michael J Somers, MD
Michael J Somers, MD
- Associate Professor of Pediatrics
- Harvard Medical School
Orthostatic (also referred to as postural) proteinuria is characterized by an elevated protein excretion while in the upright position and normal protein excretion in a supine or recumbent position. It is the most frequent cause of isolated proteinuria in children, especially adolescents.
The prevalence, pathogenesis, diagnosis, and prognosis of orthostatic proteinuria will be reviewed here. The evaluation of proteinuria in children is discussed separately. (See "Evaluation of proteinuria in children".)
Normal protein excretion — The following are definitions for normal protein excretion in children and adults:
●Children – Urinary protein excretion in the normal child is less than 100 mg/m2 per day (<4 mg/m2 per hour) or a total of 150 mg per day. (See "Evaluation of proteinuria in children", section on 'Normal protein excretion'.)
●Adults – Urinary protein excretion in the normal adult is less than 50 mg per eight-hour duration or a total of 150 mg per day. (See "Assessment of urinary protein excretion and evaluation of isolated non-nephrotic proteinuria in adults", section on 'Amounts of proteinuria'.)
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- Normal protein excretion
- Normal variant
- Subtle glomerular abnormality
- Exaggerated hemodynamic response to the upright position
- Left renal vein entrapment
- CLINICAL PRESENTATION
- Urine protein-to-creatinine ratio
- 24-hour urine collection
- Urinary dipstick
- Effect of strenuous exercise on the diagnostic evaluation
- DIFFERENTIAL DIAGNOSIS
- MANAGEMENT AND FOLLOW-UP CARE
- INFORMATION FOR PATIENTS
- SUMMARY AND RECOMMENDATIONS