Orthostatic albuminuria explained

Orthostatic albuminuria
Synonyms:	Orthostatic proteinuria, Postural proteinuria, Postural albuminuria.
Pronounce:	ȯr-thə-ˈsta-tik /ælˌbjuməˈn(j)ʊriə/^[1] ^[2]
Onset:	Under 30 years old.^[3]
Diagnosis:	Urine test strip, Urine protein/creatinine ratio, 24 hour urine collection, renal function tests, and urine microscopy.
Differential:	Transient proteinuria.^[4]
Prognosis:	Benign.
Frequency:	3 to 5% of adults and teenagers.

Orthostatic albuminuria, also known as orthostatic proteinuria is defined by raised levels of urine protein excretion while in an upright position. In orthostatic albuminuria urine protein excretion returns to normal while in a supine position, such as laying down. Orthostatic albuminuria is the most common cause of isolated proteinuria in those under 20.^[5] The prevalence of orthostatic albuminuria is suspected to be between 2 and 5%,^[6] however some studies suggest that it is more common.^[7] Orthostatic albuminuria is diagnosed if urine protein levels are normal in a morning urine sample and there are no other obvious causes of albuminuria.^[8] Patients with orthostatic albuminuria are often asymptomatic and there is no indication for any type of treatment or interventions.^[4]

Causes

The exact causes of orthostatic albuminuria are unknown however three different theories have been proposed, a normal variant, subtle glomerular abnormalities, exaggerated hemodynamic response, and left renal vein entrapment.^[9]

Diagnosis

There is no standard test for orthostatic albuminuria. Physical examination as well as a past medical history can help determine the extent of symptoms in some individuals. Urine analysis, urine cytology, complement activity, urine culture, and serological studies can help differentiate orthostatic albuminuria from other causes of proteinuria. Recumbent and upright urine protein to creatinine ratio is often used as a screening test. 24-hour split urine testing is often tested.^[10]

Additional causes of albuminuria include glomerulopathy, acute tubular necrosis, Alport syndrome, toxins, proximal renal tubular acidosis, diabetes mellitus, malignancies, polycystic kidney disease, infections, and chronic kidney disease.^[8]

Outlook

The long-term prognosis of orthostatic albuminuria hasn't yet been established. Based on current research, it seems that orthostatic albuminuria is a benign condition and typically resolves spontaneously within a couple years.^[11]

See also

• Proteinuria
• Albuminuria

Further reading

• Vehaskari . V M . Orthostatic proteinuria . Archives of Disease in Childhood . 57 . 10 . October 1, 1982 . 0003-9888 . 10.1136/adc.57.10.729 . 729–730 . 7138061 . 1627924 . none . free .
• von Bonsdorff . Martin . Törnroth . Tom . Pasternack . Amos . Renal Biopsy Findings in Orthostatic Proteinuria . Acta Pathologica Microbiologica Scandinavica Series A: Pathology. 90A . 1–6 . 1982 . 0108-0164 . 10.1111/j.1699-0463.1982.tb00058_90a.x . 11–18 . 7080809 . none. November 24, 2023.
• Brandt . John Robert . Jacobs . Aaron . Raissy . Hengameh H. . Kelly . Franceska Marie . Staples . Amy Otten . Kaufman . Ellen . Wong . Craig Stephen . Orthostatic proteinuria and the spectrum of diurnal variability of urinary protein excretion in healthy children . Pediatric Nephrology . 25 . 6 . February 18, 2010 . 0931-041X . 10.1007/s00467-010-1451-z . 1131–1137 . 20165888 . none. 3677044 .
• Vehaskari . V. Matti . Mechanism of orthostatic proteinuria . Pediatric Nephrology . 4 . 4 . 1990 . 0931-041X . 10.1007/bf00862510 . 328–330 . 2206899 . 26930865 . none. November 24, 2023.
• Sebestyen . Judith F. . Alon . Uri S. . The Teenager With Asymptomatic Proteinuria: Think Orthostatic First . Clinical Pediatrics . 50 . 3 . September 13, 2010 . 0009-9228 . 10.1177/0009922810380904 . 179–182 . 20837623 . 8219563 . none. November 24, 2023.

External links

• Cleveland Clinic Orthostatic Proteinuria

Notes and References

1. Web site: Definition of Orthostatic . Merriam-Webster . November 10, 2023 . November 24, 2023.
2. Web site: albuminuria . Oxford English Dictionary . Oxford University Press . 24 November 2023 . July 2023.
3. Web site: Moses . Scott . Orthostatic Proteinuria . Family Practice Notebook . February 17, 2017 . November 24, 2023.
4. Web site: UpToDate . UpToDate . November 24, 2023.
5. Uehara . K. . Tominaga . N. . Shibagaki . Y. . Adult orthostatic proteinuria . Clinical Kidney Journal . 7 . 3 . May 25, 2014 . 2048-8505 . 10.1093/ckj/sfu040 . 327–328 . 25852903 . 4377758 . free .
6. Mazzoni . M. B. M. . Kottanatu . L. . Simonetti . G. D. . Ragazzi . M. . Bianchetti . M. G. . Fossali . E. F. . Milani . G. P. . Renal vein obstruction and orthostatic proteinuria: a review . Nephrology Dialysis Transplantation . 26 . 2 . July 23, 2010 . 0931-0509 . 10.1093/ndt/gfq444 . 562–565 . 20656752 . free . November 24, 2023.
7. Vehaskari . V. Matti . Rapola . Juhani . Isolated proteinuria: Analysis of a school-age population . The Journal of Pediatrics . 101 . 5 . 1982 . 0022-3476 . 10.1016/s0022-3476(82)80287-4 . 661–668 . 7131137 . November 24, 2023.
8. AK . Leung . AH . Wong . SS . Barg . Proteinuria in Children: Evaluation and Differential Diagnosis . American Family Physician . 2017 . 95 . 4 . 248–254 . 1532-0650 . 28290633 . November 24, 2023.
9. Web site: Ingold . Curtis J. . Bhatt . Harshil . Orthostatic Proteinuria . StatPearls Publishing . August 8, 2023 . 32965979 . November 24, 2023.
10. Kovvuru . Karthik . Kanduri . Swetha R. . Thongprayoon . Charat . Cheungpasitporn . Wisit . Diagnostic approach to orthostatic proteinuria: a combination of urine micro-proteinuria with ultrasonography of the left renal vein . Annals of Translational Medicine . 8 . 12 . 2020 . 2305-5839 . 10.21037/atm.2020.02.50 . 779. 32647704 . 7333150 . free .
11. Arslan . Zümrüt . Koyun . Mustafa . Erengin . Hakan . Akbaş . Halide . Aksoy . Gülşah Kaya . Çomak . Elif . Akman . Sema . Orthostatic proteinuria: an overestimated phenomenon? . Pediatric Nephrology . 35 . 10 . May 11, 2020 . 0931-041X . 10.1007/s00467-020-04586-4 . 1935–1940 . 32394189 . 218592496 . November 24, 2023.