Jump to content

Microalbuminuria

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by 196.3.50.254 (talk) at 10:15, 6 March 2014 (→Diagnosis). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Microalbuminuria

Microalbuminuria (Urine albumin) occurs when the kidney leaks small amounts of albumin into the urine, in other words, when there is an abnormally high permeability for albumin in the renal glomerulus.

Diagnosis

The level of albumin protein produced by microalbuminuria can be detected by special albumin-specific urine dipsticks. A microalbumin urine test determines the presence of the albumin in urine. In a properly functioning body, albumin is not normally present in urine because it is retained in the bloodstream by the kidneys.

Microalbuminuria can be diagnosed from a 24-hour urine collection (between 30–300 mg/24 hours) or, more commonly, from elevated concentrations in a spot sample (30 to 300 mg/L). Both must be measured on at least two of three measurements over a two- to three-month period.[1]

An albumin level above the upper limit values is called "macroalbuminuria", or sometimes just albuminuria. Sometimes, the upper limit value is given as one less (such as 300 being given as 299) to mark that the higher value (here 300) is defined as macroalbuminuria.[2]

To compensate for variations in urine concentration in spot-check samples, it is helpful to compare the amount of albumin in the sample against its concentration of creatinine. This is termed the albumin/creatinine ratio (ACR)[3] and microalbuminuria is defined as ACR ≥3.5 mg/mmol (female) or ≥2.5 mg/mmol (male),[4] or, with both substances measured by mass, as an ACR between 30 and 300 µg albumin/mg creatinine.[5] For the diagnosis of microalbuminuria, care must be taken when collecting sample for the urine ACR. An early morning sample is preferred. The patient should refrain from heavy exercises 24 hours before the test. A repeat test should be done 3 to 6 months after the first positive test for microalbuminuria. Lastly, the test is inaccurate in a person with too much or too little muscle mass. This is due to the variation in creatinine level which is produced by the muscle.[6]

Definitions of microalbuminuria
Individual Lower limit Upper limit Unit
24h urine collection 30[2] 300[2] mg/24h (milligram albumin per 24 hours)
Short-time urine collection 20[2] 200[2] µg/min (microgram albumin per minute)
Spot urine albumin sample 30[7] 300[7] mg/l (milligram albumin per litre of urine) or
mg/g (milligram albumin per gram of creatinine)
Spot urine albumin/creatinine ratio Women 3.5[8] 25[8] or 35[8] mg/mmol (milligram albumin per millimole creatinine)
30[8] 400[8] μg/mg (microgram albumin per milligram creatinine)
Men 2.5[8] or 3.5[8] 25[8] or 35[8] mg/mmol
30[8] 300[8] μg/mg

Significance

See also

References

  • Abid O, Sun Q, Sugimoto K, Mercan D, Vincent JL (2001). "Predictive value of microalbuminuria in medical ICU patients: results of a pilot study". Chest. 120 (6): 1984–8. doi:10.1378/chest.120.6.1984. PMID 11742932.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  • Andersen S, Blouch K, Bialek J, Deckert M, Parving HH, Myers BD (2000). "Glomerular permselectivity in early stages of overt diabetic nephropathy". Kidney Int. 58 (5): 2129–37. doi:10.1111/j.1523-1755.2000.00386.x. PMID 11044234.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  • Heart Outcomes Prevention Evaluation Study Investigators (2000). "Effects of ramipril on cardiovascular and microvascular outcomes in people with diabetes mellitus: results of the HOPE study and MICRO-HOPE substudy". Lancet. 355 (9200): 253–9. doi:10.1016/S0140-6736(99)12323-7. PMID 10675071.
  • Lemley KV; Abdullah I; Myers BD; et al. (2000). "Evolution of incipient nephropathy in type 2 diabetes mellitus". Kidney Int. 58 (3): 1228–37. doi:10.1046/j.1523-1755.2000.00223.x. PMID 10972685. {{cite journal}}: Unknown parameter |author-separator= ignored (help)
  • Lièvre M; Marre M; Chatellier G; et al. (2000). "The non-insulin-dependent diabetes, hypertension, microalbuminuria or proteinuria, cardiovascular events, and ramipril (DIABHYCAR) study: design, organization, and patient recruitment. DIABHYCAR Study Group". Controlled Clinical Trials. 21 (4): 383–96. doi:10.1016/S0197-2456(00)00060-X. PMID 10913814. {{cite journal}}: Unknown parameter |author-separator= ignored (help)
  • Parving HH, Lehnert H, Bröchner-Mortensen J, Gomis R, Andersen S, Arner P (2001). "The effect of irbesartan on the development of diabetic nephropathy in patients with type 2 diabetes". N. Engl. J. Med. 345 (12): 870–8. doi:10.1056/NEJMoa011489. PMID 11565519.{{cite journal}}: CS1 maint: multiple names: authors list (link)

Footnotes

  1. ^ "Person—microalbumin level (measured), total micrograms per minute N[NNN].N". Retrieved 2007-07-05.
  2. ^ a b c d e Page 291 in: . ISBN 978-1-58528-180-0Template:Inconsistent citations {{cite book}}: Missing or empty |title= (help); Unknown parameter |booktitle= ignored (help)CS1 maint: postscript (link)
  3. ^ Bakker AJ (February 1999). "Detection of microalbuminuria. Receiver operating characteristic curve analysis favors albumin-to-creatinine ratio over albumin concentration". Diabetes Care. 22 (2): 307–13. PMID 10333950.
  4. ^ "Proteinuria". UK Renal Association. December 15, 2005.
  5. ^ clinlabnavigator.com > Test Interpretations Last Updated on Saturday, 19 June 2010
  6. ^ Microalbuminura in diabetes
  7. ^ a b Person—microalbumin level (measured) at Australian Institute of Health and Welfare. 01/03/2005
  8. ^ a b c d e f g h i j k [1] Attention: This template ({{cite pmid}}) is deprecated. To cite the publication identified by PMID 16567839, please use {{cite journal}} with |pmid=16567839 instead.
  9. ^ Mahmoodi, BK; Gansevoort, RT; Veeger, NJ; Matthews, AG; Navis, G; Hillege, HL; Van Der Meer, J; Prevention of Renal Vascular End-stage Disease (PREVEND) Study Group (2009). "Microalbuminuria and risk of venous thromboembolism". JAMA: the Journal of the American Medical Association. 301 (17): 1790–7. doi:10.1001/jama.2009.565. PMID 19417196.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Microalbuminuria&oldid=598379829"