Microalbuminuria

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Microalbuminuria

ICD-9	791.0
MedlinePlus	003591

Microalbuminuria 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.

Contents 1 Diagnosis 2 Significance 3 See also 4 References 5 Footnotes 6 External links

[edit] Diagnosis

The level of albumin protein produced by microalbuminuria cannot be detected by urine dipstick methods. 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 is diagnosed either from a 24-hour urine collection (20 to 200 µg/min) or, more commonly, from elevated concentrations (30 to 300 mg/L) on at least two occasions.^[1]. An albumin level above these values is called "macroalbuminuria", or sometimes just albuminuria.

To compensate for variations in urine concentration in spot-check samples, it is more typical in the United Kingdom to compare the amount of albumin in the sample against its concentration of creatinine. This is termed the albumin/creatinine ratio (ACR)^[2] and microalbuminuria is defined as ACR ≥2.8 mg/mmol (female) or ≥2.0 mg/mmol(male).^[3]

[edit] Significance

• an indicator of subclinical cardiovascular disease
• marker of vascular endothelial dysfunction
• an important prognostic marker for kidney disease
  • in diabetes mellitus
  • in hypertension
• increasing microalbuminuria during the first 48 hours after admission to an intensive care unit predicts elevated risk for acute respiratory failure , multiple organ failure , and overall mortality
• a risk factor for venous thromboembolism ^[4]

[edit] See also

• albuminuria

[edit] 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. 
• 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. 
• 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. 
• 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. 
• 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. 

[edit] Footnotes

[edit] External links

• Online Microalbumin Urine Calculator
• first-ever large-scale clinical trial to evaluate whether an ARB can prevent the initial development of Microalbuminuria

v • d • e Abnormal clinical and laboratory findings for urine (R80-R82, 791) Urine test/ Urination disorder Red blood cells Hematuria (Microscopic hematuria) White blood cells Eosinophiluria Proteinuria Albuminuria/Microalbuminuria · Myoglobinuria · Hemoglobinuria Small molecules Glycosuria · Ketonuria · Bilirubinuria · Hyperuricosuria · Hypouricosuria Pathogens Bacteriuria Other Chyluria  · Crystalluria · Isosthenuria · Hypersthenuria see also urine tests