Microalbuminuria is a term to describe a moderate increase in the level of urine

albumin Albumin is a family of globular proteins, the most common of which are the serum albumins. All the proteins of the albumin family are water-soluble, moderately soluble in concentrated salt solutions, and experience heat denaturation. Albumins ...

. It occurs when the

kidney The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blood ...

leaks small amounts of albumin into the urine, in other words, when an abnormally high permeability for albumin in the

glomerulus ''Glomerulus'' () is a common term used in anatomy to describe globular structures of entwined vessels, fibers, or neurons. ''Glomerulus'' is the diminutive of the Latin ''glomus'', meaning "ball of yarn". ''Glomerulus'' may refer to: * the filter ...

of the kidney occurs. Normally, the kidneys filter albumin, so if albumin is found in the urine, then it is a marker of kidney disease. The term microalbuminuria is now discouraged by Kidney Disease Improving Global Outcomes and has been replaced by moderately increased albuminuria.

Causes

Higher dietary intake of animal protein, animal fat, and cholesterol may increase risk for microalbuminuria, and generally, diets higher in fruits, vegetables, and whole grains but lower in meat and sweets may be protective against kidney function decline.

Associations

* Marker of vascular

endothelial dysfunction In vascular diseases, endothelial dysfunction is a systemic pathological state of the endothelium. Along with acting as a semi-permeable membrane, the endothelium is responsible for maintaining vascular tone and regulating oxidative stress by ...

* An important prognostic marker for kidney disease ** in

diabetes mellitus Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ap ...

** in

hypertension Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms. Long-term high bl ...

** in post-streptococcal glomerulonephritis * Increasing microalbuminuria during the first 48 hours after admission to an

intensive care unit 220px, Intensive care unit An intensive care unit (ICU), also known as an intensive therapy unit or intensive treatment unit (ITU) or critical care unit (CCU), is a special department of a hospital or health care facility that provides intensiv ...

predicts elevated risk for acute

respiratory failure Respiratory failure results from inadequate gas exchange by the respiratory system, meaning that the arterial oxygen, carbon dioxide, or both cannot be kept at normal levels. A drop in the oxygen carried in the blood is known as hypoxemia; a rise ...

multiple organ failure Multiple organ dysfunction syndrome (MODS) is altered organ function in an acutely ill patient requiring medical intervention to achieve homeostasis. Although Irwin and Rippe cautioned in 2005 that the use of "multiple organ failure" or "multisy ...

, and overall mortality * A risk factor for venous thromboembolism Microalbuminuria is an important adverse predictor of glycemic outcomes in prediabetes. Prediabetes individuals with increased microalbuminuria even in the so-called normal range is associated with increased progression to diabetes and decreased reversal to normoglycemia. Hence, prediabetes individuals with microalbuminuria warrant more aggressive intervention to prevent diabetes in them.

Diagnosis and treatment

The level of albumin

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

produced by microalbuminuria can be detected by special albumin-specific urine dipsticks, which have a lower detection threshold than standard 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 and 300 mg/24 hours) or, more commonly, from elevated concentration in a spot sample (20 to 200 mg/L). Both must be measured on at least two of three measurements over a two- to three-month period. An albumin level above the upper limit values is called "macroalbuminuria", or sometimes just

albuminuria Albuminuria is a pathological condition wherein the protein albumin is abnormally present in the urine. It is a type of proteinuria. Albumin is a major plasma protein (normally circulating in the blood); in healthy people, only trace amounts of ...

. 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.

Taurine Taurine (), or 2-aminoethanesulfonic acid, is an organic compound that is widely distributed in animal tissues. It is a major constituent of bile and can be found in the large intestine, and accounts for up to 0.1% of total human body weight. I ...

in combination with ''N''-acetylcysteine (Nefrosave Tablet) was useful in attenuating UACR in microalbuminuric type 2 diabetic patient as per ''Indian Journal of Nephrology'' 2008 To compensate for variations in urine concentration in spot-check samples, comparing the amount of albumin in the sample against its concentration of

creatinine Creatinine (; ) is a breakdown product of creatine phosphate from muscle and protein metabolism. It is released at a constant rate by the body (depending on muscle mass). Biological relevance Serum creatinine (a blood measurement) is an importa ...

is helpful. This is termed the albumin/creatinine ratio (ACR) and microalbuminuria is defined as ACR ≥3.5 mg/mmol (female) or ≥2.5 mg/mmol (male), or with both substances measured by mass, as an ACR between 30 and 300 µg albumin/mg creatinine. 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.Microalbuminura in diabetes
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References

* * * * * * * Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney inter., Suppl. 2013; 3: 1–150.

Footnotes

External links

Microalbumin and Urine Albumin/Creatinine Ratio
– Lab Tests Online {{Abnormal clinical and laboratory findings for urine Abnormal clinical and laboratory findings for urine