Albumin, Urine

What is Albumin?

Albumin is one of the proteins found in your blood. It’s normally present in the blood. Other proteins in your blood are globulin and fibrinogen. Proteins are important building blocks of all cells and tissues. They are necessary for your body’s growth, development, and health.

Function of Albumin:

Your body uses Albumin for cell growth and to help repair tissues. Albumin also helps keep the correct balance of fluid between your blood vessels and the body tissues they supply.

Albumin and the kidneys:

The kidneys filter your blood to remove waste products. Ideally, the waste products end up in your urine, and albumin and other proteins stay in your blood vessels. So if albumin shows up in your urine, it may be a sign of kidney damage.

What is albuminuria?

Albuminuria is a sign of kidney disease and means that you have too much albumin in your urine. One of the many functions of the kidneys is to conserve plasma proteins so that they are not released along with waste products when urine is produced. A healthy kidney doesn’t let albumin pass from the blood into the urine. A damaged kidney lets some albumin pass into the urine. The less albumin in your urine, the better.

A small amount of albumin in the urine is sometimes referred to as urine microalbuminuria. "Microalbuminuria" is slowly being replaced with the term "albuminuria," which refers to any elevation of albumin in the urine.

Who is at risk for albuminuria?

People who have:

- diabetes,

- high blood pressure,

- heart disease, or

- a family history of kidney failure

are at risk for kidney disease. Talk with your health care provider about how often you should get a urine test for albumin.

How can you reduce albuminuria?

You may be able to reduce the amount of albumin in your urine by taking medicines that lower blood pressure called ACE inhibitors or ARBs.

You may also be able to protect your kidneys and reduce albuminuria by working with a registered dietitian who can help you plan meals and change your eating habits. The meal plan may help you:

- lose weight, if you are overweight

- avoid foods high in sodium or salt

- eat the right amounts and types of protein

Normal ranges:

A normal amount of albumin in your urine is less than 30 mg a day. 30 to 300 mg is known as microalbuminuria, and it may indicate early kidney disease. 300 mg or more is known as macroalbuminuria, and it indicates more advanced kidney disease.

References:

- American Diabetes Association. Microvascular complications and foot care. Sec. 10. In Standards of Medical Care in Diabetes-2017. Diabetes Care 2017;40(Suppl. 1);S88-S98. Diabetes Care. 2017;40(7):986. PMID: 28522554 www.ncbi.nlm.nih.gov/pubmed/28522554.

- Brownlee M, Aiello LP, Cooper ME, Vinik AI, Plutzky J, Boulton AJM. Complications of diabetes mellitus. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology. 13th ed. Philadelphia, PA: Elsevier; 2016:chap 33.

- Chernecky CC, Berger BJ. Albumin - serum, urine, and 24-hour urine. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. Philadelphia, PA: Elsevier Saunders; 2013:110-112.