What is the Albumin/Globulin Ratio?

The Albumin to Globulin ratio (A:G) is the ratio of albumin present in serum in relation to the amount of globulin. Serum is the clear fluid part of blood that contains no blood cells and clotting components. This serum contains proteins, which are known as serum protein.

Serum protein consists of main proteins:

Albumin proteins: Albumin, which makes up 50 percent of serum protein, reflects your nutritional status. Albumin proteins transport substances like hormones, fatty acids, and drugs throughout your body.

Globulin proteins: Globulin proteins, which are made by your immune system, make up around 48 percent of serum protein. These proteins indicate the state of your immune function and the severity of any inflammationTrusted Source.

The ratio can be interpreted only in light of the total protein concentration. Very generally speaking, the normal ratio in most species approximates 1:1. For example, high total protein with a normal A:G ratio suggests dehydration, while the same protein with a low A:G ratio would indicate hyperglobulinemia (= an abnormally high concentration of globulins in the circulating blood plasma).

Typically, an A/G ratio test is done as part of a routine protein blood test. It’s used to check your general health, including nutritional status and immune function.

What does the Albumin/Globulin Ratio measure?

An A/G ratio test measures albumin and globulin, the two main proteins in your blood. This simple blood test is used to monitor your nutritional status, immune function, and overall health.

What do Albumin/Globulin results mean?

The normal range for albumin/globulin ratio is over 1, usually around 1 to 2. That’s because there’s a bit more albumin than globulin in serum protein.

If your body is producing too much or too little of either protein, your A/G ratio will be classified as high or low.

High or low A/G ratios are particularly associated with kidney and liver disease. A low A/G ratio can also indicate chronic infections, cancers, and more. A high A/G ratio is associated with dehydration, malnutrition, and other gastrointestinal conditions.

Serum albumin/globulin ratio (AGR) has been shown in several recent studies to be able to predict the prognosis of a number of illnesses, including cancer, chronic renal disease, heart failure, low thyroid activity, and peritoneal dialysis. If your doctor feels any of your levels are too high or low, you may need to have more precise blood or urine tests.

These tests can be used to check on the condition of your liver or kidneys if you have already experienced an aberrant test result or have been previously diagnosed with an underlying problem. Additionally, testing can be used to keep track of prescription drug side effects that may have an influence on the liver or kidneys.

Your doctor might check your A/G ratio if you’re experiencing unexplained weight loss, extreme fatigue, or swelling. 

What is Albumin and what are its functions?

The most prevalent plasma protein produced by the liver is Albumin. Blood leaks from blood arteries are prevented by Albumin. Additionally, it aids in the movement of hormones, medications, vitamins, and other critical elements throughout the body. The liver is where Albumin is produced. 

What are globulins and what are their functions?

The majority of the blood's other proteins are globulins. Globulins transport nutrients throughout the body and aid in the fight against infection. The liver creates some globulins. The immune system produces others. It is less water soluble than Albumin. The terms alpha, beta, and gamma globulins refer to several types of globulins.

When is the Albumin/Globulin Ratio tested?

A comprehensive metabolic panel test frequently includes a total protein and albumin/globulin (A/G) ratio test to evaluate the Protein in the blood. The test can help diagnose several kinds of health problems, including liver and kidney disease, as well as nutritional deficiencies.

The test also compares the levels of Globulin and Albumin in your blood. The ratio between Albumin and Globulin is referred to as the A/G ratio. If your A/G ratio or total protein levels are abnormal, this could indicate a major health issue. 

This blood test is also used to screen and monitor various health conditions, including kidney disease, chronic infections, various cancers, and more.

If you experience symptoms that point to aberrant protein levels, you could also require this test. These include:

• Swelling of the ankles, feet, legs, and/or abdomen brought on by an abundance of fluid in your tissues
• Fatigue
• Unexplained weight loss
• Loss of appetite
• Nausea and vomiting
• Jaundice (yellowing of the skin or eyes). 
• Blood in the urine, a common symptom of kidney disease
• Spider-like blood vessels on the skin.
• those who are more likely to suffer from renal or liver illness
• Diabetes
• High blood pressure

References:

Mutlu EA, Keshavarzian A, Mutlu GM. Hyperalbuminemia and elevated transaminases associated with high-protein diet. Scand J Gastroenterol. 2006 Jun;41(6):759-60. doi: 10.1080/00365520500442625. PMID: 16716979.

Thakkinstian A, Tran H, Reeves G, Murch S, Attia J. A clinical decision rule to aid ordering of serum and urine protein electrophoresis for case-finding of paraproteins in hospitalized inpatients. J Gen Intern Med. 2008 Oct;23(10):1688-92. doi: 10.1007/s11606-008-0712-z. Epub 2008 Jul 30. PMID: 18665429; PMCID: PMC2533374.

Bae JC, Seo SH, Hur KY, Kim JH, Lee MS, Lee MK, Lee WY, Rhee EJ, Oh KW. Association between Serum Albumin, Insulin Resistance, and Incident Diabetes in Nondiabetic Subjects. Endocrinol Metab (Seoul). 2013 Mar;28(1):26-32. doi: 10.3803/EnM.2013.28.1.26. Epub 2013 Mar 25. PMID: 24396647; PMCID: PMC3811792.

Cho HM, Kim HC, Lee JM, Oh SM, Choi DP, Suh I. The association between serum albumin levels and metabolic syndrome in a rural population of Korea. J Prev Med Public Health. 2012 Mar;45(2):98-104. doi: 10.3961/jpmph.2012.45.2.98. Epub 2012 Mar 31. PMID: 22509450; PMCID: PMC3324721.

Kadono M, Hasegawa G, Shigeta M, Nakazawa A, Ueda M, Yamazaki M, Fukui M, Nakamura N. Serum albumin levels predict vascular dysfunction with paradoxical pathogenesis in healthy individuals. Atherosclerosis. 2010 Mar;209(1):266-70. doi: 10.1016/j.atherosclerosis.2009.09.006. Epub 2009 Sep 12. PMID: 19819455.

JEEJEEBHOY KN, BOUCHER BJ, HARTOG M. THE EFFECT OF GROWTH HORMONE ON ALBUMIN TURNOVER IN MAN. Metabolism. 1965 Jan;14:67-74. doi: 10.1016/0026-0495(65)90082-x. PMID: 14252344.

Rahman MZ, Begum BA. Serum total protein, albumin and A/G ratio in different grades of protein energy malnutrition. Mymensingh Med J. 2005 Jan;14(1):38-40. PMID: 15695952.

Hausmann O, Warnatz K. Immunodeficiency in adults a practical guide for the allergist. Allergo J Int. 2014;23(7):261-268. doi: 10.1007/s40629-014-0030-4. Epub 2014 Nov 6. PMID: 26120536; PMCID: PMC4479546.

Walker HK, Hall WD, Hurst JW, editors. Chapter 101 - Serum Albumin and Globulin, Boston: Butterworths; 1990. [https://www.ncbi.nlm.nih.gov/books/NBK204/]