What is serum albumin?
For the purpose of the information below the terms serum albumin, plasma albumin and blood albumin can be considered synonymous.
Serum albumin is the major water soluble blood protein in the body. The amount of
albumin in blood is approximately one quarter the amount of hemoglobin in red blood
cells. Because of its importance, serum albumin has been studied extensively -
Serum albumin appears to be the most important circulatory antioxidant in the body.
It renders potential toxins harmless and transports toxins to disposal sites. Serum
albumin functions as a nitric oxide (NO) carrier and has enzymatic properties that
can be utilized to convert prodrugs to active therapeutics. It appears to have a
protective effect on the lining cells of blood vessels by decreasing the inflammatory
process. Serum albumin plays a role in clearing toxic peptides (amyloid-
Human serum albumin is a small globular protein consisting of 609 amino acids. Synthesis of serum albumin occurs in the liver (approximately 15 grams per day). Pathology of liver cells decreases albumin synthesis. Serum albumin has a half life of approximately 20 days and normal serum levels range from 35 to 45 grams per liter. Serum albumin has been shown to distribute into the extracellular spaces of the skin in particular and into the extracellular spaces of other tissues to a lesser extent.
Most cases of low serum albumin and hypoalbuminemia are caused by acute and chronic inflammatory processes, liver disease, kidney disease or malnutrition. Excess alcohol consumption decreases liver synthesis of albumin.
Among hospitalized patients, low serum albumin levels are correlated with increased risk of morbidity and mortality. Indeed, low serum albumin levels are important predictors of mortality in heart disease and cancer patients.