Low levels of plasma proteins: malnutrition or inflammation?

Levels of several plasma proteins, including albumin, transferrin, and transthyretin (prealbumin), have been proposed as markers for protein energy malnutrition. However, many other factors, especially inflammatory disease and drug or hormone therapy, affect levels of these proteins. These factors probably account for the majority of low levels of transthyretin. Levels of albumin and other proteins may be helpful in determining increased risk of morbidity and mortality, but better markers are needed for diagnosis of protein energy malnutrition per se.