Use of retinol-binding protein and prealbumin as indicators of the response to nutrition therapy.

There is no single available measurement for evaluating the short-term response to nutrition therapy. The ideal parameter should have high sensitivity and specificity and should be unaffected by non-nutritional factors. A literature review suggested that plasma retinol-binding protein and prealbumin concentrations change earlier than albumin and transferrin levels and appear to correlate better with nitrogen balance during nutrition therapy. That conclusion was supported by our own findings in patients receiving total parenteral nutrition and following the transition to oral or enteral feedings. Although concentrations of these plasma proteins have been shown to be affected by stress and renal and hepatic disease, they appear to be more sensitive indicators of the adequacy of nutrition support than other more commonly used assessment parameters.