The Use of Prealbumin and C-Reactive Protein for Monitoring Nutrition Support in Adult Patients Receiving Enteral Nutrition in an Urban Medical Center

Background: Serum prealbumin (PAB) is commonly used to assess protein status and is often used to monitor the response to nutrition support. However, during inflammation, the liver synthesizes acute-phase proteins such as C-reactive protein (CRP) at the expense of PAB. Objective: The purpose of this retrospective study was to determine whether changes in PAB reflect the delivery of adequate nutrients or changes in inflammatory status in hospitalized adults (≥18 years) receiving enteral nutrition (n = 154). Methods: Protein and energy intake were compared to changes in PAB, assessed at baseline and twice weekly. C-reactive protein was assessed when PAB was <18 mg/dL to determine the presence and severity of inflammation. Results: In a sample of mostly critically ill patients, there was no significant difference in change in PAB for those receiving ≥60% of calorie needs (2.74 ± 9.50 mg/dL) compared to <60% of calorie needs (2.48 ± 9.36 mg/dL; P = .86). Changes in PAB correlated only with changes in CRP (r = -0.544, P < .001). In a subgroup analysis of 62 patients with repeated measures of PAB and CRP, PAB increased significantly only in the bottom 2 tertiles for calorie delivery and the lowest tertile for protein delivery. Conclusions: These results indicate that PAB may not be a sensitive marker for evaluating the adequacy of nutrition support in critically ill patients with inflammation. Only change in CRP was able to significantly predict changes in PAB, suggesting that an improvement in inflammation, rather than nutrient intake, was responsible for the increases in PAB levels.