From the Guidelines
Prealbumin serves as a valid measure of protein-energy nutritional status in patients with hypoalbuminemia, with a recommended outcome goal of a value greater than or equal to 30 mg/dL. This is based on the most recent and highest quality study available, which suggests that prealbumin levels less than 30 mg/dL are associated with increased mortality risk and correlate with other indices of protein-energy malnutrition 1. Prealbumin is a protein produced by the liver that transports thyroid hormones and vitamin A in the bloodstream, and its shorter half-life of approximately 2-3 days makes it more responsive to acute changes in nutritional status compared to albumin.
Key Points to Consider
- Prealbumin has a shorter half-life than albumin, making it a more sensitive marker of nutritional status
- Prealbumin levels are affected by inflammation, infection, and renal failure, which can limit its use as a nutritional marker
- Normal prealbumin levels range from 15-36 mg/dL, with values below 30 mg/dL suggesting malnutrition
- Monitoring prealbumin can help guide nutritional support strategies, including protein supplementation and adequate caloric intake
In patients with hypoalbuminemia, measuring prealbumin levels can provide a more immediate assessment of protein synthesis and nutritional interventions. The rapid turnover of prealbumin makes it particularly useful for tracking the effectiveness of nutritional interventions in real-time, allowing for timely adjustments to treatment plans before more severe malnutrition develops, as suggested by the study published in the American Journal of Kidney Diseases 1.
From the Research
Function of Prealbumin in Hypoalbuminemia
- Prealbumin, also known as transthyretin, is a protein that has been evaluated as a nutritional and prognostic marker 2.
- In patients with hypoalbuminemia, prealbumin levels can be used to assess malnutrition, as it is a negative acute-phase reactant that falls promptly with injury or illness regardless of nutrient intake 3.
- Prealbumin has a shorter half-life compared to albumin, making it a useful biomarker for assessing patients at nutrition risk 4.
- Low prealbumin levels have been associated with higher all-cause mortality rates and can be used to identify patients who may benefit from nutrition support 4.
Clinical Utility of Prealbumin
- Prealbumin can complement clinical history, anthropometric assessment, and physical examination to assess malnutrition with more certainty 2.
- Prealbumin serum concentrations have been shown to be closely related to early changes in nutritional status, making it a potential useful marker for malnutrition 5.
- Prealbumin has been used as a predictor of malnutrition in cirrhotic patients and has been shown to be effective in identifying patients who may benefit from nutritional support 6.
Analytical Methodologies
- Several analytical methodologies have been developed to measure prealbumin levels, which can help establish it as a useful biomarker in routine clinical practice 2.
- The measurement of prealbumin levels can be challenging due to its small size and concentration in blood, but advances in analytical methodologies have improved its sensitivity and specificity 2.