Nutritional Status Assessment in Adults Laboratory Medicine

Updated: Sep 25, 2020
  • Author: William Aaron Hood, DO; Chief Editor: Vikram Kate, MBBS, PhD, MS, FACS, FACG, FRCS, FRCS(Edin), FRCS(Glasg), FIMSA, FFST(Ed), MAMS, MASCRS  more...
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Laboratory Medicine

Laboratory Medicine Summary

Serum proteins (albumin, transferrin, prealbumin, retinol-binding protein) are perhaps the most widely used laboratory measures of nutritional status. They are hepatically produced negative acute-phase reactants with reduced levels during systemic inflammation. However, in the absence of inflammation, a low concentration of these proteins correlates strongly with malnutrition. [3] Details of these proteins can be found in Table 3.

Table 3: Serum Proteins Used for Assessment of Nutritional Status [3, 33, 34] (Open Table in a new window)

Protein

Half-life, days

Function

Comment

Albumin

14-20

Maintenance of plasma oncotic pressure; carrier protein

levels increase with dehydration, blood and albumin transfusion, and anabolic steroids

levels decrease in liver failure, inflammation, volume overload states (cirrhosis, congestive heart failure, renal failure), zinc deficiency, protein-losing states (nephrotic syndrome, enteropathy), corticosteroid use, and bedrest

Transferrin

8-9

Iron transport

levels increase during dehydration, iron deficiency, pregnancy, estrogen therapy, and acute hepatitis

levels decrease in liver and renal failure, inflammation, anemia due to chronic disease and vitamin B12 and folate deficiency, corticosteroids, zinc deficiency, and protein-losing states (nephrotic syndrome, enteropathy)

Often measured indirectly as total iron-binding capacity (TIBC)

Prealbumin (transthyretin)

2-3

Binds thyroxine; carrier for retinol-binding protein

levels increase in renal failure (degraded by the kidney) and corticosteroid and oral contraceptive use

levels decrease in liver failure, inflammation, and hyperthyroidism

Retinol-binding protein (RBP)

12-24

Vitamin A transport; binds to prealbumin

levels increase in renal failure (degraded by the kidney)

levels decrease in cirrhosis, inflammation, vitamin A and zinc deficiency, and hyperthyroidism