Sun21November0452PM 18

In the context of malnutrition which of these plasma proteins has the shortest half-life?

(Please select 1 option)

Transferrin

Transthyretin

Retinol binding globulin Correct

Albumin

Fibronectin

Explanation

Retinol binding protein has a half life of 10-12 hours and may therefore reflect more acute changes in protein metabolism than any of these proteins. It is not commonly used as a nutritional assessment parameter.

Transthyretin (thyroxine binding pre-albumin) levels are less sensitive as the half life is only one to two days. This protein is not an albumin precursor. A value 15 mg/dL reflects early malnutrition and the need for nutritional support.

Albumin levels have been frequently used. However, it is not a very sensitive marker. The half life of albumin is over 30 days so it takes a long time to see a change. In addition, albumin synthesis is decreased with onset of the stress response after burns. Acute phase protein synthesis increases and albumin decreases unrelated to nutritional status.

Transferrin is a more accurate indicator of protein stores. It responds more readily than serum albumin to acute changes in protein status. Serum transferrin has a shorter half life (8-10 days) and smaller body stores than albumin. A serum transferrin level below 200 mg/dL is considered low and below 100 mg/dL is considered severe. Non-nutritional factors can also affect serum transferrin level.

Fibronectin is a glycoprotein that plays a role in enhancing the phagocytosis of foreign particles. It is used a nutritional marker but levels decrease after seven days of starvation.

Answer Statistics

1

18%

2

14%

3

21%

4

31%

5

17%

Times answered: 255