A blood sample taken from a vein in the arm
The test measures levels of prealbumin, an important protein found in the blood and produced mainly by the liver. Prealbumin breaks down quickly in the body and therefore the amount in the blood changes rapidly and can provide an immediate picture of your nutritional status.
How is the sample collected for testing?
A blood sample is taken by a needle from a vein in the arm.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.
How is it used?
The prealbumin test may be used to help your doctor make an assessment of your nutrition. This test is not widely available, and samples may need to be sent to specialist laboratory. Prealbumin is most often used to help doctors diagnose 'protein-calorie' malnutrition. In this condition, which can affect more than 30% of hospitalised patients, the body breaks down muscle, protein, and body fat. This type of malnutrition can lead to complications and even death if not treated. Children with malnutrition may be unwell or have stunted growth.
The test may also be used to make an assessment of nutritional status:
- before a scheduled operation,
- in patients who are hospitalised with certain conditions, and
- in patients who have been ill for a long period of time.
Many patients have a decline in nutrition during their hospital stay, especially after surgery. Studies have shown that good nutrition prior to surgery helps to avoid complications, such as pneumonia and infection, after surgery.
The test may also used to monitor changes in patients who are receiving nutrition support such as parenteral nutrition (nutrition from outside of the gastrointestinal tract, such as nutrients given directly into a vein through a drip). The test may also used to monitor changes in nutritional status for patients who are receiving haemodialysis, a process that removes waste substances from your circulating blood. Haemodialysis is part of treatment for patients with kidney disease.
When is it requested?
A doctor may consider requesting prealbumin when signs of malnutrition or poor nutrition are present. However, this test is not widely available, and samples may need to be sent to specialist laboratory. Signs of malnutrition include extreme weight loss, stunted growth (in a child), weakened resistance to infection, or being unable to think clearly. Hair may become brittle or begin to fall out, the skin may be dry or yellowish, muscles may feel weak, and fainting spells may occur. In younger women, menstrual periods may stop.
What does the test result mean?
The prealbumin measurement may reflect the state of your nutrition. If prealbumin is low, other proteins and substances in your blood may also be low.
If your test shows that prealbumin is low, your nutrition may need to be corrected. If prealbumin is very low, you may be considered malnourished and need immediate medical attention. Lower levels of prealbumin may be seen in patients with:
- severe or long-term illness, such as cancer
- liver disease
- serious infections
- certain digestive disorders
If a patient has Inflammation, however, it is impossible to know exactly what the prealbumin value means. When inflammation and malnutrition are both present, prealbumin levels fall very quickly. When the prealbumin level is low it can be difficult for the doctor to know whether this is as a result of malnutrition, illness or both. This limits the usefulness of the prealbumin test.
Higher levels of prealbumin are common in patients with:
- high-dose corticosteroid therapy;
- hyperactive adrenal glands;
- high-dose nonsteroidal anti-inflammatory medications; and
- Hodgkin's disease
Is there anything else I should know?
Inflammation can interfere with the results of your prealbumin test, causing it to be lower than it would otherwise be. Certain drugs can also lower your prealbumin level, including amiodarone, oestrogens, and oral contraceptives (the pill).
Recent research has shown that the prealbumin test can predict poor outcomes for haemodialysis patients. A low initial reading (baseline level) of prealbumin predicts that a patient may have problems, and steadily dropping prealbumin values are associated with reduced survival. The prealbumin test is not widely used in the UK, and albumin may be measured instead.
What conditions could lead to malnutrition?
Various diseases can lead to so-called 'protein-calorie' malnutrition. Common diseases linked with this form of malnutrition include:
- chronic (long-term) illness
- protein loss in the gastrointestinal tract
- anorexia and other eating disorders
- liver disease
- multiple traumas
- burns over 30% or more of your body
What is the difference between prealbumin, albumin, and microalbumin tests?
The prealbumin test measures a protein that reflects your nutritional status, particularly before and after surgery, or if you are hospitalised or taking nutritional supplements. Albumin testing is more often used to test for liver or kidney disease or to learn if your body is not absorbing enough amino acids. Albumin can also be used to monitor nutritional status, however, prealbumin changes more quickly, making it more useful for detecting changes in short-term nutritional status than albumin. The microalbumin test measures very small levels of albumin in your urine and may indicate whether you are at risk for developing kidney disease.