Prealbumin

What is being tested?
The test measures levels of prealbumin, an important protein found in serum. Prealbumin has a half-life of only two days, which means it breaks down quickly in the body and its concentration changes constantly. This short half-life gives doctors an immediate picture of your nutritional status.

How is the sample collected for testing?
A blood sample is taken with a needle from a vein in the arm.

How is it used?
When is it requested?
What does the test result mean?
Is there anything else I should know?

How is it used?
The prealbumin test is used to help your doctor diagnose problems with your nutrition. 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 it is not treated. Malnourished children may fail to thrive or show delayed growth.

The test is also used to assess nutritional status:

• Before planned surgery
• In patients admitted to hospital with certain conditions
• In patients who are chronically ill.

Many patients show a decrease during their hospital stay, especially after surgery. Studies have shown that good nutrition before surgery helps to prevent complications, such as pneumonia and infection, after the operation. If the prealbumin test shows that you are malnourished or poorly nourished, your doctor can help you correct your diet so that you are stronger before surgery. Albumin may be tested instead to determine nutritional status.

The test is also used to monitor changes in patients receiving parenteral nutrition (nutrition given outside the gastrointestinal tract, such as nutrients given intravenously). It is also used to monitor changes in the nutritional status of patients on haemodialysis, a process that removes waste substances from the bloodstream. Haemodialysis is part of the treatment for patients with kidney disease.

When is it requested?
A doctor orders a prealbumin test when there are signs of malnutrition or poor nutrition. Signs of malnutrition include excessive weight loss, delayed growth (in children), reduced resistance to infection, or being unable to think clearly. Hair may become brittle or start to fall out, the skin may be dry or yellowish, the muscles may feel weak, and fainting may occur. In young women, menstrual periods may stop.

Generally, a prealbumin or albumin test will be ordered before surgery or when a patient is being treated for certain illnesses. Doctors may order the test regularly to monitor patients who have had low prealbumin results. How often monitoring is done depends on the test result.

What does the test result mean?
The prealbumin level reflects your nutritional status. If prealbumin is low, other proteins and substances in the blood may also be low.

If the test shows that prealbumin is low, your nutrition probably needs to be corrected. If prealbumin is very low, you may be considered malnourished and need immediate medical attention. Lower prealbumin levels may be seen in patients with:

• Severe or chronic illness, such as cancer
• Hyperthyroidism
• 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 sharply and very quickly.

Higher prealbumin levels are common in patients with:

• High-dose corticosteroid therapy
• Overactive adrenal glands
• High-dose non-steroidal anti-inflammatory drug therapy
• Hodgkin’s disease

If a patient has kidney failure, prealbumin values may be falsely higher than they actually are.

Is there anything else I should know?
Inflammation can interfere with prealbumin test results, making them lower than they should be. Some medicines can also lower prealbumin levels, including amiodarone, oestrogens and oral contraceptives (the contraceptive pill).

Medicines that can raise blood prealbumin levels include anabolic steroids, androgens (male hormones) and prednisolone.

Recent research has shown that the prealbumin test can predict poor outcomes for patients on haemodialysis. A low initial (baseline) prealbumin reading predicts that a patient may have problems, and persistently low prealbumin values are associated with lower survival.

1. What conditions can lead to malnutrition?
2. What is the difference between the prealbumin, albumin and microalbumin tests?

1. What conditions can lead to malnutrition?
Various illnesses can lead to what is known as protein-calorie malnutrition. Common illnesses linked to this form of malnutrition include:

• cancer
• chronic illnesses
• protein loss from the gastrointestinal tract
• anorexia and other eating disorders
• liver disease
• multiple trauma
• obesity
• pancreatitis
• burns covering 30% or more of the body

2. What is the difference between the prealbumin, albumin and microalbumin tests?
Albumin and microalbumin are the same molecule, whereas prealbumin, despite its similar-sounding name, is a completely unrelated molecule. The prealbumin test measures a protein that reflects your nutritional status, particularly before and after surgery, or if you are in hospital or taking nutritional supplements. The albumin test is more often used to check for liver and kidney disease or to find out whether your body is not absorbing enough amino acids. Albumin can also be used to monitor nutritional status. However, because prealbumin changes more quickly, it is more useful than albumin for detecting short-term changes in nutritional status. The microalbumin test measures very low levels of albumin in your urine and can indicate whether you are at risk of developing kidney disease.