Alkaline phosphatase Test
|What is the purpose of this test:
The alkaline phosphatase test is used to help detect hepatobiliary and bone disorders.
|How to prepare:
- A simple blood sample is taken.
- Overnight fasting is usually required.
Children/adolescents and women who are pregnant have higher levels of alkaline phosphatase due to bone growth in children and placental growth in women during pregnancy.
- Women: 35 to 104 U/L
- Men: 40 to 129 U/L
A liver function test, a gamma-glumatyl-transpeptidase test and a 5'-nucleotidase test can help confirm hepatobiliary disorder.
Alkaline phosphatase is an enzyme found in the intestines, spleen, kidneys and placenta. It is the alkaline phosphatase enzymes in the liver and bones however, that are responsible for serum alkaline phosphatase activity.
What does an abnormal test result mean?
If test results are high
If test results are low
- High alkaline phosphatase levels may be indicative of disease in the liver (cholestasis, neoplasia, hepatitis, cirrhosis, etc.) or bone (fracture, tumour, Paget's disease, etc.).
- Abnormally low alkaline phosphatase levels may be the result of: Wilson's disease, hypothyroidism, pernicious anemia, zinc deficiency or hypophosphatasia.
Factors that can affect results
- Race (higher incidence in African Americans)
- High body mass index
Some drugs may affect levels of alkaline phosphatase in the blood. A few examples are listed below:
- Acetylsalicylic acid (Aspirin®)
- Alendronate (Fosamax®)
- Amiodarone (Cordarone®)
- Chlorpromazine (Largactil®)
- Clofibrate (Atromide ®)
- Erythromycin (Eryc®)
- Esterified estrogens
- Isoniazid (Isotamine®)
- Levothyroxine (Synthroid®)
- Lithium (Carbolith®)
- Methyltestosterone (Metandren®)
- Oral contraceptives
- Oral hypoglycaemic drugs
- Theophylline (Theo Dur®)
What you should know before going for this test
Before going for a blood test, examination or other, it is always a good idea for you to have a complete list of all prescription and over the counter medications and/or natural products you may be taking. If you are unsure or have any questions, your pharmacist will be able provide you with additional information.