What are the other Names for this Test? (Equivalent Terms)
- Urine Homocysteine Test
What is Homocysteine Urine Test? (Background Information)
- Homocysteine is an amino acid found in most cells of the body, in trace amounts. It is an intermediate in the conversion of the amino acid methionine into other products, such as cysteine
- The metabolism of methionine through homocysteine involves enzymes that use vitamins B6 (pyridoxine), B9 (folate), and B12 (cobalamin). Ample supplies of these B vitamins keep the enzymes functioning and prevent homocysteine buildup
- Normally, homocysteine levels are low, because it is constantly turned into other products. In the case of vitamin B deficiencies or genetic enzyme defects, the metabolism of methionine through homocysteine may slow or stop. This results in elevated homocysteine levels and it accumulates in the body cells
- This may increase the risk of cardiovascular disease, because large amounts of homocysteine can damage the inner endothelial lining of blood vessels, change clotting factor levels, and make platelets more prone to aggregation
- The Homocysteine Urine Test measures homocysteine levels in urine. It is used to detect vitamin B deficiency or genetic disorders affecting homocysteine metabolism. This also provides an indirect assessment of the risk for cardiovascular diseases
What are the Clinical Indications for performing the Homocysteine Urine Test?
Following are the clinical indications for performing a Homocysteine Urine Test:
- Pale appearance
- Rapid heart rate
- Trouble breathing
- Chest pain radiating to the jaw
- Tingling in the extremities
How is the Specimen Collected for Homocysteine Urine Test?
Following is the specimen collection process for Homocysteine Urine Test:
Sample required: Urine
Process: Urination into a sterile container.
Preparation required: Fasting for 2-12 hours may be necessary
What is the Significance of the Homocysteine Urine Test Result?
The significance of the Homocysteine Urine Test is explained:
- Increased homocysteine urine levels may indicate:
- Vitamin Bdeficiency
- Chronic kidney failure
- Homocystinuria (a genetic disorder)
- Coronary artery disease (CAD)
The laboratory test results are NOT to be interpreted as results of a "stand-alone" test. The test results have to be interpreted after correlating with suitable clinical findings and additional supplemental tests/information. Your healthcare providers will explain the meaning of your tests results, based on the overall clinical scenario.
Additional and Relevant Useful Information:
- In pregnant women, elevated urine homocysteine levels may affect fetal development, especially of the nervous system
- Homocysteine levels lag behind vitamin B12 levels; so treatment for possible vitamin B12 deficiency may be started, even before the results of this test becomes available
- With rare exceptions, vitamin B12 is available only from animal sources. Individuals with vegan diets are at an increased risk for vitamin B12 deficiency, and must supplement their diets with foods containing vitamin B12
Certain medications that you may be currently taking may influence the outcome of the test. Hence, it is important to inform your healthcare provider, the complete list of medications (including any herbal supplements) you are currently taking. This will help the healthcare provider interpret your test results more accurately and avoid unnecessary chances of a misdiagnosis.
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References and Information Sources used for the Article:
Lab Tests Online (2014, April 30). Retrieved August 31, 2014 from http://labtestsonline.org/understanding/analytes/homocysteine/
Martini, F., Nath, J. L., & Bartholomew, E. F. (2012). Fundamentals of anatomy & physiology (9th ed.). San Francisco: Benjamin Cummings.
Schnell, Z. B., Van, L. A., & Kranpitz, T. R. (2003). Davis's Comprehensive handbook of laboratory and diagnostic tests: With nursing implications. Philadelphia: F.A. Davis.