The Blood Test for Homocysteine

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Homocysteine - An Amino Acid

Homocysteine is an amino acid that can not be directly produced by the body. It is metabolized from a precursor called methione which is considered to be one of the essential amino acids. An essential amino acid is one that cannot be produced by the body and must be part the daily diet. Homocysteine is affected by diet as well as genetic history. The utilization of homocysteine is impacted by the presence of folic acid as well as vitamin B6 and vitamin B12. These vitamins help to break down homocysteine. The absence of or low levels of folic acid, and the B vitamins results in increased homocysteine levels in the blood. People with low folic acid and high homocysteine are at higher risk for coronary heart disease, stroke and blood clots. The blood test for homocysteine is essential for diagnosing people at risk for these conditions.

What do Homocysteine Blood Results Mean?

The blood test for homocysteine is done on plasma. The normal values are 6.3 - 15.0 micro-moles/liter. Elevated results from the blood test for homocysteine may be indicators of high risk for coronary heart disease, clotting and stroke. Identifying risk factors for these conditions can aid the physician to create a preventative treatment plan which may include dietary changes. Since folic acid and vitamins B6 and B12 are required to breakdown homocysteine, eating foods containing large amounts of these nutrtitional substances can reduce homocysteine levels.

Follow up with further blood test for homocysteine will determine if the dietary changes are adequate or if further monitoring or vitamin therapy is needed.

The American Heart Association does not consider elevated homocysteine levels to be a major factor in coronary heart disease. However, the AHA has determined that elevated homocysteine levels are related and should be monitored as a risk factor.

Other Testing for Diagnosis

There are other risk factors in coronary heart disease and consideration must be made of cholesterol levels (both LDL and HDL cholesterol) and triglycerides. These can result in a build up of plaque in arteries which can decrease the blood flow and increase the potential for forming clots. Other testing can include fibrinogen levels. An increase in fibrinogen can cause clotting which can lead to a heart attack or stroke. Other testing can include a C-Reactive Protein which will identify inflammation in the body. While the C-Reactive Protein is not specific for heart disease, along with other indicators can be a useful diagnostic tool.

Other Factors to Consider

Lifestyle choices that increase risk of coronary heart disease include smoking, lack of exercise, diet high in fat, diabetes and obesity. These are factors that can be changed or improved through lifestyle changes. High stress is considered a risk factor as well as drinking too much alcohol, both of which can lead to high blood pressure.