Homocysteine

Description: Homocysteine is an amino acid that is present in every cell. There is a small amount present as it is an amino acid that changes quickly into other needed products in the body.

Also Known As: Homocysteine Cardiac Risk Test, Homocysteine Blood Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: Fasting for at least 8 hours is preferred

When is a Homocysteine test ordered?

When a doctor feels a person may be deficient in vitamin B12 or folate, he or she may request this test. At first, the signs and symptoms are vague and ambiguous. People who have an early deficit may be diagnosed before they show any visible symptoms. Other persons who are impacted may experience a range of moderate to severe symptoms, including:

Depending on an individual's age and other risk factors, homocysteine may be requested as part of determining a person's risk of developing cardiovascular disease. It may also be ordered after a heart attack or stroke to aid in treatment planning.

When newborn screening identifies an increased level of methionine or if an infant or kid shows signs and symptoms of homocystinuria, this test may be ordered. Babies with this illness will appear normal at birth, but if left untreated, they will develop symptoms such as a displaced lens in the eye, a long slender build, long thin fingers, and skeletal abnormalities within a few years.

What does a Homocysteine blood test check for?

Homocysteine is an amino acid that is found in trace amounts in all of the body's cells. The body generally converts homocysteine to other compounds fast. Because vitamins B6, B12, and folate are required for homocysteine metabolism, elevated levels of the amino acid could indicate a vitamin deficit. The level of homocysteine in the blood is determined by this test.

Increased homocysteine levels have also been linked to an increased risk of coronary heart disease, stroke, peripheral vascular disease, and artery hardening. Homocysteine has been linked to cardiovascular disease risk through a variety of processes, including damage to blood vessel walls and support for the production of abnormal blood clots, but no direct linkages have been established. Several studies have also found no benefit or reduction in CVD risk with folic acid and B vitamin supplementation. The American Heart Association does not believe it to be a significant risk factor for heart disease at this time.

Homocysteine levels in the blood can also be dramatically increased by a rare genetic disorder known as homocystinuria. In homocystinuria, one of multiple genes is mutated, resulting in a defective enzyme that prevents the normal breakdown of methionine, the precursor of homocysteine. Methionine is one of the eleven necessary amino acids that the body cannot make and must therefore be obtained from food.

Homocysteine and methionine build up in the body without the necessary enzyme to break them down. Babies born with this condition appear normal at birth, but develop symptoms such as a long slender build, a dislocated lens in the eye, long thin fingers, osteoporosis, skeletal abnormalities, and a significantly increased risk of thromboembolism and atherosclerosis, which can lead to premature CVD within a few years.

In addition to intellectual disability, mental illness, a little low IQ, behavioral issues, and seizures, artery blockages can induce intellectual disability, mental illness, and seizures. Some of them can be avoided if homocystinuria is diagnosed early, which is why all states screen neonates for the disease.

Lab tests often ordered with a Homocysteine test:

Conditions where a Homocysteine test is recommended:

How does my health care provider use a Homocysteine test?

The homocysteine test can be used in a variety of ways, including:

A homocysteine test may be ordered by a doctor to see if a person is deficient in vitamin B12 or folate. Before B12 and folate tests are abnormal, the homocysteine level may be raised. Homocysteine testing may be recommended by some health professionals in malnourished people, the elderly, who absorb less vitamin B12 from their diet, and people who have poor nutrition, such as drug or alcohol addicts.

For those at high risk of a stroke or heart attack, homocysteine testing may be requested as part of a health screening. It could be beneficial for someone who has a family history of coronary artery disease but no other recognized risk factors like smoking, high blood pressure, or obesity. However, because the specific role of homocysteine in the course of cardiovascular disease is unknown, the screening test's efficacy continues to be questioned.

If a health professional believes that an infant or kid has homocystinuria, tests for both urine and blood homocysteine can be utilized to assist diagnose the genetic condition. As part of their newborn screening in the United States, all babies are regularly tested for excess methionine, a symptom of homocystinuria. If a baby's test results are positive, urine and blood homocysteine tests are frequently used to confirm the results.

What do my homocysteine test results mean?

Homocysteine levels may be high in cases of suspected malnutrition, vitamin B12, or folate insufficiency. If a person does not consume enough B vitamins and/or folate through diet or supplements, the body may be unable to convert homocysteine into forms that the body can use. The level of homocysteine in the blood may rise in this scenario.

According to studies conducted in the mid- to late-1990s, those with high homocysteine levels have a substantially higher risk of heart attack or stroke than those with normal levels. The study of the relationship between excessive homocysteine levels and heart disease is still ongoing. However, considering that multiple trials studying folic acid and B vitamin supplementation have found no benefit or reduction in CVD risk, the use of homocysteine levels for risk assessment of cardiovascular disease, peripheral vascular disease, and stroke is now questionable.

A 2012 research study using various datasets, including 50,000 persons with coronary heart disease, called into question the possibility of a cause-and-effect relationship between homocysteine levels and heart disease. Although the American Heart Association recognizes a link between homocysteine levels and heart attack/stroke survival rates, it does not consider high homocysteine to be a major CVD risk factor.

While the AHA does not advocate for widespread use of folic acid and B vitamins to reduce the risk of heart attack and stroke, it does advocate for a balanced, nutritious diet and advises doctors to consider total risk factors as well as nutrition when treating cardiovascular disease.

Significantly elevated homocysteine concentrations in the urine and blood indicate that an infant is likely to have homocystinuria and need additional testing to confirm the reason of the increase.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.