Homocysteine Test

Homocysteine is an amino acid (a building block of the body) produced during protein breakdown. It is produced in small amounts in the blood. The primary sources of methionine like fisheries, meats and dairy products are converted into homocysteine. This conversion takes place through several compounds like vitamin B6, B12 and folic acid.

Homocysteine is typically low in the body, so elevated levels may indicate deficiencies of several vitamins. To rule out this vitamin deficiency, your doctor may prescribe you a blood homocysteine test, a test that examines levels of vitamin B6, vitamin B12 and vitamin B9 (folic acid). In some countries, the homocysteine test is a routine newborn screen test.

Some of the symptoms seen in vitamin deficiencies like dizziness, weakness, fatigue, increased heart rate, loss of appetite, paleness, sore tongue and mouth, tingling, numbness and burning in the feet, hands and arms can be signs of abnormal levels of homocysteine in the blood.

A high homocysteine level is also associated with some disease conditions like atherosclerosis, osteoporosis, heart attack, thyroid dysfunction, kidney disease, psoriasis and side effects of certain medications.

Moreover, high homocysteine levels can cause risk complications such as heart attacks, strokes, dementia and others if they aren't properly treated. Although, the high homocysteine condition may be more prevalent in some populations, such as alcoholics (due to their poor vitamin intake) or patients with chronic kidney disease.

The statistics indicate that between 5% and 12% of people have mildly elevated levels of homocysteine (hyperhomocysteinemia). The National Health and Nutrition Examination Survey (NHANES III) states that 92.85% of men (>11.4umol/L) and 81.60% of women (10.4umol/L) have high homocysteine levels in their blood.

Other names of the homocysteine test

• Total Homocysteine Test
• Plasma Total Homocysteine Test
• HCY SP Test

What does the homocysteine test measure and who is this prescribed for?

The homocysteine test measures the level of homocysteine in the blood and also gives ideas of vitamin deficiencies. Abnormal results may depict a heart problem.

A low or high level of homocysteine in the blood can have symptoms correlated with a deficiency of some vitamins.

Some of the symptoms with increased levels of homocysteine in the blood are:

• Pale skin
• Weakness
• Dizziness
• Mood swings
• Mouth sores
• Burning or tingling sensation in the hands and legs
• Muscle weakness
• Pale or yellowish skin
• Depression
• Shortness of breath
• Irregular heartbeat
• Weight loss
• Mental confusion
• Stress

Some disease conditions which show variation in homocysteine levels are:

• Atherosclerosis
• Osteoporosis
• Heart attack
• Thyroid dysfunction
• Kidney disease
• Psoriasis

So if you are suffering from the above symptoms and the above-mentioned diseases, it is best to detect homocysteine in the blood. Also, if you have a positive family history of heart disease or strokes, it is best to get tested for homocysteine.

However, abnormal homocysteine levels in the blood always do not necessarily mean you have a medical condition. Some factors like ageing, high alcohol consumption and being male can affect your homocysteine blood levels.

After a homocysteine blood test, if the higher levels indicate vitamin deficiency or heart disease, further management will be decided by the cardiologist. Regular testing every three months is required for monitoring and adjusting the dosage.

Drug medications like phenytoin, sulfasalazine and methotrexate are used to treat high levels of homocysteine in the blood.

The homocysteine test is performed on a blood sample. A 10-12 hour fasting blood sample requires taking accurate results of blood homocysteine level.

Test Preparation

• The homocysteine test is a simple blood test that requires a fasting preparation of 10 to 12 hours.
• You should avoid taking any beverages like tea, coffee and milk until your blood sample is collected.
• You can drink only water during this period.

What are the parameters included in the test?

This test measures the level of homocysteine in the blood.

The homocysteine test values give an idea about the decrease of homocysteine level or its higher levels in the blood. If the value is on the higher side or lower side, it indicates a disorder related to cardiovascular, blood clotting, stroke, osteoporosis and dementia, etc. Although, a low level of homocysteine is rare.

How frequently should you take this test?

The homocysteine test measures the amount of homocysteine amino acid present in the blood. The test helps diagnose and monitor deficiencies of vitamins B6, B12 and folic acid. Also, this homocysteine blood test gives an idea about heart-related problems or rare inherited diseases.

Your doctor may recommend repeating the homocysteine blood test every three months if you have detected a high level of homocysteine in the blood. But, if no abnormal results are shown with the test, an annual testing recommendation will be recommended by your doctor.

Homocystinuria, Vitamin deficiency, Cardiovascular diseases

The normal range of homocysteine in the blood is measured in micromoles per litre (μmol/L).

Normal range: 6.6-14.80 μmol/L

High levels of homocysteine are considered above 14.80 μmol/L and termed as a condition called hyperhomocysteinemia.

This condition is further classified into other ranges:

• Moderate hyperhomocysteinemia: 15 to 30 μmol/L

• Intermediate hyperhomocysteinemia: 30 to 100 μmol/L

• Severe hyperhomocysteinemia: more than 100 μmol/L

Increased or decreased levels of homocysteine in the blood can cause several medical conditions.

High levels of homocysteine are indicators of these diseased conditions:

• Osteoporosis: Excess homocysteine levels in the blood can generate a diseased condition in which bones get weaker or thinner than usual and lead to mild to severe pain in joints and bones.

• Thrombosis: A condition in which blood clots form in arteries due to excessive homocysteine levels and other factors in the blood.

• Venous thrombosis: A condition in which blood clots deposit in the venous vessels of the body as a result of high homocysteine levels.

• Heart attack: With an excess of homocysteine levels and clotting in blood vessels, the blood flow to the heart can be restricted, resulting in heart attacks or strokes.

• Dementia: It is a term used to determine a medical condition in which a person has an impaired ability to remember, think and disturb their daily life. If the homocysteine level remains elevated irrespective of treatment, then it can lead to dementia.

• Alzheimer's disease: A dementia condition that impairs memory and mental functions of the individual.

Low levels of homocysteine:

There are some rare cases of low levels of homocysteine in the blood. Low homocysteine has been associated with peripheral neuropathy (weakness, pain from nerve damage, usually in hands and feet).