What is homocysteine?

Homocysteine is an amino acid containing sulfur and is a product of the metabolism of methionine, which is an essential amino acid that the body derives its energy from. This amino acid which is produced by the human body, is usually as a byproduct of the consumption of meat products. Homocysteine is normally converted into other amino acids. An abnormal accumulation of homocysteine, which can be measured in the blood, can be a marker for the development of heart disease. Elevated levels of homocysteine in the blood appear to increase the risk of heart attack, stroke, peripheral vascular disease, and venous thromboembolism (blood clots in the veins). Homocysteine is believed to damage blood vessels in several ways. Firstly it injures the cells that line arteries and stimulates the growth of smooth muscle cells. Homocysteine can also disrupt normal blood clotting mechanisms. Elevated levels of homocysteine also appear to increase the risk of Alzheimer's disease in patients

Homocystinuria is a rare genetic disorder that occurs in about one in every 200,000 individuals. This congenital metabolic disorder causes large amounts of homocysteine to be excreted in the urine. Homocystinuria is associated with mental retardation and the development of heart disease before the age of 30.

Why measure the level of homocysteine?

The examination of the levels of homocysteine present in the human body, can be useful for assessing cardiovascular health problems. High levels of homocysteine in fact, may pose a risk to the patient’s heart. High levels of homocysteine is associated with low levels of the vitamin B6 and B12, and folate and renal disease. Research has shown, however, that reducing your homocysteine levels with vitamins does not reduce the risk of heart disease.

Homocysteine is thought to be irritate the lining of the blood vessels causing them to become scarred, hardened, and narrowed. This hence increases the work the heart must do (pumping blood to the organs), leading to heart disease. High levels of homocysteine also cause increased blood clotting. Blood clots can decrease or block the flow of blood through blood vessels, resulting in strokes and heart attacks. The level of homocysteine in the blood naturally varies with many factors, such as age, gender, diet, hereditary factors, and general health, but it is estimated that nearly 5-10% of the population has homocysteine levels that are considered high. With the exception of rare individuals who have congenital homocystinuria, people with high blood levels of homocysteine do not have any obvious signs or symptoms.

Preparation standard

Sampling is usually done in the morning in the hospital. There are no special preparations needed for this test. The doctor will advise and recommend if you need to be fasting prior to the blood examination. You should inform your doctor of any medication you are taking prior to the exam, as some medical treatments may interfere with the blood results.

Is the examination painful or dangerous?

The examination is neither painful nor dangerous. The patient may feel a tingling sensation with the entrance of the needle in the arm when blood is being extracted for examination.

How is the exam performed?

The exam consists of a simple blood sample test.