Understanding Homocysteine
What is homocysteine?
Homocysteine is an amino acid released as the body digests protein; it is known to be toxic to the blood vessels when elevated.
Hyperhomocysteinemia is a condition caused by elevated levels of homocysteine in the bloodstream and has been shown to increase the risk of diabetic complications, such as peripheral neuropathy and non-healing foot ulcers.
Determinants and factors that can increase homocysteine concentrates
Several diseases, physiological determinants, lifestyle factors, genetic defects and drugs can cause hyperhomocysteinemia.
| Genetic Defects | Disease | Drugs | Unhealthy Lifestyle | Other Key Factors |
|---|---|---|---|---|
| MTHFR-Polymorphism (frequent) | B-vitamin deficiency (folate, B12, B6, B2) | niacin | Low exercise | Post-Menopause |
| CBS deficiency (rare) | Impaired renal function | fenofibrate | Smoking/Tobacco use | Older Age |
| Malabsorption/chronic inflammatory bowel disease | metformin | High alcohol consumption | Post-heart attack | |
| Diabetes | methotrexate | High coffee consumption | Post-Stroke | |
| Hypothyroidism | levodopa | Poor nutrition | Kidney Failure | |
| phenytoin |
How do homocysteine levels become elevated?
Elevated levels of homocysteine occur when your body does not have the necessary co-factors to breakdown homocysteine.
The necessary co-factors are L-methylfolate, pyridoxal 5'-phosphate, and methylcobalamin.
What happens when my homocysteine is elevated?
Elevated Homocysteine levels may reduce blood flow to the peripheral vessels and nerves in the following ways:
- Homocysteine can interfere with the production of Nitric Oxide (NO) and alter the elastic properties of the arteries.15
- Homocysteine can induce the initial injury to the arterial wall and facilitate the accumulation of the LDL or "bad" cholesterol beneath the damaged vessel wall.16
- Homocysteine promotes the growth of smooth muscle cells in the artery, which narrows the vessel.
- Homocysteine contributes to the abnormal accumulation of blood platelets around the damaged vessel wall, increasing the risk of blood clots.16
How do you reduce homocysteine levels?
- L-methylfolate and Methylcobalamin (B12) reduce homocysteine levels by metabolizing it back to methionine, a necessary amino acid.
- Pyridoxal 5'-Phosphate (B6) facilitates the breakdown of homocysteine to cysteine and other waste products.
- Increased doses of folate, vitamin B12 and vitamin B6 have been shown to reduce elevated homocysteine levels up to 72%.17
What are normal homocysteine levels?
The American Heart Association has indicated that a reasonable therapeutic goal for homocysteine, especially for those patients at increased risk of heart disease, is less than 10 µmol per liter.18
| Classifications of Hyperhomocysteinemia | |
|---|---|
| Mild | 15-30 µM/L |
| Intermediate | 30-100 µM/L |
| Severe | >100 µM/L |
| Indications for Regular Testing of Homocysteine in High Risk Patients16,18-21 | ||
|---|---|---|
| Indicated | Not Indicated | |
| Asymptomatic Subjects | X | |
| Patients with manifest CVD | X | |
| Strong family history of Premature CVD | X | |
Asymptomatic, high risk patients:
|
X X X X X |
|
Getting your homocysteine tested is as easy as having your cholesterol tested. Just ask your doctor if a homocysteine test is appropriate for you or your loved one. If it is deemed necessary by your healthcare provider, you will be asked to provide a small blood sample. After the results are returned, your doctor will provide you with an appropriate course of action according to your specific needs.