Hyperhomocysteinemia

Overview

Hyperhomocysteinemia is a medical condition characterized by an abnormally large level of homocysteine in the blood. As a consequence of the biochemical reactions in which homocysteine is involved, deficiencies of the vitamins folic acid, pyridoxine (B6), or B12 can lead to high homocysteine levels. Supplementation with pyridoxine, folic acid, B12 or trimethylglycine (betaine) reduces the concentration of homocysteine in the bloodstream.

Symptoms

* general pain and achiness * heart disease * inflammation * recurring blood clots * vascular damage.

Causes

* genetic mutations: Recent studies have determined that mutations on the MTHFR gene may be responsible for moderate cases of hyperhomocysteinemia. * medications: Some people acquire hyperhomocysteinemia by taking certain medications, including anticonvulsants, cyclosporine, methotrexate and theophylline. * nutritional deficiencies: Up to two-thirds of all hyperhomocysteinemia cases are due to nutritional deficiencies. These deficiencies make it difficult to metabolize folate, B12 and B6, all vitamins that in turn help control levels of homocysteine. * other medical conditions: The presence of other, more serious underlying disorders can cause hyperhomocysteinemia. Liver disease, kidney disease, hypothyroidism and some cancers can all increase homocysteine to dangerous levels. * rare metabolic disorders: When a person’s metabolism isn’t fast enough to process the homocysteine in the blood, levels of this amino acid increase to unhealthy levels, causing hyperhomocysteinemia.

Diagnosis

In general, doctors diagnose hyperhomocysteinemia when performing blood work to check homocysteine levels when treating the following conditions: * heart attack * heart or kidney transplants * high levels of homocysteine in urine * kidney failure * peripheral vascular disease * premature arteriovascular disease * recurring pulmonary embolism * stroke * venous thrombosis.

Treatment

Unlike many other thrombophilic disorders, hyperhomocysteinemia can be treated directly with vitamin supplementation. The primary vitamin used to lower homocysteine levels is folate and studies have clearly shown a decrease in homocysteine levels with folate. Taking folate and vitamin B12 can lead to an additional decrease in homocysteine levels above that seen with folate alone. A study looking at the use of vitamin B6 did not show any increased benefit in using folate and vitamin B6 over just folate alone. Although vitamin supplementation has been shown to lower homocysteine levels, there is no data at this time that addresses what impact this has on a person's risk of venous or arterial thrombotic problems.