Homocysteine Levels and Heart Risks

June 23, 2010) - Scientists are still trying to figure out if homocysteine (Read about "Homocysteine") is a risk factor for heart disease or not. A new study has found that it appears that using supplements to lower homocysteine levels after a heart attack (Read about "Heart Attack") doesn't do much to lower the risk of another heart attack. Blood homocysteine levels are positively associated with cardiovascular disease, but it is uncertain whether the association is causal, according to background information in the article.

Patients who had experienced a heart attack and lowered their blood homocysteine levels with folic acid and vitamin B12 supplementation (Read about "Vitamins & Minerals") did not have an associated lower risk of heart attack, coronary death or stroke (Read about "Stroke"), according to a study in the Journal of the American Medical Association. However, the researchers did find that folic acid supplementation did not increase the risk of cancer (Read about "Cancer: What It Is"), which has been speculated.

Researchers assessed the effects of lowering homocysteine levels with folic acid plus vitamin B12 in 12,064 survivors of heart attack. Patients were randomized to receive either 2 mg. folic acid plus 1 mg. vitamin B12 daily or matching placebos. The primary outcomes measured included first major vascular event, defined as major coronary event (coronary death, heart attack, or coronary revascularization), fatal or nonfatal stroke, or noncoronary revascularization.

Patients who received the study vitamins reduced homocysteine by an average of 28 percent. During 6.7 years of follow-up, major vascular events occurred in 1,537 of 6,033 participants (25.5 percent) allocated folic acid plus vitamin B12 vs. 1,493 of 6,031 participants (24.8 percent) allocated placebo. "There was no evidence of any benefit beginning to emerge with more prolonged treatment and follow-up," the authors write.

Receipt of study vitamins also was not associated with a significant effect on any stroke (vitamins, 4.5 percent vs. placebo, 4.4 percent); noncoronary revascularizations (vitamins, 3.0 percent vs. placebo, 2.5 percent); or major coronary events (vitamins, 20.4 percent vs. placebo, 19.6 percent). There were no apparent differences in the numbers of deaths attributed to vascular causes or nonvascular causes.

"These results highlight the importance of focusing on drug treatments (e.g., aspirin, statins, and antihypertensive therapy) and lifestyle changes (in particular, stopping smoking and avoiding excessive weight gain) that are of proven benefit, rather than lowering homocysteine with folic acid-based vitamin supplements, for the prevention of cardiovascular disease," the authors conclude. (Read about "Quit Smoking" "Fighting Weight Gain")