By Michael F. Richman, MD, FACS, FCCP
So, your doctor looks at your blood test and says, “You have high homocysteine levels.” What does that mean? And what should you do about it?
Homocysteine is a common amino acid (one of the building blocks that make up proteins) found in the blood and is acquired mostly from eating meat. I have written before about the possible role of elevated homocysteine levels in causing heart attacks or strokes. High levels of homocysteine are related to the early development of heart and blood vessel disease. In fact, it is considered an independent risk factor for heart disease. High homocysteine is associated with low levels of vitamin B6, B12 and folate and kidney disease.
Research has shownthat both folic acid and B vitamins lower homocysteine levels, and many researchers and physicians believed that this would lower a patient’s overall cardiovascular risk. Not so. Recently, a study called the Women’s Antioxidant and Folic Acid Cardiovascular Study found that supplemental folic acid and B vitamins do not lower the risk for important vascular events in women who are otherwise at high risk for such events, even though these supplements lower homocysteine levels.
What is high risk? A minimum of three “cardiac risk factors” puts anyone at high risk. They are: high cholesterol, hypertension, metabolic disorder, a family history of heart disease and a prior heart-related event, such as heart attack or stroke. Lifestyle indicators include obesity and cigarette smoking.
The study was a randomized, double-blind, placebo-controlled trial conducted in Boston that began in 1998 with 5,442 women, age 40 and older with a history of cardiovascular disease, and studied them over the course of seven years. Study participants received either a folic acid/B vitamin combination or a matching placebo. What they found was startling to the medical community. Over the course of 7.3 years, there was a similar incidence of heart attacks and strokes between the group that received the vitamins and the one that didn’t. In fact, 406 women in the treatment group and 390 in the placebo group experienced at least one “event” of heart attack or stroke.
These findings are identical to those seen in the Heart Outcomes Prevention Evaluation trial, the Norwegian Vitamin Trial and the Vitamin Intervention for Stroke Prevention trial, among others (which enrolled mostly men), even though the therapy is successful in reducing homocysteine levels. While numerous observational, epidemiological studies have confirmed that elevated homocysteine is a predictor of cardiovascular risk, it has become very clear that lowering homocysteine levels has little to no outcome for men or women at high risk of cardiovascular disease. So, why are people with elevated homocysteine levels at high risk for cardiovascular disease? Medical researchers are working on this one. As a heart surgeon, I see clogged arteries every week, up close and personal. It makes you wonder, is homocysteine really the culprit? Or, is it just the result of something else that is going on in the body? I will keep you updated as new trials and information are released on this important subject.