TUESDAY, Feb. 13, 2007 (HealthDay News) -- Reducing iron levels by removing blood seems to have a beneficial effect on people with peripheral arterial disease (PAD) -- a partial or total blockage of an artery, usually one leading to an arm or a leg.
However, the blood-letting treatment is only effective against PAD if the process of iron reduction begins at a relatively young age, researchers say.
The findings, published in the Feb. 14 issue of the Journal of the American Medical Association, add more fuel to the debate regarding iron and cardiovascular disease. But they also point to some practical measures people can take, such as paying attention to iron intake through food and supplements.
"I don't think we can make the flat-footed recommendation [for iron removal] on the basis of this data," said Dr. Leo R. Zacharski, lead author of the study and a physician-researcher at White River Junction (Vt.) Veterans Affairs Medical Center and Dartmouth Medical School. "But it definitely raises very practical issues of everyday life."
"The issue of iron is one we need to pay attention to," added Dr. Suzanne Steinbaum, a cardiologist with the Heart and Vascular Institute at Lenox Hill Hospital in New York City. "We know that women develop heart disease later in life after they stop menstruating, while men have a high storage of iron throughout their life. For men, it's very important to take a multivitamin that doesn't have iron. Women need iron while they're menstruating, but after they hit menopause, they don't need it."
Excess accumulation of iron in the body is thought to be a risk factor for coronary heart disease. So, by that theory, reducing iron stores would also reduce cardiovascular risk.
This hypothesis is based on the fact that premenopausal women (who lose iron through menstruation) had a lower incidence of coronary heart disease, while men and postmenopausal women (who do not excrete iron) have a higher risk. Also, men who donated blood were found to have fewer heart problems than men who did not. Other studies, however, have had mixed results.
"There is evidence that iron accumulates over time. There's no question about that," Zacharski said. "We have no way of excreting iron and, as it builds up in the system, it exerts oxidative stress that causes damage to the tissue. It has been correlated with disease risk."
To test the iron hypothesis, these researchers randomized 1,277 patients with symptomatic but stable PAD to undergo phlebotomy (blood-letting) every six months or to a control group that did not undergo the procedure.
Phlebotomy was chosen because, Zacharski said, "there's no drug or device, and it's totally safe." Researchers could also measure the amount of blood needed to lower iron levels (it turned out to be just under a unit of blood every six months).
There were no significant differences between the two groups when it came to all-cause mortality or death plus nonfatal heart attack and stroke.
But, differences were seen when the participants were stratified by age. Younger patients (aged 43 to 61) in the iron unloading group had 54 percent fewer deaths from all causes and 57 percent fewer deaths occurring after nonfatal heart attacks and strokes. Smokers and individuals without diabetes who underwent phlebotomy also seemed to have better outcomes.
"Taking the total cohort, there isn't an effect, but if you look at younger people or smokers, it looks like there's an effect," Zacharski said. "It looks like there are factors that come into play early in a person's life that contribute to morbidity and mortality later, [so] the earlier you intervene, the better the outcome."
There's more on PAD at the American Heart Association.