Research finds new risk for fractures

Amino acid cited; vitamins urged

By Alice Dembner, Globe Staff | May 13, 2004

Researchers have identified a significant new risk factor for fractures in people with osteoporosis - high levels of an amino acid that typically result from eating too little of certain nutrients.
Parallel studies conducted in Boston and the Netherlands found that people with high levels of homocysteine had double to quadruple the risk of suffering fractures, according to the papers published today in the New England Journal of Medicine.

Although researchers have yet to prove that the fractures are caused in part by high homocysteine levels, they suggest that seniors may be able to lower their levels -- and potentially lower their risk of fractures -- by eating more green leafy vegetables and fortified grains that contain folic acid, as well as vitamins B-6 and B-12.

Other measures already proven to reduce the risk of osteoporosis are taking vitamin D and calcium, and increasing weight-bearing exercise. Osteoporosis results in more than 1.5 million fractures each year in the United States.

"It's safe to say that seniors should take a multivitamin," said Dr. Douglas Kiel, director of medical research at the Hebrew Rehabilitation Center for Aged and the senior author of the Boston paper. "But we don't recommend that everyone go out and get their homocysteine checked."

Boston researchers studied hip fractures in 2,043 men and women, aged 59 to 91, from Framingham, who had given blood samples between 1979 and 1982 as part of the long-running Framingham Study. Tracking the subjects' health through 1998, they found that the men with the highest levels of homocysteine had nearly four times the risk of suffering a fractured hip as those with the lowest levels. Among women, the risk was nearly double.

The Dutch researchers studied 2,406 people 55 and older and found a nearly twofold increase in all kinds of fractures resulting from osteoporosis in those with the highest homocysteine levels. The link appeared to be stronger than with long-identified risk factors such as smoking and low bone mineral density.

"It is predictive" of fractures, said Joyce B. J. van Meurs, a researcher at the department of internal medicine at Erasmus Medical Center in Rotterdam, and lead author of the Dutch paper.

The researchers are unsure how the homocysteine might affect bones, but believe it might weaken the connective tissue called collagen that forms the framework for bones.
"It's still possible it's an innocent bystander," said Dr. Lawrence Raisz, professor of medicine and director of the Center for Osteoporosis at the University of Connecticut, who wrote an editorial accompanying the articles. "But it's a new approach that's going to help us understand bone diseases and how to treat them."

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Source: http://www.boston.com/news/nation/articles/2004/05/13/research_finds_new_risk_for_fractures/