Blood protein doubles heart disease risk

Very high levels of a blood protein helps cholesterol stick to artery walls and nearly doubles the risk of heart disease, says a Boston study.

Jacqueline Suk Danik and colleagues at Boston's Brigham and Women's Hospital analysed frozen blood samples collected 10 years ago from nearly 28,000 middle-aged women who were healthy at the start of the study, reported the online edition of the science magazine WebMD.

Thy found that women who have 65.5 mg/dL or greater level of lipoprotein(a) may have a 66 percent higher risk of heart disease. One in 100 women has a level of 130.7 mg/dL or greater. That doubles a woman's risk of heart disease, the researchers said.

Lipoprotein(a) doesn't do its dirty work alone. It teams up with LDL cholesterol -- the bad cholesterol.

The link between lipoprotein(a) and heart disease is strongest among women with above-normal LDL cholesterol levels, the researchers found.

Because lipoprotein(a) showed increased risk only at very high levels, and because there is no proof yet that lowering lipoprotein(a) levels lowers heart risk, the researchers don't advise routine testing.

"Determination of lipoprotein(a) levels should be reserved for high-risk subsets of the population, such as individuals with premature [heart attacks] who have otherwise normal risk profiles," they said.