New Predictor of Heart Disease Found in African Americans
Staff reports
Blood biomarker underscores role of inflammation in vascular disease
Researchers at the University of California-Davis have discovered that a blood component linked with inflammation can predict coronary artery disease in African-Americans.
Known as lipoprotein-associated phospholipase A2 (Lp-PLA2), the blood factor is also associated with, but does not accurately predict, heart-disease risk in Caucasians. The findings are published in the current issue of the Journal of Clinical Endocrinology and Metabolism.
“This study suggests that inflammation may be a more important mechanism in heart disease for African Americans than it is for Caucasians and increases our growing understanding of how heart disease processes vary in different ethnic groups,” said Lars Berglund, senior study author and associate dean for research at the UC Davis School of Medicine. “The more we appreciate such differences, the better we can individualize treatment and prevention approaches.”
Lp-PLA2 was recently identified as a marker for the inflammatory
processes involved in atherosclerosis. It is considered key to the
progression and rupture of fatty plaques that can block coronary
arteries and lead to heart attacks. It predominately binds to
low-density lipoprotein, or LDL, which is a general marker of increased
heart-disease risk. Berglund noted, though, that more well-known factors
like LDL and high cholesterol cannot provide the whole picture of heart
disease.
“There are other important elements of heart disease—like
inflammation—that need to be better explained,” he said.
For the current study, Berglund and his team measured Lp-PLA2 levels in
the blood of 336 Caucasians and 224 African-Americans who were about to
undergo diagnostic coronary arteriography—a test used to determine
coronary artery disease in high-risk patients—at two hospitals in New
York. Coronary arteriography findings were compared with the amount and
activity levels of Lp-PLA2 from each research subject.
During the procedure, contrast dye and X-rays are used to detect
narrowed or blocked arteries, indicating the potential for heart
attacks.
“Arteriography is highly effective but considered too risky and
expensive for general screening,” said Berglund. “That is why
researchers are always on the lookout for other reliable predictors of
heart-attack risk that can be identified with a simple blood test.”
The outcomes showed that Lp-PLA2 activity was higher among Caucasians
and African Americans with coronary artery disease. In addition, only in
African Americans was the Lp-PLA2 index found to independently predict
coronary artery disease.
Although the test for Lp-PLA2 is widely available, Berglund said it is
too soon to recommend widespread testing to affect treatment decisions.
The study population was not representative of the general population as
all participants already had symptoms of heart disease. Berglund’s team
plans further studies of Lp-PLA2 and other inflammatory components of
the blood in a wider range of patients to get a clearer picture of their
roles in predicting heart disease for different ethnic and racial
groups. The outcomes of his current study, however, give him hope that
African Americans at high risk for heart disease will one day be treated
for inflammation more aggressively and earlier in the disease process.
“This study has helped open the field,” said Berglund. “More information
will allow us to better tailor therapy to specific patient needs.”
In addition to Berglund, other study authors included Erdembileg Anuurad
and Byambaa Enhkmaa of UC Davis, Thomas Pearson of the University of
Rochester, and Zeynep Ozturk of the University of Istanbul.
The study was funded by grants from the National Heart, Lung and Blood
Institute, the UC Davis Clinical and Translational Science Center and
the American Heart Association.
The UC Davis Clinical and Translational Science Center is part of a
national consortium, led by the National Center for Research Resources
at the National Institutes of Health, which is improving how biomedical
research is conducted across the nation. Its goals are to reduce the
time it takes for research discoveries to become treatments for
patients, as well as to train the next generation of clinical
researchers. For more information, visit www.ucdmc.ucdavis.edu/ctsc.
