November 18, 2002
MEDIA CONTACT: Karen Blum
Blood Proteins Tied to Inflammation, Malnutrition Put Dialysis Patients at Higher Risk of Heart Disease
A Johns Hopkins-led study shows that two proteins, C-reactive protein and albumin, are accurate predictors of heart attack or stroke in kidney dialysis patients. The research team found that high levels of C-reactive protein, a marker of inflammation, and low levels of albumin, a sign of malnutrition, had strong ties to heart disease in these patients, who are many times more likely to develop heart problems than the general population.
"Both inflammation and malnutrition play an important role in the high risk of cardiovascular disease among dialysis patients," says Josef Coresh, M.D., Ph.D., lead author of the study and associate professor of epidemiology, medicine and biostatistics at Hopkins. "Testing for these proteins will allow us to sooner identify patients at high risk, and to manage heart disease risk factors more effectively."
Results of the study are to be presented Nov. 18 at the American Heart Association's 75th annual Scientific Sessions in Chicago.
Coresh and colleagues examined data from the Choices for Healthy Outcomes in Caring for End-stage renal disease (CHOICE) Study, a Hopkins effort that followed more than 1,000 dialysis patients nationwide between October 1995 and June 1998. For this study, they collected blood samples from 810 patients who had been on dialysis for an average of four months and measured levels of C-reactive protein and albumin. They also reviewed the patients' medical records until November 2000.
During the follow-up period, the patients had a combined 278 heart events, including heart attack, bypass surgery, angioplasty, stroke, carotid endarterectomy (a procedure to remove plaque from the neck artery), peripheral vascularization (a type of angioplasty used to dilate narrowed arteries in the legs), or amputation. The risk of heart disease increased with high C-reactive protein levels and low albumin levels, even after adjusting for factors like cholesterol level, smoking status and blood pressure.
C-reactive protein's level increases when there is an inflammation of blood vessels. Studies have shown that blood levels of the protein are elevated many years before a first heart attack or stroke. Despite that, scientists are undecided whether to test routinely for the protein, Coresh says.
Of the 20 percent of patients on dialysis who die, half do so from heart disease, Coresh says. The risk of heart disease among this population is between five and 100-fold higher than for the general population.
Study co-authors were J. Craig Longenecker, Joseph A. Eustace, Yongmei Liu, Nancy Fink, Neil R. Powe and Michael J. Klag of Hopkins; Nathan Levin of the Renal Research Institute; and Russell P. Tracy of the University of Vermont.
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Abstract #112334: Coresh, J. et al, "C-Reactive Protein and Serum Albumin Independently Predict Cardiovascular Disease (CVD) Risk Among Incident Dialysis Patients: The CHOICE Study."
Related Web sites:
Johns Hopkins' Welch Center for Prevention, Epidemiology and Clinical Research
American Heart Association