Diabetics’ coronary calcium levels strongly linked to heart attack risk

Results of UC Irvine-led study underscore value of screening

Notable levels of calcium buildup in coronary arteries can be strong predictors of heart attacks and strokes in people with diabetes and metabolic syndrome, according to a study led by UC Irvine’s Heart Disease Prevention Program.

The researchers also found that individuals with diabetes or metabolic syndrome but no evidence of coronary calcium had cardiac-event risks as low as many without these conditions.

Supported by the National Institutes of Health, the multiethnic study of atherosclerosis involved 6,600 people ages 45 to 84. About 16 percent were diabetic (primarily type 2); another 25 percent had metabolic syndrome, a combination of disorders that can lead to cardiovascular disease and diabetes.

The researchers wanted to know whether information from a heart scan for coronary calcium or an ultrasound of the neck’s carotid artery could supplement standard factors—high cholesterol, smoking, elevated blood pressure—in assessing a person’s chance of heart attack or stroke.

“Our study points out that there’s a wide range in risk for cardiovascular consequences seen in persons with metabolic syndrome and diabetes and that screening of coronary calcium by heart scans—and, to a lesser extent, carotid arteries by ultrasound—may be helpful in picking out those most vulnerable,” said Nathan Wong, UC Irvine professor of medicine, director of the Heart Disease Prevention Program and senior author of the study.

“Our findings also suggest that individuals with significantly high levels of coronary calcium or carotid wall thickness should receive more aggressive monitoring and treatment for any associated risk factors,” added co-author Dr. Shaista Malik, a UC Irvine cardiologist.

These observations are consistent with guidelines released last year by the American Heart Association and American College of Cardiology recommending such screenings for diabetics 40 and older without known cardiovascular disease, as well as many people with metabolic syndrome.

Researchers from UC Irvine, Harbor-UCLA Medical Center, the University of Washington, Johns Hopkins University, Wake Forest University and Columbia University participated in the study. Results appear in the October 2011 issue of Diabetes Care.

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