Barry I. Freedman, M.D., and colleagues report in the December issue (Volume 48, No. 12) of Diabetologia that African-American men had significantly lower levels of calcified atherosclerotic plaque in the coronary (heart) arteries and the carotid arteries in the neck that supply blood to the brain. The report was published on line today (Nov. 1, 2005.)
"This striking result was observed despite black subjects having higher levels of conventional risk factors for heart disease," said Freedman. "These risk factors would normally be expected to promote coronary artery disease in the black participants."
This result was also observed in the face of increased thickness of carotid artery walls in black diabetic subjects. Increased wall thickness is widely accepted including by the U.S. Food and Drug Administration as a marker for atherosclerosis and a predictor of coronary heart disease, so the result was surprising.
Freedman said that in women, "ethnic differences in calcified carotid artery plaque, but not coronary artery plaque, were observed."
The amount of plaque was measured using high-speed computed tomography (CT) scans.
The results came from the Diabetes Heart Study, made up of North Carolina families in which at least two siblings have type 2 or non-insulin-dependent diabetes. The investigators all from Wake Forest recruited 1,000 white participants from 369 families and 180 blacks from 74 families for this study.
Freedman said the black subjects had higher blood pressures, higher levels of low-density lipoprotein (LDL ) cholesterol (the bad cholesterol), higher overall cholesterol, elevated blood sugars and a host of other measures that are considered risk factors for atheroscler
Contact: Robert Conn
Wake Forest University Baptist Medical Center