Teen arteries show early signs of plaque.

Teen arteries show early signs of plaque

Preliminary results from a multicenter study show that teenagers can develop well-established fatty streaks in their coronary artery walls, and that some teens even develop artery-narrowing plaque. The findings add weight to previous research suggesting the first stages of coronary artery disease can begin early in life. In complementary work, other project scientists have borrowed a computer technique from the space program to identify specific arterial sites where the relatively harmless fatty streaks seem most likely to progress to full-fledged atherosclerotic plaque, which can lead to heart attacks.

Research indicating that coronary artery disease begins in childhood stems from now-classic studies of U.S. soldiers killed in Korea and Vietnam. Scientists found some of these yound men had advanced plaque buildup on the walls of their heart arteries. More recently, the ongoing Bogalusa (La.) Heart Study uncovered evidence of fatty streaks in children's arterial walls and showed that children with high blood cholesterol are likely to remain at risk of elevated blood choletserol as they grow older (SN:10/8/88, p.234).

Now, early results of another ongoing study, caled Pathobiological Determinants of Atherosclerosis in Youth (PDAY), confirm that by the time a person reaches age 19, smooth fatty streaks can form beneath the endothelial tissue lining the insides of arteries, developing into raised lesions by age 34. Henry C. McGill Jr. of the University of Texas Health Science Center at San Antonio presented the preliminary results this week at the American Heart Association's Science Writers Forum in San Antonio.

PDAY investigators obtain blood and coronary artery samples from the legally required autopsies of trauma victims aged 15 to 34. They test the blood for cholesterol and examine the artery specimens for signs of disease.

Analysis of data from about 300 cases shows that the teenagers and young adults who had high blood levels of low-density lipoprotein (LDL) cholesterol at the time of autopsy were more likely to show raised, artery-narrowing lesions on vessel walls, McGill says. LDL transports choleterol to artery walls, where deposits may form. Conversely, subjects who had elevated blood levels of high-density lipoprotein (HDL) at the time of autopsy were less likely to show such lesions. Scientists believe high blood levels of HDL help ward off artery disease because HDL transports cholesterol to the liver for excretion. The PDAY researchers also found that people with high concentrations of thiocyanate, a chemical found in the blood of cigarette smokers, were more likely to have advanced lesions than were those whose blood showed no trace of it.

In a related PDAY effort, J. Fredrick Cornhill and his colleagues at Ohio State University in Columbus have created composite views of how atherosclerosis may progress, using a computerized method similar to the photo-enhancing technique used by Voyager 2 scientists. The Ohio team has photographed coronary artery tissue taken from 504 of the deceased trauma victims in the PDAY project and converted each photograph to a digitized image made up of 4 million separate points. Composite images incorporating data from the various photographs show that certain sites, including those where arteries bend or branch, are especially prone to developing fatty streaks in youths aged 15 to 19, Cornhill reports. Fatty streaks form when white blood cells become engorged with fats and cluster beneath the endothelium. Cornhill says the same trouble spots identified in youths often display full-blown raised lesions in composite images reflecting data from people aged 30 to 34.

That finding suggests specific areas of the vessel wall are at risk of developing atherosclerotic lesions over the years, he says. His team is now working to produce a map of lesion-prone arterial sites.