DISTRIBUTION OF LIPID AND RAISED LESIONS IN AORTAS OF YOUNG-PEOPLE OFDIFFERENT GEOGRAPHIC ORIGINS (WHO-ISFC PBDAY STUDY)

At the Morphometric Reference Center of the World Health Organization- International Society and Federation of Cardiology PBDAY (Pathobiologi cal Determinants of Atherosclerosis in Youth) project, we studied left hemiaortas of 5- through 34-year-old male and female healthy subjects who died of traumatic injury. The subjects were either of European, A merican, Asian, or African origin. Three hundred fifty-five thoracic a nd 343 abdominal left hemiaortas, stained and photographed at the Malm o, Sweden, World Health Organization Reference Center, were studied. L ipid and raised lesion extent was evaluated by using computerized tech niques. Probability-of-occurrence maps of lipid and raised lesion dist ribution were obtained by image processing. Our data have shown that t he distributions of atherosclerotic lesions in the aortic intimal surf ace, which were similar in the different ethnic groups, also prevailed in branching regions, where low-blood flow shear stress and turbulenc e occur. The areas involved by raised lesions and by lipid lesions onl y partially overlapped. Lipid lesion extent, which was different among the ethnic groups, continuously increased with age in males but not i n females, in whom the increase ceased at an age range from 15 through 24 years. This suggests that ethnic and dietary factors influence the extent but not the distribution of atherosclerotic lesions in the hum an aorta. Probability-of-occurrence maps also provided evidence that n ot every fatty streak will develop into a raised lesion, or will not d evelop quickly.