World Health Organization (WHO) and the World Heart Federation (WHF) Pathobiological Determinants of Atherosclerosis in Youth (PBDAY) Study. Histomorphometric investigation of the aorta and coronary arteries in young people from different geographical locations

BACKGROUND AND AIM: At the Morphometric Reference Center of the World Health Organization (WHO) and the World Heart Federation (WHF) for the Pathobiological Determinants of Atherosclerosis in Youth (PBDAY) Project, histomorphometric studies were carried out on aortic and coronary artery walls of 590 people ranging from 5 to 34 yr of age, who were of European, American, Asian and African origin (6 countries) and died of trauma. The aim was to evaluate the mean intimal and medial thickness of arterial tissues. METHODS AND RESULTS: Computerized operator-assisted morphometry with a semiautomatic image analyzer was carried out on 2,893 histological slides (prepared at the WHO Reference Center in Malmö, Sweden). Our data show that age-dependent trends for prevalence of fatty streaks and atherosclerotic plaques in arteries are different: prevalence of fatty streaks increases until a plateau is reached, while exponential growth characterizes atherosclerotic plaque prevalence. Age is statistically associated with an increase in mean intimal and medial thickness in all specimens. CONCLUSIONS: Mean intimal and medial thickness differs in arterial wall specimens of individuals from various geographic locations: persons from countries with high mortality rates from cardiovascular disease tend to have greater mean intimal thickness in youth. Men with hypertension and those who smoke have significantly greater combined means of intimal thickness than normotensives and non-smokers respectively. The also have significantly greater combined means of medial thickness than normotensive men. Histomorphometric data provide evidence of the development of atherosclerotic lesions at an early age and relate their progression to ethnic and lifestyle factors and to major coronary heart disease risk factors.