World Health Organization(WHO) and the World Heart Federation (WHF) * Pathobiological Determinants of Atherosclerosis in Youth Study (WHO/WHF PBDAY Study) 1986-1996: Histomorphometry and histochemistry of atherosclerotic lesions in coronary arteries and the aorta in a young population

BACKGROUND AND AIM: The present work is a chapter in an investigation directed by the World Health Organization on the Pathobiological Determinants of Atherosclerosis In Youth (WHO-PBDAY). Our aim was to study the development of atherosclerotic lesions in a young population. METHODS AND RESULTS: Samples of left anterior descending coronary artery (LDC) and thoracic (TA) and abdominal aorta (AA) from five Collaborating Centres (Budapest/Hungary, Havana/Cuba, Heidelberg/Germany, Mexico City/Mexico, Peradeniya/Sri Lanka) of 214 subjects who died aged 15 and 34 were analysed at the Budapest Reference Centre. Slides stained with haematoxylin-eosin and with stains for extracellular matrix were quantitatively and qualitatively evaluated. Mean intima/media (I/M) ratio and the prevalence of type III-IV lesions (preatheroma; atheroma; calcified and fibrous atheroma) were determined and compared in different risk factor (high blood pressure, smoking) groups. High I/M ratio was found in the LDC and type III-IV lesions were frequently found both in the LDC and in the AA. I/M ratio and the occurrence of type III-IV lesions increased in all arteries by age. Atherosclerotic lesions in men were more severe, particularly in the LDC. Geographic origin had a limited effect on the histologic lesion parameters. Appearance of type III-IV lesions was associated with substantially different extracellular matrix changes. Myoelastic layer formation was found in each artery in both early and type III-IV lesions. Hypertension was associated with higher prevalence of type III-IV lesions in all arteries, in particular, in the TA; smoking showed a significant effect on the AA only. CONCLUSIONS: Atherosclerotic lesions were found in many of these young subjects. The effect of hypertension and smoking on their development suggests that control of risk factors, beginning in early adolescence, could help to prevent cardiovascular diseases.