Variations in human aortic fatty streaks among geographic locations.

Histologic features of aortic fatty streaks were examined in male subjects aged 10-39 from Guatemala, Jamaica Negro, Durban Bantu, New Orleans Negro, New Orleans white, Lima and Santiago. These groups were selected from the 19 available in the IAP (International Atherosclerosis Project) because they represented the greatest contrasts between the exten of fatty streaks in the young and raised lesions in the elders. Among these seven groups the extent of raised lesions in the older subjects was significantly but weakly correlated with the type of fatty streaks in the young as measureed by lesion thickness, content of demonstrable lipid, numbers of foam and spindle cells. The severity of leukocytic infilitration and prevalence of foci of necrosis in fatty streaks however, correlated strongly with raised lesions (rank r equals 0.90). We interpret this to imply that the presence of leukocytes and of foci of necrosis in the fatty streak marks its propensity to progress into raised lesions. If this formulation is correct, then the presence of both features in the histology of fatty streaks could be used as a marker in future studies of factors bearing upon the emergence of raised lesions out of fatty streaks.