Extrinsic and intrinsic factors relating to intimal thickening in children.

Children already have intimal thickenings occupying over half of the vascular lumen. Intimal thickening is one of the first steps in atherogenesis. Classical risk factors such as hypercholesterolaemia, genetic background and acute noxious factors play a role in its development. Genetic origin of the children from high-risk groups for coronary heart disease seems to be a determinant of the magnitude of thickenings. Extrinsic factors such as infections also seem to play a role. The magnitude of the thickening is related to viral and bacterial infections. Infections may lead to endothelial injury and secondary intimal thickening. The process may advance stepwise with acute exacerbations of endothelial dysfunction and intimal thickening followed by incomplete healing. In particular, repeated acute infections might lead to permanent damage. Morphological evidence for early atherogenesis in children is presented.