Pathology of macrovascular disease

In this chapter we have presented information on the development of large vessel damage in diabetes mellitus. A series of changes occur independent of the presence of atherosclerosis. The abnormalities include accumulation of PAS-positive material, laminin, fibronectin, type IV collagen and connective tissue with lack of acid mucopolysaccharides, and deposition of calcium. It is of particular interest that accumulation of PAS-positive material and lack of acid mucopolysaccharides are recognized as the histological markers of diabetic microangiopathy. These changes are in agreement with the hypothesis of a non-atherosclerotic large vessel damage, that is, diabetic macroangiopathy. From this standpoint the working hypothesis of a specific diabetic macroangiopathy should generate new ways to study the mechanism of the large vessel disease of diabetes over and above the traditional concept of classical atherosclerosis.