Endothelial effects of hyperglycaemia

In basic terms the capillary wall becomes thickened in small areas, which form microaneursyms, which eventually burst, causing haemorrhage. If enough of this abnormal physiology occurs then the organs affected do not receive enough blood supply to function properly, which leads to triggering of ischeamic and scarring responses. This process can best be understood by looking at the following animation.

Below is an animated diagram demonstating how the capillary network operates and what happens when hyperglycaemia affects the capillary wall. Click on the button marked 'capilliary' to view the animation and continue to click the button to view the sequence of pathophysiology events.

Explanation of Animation

The animation shows firstly the capillary network and blood flow from arterioles to venules. Then the animation progresses to show the structure of a capillary with blood flow and main structures indicated of pericytes, endothelial cells and basement membrane. Then the pathophysiological process of microaneursym formation is shown followed by vessel wall bursting and haemorrhage.

This process is fundamental to why micro-vascular complications in diabetes occur and can progress rapidly to disabling levels.