Diabetes mellitus is a risk factor for coronary heart disease because it

There are two primary diseases that make up CAD Arteriosclerosis (hardening of artery wall) and Artherosclerosis (build up of plaque deposits). Daibete mellitus are a two diseases that result from either no insulin which breaks down sugars or the body's insulin is unable to break down sugar efficiently, or their isn't enough insulin. These are charactized as Type I and Type II Diabetes respectively. The sugar molecules that build up in the blood are capable of scratching the walls of blood vessels which both harden and create clots that can build up.