Heart disease is the leading cause of diabetes-related deaths because the constant high blood sugar is associated with narrowing of the arteries, increased blood triglycerides (a type of fat), decreased levels of HDL ("good") cholesterol, high blood pressure and heart attack. As one gets older, blood vessels are damaged and narrow progressively (atherosclerosis). This could lead to a heart attack or stroke. Diabetics are more prone to the development of atherosclerosis and blood clot formation. Smoking also causes damage to blood vessels and therefore diabetic smokers are at higher risk.