The most common cause of death in patients with Type 2 diabetes, CAD also develops in many patients with Type 1 diabetes. Patients who have had diabetes for 20 years or longer, are over age 40, or have many cardiovascular risk factors, such as hypertension, obesity, or lipid abnormalities, have a high risk of developing CAD. Men and women with diabetes develop CAD at about the same age.The development of atherosclerotic changes in the coronary arteries is closely related to the duration and severity of diabetes. The prolonged high levels of blood glucose, free fatty acids, and cholesterol damage the endothelial layer of the arteries. Monocytes adhere to the damaged arteries, and macrophages migrate to these areas. If your patient also has hypertension, the high pressure of blood flowing through the vessels increases the endothelial damage.

This all contributes to lipid accumulation and the development of atherosclerotic plaque. The macro phages release growth factor, which stimulates smooth-muscle cells to enlarge, multiply, and migrate through the layers of the arteries. This further narrows the lumen of the arteries. At the same time, increased numbers of platelets adhere to the damaged endothelium, which causes thrombus formation. If your patient has hyperglycemia, platelets are more likely to adhere to the artery wall. The combination of endothelial damage and increased platelet aggregation leads to accelerated thickening of the lumen, which results in vasoconstriction.

If your patient has insulin resistance, her triglyceride and lipoprotein levels will be elevated, which can damage the endothelial lining even further. Her pancreas produces excessive amounts of substandard insulin to overcome the body’s resistance to insulin. So, her body does not have sufficient, effective insulin, which is required to produce lipoprotein lipase, the enzyme that regulates cholesterol.

Progressive atherosclerosis, of course, reduces coronary artery blood flow, which increases the risk of developing myocardial ischemia and infarction.

If your patient has a myocardial infarction (MI), she’s at risk for developing diabetic ketoacidosis (DKA). The stress of an Ml causes the release of adrenal corticosteroids and catecholamines, which inhibit insulin action and stimulate glucose production. As the glucose level rises, the heart and other vital organs are deprived of their main energy source. As a protective mechanism, the body begins to break down fat to use as a substitute energy source. Fat breakdown is incomplete, causing excessive amounts of ketones to be released into the bloodstream. Because the kidneys can’t adequately excrete the ketones, DKA develops. This condition results in electrolyte disturbances, which can lead to life-threatening cardiac arrhythmias.