Complications of the Diabetic Cardiovascular System

The large blood vessels in people with diabetes undergoes changes due to atherosclerosis; abnormalities in platelets, red blood cells, and clotting factors, and changes in arterial walls. It has been shown through research that atherosclerosis has an increased incidence and an earlier age of onset in people with diabetes, although the reasons for this are unknown. Other risk factors that contribute to the development of macrovascular disease of diabetes are hypertension, hyperlipidemia, cigarette smoking, and obesity. Alterations in the vascular system increase the risk of the long term complications of coronary artery disease, cerebral vascular disease, and peripheral vascular disease.

Alterations in the small blood vessels in people with diabetes involve structural defects in the basement membrane of smaller blood vessels and capillaries. The basement membrane is the structure that supports and serves as the boundary around the space occupied by epithelial cells. These defects cause the capillary basement membrane to thicken, eventually resulting in decreased tissue perfusion. Changes in basement membranes are believed to be due to one or more of the following: the presence of increased amounts of sorbitol (a substance formed as an intermediate step in the conversion of glucose to fructose), the formation of abnormal glycoproteins, or problems in the release of oxygen from hemoglobin. The affects of these alterations affect all body tissues but are seen primarily in the eyes and kidneys.

Coronary Artery Disease:

Coronary artery disease is a major risk factor in the development of myocardial infarction in people with diabetes, especially in the middle to older adult with type 2 diabetes. Coronary artery disease is the most common cause of death in people with diabetes, accounting for 40 to 60 percent of all cases of mortality. Diabetics who have myocardial infarction are more prone to develop congestive heart failure as a complication of the infarction and are also less likely to survive in the period immediately following the infarction.

High Blood Pressure (Hypertension):

High blood pressure is a common complication of diabetes. It affects 20 to 60 percent of all people with diabetes, and is a major risk factor for cardiovascular disease and microvascular complications such as retinopathy and nephropathy. Hypertension may be reduced by weight loss, exercise, and decreasing sodium intake and alcohol consumption. If these methods are not effective, treatment with high blood pressure drugs is necessary.

Stroke:

Diabetics, especially older adults with type 2 diabetes, are 2 to 6 times more likely to have a stroke. Although the exact relationship between diabetes and cerebral vascular disease is unknown, high blood pressure, which is a risk factor for a stroke, is a common health problem in those with diabetes. I addition, atherosclerosis of the cerebral vessels develops at an earlier age and is more extensive in people with diabetes.

The signs and symptoms of impaired cerebral circulation are often similar to those of hypoglycemia and include blurred vision, slurred speech, weakness, and dizziness. Diabetics with these symptoms have potentially life threatening health problems and require constant medical attention.

Peripheral Vascular Disease:

Peripheral vascular disease of the lower extremities accompanies both types of diabetes, but the incidence is greater in people with type 2 diabetes. Atherosclerosis of vessels in the legs of diabetics begins at an early age, advances more rapidly, and is common in both men and women. Impaired peripheral vascular circulation leads to peripheral vascular insufficiency with intermittent pain in the lower legs and ulcerations of the feet. Occlusion and thrombosis of large vessels and small arteries and arterioles, as well as alterations in neurologic function and infection, result in gangrene.

Gangrene in diabetics is the most common cause of non-traumatic amputations of the lower leg. In people with diabetes, dry gangrene is the most common, and is manifested by cold, dry, shriveled, and black tissues of the toes and feet. The gangrene usually begins in the toes and moves proximally into the feet.