What is the connection between diabetes, heart disease, and stroke?
If you have diabetes, you are at least twice as likely as someone who does not have diabetes to have heart disease or a stroke. People with diabetes also tend to develop heart disease or have strokes at an earlier age than other people. If you are middle-aged and have type 2 diabetes, some studies suggest that your chance of having a heart attack is as high as someone without diabetes who has already had one heart attack. Women who have not gone through menopause usually have less risk of heart disease than men of the same age. But women of all ages with diabetes have an increased risk of heart disease because diabetes cancels out the protective effects of being a woman in her child-bearing years.
People with diabetes who have already had one heart attack run an even greater risk of having a second one. In addition, heart attacks in people with diabetes are more serious and more likely to result in death. High blood glucose levels over time can lead to increased deposits of fatty materials on the insides of the blood vessel walls. These deposits may affect blood flow, increasing the chance of clogging and hardening of blood vessels (atherosclerosis)
What are the risk factors for heart disease and stroke in people with diabetes?
Diabetes itself is a risk factor for heart disease and stroke. Also, many people with diabetes have other conditions that increase their chance of developing heart disease and stroke. These conditions are called risk factors. One risk factor for heart disease and stroke is
having a family history of heart disease. If one or more members of your family had a heart attack at an early age (before age 55 for men or 65 for women), you may be at increased risk.
You can’t change whether heart disease runs in your family, but you can take steps to control the other risk factors for heart disease listed here:
- Central obesity means carrying extra weight around the waist, as opposed to the hips. A waist measurement of more than 40 inches for men and more than 35 inches for women means you have central obesity. Your risk of heart disease is higher because abdominal fat can increase the production of LDL (bad) cholesterol, the type of blood fat that can be deposited on the inside of blood vessel walls.
- Having abnormal blood fat (cholesterol) levels.
– LDL cholesterol can build up inside your blood vessels, leading to narrowing and hardening of your arteries—the blood vessels that carry blood from the heart to the rest of the body. Arteries can then become blocked. Therefore, high levels of LDL cholesterol raise your risk of getting heart disease.
– Triglycerides are another type of blood fat that can raise your risk of heart disease when the levels are high.
– HDL (good) cholesterol removes deposits from inside your blood vessels and takes them to the liver for removal. Low levels of HDL cholesterol increase your risk for heart disease.
- Having high blood pressure.
If you have high blood pressure, also called hypertension, your heart must work harder to pump blood .High blood pressure can strain the heart, damage blood vessels, and increase your risk of heart attack,stroke, eye problems, and kidney problems.
- Smoking. Smoking doubles your risk of getting heart disease. Stopping smoking is especially important for people with diabetes because both smoking and diabetes narrow blood vessels. Smoking also increases the risk of other long-term complications, such as eye problems. In addition, smoking can damage the blood vessels in your legs and increase the risk of amputation.
What types of heart and blood vessel disease occur in people with diabetes?
Two major types of heart and blood vessel disease, also called cardiovascular disease, are common in people with diabetes: coronary artery disease (CAD) and cerebral vascular disease. People with diabetes are also at risk for heart failure. Narrowing or blockage of the blood vessels in the legs, a condition called peripheral arterial disease, can also occur in people with diabetes.
Coronary artery disease, also called ischemic heart disease, is caused by a hardening or thickening of the walls of the blood vessels that go to your heart. Your blood supplies oxygen and other materials your heart needs for normal functioning. If the blood vessels to your heart become narrowed or blocked by fatty deposits, the blood supply is reduced or cut off, resulting in a heart attack.
Cerebral Vascular Disease
Cerebral vascular disease affects blood flow to the brain, leading to strokes and TIAs. It is caused by narrowing, blocking, or hardening of the blood vessels that go to the brain or by high blood pressure.
A stroke results when the blood supply to the brain is suddenly cut off, which can occur when a blood vessel in the brain or neck is blocked or bursts. Brain cells are then deprived of oxygen and die. A stroke can result in problems with speech or vision or can cause weakness or paralysis. Most strokes are caused by fatty deposits or blood clots—jelly-like clumps of blood cells—that narrow or block one of the blood vessels in the brain or neck. A blood clot may stay where it formed or can travel within the body. People with diabetes are at increased risk for strokes caused by blood clots.
A stroke may also be caused by a bleeding blood vessel in the brain. Called an aneurysm, a break in a blood vessel can occur as a result of high blood pressure or a weak spot in a blood vessel wall.
TIAs are caused by a temporary blockage of a blood vessel to the brain. This blockage leads to a brief, sudden change in brain function, such as temporary numbness or weakness on one side of the body. Sudden changes in brain function also can lead to loss of balance, confusion, blindness in one or both eyes, double vision, difficulty speaking, or a severe headache. However, most symptoms disappear quickly and permanent damage is unlikely. If symptoms do not resolve in a few minutes, rather than a TIA, the event could be a stroke. The occurrence of a TIA means that a person is at risk for a stroke sometime in the future.
Heart failure is a chronic condition in which the heart cannot pump blood properly—it does not mean that the heart suddenly stops working. Heart failure develops over a period of years, and symptoms can get worse over time. People with diabetes have at least twice the risk of heart failure as other people. One type of heart failure is congestive heart failure, in which fluid builds up inside body tissues. If the buildup is in the lungs, breathing becomes difficult.
Blockage of the blood vessels and high blood glucose levels also can damage heart muscle and cause irregular heart beats. People with damage to heart muscle, a condition called cardiomyopathy, may have no symptoms in the early stages, but later they may experience weakness, shortness of breath, a severe cough, fatigue, and swelling of the legs and feet. Diabetes can also interfere with pain signals normally carried by the nerves, explaining why a person with diabetes may not experience the typical warning signs of a heart attack.
Peripheral Arterial Disease
Another condition related to heart disease and common in people with diabetes is peripheral arterial disease (PAD). With this condition, the blood vessels in the legs are narrowed or blocked by fatty deposits, decreasing blood flow to the legs and feet. PAD increases the chances of a heart attack or stroke occurring. Poor circulation in the legs and feet also raises the risk of amputation. Sometimes people with PAD develop pain in the calf or other parts of the leg when walking, which is relieved by resting for a few minutes.