With few exceptions, the treatment of CHD and stroke is the same for people with diabetes as for the general population. High blood pressure and high cholesterol levels are initially treated with diet and other lifestyle measures in an effort to get these conditions under control without medication.
Many of these lifestyle measures—for example, diet, weight loss, and exercise—are the same as the ones recommended by the American Diabetes Association for everyone with diabetes. Medication is needed when elevated blood pressure or blood cholesterol persists despite making the necessary lifestyle changes.
Blood pressure control
The latest American Diabetes Association guidelines recommend that people with diabetes have their blood pressure checked at every doctor's visit. If your blood pressure is higher than 130/80 mm Hg, you need drug treatment in addition to lifestyle measures. People with diabetes often need two or more blood pressure–lowering drugs to achieve blood pressure control. The guidelines recommend using drugs such as ACE inhibitors, angiotensin II receptor blockers, beta-blockers, diuretics, and calcium channel blockers.
An ACE inhibitor is one of the best drugs for lowering high blood pressure in people with diabetes. These drugs decrease production of angiotensin II, a hormone that increases blood pressure. ACE inhibitors also help to prevent or delay progression of kidney damage (nephropathy). If an ACE inhibitor cannot be used, the best substitute is an angiotensin II receptor blocker. Diuretics can raise blood glucose levels and reduce serum potassium levels, and beta-blockers can reduce the warning symptoms of hypoglycemia, so extra caution is needed with these medications.
If you haven't been taking an ACE inhibitor or a beta-blocker and you have a heart attack, studies show that immediately starting treatment with these drugs can significantly reduce your risk of dying.
If your LDL cholesterol is not at the target of less than 100 mg/dL (or less than 70 mg/dL if you have had a heart attack), the American Diabetes Association recommends treatment with a statin drug. Several large studies have shown a significant reduction in heart attacks and strokes in people with diabetes who took statin drugs to lower their LDL cholesterol. Six statins are available: atorvastatin (Lipitor); fluvastatin (Lescol); lovastatin (Mevacor); pravastatin (Pravachol); rosuvastatin (Crestor); and simvastatin (Zocor).
The American Diabetes Association recommends niacin (nicotinic acid) for people with diabetes who have low levels of HDL cholesterol (less than 40 mg/dL in men or 50 mg/dL in women) and fibrate drugs (Lopid, Lofibra, Tricor) for elevated levels of triglycerides (more than 200 mg/dL). Since niacin can increase blood glucose levels, your doctor will monitor you while you are using the drug.
Other cholesterol-lowering drugs are available, including bile acid sequestrants (Colestid, Questran, Welchol), ezetimibe (Zetia), and a combination of ezetimibe and simvastatin (Vytorin).
Blood clot prevention
Diabetes produces changes in your blood that make it more prone to clotting, which increases your risk of a heart attack and stroke. Taking a daily aspirin tablet can reduce the risk. The American Diabetes Association recommends preventive treatment with aspirin for people with type 1 and type 2 diabetes who have a high risk of cardiovascular disease or who have had a heart attack, stroke, or bypass surgery. The recommended dosage is 75–162 mg a day.
Always talk to your doctor before starting treatment with aspirin. You should not take aspirin if you are allergic to it, are taking anticoagulant drugs like warfarin (Coumadin), or have a bleeding disorder.
Chest pain due to reduced blood flow to the heart is called angina. Most often, angina results from the buildup of plaque in the coronary arteries that carry blood to the heart. Nitrate drugs (such as nitroglycerin) can alleviate angina when it occurs. Nitrates can also be used preventively before you engage in activities that are likely to cause chest pain, such as rapid walking or playing tennis. Many people with diabetes take a beta-blocker to treat high blood pressure; these drugs help to prevent angina as well.
If angina cannot be controlled with drug treatment, it's often a sign that you have severe blockages in one or more of your coronary arteries. When this happens, you may need angioplasty or bypass surgery to maintain adequate blood flow and prevent a heart attack.
Angioplasty involves inserting a catheter with a balloon at its tip into a femoral artery in your groin and guiding it to the narrowed portion of the coronary artery. The surgeon then inflates the balloon several times to squeeze the plaque against the wall of the artery, thus widening the artery opening and increasing blood flow to the heart. In most angioplasty procedures, a metal tube called a stent is placed in the artery to keep it propped open.
In bypass surgery, the surgeon connects a healthy artery in your chest to an area beyond the blocked portion of the coronary artery. Alternatively, the surgeon may remove a portion of one of your large leg veins and attach the vein on each side of the blocked area. Blood flow is then rerouted through this new blood vessel, "bypassing" the blockage.
The choice between angioplasty and bypass surgery depends on many factors, including how many blockages you have, the location of the blockages, and your overall health. Studies show an advantage for bypass surgery in people with diabetes who can withstand this major invasive procedure. One ongoing study of more than 1,800 people found that survival at seven years was significantly better with bypass surgery (74%) than with angioplasty (56%) for people with diabetes. However, recent developments in angioplasty, including the use of stents coated with drugs that prevent arteries from reclogging, may make this alternative to bypass surgery an option for more people with diabetes.
Peripheral arterial disease
Just as plaques can build up in the coronary arteries, similar fatty deposits can develop in the arteries of the legs. This reduces blood flow to your feet and legs. Narrowing of the leg arteries is called peripheral arterial disease. The characteristic symptom is intermittent claudication—cramping pain in the thighs, calves, and, sometimes, the buttocks that is brought on by exercise and subsides promptly with rest. It's called intermittent because it comes and goes. You may also feel numbness, tingling, burning, or cold in your feet and lower legs.
Smoking is the major risk factor for peripheral arterial disease, but diabetes doubles the risk. Peripheral arterial disease is most common in people with high blood pressure and high blood cholesterol levels (especially in cigarette smokers), so it's not surprising that people with peripheral arterial disease have a higher risk of CHD and heart attack, as well as strokes.
An estimated one of every three people with diabetes over age 50 will develop peripheral arterial disease. That's why the American Diabetes Association recommends that people with diabetes who are older than age 50 have an ankle brachial index (ABI) test. The test compares systolic blood pressure in your arm to that in your lower legs. If blood pressure in your ankle is lower than that in your arm, you may have peripheral arterial disease.
Symptoms of peripheral arterial disease usually progress slowly, but eventually the pain can interfere with normal activities and may even occur at rest. Reduced blood flow in the legs can also result in slow healing of foot blisters and other skin injuries and can lead to open sores (ulcers) and tissue death (gangrene) in the feet and legs. In severe cases, amputation may be necessary.
Treatment is identical to the "ABCs" for preventing peripheral arterial disease: HbA1c less than 7%, blood pressure below 130/80 mm Hg, and "bad" LDL cholesterol levels lower than 100 mg/dL (ideally, less than 70 mg/dL), with medication given if these goals aren't achieved. Quitting smoking is absolutely essential. In addition, antiplatelet drugs such as aspirin or clopidogrel (Plavix) may be prescribed to reduce the risk of blood clots.
Although it may seem surprising, walking a prescribed distance several times a week gradually increases the pain-free distance you can walk. Your doctor may also prescribe medications such as pentoxifylline (Trental) and cilostazol (Pletal) to relieve walking-related leg pains. But if exercise and drug treatments fail to prevent severe blockages, you may need leg surgery using angioplasty or bypass procedures to treat the plaque buildup.