Having a stroke can have devastating consequences. A stroke occurs when the flow of blood to the brain is disrupted. Brain tissue that is deprived of blood for more than three minutes will begin to die. Emergency treatment should be started as soon as possible and ideally within three hours after the onset of stroke symptoms. The longer the brain goes without fresh blood and oxygen, the greater the damage. Depending on what part of the brain is affected, a stroke can cause a wide range of physical and mental disabilities.
Unfortunately, having diabetes raises the risk of having a stroke. But like many potential diabetes complications, stroke is not inevitable, and the risk of having one can be lowered by identifying and addressing any risk factors you may have besides diabetes.
You may already be aware of some of your risks, but if you’re not sure about any of the items listed here, ask your doctor whether you have these risk factors.
Uncontrollable risk factors
Some of the risk factors for stroke cannot be changed by your actions. Those that cannot include the following:
Age. The likelihood of having a stroke increases after age 55.
Sex. Stroke is more common in men than women. Women, however, are more likely to die of stroke.
Heredity. People who have a family history of stroke are more likely to have a stroke than someone whose family has not had strokes. African-Americans have a higher risk of stroke than other races and a much higher risk of death from stroke, in part because of their higher rates of diabetes, hypertension (high blood pressure), obesity, and smoking.
Prior stroke or heart attack. People who have previously had a stroke or heart attack are at greater risk of having a stroke.
Mini-stroke. People who have had a transient ischemic attack (TIA), or a mini-stroke, are almost 10 times more likely to have a stroke than a person of the same age and sex who has not. A TIA occurs when blood flow to the brain is cut off temporarily, usually for less than five minutes. The symptoms of a TIA are the same as those of a major stroke, but a TIA causes no permanent brain damage. A TIA might seem to be insignificant, but it also should be taken seriously and treated immediately.
Because it is difficult to distinguish between a stroke and a TIA, people who think they are experiencing stroke symptoms should call 9-1-1 immediately to be taken to a hospital. Diagnostic tests will be performed at the hospital to determine whether the symptoms are from a TIA or a stroke. Treatment for a TIA depends on its underlying cause but often includes taking daily aspirin.
Risk factors you can influence
There are also many risk factors for stroke that can be treated or reduced. Those include heart disease, high blood pressure, high cholesterol, obesity, smoking, and high alcohol consumption. Treatment often involves a combination of changes in lifestyle, medicines, and possibly other forms of therapy.
Heart disease. One of the most important things people with diabetes can do to avoid stroke is find out whether they have heart disease and, if so, get treatment. While there are many types of heart disease, one that poses particular risk for stroke is atrial fibrillation, an abnormal heart rhythm. Tests to diagnose atrial fibrillation include electrocardiogram, Holter monitor, and echocardiogram.
The risk of atrial fibrillation increases with age; it becomes more common after age 60. It is often caused by other forms of heart disease and high blood pressure, but it can occur in people who do not have either condition. Atrial fibrillation raises the risk of stroke because irregular heartbeats allow blood to pool in the heart, and pooled blood is more likely to develop clots. Those clots can then travel to the brain and block blood flow. People with atrial fibrillation are usually prescribed warfarin (brand name Coumadin) to prevent blood clots from forming. A pacemaker can also be implanted to control the rhythm of the heart.
Atherosclerosis. A major risk factor for heart disease and stroke is atherosclerosis, in which fatty material, cholesterol, calcium, and other substances accumulate within the inner lining of the artery walls, reducing the flow of blood. Atherosclerosis is diagnosed with stress testing, blood tests, angiogram, and electrocardiogram.
One approach to treating atherosclerosis is described in the book Prevent and Reverse Heart Disease by Caldwell B. Esselstyn, Jr., MD, a former surgeon at the Cleveland Clinic. Dr. Esselstyn recommends consuming a strictly plant-based diet of fruits, vegetables, whole grains and products made from whole grains, and dried beans and other legumes — but no added fats, not even olive oil. Dr. Esselstyn has prescribed this diet to patients with heart disease for more than 20 years and has documented its ability to lower cholesterol, improve blood flow, and prevent cardiac “events” such as heart attacks in this population.
Not all doctors will recommend exactly this dietary approach, but most agree that diet and lifestyle choices play an important role in treating atherosclerosis and will recommend some form of dietary changes. (For more resources on lowering your risk for stroke through diet, see “Eating Your Way to Lower Stroke Risk.”)
Other treatments for atherosclerosis include cholesterol-lowering medicines, procedures such as balloon angioplasty, in which the plaque buildup in the arteries is flattened against the artery walls, or inserting a stent to ease the flow of blood in the arteries. For people with severely clogged arteries, coronary bypass surgery can be performed to restore blood flow to the heart.
High blood pressure. Having high blood pressure greatly increases the risk of stroke. Called “the silent killer,” high blood pressure usually has no symptoms, although extremely high blood pressure can cause severe headache, irregular heartbeat, blurred vision, and chest pain. Such symptoms should be checked immediately by a doctor.
People who have diabetes and hypertension should follow their doctors’ advice for controlling their blood pressure. The American Diabetes Association recommends a target blood pressure of less than 130/80 millimeters of mercury (or mm Hg) for people with diabetes. As a first line of treatment to lower blood pressure, doctors often prescribe regular exercise, dietary measures including lowering sodium intake, and reduced alcohol consumption. If these measures do not lower blood pressure to the desired level, doctors may recommend anti-hypertension medicine.
Some of the dietary measures that can help to lower blood pressure besides lowering sodium intake are the following:
- Consuming at least 3,500 mg of potassium daily in such foods as bananas, oranges, dried fruits, sweet potatoes, white potatoes, greens, and skim milk
- Consuming at least 1,200 mg of calcium a day from foods such as yogurt and skim milk
- Getting at least 420 mg of magnesium a day for men — and 320 mg for women — from foods such as spinach, whole-grain cereals, brown rice, almonds, and bananas
- Eating foods that contain polyphenols (a type of antioxidant) such as chocolate. Eating about 30 calories of dark chocolate daily may help to lower blood pressure without increasing weight.
Diabetes. High blood glucose raises the risk of stroke. Having a plan to lower your blood glucose is therefore as important for stroke prevention as it is for preventing other long-term diabetes complications.
Unhealthy cholesterol. People who have high total or LDL (“bad”) cholesterol can lower it through healthy eating habits, exercise, and medication, if necessary. It is possible to lower cholesterol to levels recommended to reduce the risk of heart disease and stroke by consuming a low-fat, low-cholesterol diet comprised primarily of fruits, vegetables, whole grains, and beans, with fish, lean meat, and low-fat dairy products as additional sources of protein. A cholesterol-lowering diet should also limit the intake of sugars, desserts, soda, and alcohol.
The American Diabetes Association recommends maintaining an LDL cholesterol level below 100 mg/dl for most people with diabetes and below 70 mg/dl for those who have heart disease. It also recommends that women aim for an HDL of 50 mg/dl or higher and that men keep their HDL at 40 mg/dl or higher.
Obesity. Obesity, defined as having a body-mass index (BMI) of 30 or greater, raises the risk of heart disease and stroke. Losing even a modest amount of weight can lower blood pressure and improve cholesterol levels.
While losing weight and keeping it off is difficult, following the healthy dietary pattern recommended for reversing heart disease and engaging in regular physical activity can be effective at promoting and sustaining weight loss, as long as the lifestyle is maintained.
Inactivity. Sedentary living tends to lead to high blood pressure, unhealthy cholesterol levels, and weight gain. Regular aerobic activity — such as walking, jogging, swimming, or bicycling — can lower blood pressure, raise HDL (“good”) cholesterol, and improve the overall health of the heart and blood vessels.
Smoking. People who smoke are at double the risk of having a stroke as nonsmokers. Smoking irritates the lining of the blood vessels and decreases the body’s ability to dissolve blood clots. Light-to-moderate smokers who quit smoking will decrease their risk of stroke to that of a nonsmoker in about five years. For heavy smokers, it may take as many as 10 years or more to lower their risk to that of a nonsmoker.
Alcohol. Drinking more than two drinks a day for men and one for women may contribute to the risk of stroke.
If a stroke occurs
If you or someone else experiences symptoms of stroke, it’s important to get medical help immediately. In most places, the fastest way to do this is to call 9-1-1. The faster you get help, the more brain function you may be able to preserve. (See “Immediate Action Needed” for more information on stroke symptoms.)
After you call 9-1-1, write down the time that you (or the other person) first began to experience symptoms so you don’t forget. The emergency room staff will ask when the symptoms began to help them decide how to treat the stroke.
While you wait for the ambulance, the person with stroke symptoms should lie down. If he is conscious, those assisting him should try to reassure him and should not give him anything to eat or drink. If the person is unconscious, those assisting him should check for breathing and, if necessary, tilt his head back to open his airway and perform CPR. A person who is breathing but unconscious should be rolled onto his side to help keep his airway open.
When a person who is experiencing stroke symptoms first arrives at the hospital, he is given diagnostic tests to determine what type of stroke — ischemic or hemorrhagic — is occurring. This is critical because the treatments for different types of stroke are different.
Ischemic stroke. The most common type of stroke is an ischemic stroke (pronounced is-kee-mik), in which blood flow to the brain is cut off, commonly by a blood clot. Ischemic strokes are usually caused by atherosclerosis, the buildup of fatty deposits in blood vessels.
To treat an ischemic stroke, a clot-busting medicine — called tPA, or tissue plasminogen activator — is administered to break up the clot that is blocking the flow of blood to the brain. This medicine can prevent or minimize disability from stroke if properly administered within three hours of the onset of symptoms. If the three-hour window has passed, other medicines may be used, such as aspirin or warfarin. The blood vessel blockage can also be removed surgically, or a stent can be inserted into the clogged artery.
Hemorrhagic stroke. A hemorrhagic stroke (pronounced he-me-ra-jik) occurs when a weakened blood vessel ruptures and spills blood into the surrounding brain tissue. Risk factors for hemorrhagic strokes include having high blood pressure or an aneurysm (a ballooning of a weakened artery).
A person having a hemorrhagic stroke may experience severe headache, nausea, vomiting, drowsiness, or coma. Hospital personnel will stabilize the person and monitor his condition. Medication can be given to relieve swelling and pressure on the brain, and a tube can be inserted into the aneurysm to ease severe pressure.
A person who is having a stroke often cannot help himself. That’s why it’s important for as many people as possible to know the signs and symptoms of stroke and to know to call for help as quickly as possible if they observe those signs or symptoms in another person.
Since diabetes puts you at increased risk of stroke, talk to the people you spend the most time with about that risk and about what they should do if they suspect you are having a stroke. Instruct them to call 9-1-1 immediately, even if they are not 100% sure you’re having a stroke. It’s better to go to the hospital for something that turns out not to be a stroke than to not go to the hospital for something that is.