The Feminine Side of Stroke
Stroke is one of the most common causes of disability and the No. 4 killer, but many people don’t know it kills more women than men.
Stroke is one of the most common causes of disability and the No. 4 killer, but many people don’t know it kills more women than men. Of the 6.8 million Americans who have survived a stroke, 3.8 million are female. Mostly, this is because stroke increases with age. Seventy-five percent of strokes occur in people over 65 – and women live longer than men. The lifetime risk of stroke for those between 55 and 75 is 20 percent for women and 17 percent for men.
By 2030 almost a fifth of Americans will be over age 65, and the majority will be women. This has profound implications for our society. For example, stroke is the third leading cause of death for women while it ranks fifth for men. Because stroke occurs later in life for women, they are less likely to recover fully and return home to live independently, and thus they are more likely to be institutionalized. These demographics indicate there will be approximately 200,000 more women than men living with the effects of stroke.
Dr. Louise McCullough
But age is not the only reason women have increased risk of stroke. Some risks are because of their gender. For this reason, the American Heart Association/ American Stroke Association recently published “Guidelines for the Prevention of Stroke in Women.”
“Emerging data suggest that men and women have a different expression and different incidence of disease,” says Louise McCullough, M.D., professor of neurology and neuroscience at the University of Connecticut Health Center and The Stroke Center at Hartford Hospital, and a co-author of the guidelines. “The original [stroke prevention] guidelines didn’t take into account some of the factors that are unique to women — pregnancy and pregnancy complications being examples — but also that women have poorer recovery from stroke. Women have higher rates of recurrent stroke. A lot of that is related to age.”
The guidelines review risk factors unique to women or that affect women differently and try to determine if there is a need for a stroke-risk score for women using female-specific factors such as pregnancy and menopause.
High Blood Pressure
Hypertension is the leading modifiable cause of stroke, and because women live longer, it affects them more than men. While women have lower blood pressure for most of their lives, this changes as they go through menopause. About 75 percent of women over age 60 have high blood pressure.
Inga Tuvesson of Ocean City, Maryland, had never been a big believer in doctors and medicine, even after she was diagnosed with high blood pressure. “My mother dabbled in the new age arts,” says Tia, her daughter. “She attended heal-your-life workshops and read positive-thinking books.” Inga felt she didn’t need to take her medicine at the prescribed times and only took it when she felt bad. Then seven years ago Inga had a stroke at age 73. Today she still lives with the deficits caused by her stroke – aphasia, limited vision and right side weakness. “So much for the power of positive thinking,” says Tia. “Now she is very much regimented about taking her blood pressure and other meds on time. In fact, she reminds my father about them sometimes.”
“Treating hypertension is paramount, and that’s true for both women and men,” McCullough says. “Often people don’t realize that even mild hypertension is a risk because hypertension often doesn’t have any symptoms. Patients come in with a blood pressure of 160 or 170, and they feel just fine, but I put them on a medicine that makes them tired or gives them a cough or is expensive. There are multiple reasons why people aren’t compliant, but it’s exceptionally important to treat hypertension.”
By 2030 almost a fifth of Americans will be over age 65, and the majority will be women. This has profound implications for our society.
Pregnancy, Preeclampsia & Eclampsia
Pregnant women are at greater risk of stroke than women who are not pregnant (34/100,000 compared to 21/100,000). One reason is preeclampsia, a complication marked by increased blood pressure and protein in the urine. There are no symptoms, so the condition can only be diagnosed by a doctor. If left untreated, preeclampsia can become eclampsia, which involves seizures and is very dangerous.
However, the danger from this complication does not end with birth. “We know that women who have had preeclampsia have double the stroke risk of women who didn’t have preeclampsia, even 40 years later,” McCullough says. In addition, there is evidence from a Taiwanese study that not only does the woman have a high risk for stroke but her offspring may have increased risk, too. “There’s something that goes awry in the maternal-fetal unit through the placenta,” McCullough says. “Nobody knows exactly why, but it causes this significant hypertensive response and probably causes damage to the blood vessels that is long-lasting.”
Hypertension during pregnancy, even if not associated with preeclampsia, needs to be treated because “the fetus can develop what we call ‘intrauterine growth retardation,’” McCullough says. Pregnant women with high blood pressure should be started on medication. Although there are some drugs, such as ACE inhibitors, that should be avoided, there are many safe medications listed in the guidelines. “The complication of developing eclampsia or having severe hypertension is a higher risk than taking medication.” Women should be screened for hypertension before trying to get pregnant.
A history of miscarriages also appears to increase stroke risk. Although it has not been well studied, this may relate to undiagnosed clotting disorders. “These disorders put women at risk of clots, whether deep vein thrombosis in the legs or pulmonary emboli from the lungs,” McCullough says. “We know that there are a lot of these clotting risk factors and that these can cause miscarriages. If women have recurrent miscarriages, that should be a red flag there might have been a thrombosis (clot) that caused the miscarriage.”
Women with recurrent miscarriages are at much higher risk for stroke and should be treated, typically with an anticoagulant such as aspirin, McCullough says.
Women are at higher risk of stroke primarily because stroke risk increases with age, and women live longer than men.
Overall, clotting disorders such as antiphospholipid syndrome, are more common in women. “This may be related to estrogen because estrogen can sometimes cause clots as well,” McCullough says.
Oral Contraceptives (OC)
Oral contraceptives, which typically contain estrogen, are another risk factor unique to women. Although in isolation, OCs may not increase risk, when women taking them smoke or have hypertension, migraines or high cholesterol, it certainly increases their risk of stroke. Each of these factors adds to a woman’s risk, and that risk profile builds up. That is what happened to Toni Amick of Columbia, South Carolina, who had a stroke when she was 26 years old. A blood test after her stroke showed that she had two blood disorders. “However, I was also taking birth control pills and smoking,” she says. “This combination caused me to have a stroke.” She no longer takes contraceptives nor smokes and takes a blood thinner every day.
The guidelines suggest that women planning to take OCs should be screened for hypertension and treated if they have it. Any other risk factors should also be treated aggressively, and of course, they should not smoke.
Atrial Fibrillation (AFib)
AFib is the most common heart arrhythmia, and its irregular heartbeats allow blood to pool and clot. As a result, clots can be pumped into the brain, causing strokes. According to McCullough, this type of stroke, called embolic stroke, is generally larger, more debilitating and more deadly.
AFib increases ischemic stroke risk by as much as five times. Non-Hispanic whites have the highest prevalence of AFib compared to blacks, Hispanic whites, Asians or other ethnic groups. Although an equal number of men and women have AFib, it increases with age, so women represent about 60 percent of AFib patients over age 75. That means that elderly women have the highest risk for embolic stroke.
“AFib doesn’t always give you symptoms,” McCullough says. “You may not be short of breath; you may not feel your heart racing. So we often send those women home with what we call a loop monitor that should pick up AFib. Especially if a woman is over 75 and she comes in with a stroke that looks like it’s embolic but she’s not in AFib at that moment, I will send her home with a loop monitor to look for AFib.”
The standard treatment for AFib is blood thinners, but this can present a dilemma in treating older women. “Sometimes we are very hesitant to put elderly women on anticoagulants, especially if they’re living alone and at risk for falling because that can be a complication,” says McCullough. “Obviously, if you’re on a blood thinner and you live alone and you fall, that could be disastrous. But elderly women are at highest risk for AFib, so it’s kind of a Catch-22.”
Migraine with Aura
Migraine headaches are a common disorder, and most do not cause strokes. However, there is some increased risk (1.5 times) of both ischemic stroke and intracerebral hemorrhage that accompanies migraine with aura. The “aura” refers to a variety of symptoms – blind spots, zigzag patterns, prickly feelings on the skin, flashing lights – that happen 5 to 30 minutes before the headache begins. Women with this disorder have stroke about four times more often than men. Women who have this type of migraine and also smoke or take oral contraceptives have seven times the risk of stroke as women without these risks. “If a woman has migraine, she should take medicine to prevent it,” McCullough says, “but she should also stop smoking and stop taking birth control pills in order to lower her stroke risk.”
Experts estimate that 86 percent of Americans will be overweight or obese by 2030. While this is a problem for both sexes, obesity affects women more than men (35 percent compared to 32 percent).
Postmenopausal women are more likely to have abdominal obesity, which is more strongly associated with insulin resistance, high cholesterol, diabetes and cardiovascular disease than other body fat distributions.
Obesity is a risk factor for stroke. Obesity, defined as a body mass index (BMI) of 30 or more, increases the risk of stroke after considering other factors such as age, physical activity, smoking, alcohol consumption, diabetes and hypertension. The larger your waist circumference, the greater the chance for stroke.
“Obesity increases risk for men and women, probably because it interacts with other risk factors, like metabolic syndrome, especially in the 45 to 55-year-old age groups,” McCullough says. (Metabolic syndrome is a group of risk factors that increases the risk of diabetes, heart disease and stroke.) “If you have obesity, you’re more likely to have other problems, including diabetes or cholesterol issues, and those all increase risk. That’s why these guidelines recommend, and this is the same for men, to follow a Mediterranean-type diet or DASH diet – low in saturated fat, lots of fruits and vegetables. And be more active.”
Women are at higher risk of stroke primarily because stroke risk increases with age, and women live longer than men. Older women can reduce their risk by being screened for AFib and being treated with blood thinners, but this strategy is not without risk.
As for younger women, stroke is rare. However, pregnancy increases risk, especially for women who develop preeclampsia. Oral contraceptives also increase risk slightly. However, this risk rises dramatically if oral contraceptive use is combined with smoking and other risk factors.
Uncontrolled high blood pressure poses the greatest risk for women of all ages. There are lifestyle changes that may reduce blood pressure, but if they don’t work, women should consider taking medication to bring their blood pressure under control.
There are effective lifestyle interventions for many of these problems. “They’re the same for men and women and it’s exactly what you expect,” McCullough says. “It’s not rocket science. If you smoke, stop. If you’re overweight, lose weight. If you are sedentary, try to be physically active and follow a diet that is low in saturated and trans fats, sodium (salt) and added sugars. Treat hypertension. If you have high cholesterol, oftentimes that’s genetic, and we’re finding that’s a risk and that requires treatment with medications. Treat the things that we know are risk factors for stroke.”