Migraines with aura. Migraines are classified as migraine with aura or migraine without aura.12 An aura is a transient visual, sensory, or speech disturbance associated with headache.
Migraines without aura are more common than migraines with aura and aren't associated with an increased risk of stroke. On the other hand, those who have migraine with aura do have an increased risk of stroke. Although the reason for this isn't known, the vascular aspect of migraines may be what leads to stroke. About 75% of those who experience migraine are women, and almost 25% of women suffer from migraines. Luckily, less than 20% of migraines are associated with an aura.3
Depression was noted in up to 15% of the women studied in the WHI. Of those in the study, Black and Hispanic women were most likely to experience depression, followed by White women; Asian women were the least likely to be depressed. In general, twice as many women are depressed as men.1,9 The WHI research program found that women who were depressed experience more strokes. Depression may be associated with increased inflammation due to changes in levels of dopamine, norepinephrine, and serotonin. Or, it may be that people with depression are generally in poorer health. New onset of depression in older adults could be a manifestation of vascular disease.1,9
In the WHI research program, almost half of the women who'd been diagnosed with depression were on selective serotonin reuptake inhibitors (SSRIs) for depression. A known adverse effect of SSRIs is platelet inhibition, which may increase the risk of hemorrhagic stroke, but decrease the risk of acute ischemic stroke. However, no evidence has shown that treating depression reduces stroke risk.1,9 Does depression pose a risk for women taking SSRIs because platelets are inhibited or because late-onset depression is a vascular disease or due to some combination of factors? Whether depression is a cause or an early marker for stroke isn't known. More research is needed in this area.
Now consider the risks that affect women as well as men.
Atrial fibrillation. In women, the greatest single risk factor for stroke is atrial fibrillation. Ischemic strokes are caused by thrombi, and atrial fibrillation is the risk factor discussed here that's most likely to cause thromboembolism. The incidence of atrial fibrillation rises with age, with 9% of women over age 80 having this dysrhythmia.1 Among patients with atrial fibrillation, the stroke risk is three to four times greater in women than in men. This may be because women's blood vessels have smaller diameters, atrial fibrillation is more difficult to manage in women, and healthcare providers are less likely to achieve goals of care for women.1
Hypertension. For women who don't have atrial fibrillation, the most important risk factor for stroke is hypertension. Isolated systolic hypertension, common in older women, is the most significant BP risk factor for stroke. A BP greater than 140/90 mm Hg increases stroke risk; if it's combined with atrial fibrillation, stroke risk escalates substantially. BP control has improved remarkably since practice guidelines became available.1 BP control has increased from 10% in the 1980s to 70% in 2006, except in women! Only 30% of women ages 70 to 79 have achieved BP control.1 BP control can be achieved inexpensively by taking advantage of programs offered by many large chains of pharmacies that provide certain generic medications costing only $4 for a month's supply.
Sodium intake. This factor affects both BP and stroke risk. Sodium intake greater than 4,000 mg a day doubles stroke risk. The U.S. Dietary Guidelines recommend a daily sodium intake of 2,300 mg or less. In certain higher risk groups, daily intake shouldn't exceed 1,500 mg. These higher risk groups include Black Americans; people older than 51; and those with diabetes, hypertension, or chronic kidney disease.13
Potassium intake. Potassium seems to help maintain normal BP due to a mild vasodilatory effect. Patients who consume more than 1.64 g of potassium in food have less hypertension and cardiovascular disease and a 21% decrease in stroke. The reasons for these effects aren't clear.14,15
Dyslipidemia is a risk factor for stroke in both genders, especially in adults with high low-density lipoprotein (LDL) and triglyceride levels. LDL increases as a woman ages. For each 10% reduction in LDL, stroke risk can be reduced 15% to 20%.1,3,8
Obesity. A body mass index greater than 30 doubles a woman's risk for stroke. Central adiposity or an increased waist circumference may encourage production of hepatocyte growth factor (HCF), leading to inflammation and insulin resistance. In turn, inflammation and insulin resistance raise the risk of diabetes, stroke, and other cardiovascular diseases. Levels of HCF have been found to be higher in women who've suffered a stroke. In fact, increased HCF levels seem to be an independent risk factor for stroke in women ages 50 to 79.1,3
Smoking. Many people realize that smoking increases the risk of lung cancer. They may not know that smoking also doubles the risk of stroke.1
Diabetes. The risk of stroke associated with diabetes affects women more than men. Women with diabetes face two to six times the risk of stroke compared to women who don't have diabetes. Diabetes increases women's risk for obesity, hypertension, dyslipidemia, metabolic syndrome, and other comorbid conditions. A woman's risk for stroke increases with the acquisition of each comorbid condition.1
To decrease their risk of stroke, the most important steps women can take are to maintain a normal body weight, BP, and lipid profile. Patients with diabetes should also optimize glycemic control. To accomplish these goals, women can consume fewer calories from a diet lower in sodium and cholesterol, and increase physical activity. Trading simple carbohydrates (such as white bread and other baked goods) with more complex ones (such as fruits and vegetables) will increase potassium intake, which reduces stroke risk.14 Drinking less diet soda helps decrease sodium consumption. Smokers should quit the habit.3,9
To help women manage their BP and lipid profile, encourage them to participate in preventive healthcare visits and, when problems are found, to collaborate with their healthcare providers on treatment programs that suit their lifestyle. Advise them to follow up with their healthcare provider as recommended.
For women, taking an aspirin daily appears to be better at primary prevention (preventing a stroke) than secondary prevention (preventing another one). Encourage your older female patients to ask their healthcare provider about a regimen of low-dose aspirin.3
What can nurses do?
Educate all of your patients about their stroke risk, signs and symptoms of stroke, and prevention measures. And be sure to teach your female patients about risk factors and signs and symptoms that are specific to women but may not be as well-known. Remember to reinforce that stroke symptoms are sudden and that anyone experiencing one or more symptoms should act fast.
Prevention should start with living a healthy lifestyle. Teach your patients what a healthy diet means in terms of cholesterol, sodium, and calorie intake. A potential starting place can be http://www.choosemyplate.gov.16 For nurses, a more detailed nutritional guideline can be found at http://www.cnpp.usda.gov/Publications/DietaryGuidelines/2010/PolicyDoc/PolicyDoc.pdf.17 Help your patients realize that lifestyle changes can reduce stroke risk by 50% or more and that changing modifiable risk factors such as smoking and abdominal obesity can cut risk by as much as 80%. Just a few simple changes in our patients can make a world of difference.
The good news is that many strokes can be prevented, and when strokes do occur, rapid recognition and treatment can improve outcomes and minimize long-term effects. Be sure your patient doesn't become one more victim of stroke.
Statistics show women at risk
More than a third of women who have a stroke will be severely disabled, and less than 25% will fully recover.1,3 Women who experience stroke also have a longer hospital stay and a longer recovery. When finally discharged, these women are likely to be admitted to long-term care facilities. Female stroke victims are more likely to be depressed before having the stroke.18 Women are also less likely to achieve BP and lipid targets, two factors that influence stroke risk.8
In women, the highest incidence of stroke occurs in Black Americans, followed by White Americans, and then Hispanic Americans. Four in 1,000 Black women will die from stroke, which is twice the mortality of White women.1,3
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9. Rexrode KM. Emerging risk factors in women. Stroke
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13. Schwamm L, Fayad P, Acker JE, 3rd, Duncan P, Fonarow GC, Girgus M, et al. Translating evidence into practice: a decade of efforts by the American Heart Association/American Stroke Association to reduce death and disability due to stroke: a Presidential Advisory from the American Heart Association/American Stroke Association. Stroke
. 2010;41(5): 1051–1065. Epub 2010 Feb 24.
14. D'Elia L, Barba G, Cappuccio FP, Strazzullo P. Potassium intake, stroke, and cardiovascular disease: a meta-analysis of prospective studies. J Am Coll Cardiol
15. Braschi A, Naismith DJ. The effect of a dietary supplement of potassium chloride or potassium citrate on blood pressure in predominately normotensive volunteers. Br J Nutr.
19. Marsh JD, Keyrouz SG. Stroke prevention and treatment. J Am Coll Cardiol
© 2012 Lippincott Williams & Wilkins, Inc.
Experts recommend low-dose aspirin to prevent stroke in women. Lower doses are as effective as higher doses and are likely to be safer. Harv Womens Health Watch