September 2018 Issue

Heart Disease in Postmenopausal Women
By Densie Webb, PhD, RD
Today's Dietitian
Vol. 20, No. 9, P. 34

The shocking stats should motivate all dietitians to discuss prevention strategies with patients.

Although heart disease often is thought of as a "man's disease," about the same number of women as men die each year of the condition in the United States. In fact, heart disease is the leading cause of death in US women, responsible for 1 out of every 3 fatalities.1 For decades, CVD research focused primarily on men, leading to an underappreciation of the differences that exist between the sexes. It's no wonder then that only a little more than one-half of women recognize that heart disease is their No. 1 killer.1

Thanks to the hormone estrogen, premenopausal women are relatively protected against CVD compared with age-matched men; however, this difference narrows after menopause. Heart disease risk increases for everyone as they age, but for women, symptoms, if present, can become more evident after menopause.2 The average age of menopause for women is 51. An overall increase in heart attacks among women generally occurs about 10 years after menopause.2 Menopause itself doesn't cause heart disease, but risk factors such as obesity or physical inactivity are likely to have a greater impact as estrogen levels drop. Estrogen is believed to offer protection by having a positive effect on the inner layer of the artery wall, helping to keep blood vessels flexible and better able to facilitate unobstructed blood flow. The average lifetime risk of developing CVD in women at age 50 is around 40%, and this rises as the number of additional risk factors increase.3

Heart Disease Lexicon
CVD is the big umbrella over all types of diseases that affect the heart or blood vessels, including coronary heart disease (CHD), stroke, congenital heart defects, and peripheral artery disease.4

Heart disease is a type of CVD. It's a catch-all phrase for a variety of conditions that affect the heart's structure and functions. All heart diseases are cardiovascular diseases, but not all CVD is heart disease. CHD is the most common type of heart disease.4

CHD is also known as coronary artery disease (CAD) or atherosclerosis. It occurs when plaque (a combination of fat, cholesterol, calcium, and other substances found in the blood) builds up in the arteries. Plaque reduces the amount of oxygen-rich blood reaching the heart, a situation that can cause angina. Plaque also can lead to blood clots that block blood flow and are the most common cause of heart attacks.4

Stroke can be caused either by a clot obstructing the flow of blood to the brain (called an ischemic stroke), the result of CHD, or by a blood vessel rupturing and preventing blood flow to the brain (called a hemorrhagic stroke). Ischemic stroke accounts for 87% of all stroke.5 In women older than 60, stroke is the second leading cause of death. Recent research also has suggested that, among first-time stroke patients, women frequently are older (after age 75, women experience around 50% greater risk of stroke than men) and more likely to have hypertension.4

Heart failure is a chronic, progressive condition in which the heart muscle is unable to pump enough blood to meet the body's needs for blood and oxygen. The term "congestive heart failure" is used interchangeably with "heart failure." It accounts for 35% of all CVD deaths among women.6

Risk Factors
Even if a woman is symptom-free, she still may be at risk of heart disease. About two-thirds of women who die suddenly of CHD have had no previous symptoms.1 Several risk factors for heart disease have been identified; several more are suspected to be risk factors. Research suggests that any of these risk factors can interact in complicated ways that, to date, aren't quantifiable. For example, a recent case-control study of both pre- and postmenopausal women found that a higher intake of meat was associated with an increase of CHD, but only in smokers.7 The same may be true of any other risk factor, ie, the impact of any one risk factor may depend on the presence of one or more additional risk factors.

The following risk factors are among the most well recognized and most studied:

Hypertension. There's a higher prevalence of hypertension in women older than 60 than in men, and it's less well controlled in women compared with men.3 In women between the ages of 65 and 74, as much as 65.8% of women have hypertension; at age 75 or older, 81.2% have hypertension.8

Overweight and obesity. These are proven risk factors for heart disease. More than 70% of adults in the United States are either overweight or obese.9 According to the latest figures from the Centers for Disease Control and Prevention, more women than men are obese, and the impact of obesity on the development of CAD appears to be greater in women than in men.10 In the Framingham Heart Study, obesity increased the risk of CAD by 64% in women, compared with 46% in men.3

Inactivity. Sedentary behavior is a clear risk factor for heart disease, and the prevalence of inactivity is higher among women than men.3 The American Heart Association recommends 150 minutes of physical activity each week for both men and women to help prevent heart disease.11 A study presented earlier this year at the American College of Cardiology meeting found that walking for at least 40 minutes two to three times per week at an average to fast pace was associated with almost a 25% drop in the risk of heart failure among postmenopausal women. It was the first study of its kind to specifically focus on the risk of heart failure among women older than 50.12

Diabetes. It's well recognized that elevated fasting glucose both in the diabetes range (≥126 mg/dL), as well as in the impaired or prediabetes range (100 to 125 mg/dL) represents increased risk.13 In a meta-analysis of more than 85,000 individuals, the relative risk of CVD and heart failure was 44% greater in women with diabetes than in similarly affected men.14

Less Clear Risk Factors
Hormone replacement therapy. This treatment appears to reduce the risk of CAD in women younger than age 60, but not in older women. However, the consensus is that it should never be prescribed for the sole purpose of preventing CVD.3

Age at menopause. Women who experience menopause at an early age (younger than 45), whether surgically or occurring naturally, may be at greater risk of heart failure compared with women who experience menopause at a later age. "Younger women who have gone through the menopause early have different risks compared to older women and also have more benefits from taking hormone replacement therapy and other types of hormone treatment," says Louise R. Newson, BSc(Hons), MBChB(Hons), MRCP, FRCGP, a general practitioner and menopause expert based in the United Kingdom.

A meta-analysis of data from almost 3,600 women in the Atherosclerosis Risk in Communities study found a modestly greater risk of heart failure in women experiencing early menopause. Approximately 10% of women experience natural menopause before age 45, and two-thirds of all surgical menopause occurs before age 50.15,16 There's an association of the age of menopause of mothers and the age of menopause of daughters: If the mother experienced menopause at an early age, the chances of the daughter experiencing early menopause is greater.17

Previous pregnancy loss. Women who have a history of one or more stillbirths or miscarriages may be at increased risk of CHD, but no association has been found between pregnancy loss and ischemic stroke.18 The risk appears to be greater among women with a history of stillbirth than among women with a history of miscarriage. The association was found even after adjusting for traditional CVD risk factors and the number of pregnancies.

Calcium supplementation. High blood levels of circulating calcium are a risk factor for vascular disease. Some research suggests that taking calcium supplements is associated with an increased risk of CVD. No such association has been found with dietary calcium intakes. While his position is controversial, Ian Reid, PhD, a professor of medical and health sciences at the University of Auckland, New Zealand, says, "Most studies have found that 1,000 mg/day of calcium supplements are associated with a 20% increased risk of heart attack." He points out that 500 mg/day increases blood calcium by about the same amount as 1,000 mg/day and doesn't regard the lower dose as safe.

Role of Diet
Research clearly shows that diet affects heart disease risk: The higher the quality of the diet, the lower the risk.19,20 Several professional and governmental bodies have developed dietary guidelines to reduce the risk of heart disease. The following are the best of the best to share with clients and patients as a vital part of decreasing heart disease risk.21-24

• Add foods that contain plant sterols. The National Cholesterol Education Program recommends including 2 g per day of plant sterols into the diets of those with elevated serum LDL cholesterol. The sterol-fortified foods must be consumed daily, just as a lipid-lowering medication would be, to sustain LDL cholesterol reductions. Margarines fortified with plant sterols are widely available.

Choose whole grain, high-fiber foods. Diets high in whole grain products and fiber are associated with a decreased risk of CVD. At least one-half of grain intake should come from whole grains. Include such whole grains as whole wheat, oats/oatmeal, rye, barley, corn, and popcorn.

Consume foods rich in soluble fiber. Consume 10 to 25 g/day of soluble fiber. Foods such as eggplant, okra, oats, barley, and psyllium are rich in soluble fiber.

Include fatty fish in the diet. Include two servings of fatty fish per week (8 oz total). Fish such as salmon, sardines, and halibut are high in EPA and DHA, both of which are associated with a reduced risk of sudden death and death from CAD.

Snack on a single handful of nuts most days of the week. Several studies have found that making nuts a regular part of the diet can reduce CVD risk factors and the risk of dying from CVD. Choose from almonds, pecans, walnuts, and pistachios.

Drink two to three cups of fat-free or low-fat milk or equivalent dairy products per day. Regular consumption of fat-free and low-fat dairy are an integral part of the DASH (Dietary Approaches to Stop Hypertension) diet to lower blood pressure.

Choose olive oil over other fats in the diet. Research shows that a diet rich in olive oil can increase HDL cholesterol and lower C-reactive protein over and above the benefits obtained from a cholesterol-lowering diet. Other foods rich in monounsaturated fats include canola oil, avocados, hazelnuts, pecans, and pistachios.

Drink a moderate amount of alcohol. Alcohol may have beneficial effects when consumed in moderation. That's a maximum of one drink per day for women and two drinks per day for men. (A drink is one 12-oz beer, 4 oz of wine, 1.5 oz of 80-proof spirits, or 1 oz of 100-proof spirits.) However, the American Heart Association declines to make even moderate drinking a part of its heart-healthy diet recommendations. The organization states that given the risks associated with alcohol consumption, people should not start drinking if they don't already drink alcohol.

Eat more fruits and vegetables. Diets rich in vegetables and fruits have been shown to lower blood pressure and improve other CVD risk factors, resulting in a decreased risk of CVD and stroke. Most dietary guidelines recommend including 4 to 5 cups of fruits and vegetables per day in the diet.

Make beans and lentils a regular part of the diet. Include at least 11/2 cups per week of dried beans and peas. Beans and lentils are good sources of protein; research also suggests that the fiber they contain lowers blood cholesterol levels.

Include soy protein regularly. Some research suggests that a diet rich in soy protein may help lower cholesterol and reduce the risk of heart disease.25 Soyfoods are low in saturated fat and an excellent source of high-quality protein, and most are a good source of fiber. Foods rich in soy protein include soymilk, soy yogurt, tofu, soy burgers, and soy nuts.

— Densie Webb, PhD, RD, is a freelance writer, editor, and industry consultant based in Austin, Texas.

References
1. Centers for Disease Control and Prevention. Women and heart disease fact sheet. https://www.cdc.gov/dhdsp/data_statistics/fact_sheets/fs_women_heart.htm. Updated August 23, 2017. Accessed July 11, 2018.

2. Menopause and heart disease. American Heart Association website. https://www.heart.org/en/health-topics/consumer-healthcare/menopause-and-heart-disease. Updated July 31, 2015. Accessed July 10, 2018.

3. Garcia M, Mulvagh SL, Merz CN, Buring JE, Manson JE. Cardiovascular disease in women: clinical perspectives. Circ Res. 2016;118(8):1273-1293.

4. Know the differences: cardiovascular disease, heart disease, coronary heart disease. National Heart, Lung, and Blood Institute website. https://www.nhlbi.nih.gov/sites/default/files/media/docs/Fact_Sheet_Know_Diff_Design.508_pdf.pdf. Accessed June 9, 2018.

5. Ischemic strokes (clots). American Stroke Association website. https://www.strokeassociation.org/STROKEORG/AboutStroke/TypesofStroke/IschemicClots/Ischemic-Strokes-Clots_UCM_310939_Article.jsp. Accessed July 10, 2018.

6. Appiah D, Schreiner PJ, Demerath EW, Loehr LR, Chang PP, Folsom AR. Association of age at menopause with incident heart failure: a prospective cohort study and meta-analysis. J Am Heart Assoc. 2016;5(8):e003769.

7. Zyriax BC, Vettorazzi E, Hamuda A, Windler E. Interaction of smoking and dietary habits modifying the risk of coronary heart disease in women: results from a case-control study [published online March 2, 2018]. Eur J Clin Nutr. doi: 10.1038/s41430-018-0099-9.

8. Benjamin EJ, Virani SS, Callaway CW, et al. heart disease and stroke statistics — 2018 update: a report from the American Heart Association. Circulation. 2018;137(12):e67-e492.

9. Obesity and overweight. Centers for Disease Control and Prevention website. https://www.cdc.gov/nchs/fastats/obesity-overweight.htm. Updated May 3, 2017. Accessed July 9, 2018.

10. Prevalence of overweight, obesity and extreme obesity among adults aged 20 and over: United States, 1960-1962 through 2013-2014. Center for Disease Control and Prevention website. https://www.cdc.gov/nchs/data/hestat/obesity_adult_13_14/obesity_adult_13_14.htm. Updated July 18, 2016. Accessed July 8, 2018.

11. American Heart Association recommendations for physical activity for adults. American Heart Association website. https://www.heart.org/en/healthy-living/fitness/fitness-basics/aha-recs-for-physical-activity-in-adults. Updated April 18, 2018. Accessed July 8, 2018.

12. Rasla S, Lin X, el Meligy A, et al. Association of walking pace, walking frequency and duration and joint effects on the risk of heart failure in post-menopausal women. Paper presented at: American College of Cardiology 67th Annual Scientific Session and Expo; March 12, 2018; Orlando, Florida.

13. American Diabetes Association. Standards of medical care in diabetes — 2014. Diabetes Care. 2014;37(Suppl 1):S14-S80.

14. Huxley R, Barzi F, Woodward M. Excess risk of fatal coronary heart disease associated with diabetes in men and women: meta-analysis of 37 prospective cohort studies. BMJ. 2006;332(7533):73-78.

15. Subrat P, Santa SA, Vandana J. The concepts and consequences of early ovarian ageing: a caveat to women's health. J Reprod Infertil. 2013;14(1):3-7.

16. Novetsky AP, Boyd LR, Curtin JP. Trends in bilateral oophorectomy at the time of hysterectomy for benign disease. Obstet Gynecol. 2011;118(6):1280-1286.

17. Steiner AZ, Baird DD, Kesner JS. Mother's menopausal age is associated with her daughter's early follicular phase urinary follicle-stimulating hormone level. Menopause. 2008;15(5):940-944.

18. Parker DR, Lu B, Sands-Lincoln M, et al. Risk of cardiovascular disease among postmenopausal women with prior pregnancy loss: the women's health initiative. Ann Fam Med. 2014;12(4):302-309.

19. Belin RJ, Greenland P, Allison M, et al. Diet quality and the risk of cardiovascular disease: the Women's Health Initiative (WHI). Am J Clin Nutr. 2011;94(1):49-57.

20. Fung TT, Willett WC, Stampfer MJ, Manson JE, Hu FB. Dietary patterns and the risk of coronary heart disease in women. Arch Intern Med. 2001;161(15):1857-1862.

21. Your guide to lowering your blood pressure with DASH. National Heart Lung and Blood Institute website. https://www.nhlbi.nih.gov/files/docs/public/heart/new_dash.pdf. Updated April 2006. Accessed July 7, 2018.

22. The American Heart Association's diet and lifestyle recommendations. American Heart Association website. https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/nutrition-basics/aha-diet-and-lifestyle-recommendations. Updated August 2015. Accessed July 8, 2018.

23. National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III). Third report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III) final report. Circulation. 2002;106(25):3143-3421.

24. US Department of Health & Human Services. Dietary Guidelines for Americans 2015–2020: Eighth Edition. http://health.gov/dietaryguidelines/2015/guidelines/. Published January 7, 2016.

25. Food labeling: health claims; soy protein and coronary heart disease. Food and Drug Administration, HHS. Final rule. Fed Regist. 1999;64(206):57700-57733.

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