Worldwide, coronary heart disease (CHD) is one of the leading causes of death and disability. Until recently, the differences in CHD between men and women were not widely recognized nor appreciated, thus leading to a global lack of efficient CHD management strategies for women.
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An overview of CHD
Coronary heart disease (CHD) is a type of cardiovascular disease (CVD) that is the leading cause of death in the world and is responsible for most deaths among men, as well as approximately one-third of all female deaths. CHD typically arises as a result of plaque buildup within the lining of coronary arteries.
The presence of this waxy substance in high quantities within the arteries of the heart, which is also known as atherosclerosis, prevents these blood vessels from delivering oxygen-rich blood to the heart. Some of the most common risk factors of CHD include hypertension, high blood cholesterol, age, diabetes, obesity, genetics, inactivity, tobacco use, and an unhealthy diet.
Previous documentation of sex differences
Until a few years ago, CHD was widely believed by the medical community to predominantly affect men. This presumption was largely made since most epidemiologic studies at this time did not report on men and women separately, and instead referred to patients in broad terms like community-dwelling adults.
Reports from the World Health Organization during the 1980s described a male to female CHD mortality ratio of 2.5 to 4.5. For many years, this type of data implied that either men were at an inherent disadvantage or the female population was provided an advantage in terms of their susceptibility to CHD.
Cardiologists for several decades often ignored the risk of CVDs in women. These misinterpretations have led to inappropriate CVD management strategies for women and a subsequent increase in female mortality and morbidity following a coronary event.
Since many physicians are still unaware of the cardiovascular risk in women, it is estimated that as many as 1 in 2 women will eventually die of heart disease or stroke. Moreover, every year since 1984, the number of CVD deaths in women have exceeded that of men in the United States.
Differences in risk factors
Generally, men and women have the same heart disease risk factors; however, some gender differences have been documented. Men, for example, appear to have less favorable levels of these risk factors as compared to women.
More specifically, men have been shown to have less favorable patterns of cigarette smoking, dietary fiber intake, vitamin C levels, blood viscosity, uric acid, high-density lipoprotein (HDL) cholesterol, and triglycerides as compared to women. While women have similar risk factors for CHD, studies have shown that the absolute risk of CHD is lower in women as compared to men.
A woman’s age as compared to that of a man can also cause significant differences to arise in their likelihood of being diagnosed with CHD. In general, women with CHD are often older than men with CHD.
Additionally, women over the age of 55 often have a higher incidence of fatal CHD, which contributes to higher morbidity and mortality rates in older women with CHD as compared to women under the age of 55. Although men typically have a 2-fold higher incidence of CHD and related mortality as compared to women, this morbidity gap shrinks when comparing men to women older than 55 years of age.
During a woman’s fertile age, estrogens have been found to exert beneficial effects on the cardiovascular system (CVS), which often protects women from atherosclerosis during this time. However, after menopause, estrogen levels deplete, thereby leading to an exponential increase in a woman’s cardiovascular risk. Some of the structural and functional changes that arise in a woman’s CVS after menopause include altered endothelial function, imbalance of autonomic activity that leans towards a higher adrenergic status, visceral adiposity, and increased systemic inflammation.
Each of these effects of estrogen deficiency in postmenopausal women can contribute to the development of systemic hypertension, altered glucose tolerance, abnormal lipid profiles, and insulin resistance.
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Race and ethnicity throughout many countries around the world also play determining factors in whether men or women within that given ethnic group are at a higher risk of CHD.
The REGARDS prospective cohort study published in 2012, which is one of the largest studies on black and white men and women in the United States, investigated fatal and non-fatal CHD incidence of these groups. As compared to white Americans, this study found that black Americans, on average, had less education, lower-income and were more likely to smoke, have higher body mass index (BMI), be hypertensive, report diabetes, and have higher high-sensitivity C-reactive protein (hsCRP) levels.
Furthermore, both black men and women were found to have twice the age-standardized rate of fatal CHD as compared to both white men and women. Whereas black men were found to have a lower risk of nonfatal acute myocardial infarction (MI) than white men, black women were found to be at a higher risk of acute MI than white women.
A wide range of psychosocial factors, which determine most cardiovascular events, can also vary between men and women. These factors can include depression, anger, hostility, anxiety, chronic psychosocial stressors such as work-related stress, social support, and social conflict.
Although women have been found to have poorer self-rated health statuses, women often visit their primary care physicians more often than men between adolescence to late middle age, thereby reducing their likelihood of dying within this age range as compared to men.
References and Further Reading
- “Coronary Heart Disease” – National Heart, Lung and Blood Institute
- Barrett-Connor, E. (2013). Gender differences and disparities in all-cause and coronary heart disease mortality: Epidemiological aspects. Best Practice & Research Clinical Endocrinology & Metabolism 27(4); 481-500. doi:10.1016/j.beem.2013.05.013.
- Gao, Z., Chen, Z., Sun, A., & Deng, X. (2019). Gender differences in cardiovascular disease. Medicine in Novel Technology and Devices 4. doi:10.1016/j.medntd.2019.100025.
- Galiuto, L., & Locorotondo, G. (2015). Gender differences in cardiovascular disease. Journal of Integrative Cardiology 1(1); 20-22. doi:10.15761/JIC.1000107.