Violence Against Women: A Risk Factor for Cardiovascular Disease

Commentary by Barbara H. Roberts, MD, FACC Contributing editor, ProCor. WHF trustee and Chief Medical Advisor

Violence against women has been with us throughout recorded history and continues around the world today. While not generally included among the risk factors for cardiovascular disease (CVD), research amply demonstrates the association between CVD and women's abuse. According to the World Health Organization, "Violence against women and girls is a major health and human rights concern. Women can experience physical or mental abuse throughout their lifecycle, in infancy, childhood and/or adolescence, or during adulthood or older age."(1) Violence against women has been, and continues to be, ubiquitous regardless of nationality, age, socioeconomic status, level of education, or religion. How can we end violence against women around the world? Following is some brief historical background and some representative research findings on this complex issue. This is not intended to be an exhaustive review nor are the examples cited meant to single out specific countries or cultures.

A brief history of violence against women
No doubt violence against women existed before the keeping of written records, but the documentation of these abuses can be found in codes and writings that date back thousands of years. The Code of Hammurabi, about 1800 years BCE, decreed that a married woman who was raped in Babylon was as much to blame as her attacker, and both were executed by drowning.(2) Through the ages, women who chaffed at their subordinate positions or who rebelled against the limitations imposed on them by a patriarchal society, faced punishments ranging from beatings, incarceration, torture, and rape to execution. Writing in the 8th century BCE the poet Hesiod, in his account of the creation of humankind, relates the story of Pandora, whose flouting of an injunction not to open a sealed box unleashes "pains and evils among men" and henceforth "mankind has been doomed to labour, grow old, get sick and die in suffering."(3)

At about the same time, the ancient Hebrews were setting down their creation story in which the disobedience of Eve led to the casting out of Adam and Eve from the Garden of Eden. God then tells Eve: "And I will greatly multiply thy sorrow and in sorrow shalt thou bring forth children and thy desire shall be for thy husband and he shall rule over thee."(4) The first of the monotheistic religions was also the first to inculcate a sense of shame about the human body, and in particular its sexuality. After Eve's sin, men and women must clothe themselves, and the penalty for adultery is death by stoning.

Death by stoning remains the penalty for adultery to this day in several countries, including those under traditional Islamic law, and was carried out in Afghanistan under the Taliban and in Iran after the 1979 revolution. In 2007, a teenage girl in Iraq was stoned to death by her family for loving a boy of a different religion. Such "honor" killings of young women as punishment for sexual activity outside marriage, for refusing to enter into an arranged marriage, or even for seeking a divorce from an abusive husband are not infrequent and are frequently unpunished along a wide swath of Africa, the Middle East, and South Asia. They also occur sporadically in other parts of the world.

An unknown number of women, sometimes estimated to be in the millions, but certainly many tens of thousands, were hung or burned at the stake as witches between the 14th and the 17th centuries in Europe and in the new American colonies by both Catholics and Protestants. And lest one think that the persecution of witches is a thing of the past, as recently as 13 April 2008, Nicholas Kristof in the New York Times wrote: "Here's a forecast for a particularly bizarre consequence of climate change: more executions of witches...In rural Tanzania, murders of elderly women accused of witchcraft are a very common form of homicide. And when Tanzania suffers unusual rainfall-either drought or flooding-witch-killings double, according to research by Edward Miguel, an economist at the University of California, Berkeley."(5)

Rape is a particular form of violence against women which, while not always fatal, often leaves women physically and emotionally scarred for life. Mr. Kristof has also noted that rape is used as a strategy of war: "The world woke up to this phenomenon in 1993, after discovering that Serbian forces had set up a network of 'rape camps' in which women and girls, some as young as 12, were enslaved. Since then, we've seen similar patterns of systematic rape in many countries, and it has become clear that mass rape is not just a byproduct of war but also sometimes a deliberate weapon...In Sudan, the government has turned all of Darfur into a rape camp...typically, the women are scarred or branded, or occasionally have their ears cut off."(6) According to Mr. Kristof, in some areas of eastern Congo three-quarters of women have been raped, sometimes with pointed sticks that leave the victims incontinent from internal injuries.

Genital mutilation of young girls, frequently performed by family members with primitive, unsterile instruments and without benefit of anesthesia, is widespread in parts of Africa, and occurs in many other countries, including Saudi Arabia, India, Malaysia, Sri Lanka, and Indonesia. An estimated 135 million girls and women have undergone female genital mutilation and about two million are at risk each year.(7)

Trafficking of women for sexual purposes, both within countries and across international borders, is widespread and contributes to the spread of HIV/AIDS. The US Department of Justice estimates that globally 600,000 to 800,000 people, 80% of them women, are trafficked for forced labor or sex annually.(8)

In the United States, the annual incidence of violence against women by their intimate partners consisting of physical assaults and rapes (called Intimate Partner Violence or IPV) is estimated to be at least 4.8 million. According to the Centers for Disease Control and Prevention (CDC) this led to the deaths of 1158 women in the United States in 2004.(9)

Violence against women is age-old, ongoing, systematic, culturally sanctioned, and frequently defended on religious grounds.

Health effects of violence against women
The literature on the chronic health effects of violence against women is vast and growing. This is only a small sampling. As physicians and primary care practitioners we need to share additional data to increase our knowledge and enhance our understanding.

The UN's Declaration on the Elimination of Violence against Women (1993) defines violence against women as "any act of gender-based violence that results in, or is likely to result in, physical, sexual or mental harm or suffering to women, including threats of such acts, coercion or arbitrary deprivation of liberty, whether occurring in public or in private life."(10) Except in wartime, most violence against women is perpetrated by spouses, intimate partners or other family members and the perpetrators of violence against women are overwhelmingly men.(11) Interest in interpersonal violence and other forms of violence against women has tended to focus on the immediate health effects and costs. Studies of long-term sequelae primarily focus on psychological effects such as depression and post-traumatic stress syndrome, which have been well documented as occurring at an increased rate in survivors of violence.(12) More recently, interest has focused on other effects including alterations in inflammatory markers, glucose metabolism, blood pressure, and the development of morbid obesity. Morbid obesity is associated with increased left ventricular mass, left ventricular dysfunction and impairment in left ventricular diastolic filling (13) in addition to its well-recognized association with hypertension, insulin resistance, diabetes, dyslipidemia, and increased inflammatory markers.

The association between childhood sexual abuse and obesity has been noted in the medical literature for several years. A review of 131 patients published in 1991 revealed that 60% of those who reported a history of rape or sexual molestation were 50 or more pounds overweight, compared to only 28% of age-and sex-matched controls who did not have a history of abuse. Childhood sexual abuse victims were also more likely to be extremely obese. Twenty-five percent of the abused group was found to be 100 or more pounds overweight, compared with only 6% of controls.(14) In a recent study of 258 morbidly obese candidates presenting for gastric bypass surgery (81% of whom were women), 27% reported a history of sexual abuse; and 91% of those reporting a history of sexual abuse were women. All the incidents occurred in childhood or adolescence with the exception of one patient who was raped at the age of 30.(15) In this study, in contradistinction to others, there was no association between a history of sexual abuse and lesser weight loss after bariatric surgery.

A study published in 2004 examined the role of childhood sexual abuse, physical violence, and neglect in the subsequent development of depression and CVD.(16) The data were drawn from the National Comorbidity Survey (NCS) of a nationally representative sample of the US population. Between 1990 and 1992, the NCS surveyed more than 5300 non-institutionalized persons aged 15-54 years. They were evenly divided between women and men. CVD diagnosis was based on self-reported high blood pressure/hypertension, heart attack, or stroke. Women, but not men, who were maltreated as children had an odds ratio for CVD of 8.79 (p< .0001) compared to women who were not maltreated in childhood, even after adjustment for age, ethnicity, marital status, income, and education. The odds ratio for the development of depression was increased in both men and women who were maltreated as children. The authors concluded that childhood maltreatment is a potent risk factor for CVD in women and for depression in both sexes.

Another study published in 2004 found a relation between adverse childhood experiences (ACEs) and the development of ischemic heart disease.(17) Retrospective cohort study data were collected from over 17,000 adult enrollees in a California health plan between 1995 and 1997. More than half (54%) of the cohort were women. While gender-specific data were not presented, the prevalence and likelihood of having ischemic heart disease was significantly increased for the overall cohort among patients exposed to multiple types of ACEs. The adjusted prevalence of depressed affect, diabetes, and hypertension were increased two- to three-fold among persons with four or more adverse childhood experiences compared to those with no ACEs. Likewise, the greater the ACE score, the greater the prevalence of smoking, sedentary lifestyle, and severe obesity.

Sex differences in the relationship of psychological factors to alterations in glucose metabolism were found in another study published in 2006.(18) A total of 135 healthy, non-smoking, non-diabetic people aged 18-65 years (mean age 26) of whom 75 were men and 60 were women, were studied to examine the relationship of psychological risk factors such as depression, hostility, and anger to fasting glucose levels and insulin resistance. Only among women were greater severity of depressive symptoms, higher levels of hostility, and a propensity to express anger significantly associated with higher levels of fasting blood glucose and greater insulin resistance as found in the metabolic syndrome. These psychological states increased risk independent of other risk factors for the metabolic syndrome including body mass index (BMI), age, fasting triglycerides, ethnicity, or exercise amount.

Understanding the causes
How might the experience of violence lead to an increase in CVD in women? An excellent summary of pertinent research can be found in "Inflammation, cardiovascular disease and metabolic syndrome as sequelae of violence against women" by Kathleen A. Kendall-Tackett.(19) Based on her comprehensive review of the pertinent literature, the author postulates that depression, hostility, and sleep disturbance, all of which are more common among women who have experienced abuse, may increase risk by increasing levels of pro-inflammatory cytokines.

That inflammation plays a role in CVD has now been shown beyond any reasonable doubt. Depression has been associated with increased levels of interleukin (IL)-6, C reactive protein (CRP), and tumor necrosis factor (TNF) alpha. Hostility was associated with higher levels of circulating the pro-inflammatory cytokines IL-1 alpha, IL-1 beta, and IL-8 in 44 healthy, nonsmoking, premenopausal women, while the combination of hostility and depression was associated with increased levels of IL-1 beta, IL-8 and TNF alpha.(20) The authors of that study noted that increased levels of IL-6 predicted both future risk of cardiac events and all-cause mortality.

Kendall-Tackett's review also cites research on hostility and emergence of the metabolic syndrome. Over a three-year follow up of 134 white and African-American teens, with approximately equal numbers of boys and girls, hostility at initial testing predicted risk factors for metabolic syndrome at follow-up testing approximately three years later, including BMI, insulin resistance, ratio of triglycerides to HDL cholesterol, and blood pressure.(21)

Sleep disturbances are also common among survivors of abuse and Kendall-Tackett cites several studies which found that sleep deprivation increases pro-inflammatory cytokines and leads to chronic activation of the hypothalamic-pituitary-adrenal axis.

Conclusion
Multiple lines of research demonstrate that violence against women has long-lasting deleterious effects, both emotional and physical. It destroys the lives of countless women and children, and its effects reverberate down the generations, as abuse often begets abuse. Millions of women around the globe have suffered violence at the hands of intimate partners and family members, and in the course of wars or "ethnic cleansing" actions.

Quite aside from the moral issues this raises, as health care professionals we cannot and must not stand silent. - Barbara Roberts, MD

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