When someone utters the words “heart attack,” do you picture a man clutching his chest? One of the reasons picture may pop into your head is the failure of researchers to include women in studies.
Women Under-represented for Decades
The U.S. Congress which mandated the U. S. Food and Drug Administration, creating the Office of Women’s Health in 1994, addressed the exclusion of women in medical studies.
But, thirteen years later, a 2007 article by Dr. Kathleen Uhl warned “[d]ecades of female underrepresentation in clinical studies has resulted in inequality in the understanding, diagnosis, and treatment of disease between the sexes.”
One of the outcomes of inadequate research including both sexes is that experts largely assumed that the causes of heart problems are the same for both sexes. But a new study by Zainab Samad, MD, MHS of Duke University Medical Center and colleagues investigated the impact of mental stress on the hearts of people with stable ischemic heart disease (IHD) and found important differences between the way the hearts of men and women react. The study underscores the need for more research including women subjects.
The Study: Mental Stress on the Heart
The team proposed to study possible differences in the “psychobiological response” to mental stress between the sexes. Of the 310 study participants with stable coronary disease who completed baseline testing, only 56 or 18% were women.
In an exclusive interview with Decoded Science, Dr. Samad explained “[t]he percentage of women enrolled in REMIT is similar to most clinical trials of patients with ischemic heart disease and higher than studies that had tested MSIMI previously.” (MSIMI refers to mental stress–induced myocardial ischemia. Myocardial ischemia occurs when there’s a reduction in blood flow to the heart; experts associate this with pain known as angina.)
Researchers excluded individuals who had “severe psychiatric symptoms, were pregnant, or were using antidepressants.” The psychometric tests included “mental arithmetic; mirror trace; and anger recall.” Mirror trace refers to attempting to outline a star from a reflection in the mirror. (Past research used this test on ischemia published in JAMA andCirculation.)
Before and after mental stress tests, researchers employed echocardiography to measure MSMI. As Dr. Samad clarified, “MSIMI was not a self-reported measure. This was measured objectively.We looked at the heart function and how the heart walls moved on echocardiogram during the mental stress tasks.” Other data collected included heart rate and blood pressure.
The Results: Women’s Hearts at Higher Risk from Stress
The researchers found important differences in the way the hearts of men and women in the study reacted to mental stress. The study demonstrated in addition to smoking, cholesterol and high blood pressure, mental stress also increases platelet formation, especially in women.
According to the researchers, “Men were more likely than women to show changes in traditional physiological measures, such as blood pressure…”
The Implications: Changes for Medicine and Research
The researchers noted women have higher rates of “angina and death” than men, though they show less obstructive coronary disease, which experts considered “paradoxical” because women’s heart disease differed from men.
As Dr. Samad summarized in his interview, “Currently mental/psychosocial stress is not considered while evaluating and treating patients with heart disease. This needs to change.” He continued, “We need to examine the impact of negative physiological consequences of mental stress on long-term outcomes, especially among women.”
Researchers, Studies, and Women
Researchers do not study enough women overall in medical research. One of the reasons in drug trials is the fear research may affect a fetus. Samad and colleagues, for instance, excluded pregnant women.
In addition to angina research, the New England Journal of Medicine addressed this problem when discussing the ethics of flu research. Women are also prescribed more medications than men, according to MDNews. These medications may disqualify them from some research.
Samad’s team also excluded those using anti-depressants, which likely disqualified women disproportionately. Research published by the Archives of Women’s Mental Health indicates that, in the United States, doctors prescribe anti-depressants for women at a much higher rate (18.6% of women to 9.9% of men).
Women and Medicine: Towards a Healthier Future
Physicians and patients alike need to be aware of the association between heart health and mental stress.
Broader implications exist for the inclusion of women in medical research in general. As the FDA notes, researchers need to include women in more medical research to pinpoint differences in disease prevalence, response and therapy between the sexes. Researchers need to find ways to enroll more women in medical research. Women’s lives depend on it.
Decoding Science. One article at a time.