Researchers are only now discovering how heart disease risk factors affect women instead of just men.

Share on Pinterest
For years women were not as included as male subjects in heart health studies. Getty Images

High blood pressure, diabetes, and smoking are well-known risk factors for heart attack.

But do they affect the risk of heart attack in men and women to the same degree?

Not according to a new study published in The BMJ, which found these risk factors raised the chances of heart attack in both men and women — but to a much greater extent in women.

The authors of the study, from the University of Oxford, Johns Hopkins University, and other institutions, assessed data on nearly half a million people enrolled in the UK Biobank, a database of information collected from adults in the United Kingdom.

They found that high blood pressure raised a woman’s risk of heart attack by 83 percent more than it did in a man. Smoking raised the risk of heart attack by 55 percent more in a woman, compared to a man. Type 2 diabetes raised the risk by 47 percent more in a woman, relative to a man.

“The reasons for these findings are unclear but could reflect some other confounding factors, such as the duration of exposure to these risk factors. For instance, women may have had untreated high blood pressure for more [time] than men,” Dr. Michelle O’Donoghue, a cardiovascular medicine specialist at Brigham and Women’s Hospital, told Healthline.

“Nonetheless, these findings are an important reminder to clinicians and to women about the importance of risk factor management,” she continued.

According to O’Donoghue, who was not involved in the study, women often overlook their risk factors for heart disease and take longer to seek treatment.

When they do seek treatment, they are less likely than men to be treated with appropriate guideline-based therapies.

Women have been excluded from many studies

Heart disease is the leading cause of death for both men and women in the United States.

But for many decades, studies on heart disease have included more men than women.

In some cases, scientists have excluded women due to concerns about the risks that trial treatments could pose to a developing fetus if a female participant got pregnant during a study.

Changes in female participants’ hormone levels across their menstrual cycles can also confound research results. This can make it harder and more expensive to collect and analyze data from study populations that include female subjects.

Because of those factors and others, men have been historically positioned as the default subjects in research on heart disease.

But it’s become increasingly clear that sex and gender can affect how heart disease affects people.

“The assumption made in our medical community, and certainly in the cardiology community, was that there was no difference — that if you studied men, that was good enough, that you didn’t need to study women,” Dr. Martha Gulati, a professor of medicine and chief of cardiology at the University of Arizona College of Medicine, told Healthline.

“We’re finding that’s just not true,” she added, “and this is certainly a study that emphasizes that women are different than men and the impact of certain risk factors is greater on women than it is on men.”

Although some strides have been made in recent decades, more work remains to be done to address persistent sex and gender imbalances in many areas of cardiovascular research.

Many factors may contribute to persistent imbalances, Dr. Pamela Ouyang, director of the Johns Hopkins Women’s Cardiovascular Health Center, told Healthline.

“One is that older women are more cautious about entering studies,” she said.

“They may be less able to attend visits, as they may depend on others for transportation and therefore not want to inconvenience family or friends,” she continued.

Many women also want to discuss studies with others before they agree to participate, she added. In some cases, the time window for recruitment might close before they have the chance to enroll.

To address those issues and others, she suggested it might be helpful for researchers to invite greater involvement from community members in the development stages of their studies.

Managing known risk factors

Like the recent study published in The BMJ, other investigations have found that certain risk factors for heart disease appear to have a greater impact on women than men.

“The findings that smoking, hypertension, and diabetes increase the risk of heart attack in women and men is known, and several studies have shown that these risk factors are associated with a higher risk for [heart attack] in women compared to their impact in men,” Ouyang said.

Sex-specific risk factors can also increase the chances of heart disease in women.

For example, certain complications of pregnancy are associated with heightened risk of heart disease. Those complications include preeclampsia, gestational hypertension, gestational diabetes, preterm delivery, and low infant birth weight.

Some health conditions that disproportionately affect women have also been linked to higher risk of heart disease. For instance, those conditions include breast cancer, rheumatoid arthritis, and lupus.

In order to understand and manage their risk for heart disease, Gulati encourages women to speak with their doctors.

“It’s so important for women to know if they’re at risk for heart disease, to discuss each of their risk factors with their physician, and to try to address them,” Gulati said.

Some of the risk factors can be addressed early in life. For example, diet, exercise, smoking, and other lifestyle habits in early adulthood and middle age can affect one’s chances of developing diabetes, high blood pressure, and heart disease later on.

“I recommend that efforts be made to reach younger women about these risk factors and the greater impact that smoking, high blood pressure, and diabetes have on them,” Ouyang said.

“Increasing physical activity and fitness is also critically important, and we know that women have a significantly lower involvement in physical activity than men starting in young adulthood,” she added.

The bottom line

Researchers found that high blood pressure raised a woman’s risk of heart attack by 83 percent more than it did in a man.

Smoking raised the risk of heart attack by 55 percent more in a woman, compared to a man. Type 2 diabetes raised the risk by 47 percent more in a woman, relative to a man.