New findings from an analysis of sex-specific blood pressure trajectories show that starting at an early age and continuing throughout life, women experience steeper increases in blood pressure than men.
“In contrast with the notion that important vascular diseases in women lag behind men by 10 to 20 years, our findings indicate that certain vascular changes not only develop earlier but also progress faster in women than in men,” the authors state.
“In effect, sex differences in physiology, starting in early life, may well set the stage for later-life cardiac as well as vascular diseases that often present differently in women compared with men,” they suggest.
The study was published online in JAMA Cardiology on January 15.
The findings could have implications regarding different strategies for managing high blood pressure in women compared to men, senior author Susan Cheng, MD, told Medscape Medical News.
Cheng is director of cardiovascular population sciences and public health research at the Barbra Streisand Women’s Heart Center and the Smidt Heart Institute at Cedars-Sinai Medical Center, Los Angeles, California.
“If a clinician sees two patients of the same age and similarly elevated blood pressure, but one male and one female, before this paper, we would think they should receive the same kind of intervention. But now we know that in order for the woman to have reached a level of 140, her BP has risen earlier and faster than is the case for the man,” she commented.
The current data show that women start out with systolic pressure of about 105 mmHg, whereas men start out at about 115 mmHg, she noted. “We believe women’s blood pressure is supposed to be slightly lower than men’s throughout life, so when we see a level of 140 mmHg in a woman, that may indicate a higher risk than that conferred by the same pressure in a man,” Cheng explained.
“I would say that of these two patients, the woman is likely to be at higher risk of blood-pressure-related outcomes than the man,” she added.
Cheng said this had not been recognized before because women tend to present with cardiovascular disease in different ways than men. “They are more likely to have small-vessel disease rather than a large atherosclerotic plaque in a major coronary artery, and small-vessel disease is more likely to go undetected,” she said.
“I would say that in the scenario of a man and woman with similar levels of raised blood pressure, clinicians need to pay more attention to the woman. But actually, what tends to happen is the opposite. There is a perception that women are not at such high cardiovascular risk as men, and raised blood pressure is often dismissed as anxiety in women,” she said.
Cheng noted that it has typically been thought that women start out better than men because of the protective effect of estrogen, and when this wears off at the time of menopause, women’s blood pressure levels and cardiovascular risk catch up with those of men.
“But our data do not suggest that this is the case. We did not see any spike of blood pressure in women at menopause ― rather, a smooth, continuous rise of levels throughout life, which starts earlier and accelerates faster than in men.”
Cheng suggested that different thresholds for definitions of increased blood pressure and hypertension may be needed for men and women. “We need to think about what is normal and abnormal for men and for women separately and what this means for thresholds and treatments,” she stated.
In their article, the researchers note that during the past 2 decades, mounting evidence has highlighted differences between women and men in the manifestation of common cardiovascular diseases. It is now increasingly recognized that women are more likely than men to develop coronary microvascular dysfunction and heart failure with preserved ejection fraction, especially in conjunction with vascular risk factors such as hypertension.
These observations suggest that cardiovascular pathophysiology is likely to be fundamentally different between the sexes, they say.
To look into this further ― and noting that measures of blood pressure represent the single most accessible metric of vascular aging and that increased blood pressure is the largest contributor to cardiovascular risk ― the researchers used population-based multicohort data to conduct a comprehensive sex-specific analysis of blood pressure trajectories over the life course.
They analyzed data collected over a period of 43 years in four community-based US cohort studies that included a total of 32,833 participants (54% women).
Results showed that compared with men, women exhibited a steeper increase in blood pressure that began as early as the third decade and continued through the life course. After adjustment for multiple cardiovascular disease risk factors, these between-sex differences in all blood pressure trajectories persisted.
“We believe that steeper elevation represents something important about baseline differences in physiology that contributes to differences in the pathophysiology of cardiovascular disease in men and women,” Cheng said.
“I think we’re coming to understand that there are sex differences in cardiovascular risks that start much earlier than the hormonal changes associated with menopause ― probably even at birth or prebirth,” she added.
Additional work is needed “to further understand sexual dimorphism in cardiovascular risk to optimize prevention and management efforts in both women and men,” the authors conclude.
In an accompanying editorial, Nanette K. Wenger, MD, Emory University School of Medicine, Atlanta, Georgia, says these new findings introduce “the concept that biology serves as an underpinning of sex differences in the pathophysiology of cardiovascular illnesses, in subsequent distinct pathophysiologic alterations, and in the variability in treatment effectiveness.”
In an audio interview with JAMA Cardiology, Wenger stated: “Hypertension is not just the numbers of the blood pressure. It is probably the most accessible measure of vascular aging and that starts quite early. This gives us a window on the biologic changes, and certainly many of them involve the endothelium.”
She pointed out that hypertension has more adverse physiologic consequences for women than for men. “Women get more left ventricular hypertrophy, more concentric hypertrophy. Women treated for elevated blood pressure do not have as much regression of their left ventricular hypotrophy as do men, and they have more left atrial enlargement. Women with hypertension lose their gender-specific protection against coronary disease.”
But Wenger also noted that, “sadly,” women are less likely to be treated to target than men. “We see across the spectrum of care that women receive less preventative therapies, fewer diagnostic tests, less likely to receive guideline-recommended medical therapies because they are perceived not to be vulnerable to cardiovascular disease.
“I would hope that many of our colleagues will become involved in examining sex and gender differences, because there are so many influences of this on how we diagnose and treat women and men,” she concluded.
The study was funded by grants from Gilead Sciences, the National Institutes of Health, the National Center for Research Resources, the National Center for Advancing Translational Sciences, the Edythe L. Broad and the Constance Austin Women’s Heart Research Fellowships, the Barbra Streisand Women’s Cardiovascular Research and Education Program, the Society for Women’s Health Research, the Linda Joy Pollin Women’s Heart Health Program, the Erika Glazer Women’s Heart Health Project, and the Adelson Family Foundation. Cheng received grants from the National Institutes of Health during the conduct of the study and personal fees from Zogenix outside the submitted work. Wenger has disclosed no relevant financial relationships.