Women may have a lower range of normal blood pressure than men. An increased risk for cardiovascular disease (CVD) was seen in women starting at a systolic blood pressure (SBP) of 100 mm Hg, according to study findings published in Circulation.1 This lower SBP in women is well below the 120 mm Hg that is considered the normal upper limit for adults of both sexes.
“Our latest findings suggest that this one-size-fits-all approach to considering blood pressure may be detrimental to a woman’s health,” said senior author Susan Cheng, MD, MPH, MMSc, associate professor of Cardiology and director of the Institute for Research on Healthy Aging in the Department of Cardiology at the Smidt Heart Institute in Los Angeles.2 “Based on our research results, we recommend that the medical community reassess blood pressure guidelines that do not account for sex differences.”
Dr Cheng and colleagues examined blood pressure measurements from 4 large community-based cohort studies that included 27,542 participants, 54% of whom were women. The studies included the Framingham Heart Study, Multi-Ethnic Study of Atherosclerosis, Atherosclerosis Risk in Communities Study, and Coronary Artery Risk Development in Young Adults Study.
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During a median follow-up of 28 years, 7424 participants (44% women) developed nonfatal or fatal CVD: 3405 myocardial infarctions, 4081 heart failures, and 1901 strokes. The researchers examined the relationship between incident CVD and categories of SBP (ie, each 10 mm Hg increment in SBP from <100 mm Hg to ≥160 mm Hg) in the overall group and in men and women separately using cohort-stratified Cox proportional hazards models.
Sex Differences in SBP Threshold for Increased CVD Risk
In the overall group, the threshold for incident MI and HF was 120 to 129 mm Hg and for stroke was 130 to 139 mm Hg. However, when the data were analyzed by sex, women showed a significantly increased risk for CVD beginning at 100 to 109 mm Hg (relative to SBP <100 mm Hg in women); in men, the increased risk began at an SBP of 130 to 139 mm Hg.
The magnitude of the increased risk of CVD was similar between the two sexes at these thresholds (hazard ratio, 1.25 for women at 100-109 mm Hg and 1.26 in men at 130-139 mm Hg). The same pattern was found when the risks of myocardial infarction, heart failure, and stroke were evaluated separately.
“We are now pushed to rethink what we thought was a normal blood pressure that might keep a woman or a man safe from developing heart disease or stroke,” said Dr Cheng, who also serves as director of Cardiovascular Population Sciences at the Barbra Streisand Women’s Heart Center and is the Erika J. Glazer Chair in Women’s Cardiovascular Health and Population Science.
These findings build on previous research by Dr Cheng and colleagues showing that women exhibit a steeper increase in blood pressure beginning in their 30s that continues over their lifetime.3 These findings may explain why women are more likely to develop certain types of CVD — coronary microvascular dysfunction and heart failure with preserved ejection fraction —at different times in their lives than men, according to the researchers.
“If the ideal physiologic range of blood pressure truly is lower for females than males, current approaches to using sex-agnostic targets for lowering elevated blood pressure need to be reassessed,” said Christine Albert, MD, MPH, chair of the Department of Cardiology at the Smidt Heart Institute. “This important work is far-reaching and has numerous clinical implications.”
References
1. Ji H, Niiranen TJ, Rader F, et al. Sex differences in blood pressure associations with cardiovascular outcomes. Circulation. 2021;143(7):761-763. doi:10.1161/CIRCULATIONAHA.120.049360
2. Cedars Sinai. Women have a lower range of ‘normal’ blood pressure than men. February 15, 2021. Accessed March 18, 2021. https://www.cedars-sinai.org/newsroom/women-have-a-lower-range-of-normal-blood-pressure-than-men/
3. Ji H, Kim A, Ebinger JE, Niiranen TJ, Claggett BL, Bairey Merz CN, Cheng S. Sex differences in blood pressure trajectories over the life course. JAMA Cardiol. 2020;5(3):19-26. doi:10.1001/jamacardio.2019.5306
