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Peripheral resistance was a major factor in high systolic blood pressure in men but not in women.
Genetic differences among the sexes results in men and women being disproportionately affected by certain diseases, such as multiple sclerosis. New findings suggest that the same factors may hold true for the underlying causes of high blood pressure.
A study presented at the American Heart Association (AHA) Council on Hypertension, AHA Council on Kidney in Cardiovascular Disease, and American Society of Hypertension Joint Scientific Sessions 2017 found that gender differences can affect high blood pressure in adulthood, highlighting the need for tailored treatments for men and women.
The authors report that blood pressure is determined by heart rate, stroke volume—how much blood is pumped by the heart—and peripheral resistance—resistance to blood flow in the vessels. An increase in any of these factors can lead to increased blood pressure.
“The key takeaway from this study is that, for young and middle-aged women, stroke volume was the main determinant of blood pressure, while, in men, vascular resistance was the main determinant of blood pressure,” said study author Catriona Syme, PhD.
Included in the new study were 1347 participants ranging in age from adolescence to 65 years. The authors measured beat-by-beat blood pressure and the underlying forces of heart rate, stroke volume, and peripheral resistance. These factors were measured at rest, during posture change, and during mental stress.
Among women, stroke volume accounted for 55% of variance in systolic blood pressure compared with 35% among men, according to the study.
For men, total peripheral resistance was a major contributor to systolic blood pressure, but it only accounted for 30% of variance in women.
These differences among men and women were observed for the entire duration of the nearly hour-long testing. The most pronounced effects were observed during standing and were least evident during mental stress, according to the study.
This study is the first to explore how the 3 factors affect blood pressure over time and during day-to-day activities among younger adults, who are not typically investigated for hypertension.
Although current hypertension treatment is not different for men and women, these results suggest that it may be beneficial to prescribe medications based on the likely cause of the condition, according to the study.
The authors also note that future studies should investigate whether these findings translate to races other than Caucasians.
“For example, there have been many studies looking at sex differences in the usefulness of blood pressure medications. But, most of those studies have been done in people whose average age was 60-70 years — many of the women being post-menopausal,” Dr Syme said. “We think pre-menopausal women and men of a similar age may have elevated blood pressure for different reasons, and thus may need to be treated for hypertension differently. After menopause, when the production of female sex hormones decreases, reasons for hypertension may be more similar in men and women.”