Abstract
Several clinical and large population studies indicate that women are more sensitive to salt than men, however, the precise mechanisms by which the onset of sexual dimorphism manifests itself are not yet fully understood.Here, we evaluate recent epidemiological data and highlight current knowledge from studies investigating the sex-specific mechanisms of salt-sensitive blood pressure (SSBP). Emerging evidence indicates that women of all ethnicities are more sensitive to salt than men, at all ages, both premenopausal and postmenopausal. However, menopause exacerbates the severity and prevalence of SSBP, suggesting that female sex chromosomes predispose and female sex hormones mitigate salt-sensitive blood pressure (SSBP).
Comments
Results from human and rodent studies support the contribution of enhanced and inappropriate activation of the aldosterone-ECMR (endothelial cell mineralocorticoid receptor) axis that promotes vascular dysfunction in women.Increases in the adrenal response to angiotensin II, in association with increased ECMR expression and endothelial ENaC (epithelial sodium channel) activation in women compared to men, are emerging as central players in the development of endothelial dysfunction and PFPS in women. Female sex increases the prevalence and susceptibility of SSBP and sex hormones and sex chromosome complement may exert antagonistic effects on the development of female PFS.
Women of all ages and sexes have more salt-sensitive hypertension than men
There is growing evidence that women of all ethnicities and ages are more sensitive to salt than men, and that this propensity to retain more salt, which raises blood pressure, increases after menopause.
Another important emerging result is that healthy blood pressures can differ between the sexes, meaning women could benefit from earlier, different intervention to prevent heart and vasculature damage.
«The reality is that women and men regulate our blood pressure differently and our blood pressures are different at the start of the study,» says Eric Belin de Chantemele, M.D., a physiologist at the Center for Vascular Biology at the Medical College of Georgia at Augusta University.
It is generally thought that women are better protected against cardiovascular disease than men until menopause, when the risk is thought to level out.Laboratory studies in traditional models of rats with hypertension, such as the salt-sensitive Dahl rat, have generally supported those ideas, including a risk equalization in the two sexes after removal of the ovaries.
But in female humans and some mouse models, protection seems less absolute: Because more women are sensitive to salt before menopause, and menopause exacerbates both its severity and prevalence, CGM scientists report in a review article appearing on the cover of the American Heart Association’s journal Hypertension.
That supports another emerging concept that sex chromosome XX predisposes women to salt sensitivity, presumably because women need to nearly double their fluid volume during pregnancy, and estrogen does help mitigate some of the related increased risk, at least until its levels drop after menopause. says Belin de Chantemele.
Work primarily on male humans and animal models feeds the idea erroneous that women are less sensitive to salt, write Belin de Chantemele and colleagues, Dr. Anna S. S. Simpson.Jessica Faulkner, vascular physiologist in the Department of Physiology at CGM and AU graduate student Candee T. Barris.
«Salt sensitivity is one of the main factors of hypertension. And, if you look at people who have treatment-resistant hypertension, which is most people, most are sensitive to salt,» says Belin de Chantemele. «It’s very important to know the cause of that.»
Salt sensitivity means that your body has an apparent natural tendency to retain salt rather than excrete excess in urine.
Blood pressure salt sensitivity occurs when blood pressure decreases or increases more than 10% in response to the amount of salt you consume, scientists say.
Salt sensitivity is a factor in approximately half of cases in which the cause of hypertension is not obvious, such as a kidney problem.It’s also a regular contributor to treatment-resistant hypertension, and only 1 in 4 adults has hypertension under control, according to the Centers for Disease Control and Prevention.
There is also good human information that reducing salt intake reduces salt sensitivity and even more so in women, says Belin de Chantemele.
«We think it’s primarily the vasculature that doesn’t relax in response to sodium intake that leads to elevated pressure,» she says of women’s distinctive handling of salt. Animal studies on salt sensitivity generally indicate that the kidneys, which should excrete more sodium when we consume too much, work well in females.In fact, human and laboratory animal evidence indicates that female kidneys are better at excreting salt, he says. The problem, it seems, is with the vasculature, because salt should also cause blood vessels to relax.
Source — https://www.intramed.net/103803