Sex-Related Differences in Hypertension

Abstract

Much of what we understand about the regulation of arterial pressure and extracellular fluid volume has been derived from studies in men. Although the responses that can be mounted against major physiological challenges to extracellular fluid volume (hemorrhage/dehydration) are essentially similar in men and women, there are marked sex-related differences in the regulation of renal and cardiovascular physiology. These possibly underpin the greater risk of renal and cardiovascular disease (CVD) in men and, conversely, confer the relative protection from these conditions in women, at least until menopause. In recent years, advances have been made in understanding the mechanistic bases for sex-related differences in CVD and these have been reviewed in detail.1–3 Therefore, the purpose of this report is to provide an update of findings in the past few years. Increasingly, studies are incorporating sex as a factor into their analyses. Although not all studies demonstrate a sex-specific interaction,4–7 many do, exemplifying the mantra, seek and ye shall find; this appears to be particularly true for sex-related differences in CVD. In recent years, evidence that women have smaller and stiffer hearts because of a greater collagen content has received a good deal of attention for the reason that it may explain some of the puzzling differences in clinical signs of CVD between men and women. Puntmann et al8 examined aortic stiffness by pulse wave velocity and ventricular deformation indices using MRI both at rest and during dobutamine challenge in elderly men and women. At rest, women had greater aortic stiffness and ventricular deformation than men. Moreover, sex-related differences were observed during stress because men had increased longitudinal and circumferential ventricular deformation during dobutamine challenge, whereas women only had an increase in circumferential deformation.8 These data suggest that differential loading of the aortic reservoir …