Aging and sex differences in salt sensitivity of blood pressure

Abstract

Salt sensitivity of blood pressure (SSBP) is a complex physiological trait characterized by changes in blood pressure in response to dietary salt intake. Aging introduces an additional layer of complexity to the pathophysiology of SSBP, with mitochondrial dysfunction, epigenetic modifications, and alterations in gut microbiota emerging as critical factors. Despite advancements in understanding these mechanisms, the processes driving increased salt sensitivity with age and their differential impacts across sexes remain unclear. This review explores the current understanding of salt sensitivity, delving into its underlying mechanisms, the role of inflammation, and the influence of aging and sex differences on these processes. We also aim to provide insights into the multifaceted nature of salt sensitivity and its implications for personalized treatment strategies in hypertension management.

Keywords: aging; hypertension; inflammation; salt sensitivity; sex differences.

Figure 1. Factors contributing to sex differences in salt sensitivity of blood pressure

This figure highlights the potential mechanisms by which sex hormones modulate salt sensitivity of blood pressure. ENaC, epithelial sodium channel; MR, mineralocorticoid receptor; Na/H, sodium-hydrogen; PR, progesterone receptor; SNS, sympathetic nervous system. Figure was created with BioRender.

Figure 2. Cumulative influence of factors on the prevalence of salt sensitivity of blood pressure across the lifespan

This figure illustrates the cumulative influence of genetic, biological, environmental, and lifestyle factors on the prevalence of salt sensitivity in blood pressure throughout the lifespan in both males and females. The y-axis represents the increasing prevalence of salt-sensitive hypertension, while the x-axis depicts the aging process from infancy through older adulthood. The figure highlights that women are generally more salt-sensitive at all ages, with a notable increase in salt sensitivity during the postmenopausal period. SSBP, salt sensitivity of blood pressure. Figure was created with BioRender.