Neurogenic Mechanisms and Salt Sensitivity

Abstract

The concept of salt sensitivity is based on the observation that some individuals respond to a high salt intake with a marked increase in blood pressure, whereas others experience little or no blood pressure changes. Salt sensitivity is found much more frequently in hypertensive than in normotensive subjects,1 and its presence predicts a significantly greater increase of blood pressure with age,2 suggesting that salt sensitivity plays some role in the pathogenesis of hypertension. In addition, the risk for the occurrence of cardiovascular events is >3-fold higher in salt-sensitive than in salt-resistant hypertensive subjects.3 In this issue of Hypertension , Coruzzi et al4 show that in individuals with essential hypertension, even modest levels of salt sensitivity are associated with alterations in autonomic cardiovascular control. Their study strongly supports the idea that neurogenic mechanisms are involved in the pathophysiology of salt sensitivity in essential hypertension. Because the kidney is the primary site for the regulation of salt and water homeostasis, most of the previous search for mechanisms leading to salt sensitivity has focused on functional and genetic differences in renal sodium handling. In their classical analysis of long-term blood pressure control, …