Stress and salt sensitivity in childhood hypertension

The pressure response to sodium is heterogeneous among both persons with normal blood pressure and with hypertension. Nevertheless, sodium restriction is typically recommended for everyone with hypertension. As reviewed here, categorizing a person as “salt sensitive” has important prognostic and therapeutic implications. Determination of salt sensitivity is typically accomplished by assessment of the pressure response to administration of an oral or intravenous sodium load. In this chapter, we discuss an alternative way to administer a sodium load through stress exposure. Animal and human studies have demonstrated clinically significant sodium retention during and after stress, which in effect generates positive sodium balance and thus delivers a sodium load. Persons demonstrating this response develop a volume-dependent blood pressure elevation. Similar to findings in salt-sensitive populations, target organ changes have also been associated with impaired sodium handling during stress. Sodium retention in response to stress has been reported as improved or reversed after treatment with antihypertensive medications that block the reninangiotensin- aldosterone system. Evidence suggests that the variability of the pressure response to dietary sodium intake and to stress should be considered in our strategies to prevent and control hypertension.