Determinants and Mechanisms of the Renin Aldosterone Stress Response

Abstract

Objective:The renin-angiotensin-aldosterone system (RAAS) plays a relevant role in regulating blood pressure and thus maintaining cardiovascular homeostasis. While it was recently shown that RAAS parameters are responsive to acute psychosocial stress, the psychobiological determinants of the acute stress-induced RAAS activation have not yet been investigated so far. In a randomized placebo-controlled design, we investigated potential psychological and physiological determinants of the RAAS response and underlying mechanisms.Methods:57 young healthy male participants underwent either an acute standardized psychosocial stress test or a non-stress placebo task. We measured aldosterone in plasma and saliva, as well as renin, and the stress-reactive endocrine measures adrenocorticotropic hormone (ACTH), epinephrine, and norepinephrine in plasma at rest, immediately after the task and several times up to 3 h thereafter. Moreover, we assessed stress-reactive psychological (anticipatory cognitive stress appraisal, mood, physical discomfort) and basal demographic-physiological measures (age, BMI, blood pressure).Results:Acute psychosocial stress elicited changes in all assessed endocrine (p’s ≤ .028, ηp2‘s ≥ .07) and stress-reactive psychological measures (p’s ≤ .003, ηp2‘s ≥ .15). The basal parameter BMI, the stress-reactive endocrine parameters ACTH and norepinephrine, and the psychological parameter anticipatory stress appraisal were identified as determinants of higher RAAS parameter reactivity to acute psychosocial stress. The association between anticipatory cognitive stress appraisal and plasma RAAS measures was fully mediated by ACTH increases (p’s ≤ .044, ηp2‘s ≥ .05).Conclusions:Cognitive stress appraisal processes seem to modulate RAAS stress reactivity. This points to potential clinical implications for psycho-educative therapeutical interventions targeting stress appraisal processes in order to reduce endocrine stress reactivity.