Measures of Total Stress-Induced Blood Pressure Responses Are Associated With Vascular Damage

Abstract

The role of cardiovascular reactivity to study hypertension, and the assessment methods, are still controversial. We aimed to verify the association of hypertension and vascular damage with several measures of cardiovascular response. We studied 40 patients with normal-high (132 +/- 1/87 +/- 1 mm Hg) blood pressure (Group 1) and 80 untreated hypertensive subjects. Postischemic forearm vascular resistance (mFVR) served to differentiate hypertensive subjects (142 +/- 2/92 +/- 1 mm Hg v 143 +/- 2/94 +/- 2 mm Hg, P = NS) with a lower (Group 2) and higher (Group 3) hemodynamic index of vascular damage (4.8 +/- .05 v 6.3 +/- .09, P < .001). Reactivity was induced by Stroop (5') and cold pressor (90") tests. We measured muscular contraction and skin conductance as indices of emotional arousal, blood pressure, heart rate, forearm blood flow, and vascular resistance. Reactivity measures included: a) change from baseline, b) residualized score, c) cumulative change from baseline and residualized score, and d) total reactivity as area-under-the-curve (AUC), including changes occurring during baseline and recovery phases. The AUC of systolic blood pressure, diastolic blood pressure, and mFVR progressively increased in the groups (P < .001). Corrections of anthropometric and metabolic confounders were introduced in the Pearson equation between mFVR and reactivity measures. The AUC of SBP, DBP, and forearm blood flow and resistance demonstrated the highest (P < .001) correlation. On multiple regression analysis, AUC of SBP (beta = 0.634) and forearm blood flow (beta = -0.337) were predictive (P < .001) of vascular damage. Total blood pressure stress response, as AUC, including baseline and recovery phases, was significantly better associated with hypertension and vascular damage than the other reactivity measures studied.