Facilitated defensive coping, silent ischaemia and ECG left-ventricular hypertrophy: The SABPA study

Leoné Malan, Mark Hamer, Markus P. Schlaich, Gavin W. Lambert, Brian H. Harvey, Manja Reimann, Tjalf Ziemssen, Eco J.C.N.De Geus, Hugo W. Huisman, Johannes M.Van Rooyen, Rudolph Schutte, Aletta E. Schutte, Carla M.T. Fourie, Yaackob K. Seedat, Nico T. Malan

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

Background: Defensive active coping responses (being-in-control, acceptance of the stressor as reality) have been associated with vascular hyper-responsiveness in urban Africans. However, the association between active coping responses, blood pressure (BP), and ECG-derived left-ventricular hypertrophy (LVH) responses is unknown. OBJECTIVES AND Methods: Associations between BP, silent ischaemia and ECG Cornell product LVH were assessed in 161 African and Caucasian men with active coping responses identified by the Amirkhan Coping Strategy Indicator. BP, ECG and silent ischaemia data were obtained from 24-h ambulatory monitoring. Beat-to-beat BP was continuously recorded during stress testing and fasting resting blood samples obtained for biochemical analyses. Results: Enhanced ß-adrenergic central cardiac responses were evident in active coping Caucasians as opposed to a predomination of α-adrenergic vascular responses in active coping Africans. Active coping African men displayed higher 24-h BP and prevalence of silent ischaemia events compared to the Caucasian men. Regression analyses revealed that α-adrenergic responses were associated with silent ischaemic events, adjusted R 2 0.21 [ß 1.07, 95% confidence interval (CI) 0.29-1.85] and that ischaemic events predicted LVH in active coping Africans (adjusted R 0.12, ß 0.35, 95% CI 0.11-0.59). Receiver-operated characteristic (ROC) analyses indicated a defensive pathway cut point of 16 in Africans as opposed to 32 in Caucasians predicting silent ischaemia with sensitivity/specificity 100/96%. Conclusions: A defensive pathway revealed disturbed vascular function showing dissociation between behavioural and physiological ß-adrenergic active coping responses in Africans. Vascular responsiveness facilitated silent ischaemia events and structural LVH changes which potentially explain the increased risk for incident ischaemic stroke in black Africans.

Original languageEnglish
Pages (from-to)543-550
Number of pages8
JournalJournal of Hypertension
Volume30
Issue number3
DOIs
Publication statusPublished - Mar 2012
Externally publishedYes

    Fingerprint

Cite this