Defensive active coping facilitates chronic hyperglycaemia and endothelial dysfunction in African men: The SABPA study

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • L. Malan - , North West University (Author)
  • M. Hamer - , North West University, University College London (Author)
  • M. P. Schlaich - , Baker Heart Research Institute (Author)
  • G. W. Lambert - , Baker Heart Research Institute (Author)
  • T. Ziemssen - , Department of Neurology (Author)
  • M. Reimann - , Medical Faculty Carl Gustav Carus (Author)
  • H. S. Steyn - , North West University (Author)
  • R. Schutte - , North West University (Author)
  • W. Smith - , North West University (Author)
  • J. M. Van Rooyen - , North West University (Author)
  • C. M.T. Fourie - , North West University (Author)
  • N. T. Malan - , North West University (Author)

Abstract

Background: Dissociation between behavioural defensive active coping (AC) control albeit physiological "loss of control" responses was associated with silent ischaemia and structural wall abnormalities in African men. Whether it applies to structural alterations and endothelial dysfunction is uncertain. We therefore aimed to determine AC ethnic-gender specific receiver operating characteristic (ROC) carotid intima media far wall (CIMTf) cut points best associated with 24-h BP, -silent ischaemia and glycated haemoglobin (HbA1c). Methods: Participants included African and Caucasians (N=317) without pre-existing stroke or atrial fibrillation, aged 45±9 years. The Coping Strategy Indicator was used to measure AC. Ultrasound CIMTf, ambulatory BP, silent ischaemia and fasting blood samples were obtained. Results: Between 69 and 77% of AC African men showed above normal diastolic BP and HbA1c levels compared to 44-48% of AC Caucasian men. In AC African women, 41-60% showed above normal BP, silent ischaemia and HbA1c levels compared to 17-44% of their Caucasian counterparts. ROC curve analyses, detecting optimal CIMTf cut points, ranged between 0.57 and 0.65 mm (BP) and 0.71 and 0.74 mm (silent ischaemia) in AC ethnic-gender groups. Only HbA1C (>5.7%), with a sensitivity/specificity 47%/74%, after controlling for confounders, predicted structural alterations at an optimal cut point of 0.69 mm in AC African men (OR 4.5; 95% CI 2.93-18.73). Conclusion: Novel findings of behavioural resilience were apparent in the AC African female despite a high prevalence of risk markers. In AC males, chronic hyperglycaemia facilitated endothelial dysfunction, i.e. a physiological "loss of control" and susceptibility to stroke risk.

Details

Original languageEnglish
Pages (from-to)999-1005
Number of pages7
JournalInternational journal of cardiology
Volume168
Issue number2
Publication statusPublished - 30 Sept 2013
Peer-reviewedYes

External IDs

PubMed 23168003

Keywords

Keywords

  • Defensive coping, Endothelial dysfunction, Ethnicity, HbA1c