Defensive active coping facilitates chronic hyperglycaemia and endothelial dysfunction in African men: the SABPA study
Date
2013Author
Malan, L.
Hamer, M.
Steyn, H.S.
Schutte, R.
Smith, W.
Van Rooyen, J.M.
Fourie, C.M.T.
Malan, N.T.
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Show full item recordAbstract
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.