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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 27, No 6, November/December 2016
AFRICA
391
on similar lifestyle and behavioural factors. Another limitation is
the cross-sectional nature of the study where causality cannot be
inferred. ECG assessment of silent ischaemia showed a sensitivity
of 68% and a specificity of 77%,
25
therefore further studies are
needed to support silent ischaemic events, such as troponin T
determinations, in order to confirm reduced blood supply to the
heart. We recommend prospective analyses to underpin down-
regulation of the cortisol:BDNF pathway, as well as the use of
a validated depression score to substantiate chronic emotional
distress and its relationship with cortisol:BDNF ratio.
Conclusion
Central neural dysregulation may mediate cortisol levels as the
driving force in the cortisol:BDNF ratio, as it seemingly disturbs
BDNF levels during chronic stress. A possible down-regulation
may lead to neurodegeneration and add to cardiometabolic risk
in Africans. The combined impact of cortisol and BDNF levels
associated with silent ischaemia may increase future coronary
artery disease risk via compensatory increases in blood pressure.
The research was funded by the Metabolic Syndrome Institute, France; South
African Medical Research Council; National Research Foundation (NRF),
North-West University; North-West Department of Education; and ROCHE
Diagnostics, South Africa.
The funding organisations played no role in the design and conduct of
the study; collection, management, analysis and interpretation of the data;
and preparation, review or approval of the manuscript. The authors declare
no conflict of interest in the content of this article. Opinions and conclusions
are those of the authors.
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