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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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