Chronic defensiveness and neuroendocrine dysfunction reflect a novel cardiac troponin T cut point : the SABPA study

Loading...
Thumbnail Image

Authors

Malan, Leoné
Hamer, Mark
Von Känel, Roland
Lambert, Gavin W.
Delport, Rhena
Steyn, Hendrik S.
Malan, Nicolaas T.

Journal Title

Journal ISSN

Volume Title

Publisher

Elsevier

Abstract

BACKGROUND : Sympatho-adrenal responses are activated as an innate defense coping (DefS) mechanism during emotional stress. Whether these sympatho-adrenal responses drive cardiac troponin T (cTnT) increases are unknown. Therefore, associations between cTnT and sympatho-adrenal responses were assessed. METHODS : A prospective bi-ethnic cohort, excluding atrial fibrillation, myocardial infarction and stroke cases, was followed for 3 years (N = 342; 45.6 ± 9.0 years). We obtained serum high-sensitive cTnT and exposure measures [Coping-Strategy-Indicator, depression/Patient-Health-Questionnarie-9, 24 h BP, 24 h heart-rate-variability (HRV) and 24 h urinary catecholamines]. RESULTS : Blacks showed moderate depression (45% vs. 16%) and 24 h hypertension (67% vs. 42%) prevalence compared to Whites. A receiver-operating-characteristics cTnT cut-point 4.2 ng/L predicting hypertension in Blacks was used as binary outcome measure in relation to exposure measures [AUC 0.68 (95% CI 0.60-0.76); sensitivity/specificity 63/70%; P ≤ 0.001]. Bi-ethnic cTnT-incidence was similar (25-27%) with cTnT-recovery better in Blacks (9%) compared to Whites (5%), P = 0.001. In cross-sectional analyses, elevated cTnT was related to DefS [OR 1.08 (95% CI 0.99–1.16); P = 0.06]; 24 h BP [OR 1.03–1.04 (95% CI 1.01–1.08); P ≤ 0.02] and depressed HRV [OR 2.19 (95% CI 1.09–4.41); P = 0.03] in Blacks, but not in Whites. At 3 year follow-up, elevated cTnT was related to attenuated urine norepinephrine:creatinine ratio in Blacks [OR 1.46 (95% CI 1.01–2.10); P = 0.04]. In Whites, a cut point of 5.6 ng/L cTnT predicting hypertension was not associated with exposure measures. CONCLUSION : Central neural control systems exemplified a brain-heart stress pathway. Desensitization of sympatho-adrenal responses occurred with initial neural- (HRV) followed by neuroendocrine dysfunction (norepinephrine:creatinine) in relation to elevated cTnT. Chronic defensiveness may thus drive the desensitization or physiological depression, reflecting ischemic heart disease risk at a novel 4.2 ng/L cTnT cut-point in Blacks.

Description

Keywords

Defense, Depression, Heart-rate-variability, Catecholamine, Troponin T, Sympatho-adrenal responses, Cardiac troponin T (cTnT)

Sustainable Development Goals

Citation

Malan, L., Hamer, M., Von Känel, R., Lambert, G.W., Delport, R., Steyn, H.S. & Malan, N.T. 2017, 'Chronic defensiveness and neuroendocrine dysfunction reflect a novel cardiac troponin T cut point : the SABPA study', Psychoneuroendocrinology, vol. 85, pp. 20-27.