Chronic defensiveness and neuroendocrine dysfunction reflect a novel cardiac troponin T cut point: the SABPA study
von Känel, R; Hamer, M; Delport, R; Malan, L; Malan, NT; Steyn, HS; Lambert, GW
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±9.0years). We obtained serum high-sensitive cTnT and exposure measures [Coping-Strategy-Indicator, depression/Patient-Health-Questionnarie-9, 24h BP, 24h heart-rate-variability (HRV) and 24h urinary catecholamines].
RESULTS:
Blacks showed moderate depression (45% vs. 16%) and 24h hypertension (67% vs. 42%) prevalence compared to Whites. A receiver-operating-characteristics cTnT cut-point 4.2ng/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 (Blacks=27%, Whites=25%) 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]; 24h 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 3year 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 5.6ng/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 4.2ng/L cTnT cut-point in Blacks.
Copyright © 2017 Elsevier Ltd. All rights reserved.
| Journal | PSYCHONEUROENDOCRINOLOGY |
| ISSN | 0306-4530 |
| Published | 01 Nov 2017 |
| Volume | 85 |
| Issue | |
| Pages | 20-7 |
| DOI | 10.1016/j.psyneuen.2017.07.492 |
| Type | Journal Article |
| Sponsorship |
North-West University, Potchefstroom, South Africa; National Research Foundation (NRF); Department of Education, North-West Province, South Africa; ROCHE Diagnostics; Metabolic Syndrome Institute, France
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