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We examined whether there were differences in the circadian variation in blood pressure and the morning surge in blood pressure between black and white Africans. Clinic and ambulatory blood pressure data obtained from the Sympathetic Activity and Ambulatory Blood Pressure in Africans (SABPA) study was examined (n = 406; 49% black African). Ambulatory blood pressure readings were fitted to a six-parameter double logistic equation to determine the power and rate of the morning surge in blood pressure. Multiple linear regression analysis was used to examine differences in blood pressure between black and white participants. Clinic and ambulatory blood pressure were higher in black participants throughout the day and night. In those taking medications, blood pressure was less well controlled in black subjects. Despite the higher systolic blood pressure, the day-night difference estimated by the logistic function was similar in black and white participants. However, the rate of rise and power in the morning surge in blood pressure was lower in black participants. We conclude that black participants of the SABPA study present with higher blood pressure throughout the day and night but have a lower power of the morning surge in blood pressure due to a slower morning rate of increase. Moreover, they had an increased prevalence of undiagnosed hypertension and, in those taking medication, were less likely to have their blood pressure controlled than their white counterparts.

Background Defensive coping (DefS) was associated with cardiovascular disease (CVD) susceptibility in Blacks. Whether coping strategies will associate with sub-clinical left ventricular hypertrophy (electrocardiographic-left ventricular hypertrophy [ECG-LVH] or Cornell product), cardiomyocyte injury and blood pressure (BP), is unclear. Therefore, we assessed relationships between ECG-LVH, cardiac troponin T (cTnT) and 24-hour BP in bi-ethnic groups when habitually utilising a certain coping style, and these groups when having a stress-related cTnT cut-point of 4.2 ng/L. Methods A target population study included a Black (n = 190) and White (n = 204) teachers’ gender cohort (20–65 years) from South Africa. The Coping Strategy Indicator determined DefS, social support and avoidance coping scores. Fasting blood samples, 10-lead ECG, 24-hour BP and ECG data were obtained. Results Interaction effects showed no gender, social support and avoidance coping differences. Stratification of groups was done for ethnicity and DefS. Blacks sought more social support, used less avoidance coping and presented with higher CVD susceptibility. Hypertension prevalence and ECG-LVH levels in DefS Blacks (63%) were higher compared to DefS Whites (40%). Multivariate regression analyses showed positive associations between Cornell product, cTnT and BP [p ≤ 0.05] in DefS Blacks only. Their 24-hour systolic blood pressure (SBP) was associated with time-domain depressed heart-rate-variability and prolonged ST-segment-depression especially when applying an established stress-related cTnT ≥ 4.2 ng/L cut-point. Conclusions Defensive coping facilitated autonomic hyperactivity, myocardial injury and subsequent compensatory BP elevations as possible homeostatic reflexes to alleviate myocardial perfusion deficits. The resulting pressure overload increased sub-clinical wall remodelling and ischaemic heart disease risk in Blacks utilising habitual defensiveness. We therefore recommend regular ECG and high sensitivity cTnT screening in asymptomatic patients with emotional stress susceptibility. Longitudinal evidence is needed to confirm causality and progression of cardiomyopathy risk.

Background Low-renin levels in Blacks have been associated with volume-loading hypertension (HT). Depression symptoms, frequently co-occurring with vascular dysregulation, might reflect a disturbed renin-angiotensin-aldosterone-system (RAAS). We aimed to assess prospective changes (∆) in depression symptoms, RAAS (renin, aldosterone), diastolic blood pressure (DBP), and estimated glomerular filtration rate (eGFR) in a bi-ethnic sex cohort. Methods We included 195 Black and White teachers (43.7 ± 9 years) from a South African 3-year prospective study. Hypertension medication users, diabetics and human immunodeficiency virus infected individuals were excluded. Depression symptoms (Patient-Health-Questionnaire-9/PHQ-9), 24 h blood pressure measurements and fasting blood samples were obtained. Results Blacks had lower renin but higher DBP and eGFR levels at baseline (p ≤ .01) when compared to Whites. Blacks and Whites with depression (PHQ-9 ≥ 10) at baseline developed co-morbidity for having both depression plus DBP-HT at follow-up (Blacks, 49.1%; Whites, 13.1%). At 3-year follow-up, chronic depression symptoms were related to chronic lower renin in Blacks [Adjusted R2 0.20; β −0.37 (−0.66, −0.08), p = .02]. Chronic depression symptoms also predicted DBP hypertension in Blacks [ROC AUC = 0.61 (0.48–0.75); sensitivity/specificity 78.1/46.3%]. No prospective associations existed between depression symptoms, aldosterone and eGFR. Conclusion Chronic depression symptoms in Blacks activated the RAAS system activity with apparent desensitization of renin activity. Chronic depression could be causal to hypertension and in turn, lowers renin activity as a protective mechanism against volume-loading. These findings emphasize the potential impact of depression on the low renin-hypertension phenotype in Blacks in terms of diagnosis and treatment.

Taxing psychosocial stress and defensive coping have been associated with hypoactivity in cortisol, a vasoconstrictive agent. Estradiol has vasodilatory properties with cardio- and neuroprotective effects. It can however also induce αAfrican (n = 168) and Caucasian (n = 207) men and women (46 ± 9 years) were included. Preferential use of defensive coping was determined from Coping Strategy Indicator questionnaire scores. 24h Ambulatory blood pressure was obtained. Fasting serum estradiol and cortisol samples were collected before 09h00 and Cort:E2 was calculated.Estradiol was higher in ethnic-coping groups. Smaller Cort:E2, higher estradiol levels, self-reported emotional stress (19.05% vs. 9.66%) and 24h blood pressure reaching hypertensive status (65% vs. 24%) were evident in African compared to Caucasian men (p ≤ .05). A smaller Cort:E2 was associated with augmented 24h SBP and 24h DBP in African men [Adj RA smaller Cort:E2 was associated with raised blood pressure in defensive coping African men. Defensive coping, possibly via highly activated α

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 (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]; 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

Background: Hypercoagulation is associated with coronary artery disease (CAD). Whether depression symptoms dysregulate inflammatory and hemostatic markers in an African cohort is not known; therefore, we assessed the relationship between depressive symptoms and inflammatory and hemostatic markers as potential CAD risk markers in an African sex cohort. Material and Methods: We included 181 black African urban-dwelling teachers (88 men, 93 women; aged 25-60 years) from the Sympathetic Activity and Ambulatory Blood Pressure in Africans Study. The Patient Health Questionnaire was used to assess depressive symptoms. Fasting plasma concentrations of C-reactive protein, fibrinogen, D-dimer, plasminogen activator inhibitor-1 (PAI-1) and 24-hour blood pressure measures were obtained. Results: Moderately severe depression symptom status was similar in the black sex groups. Both sex groups showed a mean hypertensive state and low-grade inflammation (C-reactive protein > 3 mg/L). Levels of PAI-1 were higher in depressed men, whereas D-dimer levels were lower in depressed women when considering concomitant confounders. In black men only, depressive symptoms were associated with levels of PAI-1 (adj. R2 = 0.12; [beta] = .22 [95% confidence interval, .0-.44]; P = .04) and D-dimer (adj. R2 = 0.12; [beta] = .28 [95% confidence interval, .08-.48]; P = .01), independent of confounders. Conclusion: In black men, depression symptoms accompanied by a mean hypertensive status may up-regulate inflammatory and thrombotic processes. Depression symptoms in black men facilitated hypercoagulation or fibrinolytic dysregulation and potentially increased their CAD risk. Early screening of fibrinolytic markers and for the presence of depressive symptoms is recommended

Emotional distress has been associated with a poorer prognosis in myocardial infarction patients. Elevated adrenocorticotrophic hormone (ACTH), lower cortisol, dehydroepiandrosterone sulfate (DHEAS) and cortisol:DHEAS, as measures of emotional distress, might correlate with silent myocardial ischemia (SMI) and workload. Thus, we assessed the relationship between emotional distress, SMI and double product (systolic blood pressure (SBP) × heart rate). Cross-sectional South African biethnic single-set cohorts (N=378), aged 44.7±9.52 years, were investigated. Depressive symptoms (Patient Health Questionnaire-9), anthropometric, fasting blood, 24-h double product and 24-h 2-lead electrocardiogram (ST-segment depression) values were obtained. Blacks, mostly men, had increased depressive symptoms, hyperglycemia, SMI, double product, SBP hypertension and ACTH but lower cortisol, DHEAS and cortisol:DHEAS than their White counterparts. Black men had the highest combined SBP hypertension and below-median cortisol prevalence, 38%, compared with 5.9-13.8% in the other groups. Their SMI was associated with ACTH and cortisol:DHEAS (adj. R 0.29; β 0.27-0.31 (0.12-0.64); P≤ 1/20.05), double product (adj. R 0.29; β 0.38 (0.18-0.57); P=0.050) and SBP hypertension (area under the curve: 0.68 (95% CI: 0.56, 0.80); P=0.042; sensitivity/specificity 49/85%). Double product was positively associated with central obesity in all sex groups and with cortisol in the Black men (P

Background: Brain‐derived neurotrophic factor (BDNF) modulates brain health and cognition, which can interfere with executive cognitive function. BDNF was impli-cated with microcirculatory ischaemia and may reflect cardiomyocyte injury. We aimed to determine whether prospective changes (%Δ) in BDNF and cardiac tro-ponin T (cTnT) will be associated with executive cognitive function in a bi‐ethnic cohort.Design: A prospective investigation was conducted over a three‐year period in a bi‐ethnic sex cohort (N = 338; aged 20‐65 years) from South Africa. Fasting serum samples for BDNF and cTnT were obtained. The STROOP‐color‐word conflict test (CWT) was applied to assess executive cognitive function at baseline.Results: In Blacks, BDNF (P< 0.001) increased over the three‐year period while cTnT did not change. In contrast, in Whites, BDNF and cTnT decreased over three years. In Black men, no change in cTnT was associated with increased ΔBDNF (β= 0.25; 95% CI 0.05‐0.45; P= 0.02). In the Black men, constant cTnT levels were inversely associated with executive cognitive function (β= −0.33; 95% CI −0.53 to −0.12; P = 0.003). Three‐year increases in BDNF increased the likelihood for chronic lower cTnT levels at a pre‐established cut‐point of

Structural and functional similarities exist between the retinal, cerebral and, as previously suggested, the coronary microvasculature. Retinal microvascular structure and functionality (in response to flicker-light-induced-provocation (FLIP)) may relate to coronary artery disease risk and possible stroke risk. We investigated associations between retinal vessel structure, functionality and cardiac stress markers (cardiac troponin T [cTnT], amino-terminal B-type natriuretic peptide [NT-proBNP]) to translate these retina-heart relationships to stroke risk. We included 317 African and Caucasian teachers' (aged 23-68 years), who participated in the Sympathetic Activity and Ambulatory Blood Pressure in Africans (SABPA) study. Fasting plasma and serum samples for cTnT and NT-proBNP were collected. Retinal vascular calibres were quantified from fundus images and dynamic retinal vessel calibre responses during FLIP. The University of California stroke risk score was applied to assess sub-clinical 10-year stroke risk. cTnT levels were similar in Africans and Caucasians, whereas NT-proBNP levels were lower in Africans. In Africans, a reduced arteriolar calibre and attenuated arteriolar dilation during FLIP was associated with higher cTnT (p 0.01). Their larger retinal-venular calibre (p 0.02) and attenuated arteriolar dilation during FLIP (p 0.05) were associated with lower NT-proBNP. Again, exclusively in Africans, increased cardiac stress, wider venular calibres and retinal arteriovenous nicking predicted an increased 10-year stroke risk with odds ratios of 1.57 (95% CI, 1.34; 1.68, p = 0.031), 1.51 (95% CI, 1.26; 1.59, p = 0.002), 1.10 (95% CI, 0.94; 2.85, p = 0.002) and 1.06 (95% CI 0.83; 1.56, p = 0.052), respectively. None of these associations were evident in the Caucasian group. Investigating the retinal vasculature may serve as a tool to approximate sub-clinical coronary and cerebral microvasculature damage or dysfunction. These cardiac stress-retinal associations additionally predicted a greater stroke risk in the SABPA African cohort. Observable changes in the retinal vasculature may serve as markers for the identification and prediction of cardio-systemic and cerebral vascular morbidities and risks, thereby establishing a brain-heart link. Graphical Abstract Proposed series of events during which sustained high pressure and increased cardiac stress may alter retinal reactivity and link to increased stroke risk.

BACKGROUND AND AIMS: Decreased heart-rate-variability (HRV) indicates increased sympathetic nervous system (SNS) activity and modulation with a shift in the sympatho-vagal balance towards SNS predominance. Increased SNS activity may precede volume-loading hypertension, contribute to increases in cardiac troponin T (cTnT), endothelial dysfunction and small vessel disease. Therefore, we investigated the retinal vasculature, HRV during flicker-light-induced-provocation (FLIP) and systemic cTnT, a marker of cardiac stress, to provide further evidence in support of the brain–retina–heart link. METHODS: Cross-sectional observations were obtained from a bi-ethnic cohort (N = 264), aged 23–68 years. Fasting serum samples for cTnT were obtained. Retinal vascular calibres were quantified from mydriatic eye fundus images and dynamic retinal vessel calibre responses were determined during FLIP. Time-and frequency domain parameters of HRV were calculated during FLIP for each participant. RESULTS: Africans had wider venules and attenuated time domain parameters during FLIP. In Africans, inverse associations emerged between arteriolar dilation and both cTnT and root-mean squared of the standard deviations of successive RR-intervals (rMSSD) (p = 0.030), and between arteriolar constriction and both low-frequency expressed in normalised units (LFnu) (p = 0.003) and high-frequency expressed in normalised units (p = 0.021). Wider venules inversely associated with standard deviation of the NN intervals (SDNN) as well as LFnu (p = 0.009) in Africans. An opposite profile was observed in Caucasians with both time-and frequency domain parameters of HRV in relation to retinal vessel structure and function. CONCLUSION: FLIP elicited increased SNS activity and modulation in this bi-ethnic cohort. In Africans, decreased HRV during FLIP accompanied arteriolar and venular responses and elevated systemic levels of cTnT, implying that the SNS exerted a significant effect on the smooth muscle tone of the retinal vasculature. Disrupted retinal autoregulation may imply general autonomic nervous system dysfunction; exemplifying central control by the brain on all systemic regulatory functions, across different vascular beds.

Correction to: Eye https://doi.org/10.1038/s41433-019-0515-y Since the online publication of this article, the authors have noticed that the conclusion to the abstract contains an error. The correct abstract conclusion should read as follows: FLIP elicited increased SNS activity and modulation in this bi-ethnic cohort. In Africans, decreased HRV during FLIP accompanied arteriolar and venular dilatory responses and elevated systemic levels of cTnT, implying that the SNS exerted a significant effect on the smooth muscle tone of the retinal vasculature. Disrupted retinal autoregulation may imply general autonomic nervous system dysfunction; exemplifying central control by the brain on all systemic regulatory functions, across different vascular beds. The authors apologise for any inconvenience caused

Background Defensive coping (DefS) was associated with a vulnerable cardiovascular profile in blacks. The copeptin/vasopressin system is a manifestation of hypothalamic-pituitary-adrenal-axis activity and may act as an acute compensatory mechanism when there is a disruption in volume-loading homeostasis, i.e. when cardiac stress is evident. Whether DefS will influence associations between copeptin and cardiac stress markers, remains unclear. Here we aimed to determine associations between acute mental stress responses of copeptin, vascular responsiveness and biomarkers of cardiomyocyte injury [cardiac troponin T (cTnT)] and cardiac wall-stress [N-terminal pro-brain natriuretic peptide (NT-proBNP)] in DefS race groups. Methods South African black and white teachers (n = 378) of both sexes, participated in this target population study. Cases with a history of myocardial infarction, stroke and atrial fibrillation were excluded. We obtained coping scores (Coping Strategy Indicator), beat-to-beat blood pressure and fasting blood samples at rest and after 1-min exposure to the Stroop-Colour-Word-Conflict-test. Results Interaction effects (p

Objective: Glucose dysregulation is an independent risk factor for cardiovascular and neurodegenerative disease development through synaptic dysfunction resulting in cognitive decline. The aim of this study was to study the interplay between impaired glycaemic metabolism (hyperglycaemia and insulin resistance), cardiac stress (cardiac troponin T and N-terminal brain natriuretic peptide) and executive cognitive function prospectively, in a bi-ethnic sex cohort. Methods: Black and White teachers (N = 338, aged 20–63 years) from the Sympathetic activity and Ambulatory Blood Pressure in Africans study were monitored over a 3-year period. Fasting blood samples were obtained for cardiac troponin T, N-terminal brain natriuretic peptide, glycated haemoglobin and the homeostatic model assessment-insulin resistance for insulin resistance. The Stroop colour-word conflict test was applied to assess executive cognitive function at baseline. Results: Over the 3-year period, Black men revealed constant high levels of cardiac troponin T (⩾4.2 ng/L), pre-diabetes (glycated haemoglobin > 5.7%) and insulin resistance (homeostatic model assessment-insulin resistance >3). %Δ Glycated haemoglobin was associated with %Δ insulin resistance (p Conclusion: Progressive myocyte stretch and chronic myocyte injury, coupled with glucose dysregulation, may interfere with processes related to interference control in Black men.

Adverse changes in retinal microvasculature caliber are associated with incident hypertension, coronary heart disease and stroke. The absence of a nocturnal dipping in arterial pressure may induce changes throughout the vascular tree, including the retinal microvasculature, but the later link is not sufficiently studied. We explored the relationship between retinal vessel caliber and dipping status in a group of black and white teachers. The study included black (n=68) and white (n=81) men (24-66 years) from the SABPA study. We measured 24 h ambulatory blood pressure and the percentage mean arterial pressure dipping(%MAPdip) was calculated as (diurnal MAP-nocturnal MAP)/diurnal MAP × 100. Retinal images were captured and the central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE) calculated. Black men demonstrated higher diurnal and nocturnal MAP (P⩽0.001) and a lesser %MAPdip compared with white men (P=0.047). When stratified by dipping status, black non-dippers (n=33) revealed an increased CRVE (P0.001) compared with their dipper counterparts (n=35). In black men, CRVE was negatively (R

Acute mental stressor–induced cardiac stress responses might contribute to excessive myocardial strain and resultant cardiovascular episode risk. We assessed ethnicity-specific acute cardiac stress (by measuring cardiac troponin T (cTnT) and N-terminal prohormone of brain natriuretic peptide) related to hemodynamic activity. The prospective Sympathetic Activity and Ambulatory Blood Pressure in Africans (SABPA) study was conducted during 2007–2008 in South Africa. In the cross-sectional phase of the SABPA study, 388 black and white participants underwent a 1-minute acute mental stressor, during which blood pressure was continuously measured. Fasting blood samples for cardiac stress markers were obtained before and 10 minutes after stress (% change). Resting 10-lead electrocardiogram measured the R wave of the aVL lead (RaVL). Black participants exhibited greater cardiac stress responses (P < 0.001), diastolic blood pressure, total peripheral resistance, and stroke volume compared with white participants, who displayed decreases in cardiac stress and increases in cardiac output. Prestress and stressor cTnT cutpoints of 4.2 pg/mL predicted 24-hour, daytime, and nighttime diastolic hypertension in black participants (P < 0.001). These cTnT cutpoints were associated with an ethnicity-specific RaVL cutpoint of 0.28 mV (odds ratio = 3.49, 95% confidence interval: 2.18, 5.83; P = 0.021). Acute mental stress elicited an α-adrenergic activation pattern and cardiac stress hyperreactivity only in black participants. Mental stress might increase the black population’s risk for ischemic episodes and heart disease.

Inflammation was cross-sectionally associated with subclinical wall remodeling and hypertension. Whether longitudinal changes (∆) in inflammation, myocyte injury (troponin T), and stretch (N-terminal-pro-B-type natriuretic peptide) are associated with hypertension and ECG left ventricular hypertrophy (ECG-LVH) is unclear. The first prospective analysis in Africa assessing these associations included a cohort of Black and White teachers (N = 338; aged 20-63 years). Fasting blood samples were obtained to measure tumor necrosis factor-alpha (TNF-α), cardiac troponin T (cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP). Ambulatory blood pressure, 2-lead ECG and resting 10-lead ECG values were obtained. A higher mean hypertensive status (62%) was evident in Blacks compared to Whites (44%, p

Alcohol contributes greatly to vascular and structural modifications. Due to differences in the metabolism and tolerance of alcohol between ethnic groups, the manner of these modifications may differ. We investigated the association between alcohol consumption - measured via ethnic-specific gamma glutamyl transferase (γ-GT) cut-points - and markers of cardiac perfusion, electrical activity, and pre-clinical structural alterations. A South African target population study was performed in a bi-ethnic cohort (n = 405). Alcohol consumption was determined according to previously defined ethnic-specific γ-GT cut-points, where γ-GT ≥ 19.5 U/L and γ-GT ≥ 55 U/L indicated excessive alcohol consumption in Caucasians and Africans, respectively. Ambulatory 24-h blood pressure and electrocardiograms (ECG), 10-lead ECG left ventricular hypertrophy (LVH), ischemic events, N-terminal pro-brain natriuretic peptide (NT-proBNP), and QTc prolongation were assessed. Fasting blood samples were obtained. A poorer cardio-metabolic profile and mean 24-h hypertensive and ECG-LVH values were evident in high γ-GT groups of both ethnicities, when compared to their low counterparts. The African high γ-GT group reported a higher intake of alcohol and presented significant increases in NT-proBNP (p 0.001), QTc prolongation (p = 0.008), and ischemic events (p = 0.013). Regression analyses revealed associations between ECG-LVH and NT-proBNP, QTc prolongation, ischemic events, and SBP, in the African high γ-GT group exclusively. High alcohol consumers presented delayed electrical conduction in the heart accompanied by ECG-LVH, ischemic events, and increased vaso-responsiveness, predominantly in Africans. Ultimately, increased left ventricular distension on a pre-clinical level may elevate the risk for future cardiovascular events in this population.

OBJECTIVES Defensive coping (DefS) in Blacks has been associated with greater cardiovascular risk than in their White counterparts. We examined associations between endothelial function mental stress responses and markers of vascular structure in a bi-ethnic cohort. METHODS We examined vascular function and structure in 368 Black (43.84±8.31years) and White Africans (44.78±10.90years). Fasting blood samples, 24h blood pressure, left carotid intima-media thickness of the far wall (L-CIMTf), and left carotid cross-sectional wall area (L-CSWA) values were obtained. von Willebrand factor (VWF), endothelin-1 (ET-1) and nitric oxide metabolite (NOx) responses to the Stroop mental stress test were calculated to assess endothelial function. DefS was assessed using the Coping Strategy Indicator questionnaire. Interaction between main effects was demonstrated for 283 participants with DefS scores above the mean of 26 for L-CIMTf. RESULTS Blunted stress responses for VWF (men 16.71% vs. 51.10%; women 0.85% vs. 42.09%, respectively) and NOx (men -64.52% vs. 74.89%; women -76.16% vs. 113.29%, respectively) were evident in the DefS Blacks compared to the DefS Whites (p

Evidence of the relationship between left ventricular hypertrophy and urinary albumin excretion is contradictory and limited in black adults in whom hypertensive heart disease is common. We aimed to investigate the relationship between subclinical left ventricular hypertrophy and albuminuria in non-diabetic hypertensive blacks. Urinary albumin-to-creatinine ratio (UACR) was determined from 8-hour overnight urine collection. We recorded ambulatory blood pressure and 12-lead electrocardiogram during a typical working day. Cornell product (P = .002), UACR (P = .042), 24-hour systolic pressure (P .0001), and 24-hour pulse pressure (P .0001) were higher in the hypertensive group. Cornell product was associated with UACR in single (r = 0.25; P = .012), partial (P trend = .002), and multiple regression (β = 0.326; P = .0005) analyses in the hypertensive group only, even below the threshold for microalbuminuria and independent of 24-hour systolic pressure. Urinary albumin excretion is associated with subclinical left ventricular hypertrophy in non-diabetic hypertensive blacks and may be a useful marker of early cardiovascular disease in blacks.

Background Oestradiol has a protective effect on coronary artery health in women but the effect it has on men, is controversial. A translational approach was followed to assess whether sex hormone levels are associated with silent myocardial ischemia (SMI) and hypertension risk over a 3year period. Methods Participants included 89 Black and 91 White men (aged 21–63years) participating in both phases of the Sympathetic activity and Ambulatory Blood Pressure in Africans prospective study. Fasting blood samples, ambulatory blood pressure and 2-lead ECG recordings were obtained. Results No difference in the levels of the various baseline serum T fractions between the two ethnic groups occurred. Oestradiol of the Black men increased by 54.2% compared to a decrease of 24.1% in the White men. Changes in total oestradiol (adjusted R 2 =0.33, β=−0.31, p =0.023) and free oestradiol (adjusted R 2 =0.34, β=−0.33, p =0.019) were inversely associated with changes in SMI in the Black men but not in White men. Baseline serum nitric oxide metabolites were inversely associated with ΔSMI in the Blacks only (adjusted R 2 =0.33, β=−0.28, p =0.047). Chronic SMI was associated with 24h hypertension in Blacks [cut point 1.5 events: Area under the curve 0.71 (95% CI: 0.60, 0.82); p =0.006; with sensitivity/specificity 44%/94%]. Conclusions Chronic SMI events facilitated future ischemic heart disease in Black men. Up-regulated free oestradiol seems to be involved in the protection of the heart against SMI and hypertension risk in Black but not in White men. A similar protective role for testosterone could however not be shown.

Adapting to an over–demanding stressful urban environment may exhaust the psychophysiological resources to cope with these demands, and lead to sympathetic nervous system dysfunction. The evidence that an urban–dwelling lifestyle may be detrimental to the cardiometabolic health of Africans motivated the design of the Sympathetic activity and Ambulatory Blood Pressure in African Prospective cohort study. We aimed to determine neural mechanistic pathways involved in emotional distress and vascular remodelling. The baseline sample included 409 teachers representing a bi–ethnic sex cohort from South Africa. The study was conducted in 2008 09 and repeated after 3–year follow–up in 2011 12, with an 87.8% successful follow–up rate. Seasonal changes were avoided and extensive clinical assessments were performed in a well–controlled setting. Data collection included sociodemographics, lifestyle habits, psychosocial battery and genetic" "analysis, mental stress responses mimicking daily life stress (blood pressure and haemostatic, cardiometabolic, endothelial and stress hormones). Target organ damage was assessed in the brain, heart, kidney, blood vessels and retina. A unique highly phenotyped cohort is presented that can address the role of a hyperactive sympathetic nervous" system and neural response pathways contributing to the burden of cardiometabolic diseases in Africans.

Brain-derived neurotrophic factor (BDNF) has been linked to neurological pathologies, but its role in cardiometabolic disturbances is limited. We aimed to assess the association between serum BDNF levels and structural endothelial dysfunction (ED) as determined by cross-sectional wall area (CSWA) and albumin/creatinine ratio (ACR) in black Africans. Ambulatory blood pressure (BP) and ultrasound CSWA values were obtained from 82 males and 90 females. Fasting blood and 8 h overnight urine samples were collected to determine serum BDNF and cardiometabolic risk markers, that is, glycated haemoglobin (HbA1c), lipids, inflammation and ACR. BDNF median split × gender interaction effects for structural ED justified stratification of BDNF into low and high ($\le$/$\gt$1.37 ng ml$^{−1}$) gender groups. BDNF values (0.86–1.98 ng ml−1) were substantially lower than reference ranges (6.97–42.6 ng ml−1) in the African gender cohort, independent of age and body mass index. No relationship was revealed between BDNF and renal function and was opposed by an inverse relationship between BDNF and CSWA (r=−0.17; P=0.03) in the African cohort. Linear regression analyses revealed a positive relationship between systolic BP and structural remodelling in the total cohort and low-BDNF gender groups. In the high-BDNF females, HbA1C was associated with structural remodelling. Attenuated or possible downregulated BDNF levels were associated with hypertrophic remodelling, and may be a compensatory mechanism for the higher BP in Africans. In addition, metabolic risk and hypertrophic remodelling in women with high BDNF underpin different underlying mechanisms for impaired neurotrophin homeostasis in men and women.

Objectives Insulin-like growth factor-1 (IGF-1) has potent endothelial-protective, anti-platelet and anti-thrombotic activities, and also exerts mitogenic and proliferatory actions on vascular smooth muscle cells. Conflicting reports exist regarding the role of IGF-1 in vascular protection and atherogenesis. We therefore investigated the relationships of ambulatory blood pressure (BP) and carotid intima-media thickness (cIMT) with a range of components of the IGF-1 axis in a bi-ethnic population. Methods We included black (N = 86) and white (N = 101) men and measured growth hormone, total IGF-1, insulin-like growth factor binding protein-3 (IGFBP-3), and pregnancy-associated plasma protein-A (PAPP-A) levels. Results Ambulatory BP was almost 10 mmHg higher in black men (137/88 mmHg versus 128/80 mmHg; both p < 0.001), accompanied by an adverse profile of the IGF-axis for all measured components (all p < 0.01), including reduced bioavailable IGF-1 (IGF-1/IGFBP-3; p = 0.006) and tissue IGF-1 accessibility index as represented by IGF-1.PAPP-A/IGFBP-3 (p < 0.001). Single, partial and multiple regression analyses confirmed an independent inverse association between ambulatory systolic BP and bioavailable IGF-1 in black men (R2 = 0.24; β = −0.22; p = 0.035). cIMT was similar in the ethnic groups (p = 0.34), and was negatively associated with bioavailable IGF-1 in white men (R2 = 0.42; β = −0.17; p = 0.039) prior to adjustment for γ-glutamyl transferase (R2 = 0.45; β = −0.10; p = 0.25). Conclusion Ambulatory systolic BP is inversely related to bioavailable IGF-1 in black men who displayed low IGF-1 concentrations. An inverse relation was found between cIMT and IGF-1 in white men, which disappeared after correction for γ-glutamyl transferase – opposing reports of a detrimental role of IGF-1 in the early stages of atherogenesis.

It is known that low testosterone (T) and high cortisol levels are associated with hypertension as well as with chronic stress, linking stress with elevated blood pressure (BP). However, the association between acute stress-, chronic stress responses and BP is not clear in Africans. Therefore, we examined the association between cortisol, psychological distress and BP responses in low- and high-T male subgroups. Beat-to-beat and ambulatory blood pressure (ABPM) and electrocardiogram measures were obtained. Serum samples were collected and analyzed for sex hormones and cortisol. Chronic psychological distress was verified with the General Health Questionnaire and acute stress with the cold pressor test. More chronic psychological distress was observed in both low- and high-T Africans compared with the Caucasians. The low-T Africans tended to have more ischemic events (P=0.06) and ABPM values (Pless than or equal to0.01) than any of the other groups. Both chronic distress (cortisol) and acute stress (total peripheral resistance cold pressor responses) were associated with ABPM in the low-T African group. Acute and chronic stress may contribute to increased BP in low-T African men. Their cortisol and vascular responses supported a tendency for ischemia, increasing their risk for coronary artery disease. http://www.nature.com/jhh/journal/v28/n6/abs/jhh2013124a.html

Globally the prevalence of non-communicable diseases, such as hypertension and type 2 diabetes, are escalating. Metabolomic studies indicated that circulating branched chain amino acids (BCAAs) are associated with insulin resistance, coronary artery disease and increased risk for cardiovascular events. We aimed to extend the current understanding of the cardiovascular risk associated with BCAAs. We explored whether BCAAs are related to markers of cardiovascular disease in a bi-ethnic population and whether this relationship was influenced by chronic hyperglycaemia. We included 200 African and 209 Caucasian participants, and determined their ambulatory blood pressure and carotid intima-media thickness (cIMT). We analysed blood samples for glycated haemoglobin (HbA1c) and BCAAs. Participants were stratified into two groups according to their HbA1c value using the median cut-off value of 5.6 %. Ambulatory BP, cIMT and BCAAs were significantly higher (all p < 0.001) in the high HbA1c group. Single regression analyses indicated significant positive associations of ambulatory blood pressure and cIMT with BCAAs (all p < 0.05) in both the groups. These associations between ambulatory systolic blood pressure (SBP) (r = 0.16, p = 0.035) and cIMT (r = 0.22, p = 0.004) with BCAAs remained in the high HbA1c group after adjusting for age, gender, ethnicity and body mass index (BMI) and were confirmed in multiple regression analyses (ambulatory SBP: R2 = 0.17, β = 0.21, p = 0.005 and cIMT: R2 = 0.30, β = 0.19, p = 0.003). Our results demonstrate that BCAAs are independently related to ambulatory BP and cIMT in individuals with high HbA1c levels and suggest that potential cardiovascular deterioration accompany the rise in BCAAs in conditions of hyperglycaemia.

BACKGROUND Heart failure in the African population is reaching alarming levels. Increased afterload as a result of increased vasoconstriction during stress may lead to impaired ventricular function and stroke volume (SV) as well as vascular hypertrophy. In this study, we challenged the cardiovascular system in order to evaluate the possible contribution of indicators of α-adrenergic vasoconstriction (i.e., vascular resistance and SV reactivity) on left ventricular mass and carotid intima-media thickness (CIMT) in African and Caucasian men. METHODS We evaluated 101 African and 101 Caucasian male schoolteachers. Ambulatory blood pressure measurements were taken. Total peripheral resistance, Windkessel compliance and SV, and resting and reactivity values were obtained using a Finometer device while the Stroop color word conflict test was being applied. The electrocardiogram was recorded to obtain the Cornell product as indication of left ventricular mass. The CIMT was measured and the cross-sectional wall area (CSWA) calculated. RESULTS African men showed higher total vascular resistance resting values as well as higher positive reactivity values compared with Caucasian men. The SV decreased significantly during stress in African men while resting blood pressure and the Cornell product value increased. SV showed a consistent association with left ventricular mass (β = -0.21; P = 0.04) and CSWA (β = -0.24; P = 0.01) in single and multiple regression analyses. No such associations were evident in the Caucasian men. CONCLUSIONS African men showed a suppressed SV, possibly as a result of an increased ventricular afterload leading to end-organ damage.

Correction to: Hypertension Research (2016) 39, 730–736; doi:10.1038/hr.2016.48; published online 19 May 2016 After online publication of this article, the authors noticed an error in the affiliation of the list of authors. The affiliation of Rudolph Schutte and Walthard Vilser was wrong. The error has now been rectified, and the article with correct authors’ affiliations now appears in this issue.

The behavioral defense coping response (DefS) as a measure of coping with emotional stress may increase alcohol intake (gamma glutamyl transferase (γGT)), the risk for coronary artery disease (CAD) and insulin sensitivity (homeostasis model assessment, HOMA). We assessed associations between coping and cardiometabolic risk markers in a bi-ethnic cohort (N = 390) from South Africa. Ambulatory blood pressure (BP) and ECG, fasting blood and coping scores were obtained. Africans, and mostly when utilizing DefS, showed higher 24h BP, a low-grade inflammatory state, central obesity, increased HOMA [4.07 (3.66, 4.47)] and more ST events compared to their Caucasian counterparts. ROC γ-GT analyses predicting 24-h ambulatory hypertension showed a higher γ-GT cut-point in Africans (55.4 U/l) than in Caucasians (19.5 U/l). Odds ratios (ORs) of γ-GT cut-points predicting 24-h ambulatory hypertension was evident in DefS African men [OR: 7.37 (95% CI: 6.71–8.05), p = 0.003] and in DefS Caucasians, albeit at a lower γ-GT cut-point (19.5 U/l). Higher γ-GT cut-points in DefS Africans or Caucasians were not associated with HOMA > 3. DefS accompanied by alcohol abuse in taxing emotional situations, if no social support is forthcoming, underscores a profile of reduced coronary perfusion. It may enhance vasoconstriction of the coronary arteries, with compensatory increases in BP, and induce a risk for future coronary artery disease.

Objectives: A dissociation between behavioural (in-control) and physiological parameters (indicating loss-of-control) is associated with cardiovascular risk in defensive coping (DefS) Africans. We evaluated relationships between DefS, sub-clinical atherosclerosis, low-grade inflammation and hypercoagulation in a bi-ethnic sex cohort. Methods: Black (Africans) and white Africans (Caucasians) (n = 375; aged 44.6 ± 9.7 years) were included. Ambulatory BP, vascular structure (left carotid cross-sectional wall area (L-CSWA) and plaque counts), and markers of coagulation and inflammation were quantified. Ethnicity/coping style interaction was revealed only in DefS participants. Results: A hypertensive state, less plaque, low-grade inflammation, and hypercoagulation were more prevalent in DefS Africans (27–84%) than DefS Caucasians (18–41%). Regression analyses demonstrated associations between L-CSWA and 24 hour systolic BP (R2 = 0.38; β = 0.78; p

The prognostic significance of blood pressure (BP) variability has lately enjoyed considerable attention. The need for early markers of cardiovascular dysfunction is imperative in black South Africans who have a significant risk for cardiovascular disease. We therefore compared 24-h BP variability with various traditional and advanced BP measurements, regarding their association with sub-clinical organ damage in black and white South Africans. The study included 409 African and Caucasian teachers aged 25–60 yrs. We measured office BP, 1-min continuous (finger) BP, ambulatory BP, BP reactivity and determined weighted 24-h BP variability. Albumin-to-creatinine ratio, Cornell product and carotid cross-sectional wall area (CSWA) were measures of organ damage. Africans had higher 24-h BP, BP variability, BP reactivity and sub-clinical organ damage (P

Recent evidence suggests that low-grade urinary albumin excretion is a marker of early general attenuation of vascular function, but studies are limited to Caucasian population groups. We compared low-grade urinary albumin excretion (

§ ANCOVA: analysis of covariance; MS: metabolic syndrome; AC: active coping; PC: passive coping; ± 95% CI: 95% confidence intervals; n: number of participants; independent t-test values; *Chi-squares; HDL: high-density lipoproteins; CIMTf: carotid intima–media thickness far wall. Values in bold with identical alphabetical superscripts differ significantly, p ≤ 0.05, and in bold italics are borderline significant.

Adipokines contribute directly to the coexistence of insulin resistance and endothelial dysfunction. Most studies focus on a single adipokine. We therefore investigated the independent relationships of leptin, adiponectin, tumor necrosis factor-alpha, resistin and visfatin, as well as the gut hormone ghrelin with blood pressure and insulin resistance. Secondly we evaluated the interrelationships of adipokines and ghrelin in concert with various cardiometabolic markers.Caucasian women (N=115) with varying levels of obesity (aged 31.3 + or - 9.18 years) were included. Significant correlations of leptin, adiponectin, ghrelin and visfatin with mean arterial pressure (p0.05) disappeared after adjustment for age, body mass index and waist circumference. But significant correlations with insulin resistance (HOMA) (for leptin, adiponectin and ghrelin) remained significant after adjustments. Factor analyses yielded five factors, but two main clusters, namely a metabolic syndrome cluster (including leptin, adiponectin and ghrelin) and a vascular atherosclerotic cluster (including tumor necrosis factor-alpha, visfatin and resistin).Factor analyses identified patterns which indicate specific roles of the various adipokines. Leptin, adiponectin and ghrelin were more closely related to insulin resistance and central obesity as core components of the metabolic syndrome. Visfatin, tumor necrosis factor-alpha and resistin seem to direct their effects onto the vascular system possibly by means of mechanisms such as inflammation, vasoconstriction and coagulation.

The renin–angiotensin–aldosterone system can be activated by sympathetic nervous input and is thought to have an important role in the prevalence of hypertension and cardiovascular risk in black Africans. We examined (1) the association between plasma renin responses to mental stress and a marker of sub-clinical atherosclerosis; and (2) associations between resting renin and 24-h ambulatory blood pressure. Participants were 143 urbanized black African men and women (43.1±7.7 years) drawn from a study of Sympathetic Activity and Ambulatory Blood Pressure in Africans (SABPA). After an overnight fast, participants completed the Stroop mental stress task. Blood samples were drawn during baseline and 10 min after the task to assess the concentration of active renin in plasma. Blood pressure assessments included continuous Finometer measures during the stress testing and 24-h ambulatory monitoring. Carotid intima–media thickness (CIMT) was measured using high-resolution ultrasound. Approximately 50% of the sample responded to the task with an increase in renin concentration. Multiple linear regression analysis revealed an association between the renin stress response and CIMT (β=0.024, 95% confidence interval, 0.004–0.043), after adjustment for conventional risk factors, blood pressure stress responses and basal levels of renin activity (R2 for model=0.37). In addition, resting renin was inversely associated with ambulatory blood pressure. In summary, heightened release of renin during a laboratory mental stressor was associated with a marker of sub-clinical atherosclerosis; thus, it may be a potential mechanism in explaining the increased burden of cardiovascular disease in urbanized black Africans. http://dx.doi.org/10.1038/jhh.2010.82

Low serum IGF-I is an independent risk factor for diabetes and cardiovascular disease. These noncommunicable diseases are extremely common in urban black South Africans, but their IGF-I concentration is unknown. We aimed to compare serum IGF-I concentrations of African and Caucasian people, investigate their age-related IGF-I decline, and determine whether IGF-I could account, at least in part, for the high prevalence of noncommunicable diseases in black Africans.This cross-sectional study involved 211 African and 316 Caucasian men and women (aged 20-70 yr). Fasting glucose, insulin, lipids, albumin, creatinine, liver enzymes, cotinine, high-sensitivity C-reactive protein, reactive oxygen species, IGF-I, blood pressure (BP), and pulse wave velocity were determined.IGF-I was lower in Africans (P0.001) and in both ethnicities declined significantly by age quartiles (P0.001). In African men and women, IGF-I declined significantly from age quartile 1 to 2 (r = -0.65, P0.001), not seen in young Caucasian men and women (r = -0.08, P = 0.45; r = -0.10, P = 0.34). This was confirmed after adjustment for BP, insulin resistance, high-sensitivity C-reactive protein, cotinine, gamma-glutamyl transferase, and reactive oxygen species. Only young Africans showed significant negative correlations of IGF-I with BP, pulse wave velocity, and high-density lipoprotein cholesterol.Africans presented lower IGF-I levels than Caucasians due to an accelerated decline in serum IGF-I concentration prior to 40 yr of age. Strong associations of low serum IGF-I with blood pressure and arterial stiffness in young Africans suggest that the loss of cardiometabolic protection by IGF-I could predispose them to earlier disease onset.

Objectives: Retinal vessels are part of the intracranial vasculature and analysis thereof complements behavioural and brain measures. Mental stress was related to downregulation of norepinephrine in Africans. Hence we continue by assessing prospective associations between sympathetic nervous system activity and retinal vessel calibres. Methods: Black and Caucasian participants (n = 275; 45 ± 9 years) were stratified into tertiles according norepinephrine:creatinine (NE:Cr) ratio at baseline. Three year prospective % changes (Δ) for depression (PHQ-9), urinary NE:Cr, serum cortisol and High-Density-Lipoprotein (HDL, neuronal-membrane-integrity and ischemic stroke risk marker) were obtained. At 3yr-follow-up, retinal microvascular calibres were quantified from digital images in the mydriatic eye and salivary cortisol (sC) and α-amylase (sAA), adrenergic activity marker were obtained. Results: Only the low NE:Cr-tertile group (44% Black; 64% Men), showed chronic depression and hypertension prevalence. Over 3yrs, their NE:Cr increased whereas cortisol and HDL decreased. At 3yr-follow-up, wider venules (stroke risk marker) were apparent in the low- compared to the high-tertile group (Figure 1). In the low-tertile group, chronic depression was associated with stroke risk markers, wider venules [OR 1.7; P = 0.03] and lower HDL [OR 4.8; P = 0.04]. In this group, arteriole narrowing was associated with ΔNE:Cr, Δcortisol and sAA; whilst a wider venule was associated with ΔNE:Cr and sC. Conclusions: In reaction to depression and low NE:Cr levels, homeostatic reflexes facilitated upregulation of norepinephrine and concurrent downregulation of cortisol. Stress-induced sympathetic nervous system activity however disturbed myogenic tone, neuronal-membrane-integrity and retinal venular widening; increasing the susceptibility for ischemic stroke.

An assessment of specific coping styles in rural–urban Africans is done to evaluate its contribution as cardiometabolic risk factor. In total, 608 apparently healthy Africans were included in a cross-sectional comparative study from the North-West Province in South Africa. The adapted and translated COPE Questionnaire classified participants according to their responses into active (AC) or passive (PC) copers. Fasting resting metabolic syndrome (MS) indicators using the WHO definition (glucose, high density lipoproteins, waist/hip ratio, hypertension prevalence, and triglyceride) and associated MS values, i.e. fibrinogen were obtained. The Finapres recorded resting blood pressure continuously. Co-variates for all statistical analyses included age, body mass index (BMI) and lifestyle factors (alcohol consumption, smoking habits and physical activity). The only MS values prevalent in urbanized participants were higher hypertension prevalence rates and fibrinogen (women only) compared to their rural counterparts. Adding coping styles, it was mainly the urbanized AC participants that indicated higher MS values (hypertension prevalence, glucose and fibrinogen) when compared to their rural and PC counterparts. In conclusion, urbanization is associated with enhanced blood pressure and fibrinogen (women) values only. Coping as cardiometabolic risk is accentuated in the urbanized AC group, especially the men. The urbanized AC group with their higher blood pressure values and more MS indicators appears to have behaviorally an AC style but physiologically a dissociated AC style.

Objective To assess the risk factor pattern of the metabolic syndrome and its association with insulin resistance and hyperuricaemia in a sub-Saharan African population with different levels of urbanisation. Methods Four hundred forty-eight black South African volunteers, men and women aged 15 years and older were investigated in a cross-sectional, comparative, population-based survey. Subjects were stratified into three groups representing different levels of urbanisation in rural and urban areas. The metabolic syndrome was defined according to IDF criteria. Factor analysis was used to examine the risk factor pattern of the metabolic syndrome. Results The prevalence of the metabolic syndrome was low and did not differ across the three groups. Factor analysis showed slight differences in the metabolic syndrome pattern between the groups. Hyperuricaemia–hypertriglyceridaemia was identified as distinct component in the rural and semiurban group whereas hyperinsulinaemia was loaded together with other risk factors. In the entire study population, five factors could be identified in the following sequence: obesity, hypertension, hyperuricaemia–hypertriglyceridaemia, hyperglycaemia and hyperinsulinaemia. Subjects with hyperuricaemia but not with insulin resistance exhibited an increased risk to develop the metabolic syndrome. Conclusions Hyperuricaemia was revealed as additional component of the metabolic syndrome in sub-Saharan Africans and should be given more attention in prevention settings.

Inflammation may contribute to an increase in cardiac wall stress through pathways related to cardiac remodeling. Cardiac remodeling is characterized by myocyte hypertrophy, myocyte death and modifications of the extracellular matrix. We sought to explore associations among cardiac remodeling, inflammation and myocardial cell injury in a bi-ethnic cohort of South African men and women. We included 165 men (76 African and 89 Caucasian) and 174 women (80 African and 94 Caucasian) between 20 and 65 years of age. Inflammatory markers used were C-reactive protein (CRP), interleukin-6 and tumor necrosis factor-alpha (TNF-α), whereas troponin T (Trop T) and the N-terminal of pro B-type natriuretic peptide (NT-proBNP) were used as cardiac markers. The frequency of ischemic events (ST segment depression) and left ventricular strain (left ventricular hypertrophy: LVH) were monitored by a 24-h recording of ambulatory blood pressure (BP), ECG and 12-lead standard ECG. Hypertension diagnosed with ambulatory monitoring was more frequent in Africans (53.85 vs. 24.59%; P

Hypertension prevalence is increasing globally, yet little is known about the occurrence of masked hypertension (MHT) in young, sub-Saharan African adults, and how it relates to elevated cardiovascular risk. The African-PREDICT study (recruitment based on normotensive clinic blood pressure (BP)) determined the frequency of MHT and its relationship with arterial stiffness and biochemical markers of inflammation and endothelial activation. We included men and women (n=352), 20-30 years, screened for normotensive clinic BP (54% white, 40% men). Clinic BP, ambulatory blood pressure monitoring (ABPM), central systolic pressure, aortic pulse wave velocity (aPWV), augmentation index, anthropometry, physical activity and biochemical markers of cardiovascular risk were assessed (lipids, glucose, insulin, markers of endothelial activation and inflammation). Eighteen percent of the study population had MHT (60% white, 68% men). Those with MHT had increased adiposity, clinic-, ABPM- (24-h, day and night) and central-BP (within normal ranges), heart rate, aPWV and biochemical markers of cardiovascular risk, compared with normotensives (all P0.05). Using multivariable adjusted odds ratios, we found that MHT was associated with increased likelihood for higher aPWV (odds ratio (OR)=1.567, P=0.010), insulin (OR=1.499, P=0.049), monocyte chemoattractant protein-1 (OR=1.499, P=0.026), vascular cellular adhesion molecule (OR=1.409, P=0.042) and C-reactive protein (OR=1.440, P=0.044). In a young adult (supposedly healthy) cohort, the occurrence of MHT is alarming, especially since MHT further demonstrated elevated cardiovascular risk via increased adiposity, arterial stiffness, endothelial activation and inflammation. Detection of MHT is crucial to increase awareness of elevated cardiovascular risk, and to ensure the required lifestyle and/or pharmaceutical interventions.

Summary Aim Emotional distress has been associated with cardiovascular disease (CVD) in Africans. Cortisol and brain-derived neurotrophic factor (BDNF), as markers of emotional distress, increase cardiometabolic risk. We therefore aimed to investigate associations between cardiometabolic risk markers and the cortisol-to-BDNF ratio (cortisol:BDNF). Methods A cross-sectional study included a bi-ethnic gender cohort (n = 406) aged 44.7 ± 9.52 years. Ambulatory blood pressure (ABPM), ECG, fasting serum cortisol and BDNF levels and cardiometabolic risk markers were obtained. Results Africans had increased incidence of hyperglycaemia and 24-hour silent ischaemic events, and elevated 24-hour blood pressure (BP) and cortisol:BDNF ratios compared to Caucasians. Forward stepwise linear regression analysis underscored a similar trend with associations between hyperglycaemia, 24-hour BP [Adj R2 0.21–0.29; β 0.23 (0.1–0.4); p = 0.01], silent ischaemia [Adj R2 0.22; β 0.40 (0.2–0.6); p < 0.01] and cortisol:BDNF levels in Africans, mostly in the men. Conclusion Attenuated cortisol levels in this group may be indicative of emotional distress and if chronic, drive the cortisol:BDNF ratio to desensitise BDNF. Desensitised cortisol:BDNF may sustain cardiometabolic risk and induce neurodegeneration in African men via silent ischaemia. Compensatory increases in blood pressure to increase perfusion and maintain homeostasis may increase coronary artery disease risk.

Objective: Telomere length is a marker of biological aging that has been linked to cardiovascular disease risk. The black South African population is witnessing a tremendous increase in the prevalence of cardiovascular disease, part of which might be explained through urbanization. We compared telomere length between black South Africans and white South Africans and examined which biological and psychosocial variables played a role in ethnic difference in telomere length. Methods: We measured leukocyte telomere length in 161 black South African teachers and 180 white South African teachers aged 23 to 66 years without a history of atherothrombotic vascular disease. Age, sex, years having lived in the area, human immunodeficiency virus (HIV) infection, hypertension, body mass index, dyslipidemia, hemoglobin A1c, C–reactive protein, smoking, physical activity, alcohol abuse, depressive symptoms, psychological distress, and work" "stress were considered as covariates. Results: Black participants had shorter (median, interquartile range) relative telomere length (0.79, 0.70Y0.95) than did white participants (1.06, 0.87Y1.21; p G .001), and this difference changed very little after adjusting for covariates. In fully adjusted models, age (p G .001), male sex (p = .011), and HIV positive status (p = .023) were associated with shorter telomere length. Ethnicity did not significantly interact with any covariates in determining telomere length, including psychosocial characteristics." "Conclusions: Black South Africans showed markedly shorter telomeres than did white South African counterparts. Age, male sex, and HIVstatuswere associatedwith shorter telomere length.No interactions between ethnicity and biomedical or psychosocial factorswere found. Ethnic difference in telomere length might primarily be explained by genetic factors. Key words: cardiovascular disease, ethnicity, genetics," "psychological stress, telomere.

Specific coping mechanisms of Africans during urbanization were compared to and correlated with cardiovascular responses and perception of health data. Subjects included men (N = 286) and women (N = 360). The COPE questionnaire classified subjects as active (AC) or passive (PC) copers and the General Health Questionnaire measured subjective perception of health. The Finapres recorded blood pressure continuously before and during application of a handgrip test. Analyses adjusting for age, body mass index and resting cardiovascular data revealed that AC rural subjects showed predominantly cardiac responses and PC rural subjects predominantly vascular responses. All urbanized African men and women showed higher resting blood pressure, vascular responsiveness and hypertension prevalences than their rural counterparts. All rural AC subjects, especially women, and all urban PC subjects, especially men, reported a poorer perception of health. In conclusion, subjects with a PC style showed a predominantly vascular response in rural and urban areas whereas subjects with an AC style seem to shift from a predominant cardiac output response to a predominant vascular resistance response when moving from a rural to an urban area.

People living in large informal settlements in South Africa showed a significant increase in cardio/cerebrovascular disease. This study was undertaken to compare the cardiovascular and endocrine parameters of urbanized and rural black female and males. The hormone levels such as prolactin, cortisol and testosterone may also change with urbanization and could make a contribution to the high rate of hypertension. For this study, 1202 black subjects were selected from 37 randomly selected rural and urbanized settlements. Resting blood pressure was recorded with a Finapres apparatus. Cardiac output, stroke volume, heart rate, total peripheral vascular resistance and compliance had been obtained with the Fast Modelflow software program. An acute laboratory stressor (hand dynamometer exercise) was applied to challenge the cardiovascular system and the measurements were repeated. Blood sampling was done and hormone levels were determined by biochemical analyses. For females, significant lower levels of cortisol were found in the urban strata in comparison with the rural strata. The testosterone levels were significantly lower and the prolactin levels significantly higher for females in the informal settlements compared with the rural strata. It is noticeable that most cardiovascular parameters showed the highest changes with the application of the stressor in the informal settlement strata and the lowest in people living on farms for both male and female. The prolactin levels in males are significantly higher in the informal settlement stratum. Subjects living in informal settlements showed a noticeable endocrine pattern of ongoing stress that can be associated with changes in the cardiovascular parameters with urbanization. This can partly explain the reported high rate of cardio/cerbrovascular disease in black South Africans living in informal settlements.