Africans Who Arrive in the United States before 20 Years of Age Maintain Both Cardiometabolic Health and Cultural Identity: Insight from the Africans in America Study

The overall consensus is that foreign-born adults who come to America age \u3c 20 y achieve economic success but develop adverse behaviors (smoking and drinking) that lead to worse cardiometabolic health than immigrants who arrive age ≥ 20 y. Whether age of immigration affects the health of African-born Blacks living in America is unknown. Our goals were to examine cultural identity, behavior, and socioeconomic factors and determine if differences exist in the cardiometabolic health of Africans who immigrated to America before and after age 20 y. Of the 482 enrollees (age: 38 ± 1 (mean ± SE), range: 20–65 y) in the Africans in America cohort, 23% (111/482) arrived age \u3c 20 y, and 77% (371/482) arrived age ≥ 20 y. Independent of francophone status or African region of origin, Africans who immigrated age \u3c 20 y had similar or better cardiometabolic health than Africans who immigrated age ≥ 20 y. The majority of Africans who immigrated age \u3c 20 y identified as African, had African-born spouses, exercised, did not adopt adverse health behaviors, and actualized early life migration advantages, such as an American university education. Due to maintenance of cultural identity and actualization of opportunities in America, cardiometabolic health may be protected in Africans who immigrate before age 20. In short, immigrant health research must be cognizant of the diversity within the foreign-born community and age of immigration

Sleep and Economic Status are Linked to Daily Life Stress in African-born Blacks Living in America.

To identify determinants of daily life stress in Africans in America, 156 African-born Blacks (Age: 40 ± 10 years (mean ± SD), range 22-65 years) who came to the United States as adults (age ≥ 18 years) were asked about stress, sleep, behavior and socioeconomic status. Daily life stress and sleep quality were assessed with the Perceived Stress Scale (PSS) and Pittsburgh Sleep Quality Index (PSQI), respectively. High-stress was defined by the threshold of the upper quartile of population distribution of PSS (≥16) and low-stress as PSS \u3c 16. Poor sleep quality required PSQI \u3e 5. Low income was defined as groups, PSS were: 21 ± 4 versus 9 ± 4, p \u3c 0.001 and PSQI were: 6 ± 3 versus 4 ± 3, p \u3c 0.001, respectively. PSS and PSQI were correlated (r = 0.38, p \u3c 0.001). The odds of high-stress were higher among those with poor sleep quality (OR 5.11, 95% CI: 2.07, 12.62), low income (OR 5.03, 95% CI: 1.75, 14.47), and no health insurance (OR 3.01, 95% CI: 1.19, 8.56). Overall, in African-born Blacks living in America, daily life stress appears to be linked to poor quality sleep and exacerbated by low income and lack of health insurance

Circulating neurotrophins and hemostatic risk factors of atherothrombotic cardiovascular disease at baseline and during sympathetic challenge: the SABPA study

Sympathetic activation may trigger acute coronary syndromes. We examined the relation between circulating neurotrophic factors and hemostatic risk factors of atherothrombotic cardiovascular disease at baseline and in response to acute mental stress to establish a brain–heart link. In 409 black and white South Africans, brain-derived neurotrophic factor (BDNF) and fibrinolytic measures were assessed at baseline. Glial cell-derived neurotrophic factor (GDNF), S100 calcium-binding protein (S100B), von Willebrand factor (VWF), fibrinogen and D-dimer were assessed at baseline and 10 min after the Stroop test. Neurotrophins were regressed on hemostatic measures adjusting for demographics, comorbidities, cardiometabolic factors and health behaviors. Higher baseline BDNF was associated with greater stress-induced increase in fibrinogen (p = 0.003) and lower D-dimer increase (p = 0.016). Higher baseline S100B was significantly associated with higher baseline VWF (p = 0.031) and lower fibrinogen increase (p = 0.048). Lower baseline GDNF was associated with higher baseline VWF (p = 0.035) but lower VWF increase (p = 0.001). Greater GDNF (p = 0.006) and S100B (p = 0.042) increases were associated with lower VWF increase. All associations showed small-to-moderate effect sizes. Neurotrophins and fibrinolytic factors showed no significant associations. The findings support the existence of a peripheral neurothrophin-hemostasis interaction of small-to-moderate clinical relevance. The implications for atherothrombotic cardiovascular disease need further exploration

Ethnicity-specific changes in cardiac troponin t in response to acute mental stress and ethnicity-specific cutpoints for the R wave of the aVL lead: the SABPA study

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 diseas

QTc prolongation, increased NT-proBNP and pre-clinical myocardial wall remodeling in excessive alcohol consumers: the SABPA study

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 populatio

Retinal Vasculature Reactivity During Flicker Light Provocation, Cardiac Stress and Stroke Risk in Africans: The SABPA Study

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

Heart rate variability, the dynamic nature of the retinal microvasculature and cardiac stress: providing insight into the brain–retina–heart link: the SABPA study. (Correction)

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 cause