Associations between burnout symptoms and social behaviour: exploring the role of acute stress and vagal function.

BACKGROUND: The study aimed to investigate the link between burnout symptoms and prosocial behaviour, as well as the role of acute stress and vagally-mediated heart rate variability (vmHRV) on this association. METHODS: Seventy men were randomly assigned to either the stress or the control condition of the Trier Social Stress Test for Groups (TSST-G). Prosocial behaviour was assessed via a social decision-making paradigm during the respective TSST-G condition. RESULTS: Correlation analyses revealed negative correlations between prosocial behaviour and burnout symptoms. Acute stress was also associated with reduced prosocial behaviour, whereas no interaction effects with burnout symptoms could be revealed. Exploratory analyses showed that vmHRV was negatively correlated with burnout symptoms during the social decision-making paradigm but did not mediate the link between burnout and prosocial behaviour. CONCLUSION: In conclusion, we report first experimental evidence that burnout symptoms are negatively associated with prosocial behaviour. Further studies are needed to explore the causal relations.

Gender Differences in Cardiac Chronotropic Control: Implications for Heart Rate Variability Research.

There is a continuing debate concerning "adjustments" to heart period variability [i.e., heart rate variability (HRV)] for the heart period [i.e., increases inter-beat-intervals (IBI)]. To date, such arguments have not seriously considered the impact a demographic variable, such as gender, can have on the association between HRV and the heart period. A prior meta-analysis showed women to have greater HRV compared to men despite having shorter IBI and higher heart rate (HR). Thus, it is plausible that men and women differ in the association between HRV and HR/IBI. Thus, the present study investigates the potential moderating effect of gender on the association between HRV and indices of cardiac chronotropy, including both HR and IBI. Data from 633 participants (339 women) were available for analysis. Cardiac measures were assessed during a 5-min baseline-resting period. HRV measures included the standard deviation of inter-beat-intervals, root mean square of successive differences, and autoregressive high frequency power. Moderation analyses showed gender significantly moderated the association between all HRV variables and both HR and IBI (each p < 0.05). However, results were not consistent when using recently recommended HRV variables "adjusted" for IBI. Overall, the current investigation provides data illustrating a differential association between HRV and the heart period based on gender. Substantial neurophysiological evidence support the current findings; women show greater sensitivity to acetylcholine compared to men. If women show greater sensitivity to acetylcholine, and acetylcholine increases HRV and the heart period, then the association between HRV and the heart period indeed should be stronger in women compared to men. Taken together, these data suggest that routine "adjustments" to HRV for the heart period are unjustified and problematic at best. As it relates to the application of future HRV research, it is imperative that researchers continue to consider the potential impact of gender.

Ethnic and sex differences in the longitudinal association between heart rate variability and blood pressure.

PURPOSE: Elevated blood pressure is a risk factor for increased cardiovascular morbidity and mortality. Decreased vagally-mediated heart rate variability has previously been prospectively linked with increased blood pressure; however, to date, no such prospective data exist regarding this relationship among Blacks. MATERIALS AND METHODS: We examined this association in 387 normotensive young adults (mean age, 23 years, 52% female, 54% Black) who participated in two laboratory evaluations spanning approximately six years. Blood pressure was measured at both timepoints with a non-invasive oscillometric device and heart rate variability was assessed via bio-impedance. RESULTS: In the total sample, heart rate variability significantly predicted systolic (p = .022) and diastolic (p < .001) blood pressure increases six years into the future. However, this pattern varied as a function of ethnicity and sex with the effect of heart rate variability on Time 2 systolic blood pressure only significant among White males (p = .007). Heart rate variability was also predictive of Time 2 diastolic blood pressure in White males (p = .038) as well as among both White (p = .032) and Black (p = .015) females, but was not related to blood pressure among Black males. CONCLUSION: We report for the first time significant ethnic and sex differences in the prospective relationship between heart rate variability and blood pressure change. These findings may give clues as to the underlying mechanisms that are involved in the well-known health disparities in blood pressure and hypertension-related cardiovascular diseases.

Ethnic Differences in Resting Total Peripheral Resistance: A Systematic Review and Meta-Analysis.

OBJECTIVE: Decades of research suggest that there may be important ethnic differences in the hemodynamic mechanisms that co-determine arterial blood pressure, the primary diagnostic index of hypertension. In general, studies have observed that, compared with European Americans (EAs), African Americans (AAs) exhibit higher total peripheral resistance (TPR), an important summative index of peripheral vascular constriction. In contrast, EAs have been reliably shown to exhibit greater cardiac output (CO), which is directly linked to left ventricle and overall cardiac blood flow. We have previously proposed that elevated basal TPR, in particular, represents one component of the cardiovascular conundrum, characterized, paradoxically, by elevated resting heart rate variability among AAs relative to EAs. The present meta-analysis and systematic review of the literature sought to extend this previous work by establishing the magnitude of the empirically implied ethnic differences in resting TPR and CO. METHODS: A search of the literature yielded 140 abstracts on differences in TPR between AAs and EAs; 40 were included. Sample sizes, means, and standard deviations for baseline TPR with samples that included EAs and AAs were collected, and Hedges g was computed. RESULTS: Findings indicated that AAs had higher baseline TPR than did EAs (Hedges g = 0.307, SE = 0.043, confidence interval= 0.224 to 0.391, p < .001). In addition, EAs had higher resting CO than did AAs (Hedges g = -0.214, SE = 0.056, confidence interval = -0.324 to -0.104, p < .001). CONCLUSIONS: We discuss the present findings in the context of the role of elevated TPR in the deleterious effects of high blood pressure specifically for AAs.

Internalization of Western Ideals on Appearance and Self-Esteem in Jamaican Undergraduate Students.

Beauty ideals in the Caribbean are shifting with increased exposure to Western and European standards of appearance. Previous research has shown a consistent link between internalization of Western beauty ideals and depressive symptoms and other forms of psychological disturbance among diverse populations including Caribbeans. We examined the association between internalization of Western beauty ideals and depressive symptoms as well as the potential mediating role of self-esteem on this relation in N = 222 students (155 females, 79 males) attending a tertiary institution in Kingston, Jamaica. Internalization of Western ideals was inversely associated with self-esteem (r =- .35, p < .01) and positively associated with depressive symptoms (r =.13, p < .05). In a model adjusted for age and sex, results revealed a significant indirect effect of internalization of Western ideals of appearance on depressive symptoms via self-esteem (estimate= .21, SE = .05, 95% confidence interval [.13, .32]). The potent effects of culture must be better understood as intercontinental travel becomes less important as a mechanism for cultural exposure and exchange, and there is a significant increase of digital and internet access in the Caribbean. The current study suggest that Caribbeans are at significant risk for internalizing Western ideals of beauty, subsequently diminishing their self-esteem, and ultimately increasing depression symptomatology. The benefits and consequences of cultural exchange should continue to be a topic for research studies.

The Longitudinal Association of Reduced Vagal Tone With Burnout.

OBJECTIVE: Previous research indicates a link between burnout symptoms and reduced vagally mediated heart rate variability (HRV); however, the directionality of this relationship is still largely unknown. The objective of the present study was to examine the longitudinal relationship between HRV and burnout symptoms for 1 year, with a special focus on the emotional exhaustion (EE) burnout subdimension, which remains inadequately distinguished from overlapping with depressive symptoms. METHODS: Here we present HRV and behavioral data from 167 individuals (mean [SD] age = 43.43 [11.78] years; 30.5% male) who attended two biomarker samplings (T1 and T2) of the Dresden Burnout Study approximately 12 months apart. RESULTS: In hierarchical linear regression analyses, T1 HRV significantly inversely predicted T2 overall burnout symptoms (ß = -.16; p = .03) and EE (ß = -.23; p = .02), adjusting for age, sex, body mass index, adverse health behaviors, and depressive symptoms. Importantly, only high EE at T1 (ß = -.22; p = .04), and not the T1 Maslach Burnout Inventor total score, predicted reductions in HRV from T1 to T2. CONCLUSIONS: We report for the first time longitudinal evidence that HRV is associated with changes in burnout symptoms, independently of depressive symptoms. Results suggest vagal dysfunction being predictive and specific for burnout symptoms, making HRV a promising starting point for the explanation of biophysiological mechanisms underlying burnout symptoms and cardiovascular diseases. The finding of only EE at T1 being predictive for changes in HRV underscores the importance of exhaustion for modulations in autonomic regulation.

Sex Differences in the Impact of Racial Discrimination on Mental Health Among Black Americans.

PURPOSE OF REVIEW: Greater racial discrimination is associated with poorer mental health among Black Americans; yet, there remains an incomplete understanding of sex differences in exposure to racial discrimination, and further, of how sex differences in coping with racial discrimination may heighten or diminish risk for poorer mental health. RECENT FINDINGS: Black men may experience greater exposure to both structural and communal forms of racial discrimination, whereas Black women may face both a wider range of potential sources, as well as encounter greater variability in the subjective experience of racial discrimination. For both Black women and men, racial discrimination may be similarly associated with maladaptive coping strategies (i.e., emotional eating, rumination) that also are linked to poorer mental health; however, emerging findings suggest that mindfulness may partially buffer these deleterious effects. Overall, the recent literature reveals mixed findings with respect to sex differences in the experience and negative mental health impact of racial discrimination. Despite this heterogeneity, evidence documents sex differences in the settings, type, and qualitative experience of racial discrimination among Black Americans. Additionally, growing evidence indicating that racial discrimination is associated with physiological markers of stress reactivity and psychopathology risk further bolsters its characterization as a unique form of chronic stress among Black Americans and other minority groups in the USA.

Stereotype threat, trait perseveration, and vagal activity: evidence for mechanisms underpinning health disparities in Black Americans.

Objective: Black Americans (BAs) are at an elevated risk for morbidity and mortality in comparison to White Americans (WAs). Racial stressors are a common occurrence in American culture and is theorized to contribute to these disparities. When race-focused, stereotype threat (ST) is considered to be a factor that is detrimental to health in BAs; however few studies have directly investigated the impact of a ST manipulation on physiological function. Furthermore, it is proposed that racial stressors such as ST may have prolonged effects when more likely to perseverate (e.g. rumination) over the stressor and thus, those with greater trait perseveration may be more affected by ST. We sought to explore the impact of ST and trait perseveration on changes in vagus nerve activity - an indication of adaptive psychological and physiological well-being - as indexed by vagally mediated heart rate variability (vmHRV). Design: Forty-three (24 females, mean age of 20, standard deviation of 3 years) apparently healthy BA individuals were randomly assigned to one of three experimental conditions in which they received either implicit (subtle), explicit (blatant), or no ST priming (control condition), prior to completing a cognitive task. Resting vmHRV was assessed both at baseline (pre-task) and recovery (post-task). Results: BAs in the explicit ST condition exhibited the greatest decrease in vmHRV in comparison to the control group from pre- to post-task. BAs with moderate to high levels of trait perseveration showed the greatest decrease in vmHRV from pre- to post-task in comparison to those with lower levels of trait perseveration and BAs in the control group. Conclusion: These data suggest that racial ST, especially when explicit and coupled with trait perseveration, can decrease vagal activity, as indexed by decreased vmHRV, which when experienced frequently can have significant consequences for health and longevity in BAs.

The Autonomic Nervous System and Hypertension: Ethnic Differences and Psychosocial Factors.

PURPOSE OF THE REVIEW: In the present paper, we overview emerging research examining the autonomic nervous system (ANS), especially the parasympathetic nervous system as indexed by heart rate variability (HRV), and the impact of psychosocial factors on hypertension-related disease in African Americans. RECENT FINDINGS: A growing corpus of studies has shown that (1) usual patterns of compensatory sympathetic-parasympathetic regulation differ between African Americans and European Americans; (2) despite their enhanced cardiovascular disease risk profile, African Americans tend to exhibit higher HRV relative to European Americans; and (3) racial discrimination and other forms of psychosocial stress are associated with diminished HRV among African Americans. Significant disparities in hypertension-related disease exist such that African Americans have greater risk. The underlying factors associated with this increased risk are, to date, not fully understood. The present review provides evidence for a unique pattern of ANS regulation in African Americans and shows that psychosocial factors such as racial discrimination may contribute to this paradoxical situation.

Impact of Racial Discrimination and Hostility on Adrenergic Receptor Responsiveness in African American Adults.

OBJECTIVE: Racial discrimination is increasingly recognized as a contributor to increased cardiovascular disease (CVD) risk among African Americans. Previous research has shown significant overlap between racial discrimination and hostility, an established predictor of CVD risk including alterations in adrenergic receptor functioning. The present study examined the associations of racial discrimination and hostility with adrenergic receptor responsiveness. METHODS: In a sample (N = 57) of young to middle-aged African American adults (51% female) with normal and mildly elevated blood pressure, a standardized isoproterenol sensitivity test (CD25) was used to evaluate ß-AR responsiveness, whereas the dose of phenylephrine required to increase mean arterial pressure by 25 mm Hg (PD25) was used to assess α1-AR responsiveness. Racial discrimination was measured using the Perceived Racism Scale and hostility was assessed using the Cook-Medley Hostility Scale. RESULTS: In hierarchical regression models, greater racial discrimination, but not hostility, emerged as a significant predictor of decreased ß-adrenergic receptor responsiveness (ß = .38, p = .004). However, moderation analysis revealed that the association between racial discrimination and blunted ß-adrenergic receptor responsiveness was strongest among those with higher hostility (ß = .49, 95% confidence interval = .17-.82, p = .004). In addition, hostility, but not racial discrimination, significantly predicted α1-AR responsiveness. CONCLUSIONS: These findings suggest racial discrimination was associated with blunted ß-adrenergic receptor responsiveness, providing further evidence of the potential contribution of racial discrimination to increased CVD risk among African Americans. The adverse effects of discrimination on cardiovascular health may be enhanced in individuals with higher levels of hostility.

Reduced self-regulation mirrors the distorting effects of burnout symptomatology on task difficulty perception during an inhibition task.

Burnout, a pathological consequence of chronic work stress, shows an increasing incidence rate in industrialized countries. Previous findings indicate that burnout may be linked to a detachment of the negative association between subjectively appraised task demand and cognitive performance, which is typically seen in healthy individuals. The present study sought to confirm this relationship and to investigate whether this dissociation is mirrored in a biological marker of self-regulation, i.e., resting vagally mediated heart rate variability (HRV). A heterogeneous sample (N = 65) of working adults (M age = 43.3, SD = 10; 23.1 % male) with varying degrees of burnout symptomatology completed three cognitive tasks (2-back, number-letter, and go/nogo) to assess different domains of executive functioning (updating, set-shifting, and inhibition), and respective demand ratings. Additionally, vagally mediated HRV at rest, operationalized as the root-mean square differences of successive R-R intervals (RMSSD), was recorded. Burnout symptomatology moderated the association between subjective task difficulty and performance parameters of the go/nogo task, such that higher burnout scores were associated with reductions in the naturally occurring negative association between self-rated task demand and response inhibition. Intriguingly, this pattern was mirrored when replacing burnout with HRV. These findings suggest that burnout symptomatology, and individual differences in self-regulatory capacities (indexed by resting HRV), may alter one's capacity for accurate task evaluation, a mechanism which could potentially underlie the dissociation between self-rated cognitive function and actual performance among individuals experiencing burnout.

Active coping moderates associations among race-related stress, rumination, and depressive symptoms in emerging adult African American women.

Cross-sectional and longitudinal research has shown that race-related stress is associated with increased depressive symptoms among racial/ethnic minorities. Rumination has long been considered a maladaptive self-regulatory response to race-related stress, and growing evidence suggests that it may be an important link in the relation between race-related stress and depression. More adaptive forms of self-regulation, such as active coping, may counteract the negative impact of rumination. We examined the influence of rumination on the relation between race-related stress and depressive symptoms in a sample (N = 69) of young adult (mean age = 20 ± 1.5 years) African American women. We also considered the possible moderating effects of John Henryism, a form of persistent and determined goal striving, and vagally mediated heart rate variability, a purported biomarker of coping. Anticipatory race-related stress was indirectly associated with depressive symptoms through rumination: estimate = 0.07, 95% confidence interval [0.01, 0.16]. Both John Henryism and vagally mediated heart rate variability moderated the relationship between race-related stress and rumination; however, only John Henryism reliably influenced the indirect association between race-related stress and depression through rumination. We discuss these findings in the context of growing research examining the interplay between cultural and biological factors in the risk for poorer mental health.

Examining How Racial Discrimination Impacts Sleep Quality in African Americans: Is Perseveration the Answer?

BACKGROUND: African Americans experience more problematic and disordered sleep than White Americans. Racial discrimination has been implicated in this disparity. However, the mechanisms by which discrimination disrupts sleep are unclear. It has been theorized that Perseverative Cognition (PC), characterized by recurrent patterns of reflective (i.e., rumination) and anticipatory (i.e., worry) negative thinking about personally relevant stressors, may reflect the functional mechanism linking discrimination to sleep. The present study is the first to empirically examine the dual components of PC as a candidate functional mechanism in the association between racial discrimination and subjective sleep quality. PARTICIPANTS: Sixty-eight self-identified African American college students (55.9% female; Mage = 20.18, SD = 2.93) were recruited at a large predominantly white public university in the Midwest. METHODS: The participants completed the Perceived Ethnic Discrimination Questionnaire (PEDQ), Pittsburgh Sleep Quality Index (PSQI), Penn State Worry Questionnaire (PSWQ), and Ruminative Responses Scale (RRS). RESULTS: After adjusting for age, gender, and social class, results revealed a significant indirect effect of racial discrimination (RD) on subjective sleep quality through rumination, 95% CI [.008, .125], but not worry. RD was positively associated with rumination, b =.50, SE =.16, p = .003, and rumination, in turn, was positively associated with poorer sleep quality, b = .09, SE = .04, p = .012. CONCLUSIONS: As both RD and poor sleep quality have been directly linked to heart disease, diabetes, depression, and a number of other maladies, our findings suggest that RD, sleep, and coping strategies (e.g., rumination) employed to manage RD experiences may be important targets for addressing racial disparities in health.

Blood pressure reactivity to psychological stress is associated with clinical outcomes in patients with heart failure.

INTRODUCTION: Cardiovascular (CV) reactivity to psychological stress has been implicated in the development and exacerbation of cardiovascular disease (CVD). Although high CV reactivity traditionally is thought to convey greater risk of CVD, the relationship between reactivity and clinical outcomes is inconsistent and may depend on the patient population under investigation. The present study examined CV reactivity in patients with heart failure (HF) and its potential association with long-term clinical outcomes. METHODS: One hundred ninety-nine outpatients diagnosed with HF, with ejection fraction ≤40%, underwent an evaluation of blood pressure (BP) and heart rate reactivity to a laboratory-based simulated public-speaking stressor. Cox proportional hazards regression models were used to examine the prospective association between BP and heart rate reactivity on a combined end point of death or CV hospitalization over a 5-year median follow-up period. RESULTS: Both systolic blood pressure (SBP) and diastolic blood pressure (DBP) reactivity, quantified as continuous variables, were inversely related to risk of death or CV hospitalization (Ps < .01) after controlling for established risk factors, including HF disease severity and etiology. In similar models, heart rate reactivity was unrelated to outcome (P = .12). In models with tertiles of reactivity, high SBP reactivity, compared with intermediate SBP reactivity, was associated with lower risk (hazard ratio [HR] = .498, 95% CI .335-.742, P =.001), whereas low SBP reactivity did not differ from intermediate reactivity. For DBP, high reactivity was marginally associated with lower risk compared with intermediate DBP reactivity (HR = .767, 95% CI .515-1.14, P =.193), whereas low DBP reactivity was associated with greater risk (HR = 1.49, 95% CI 1.027-2.155, P =.0359). No relationship of heart rate reactivity to outcome was identified. CONCLUSIONS: For HF patients with reduced ejection fraction, a robust increase in BP evoked by a laboratory-based psychological challenge was associated with lower risk for adverse CVD events and may be a novel and unique marker of left ventricular systolic reserve that is accompanied by a more favorable long-term prognosis.

Racial differences in the association between heart rate variability and left ventricular mass.

NEW FINDINGS: What is the central question of this study? Decreased heart rate variability (HRV) is associated with increased cardiovascular disease (CVD) risk, including greater left ventricular mass (LVM). Despite their enhanced CVD risk profile, African Americans have been shown to exhibit higher HRV, relative to Whites; however, it is unclear whether this pattern extends to the association between HRV and LVM. What is the main finding and its importance? Using ECG and echocardiographic data, HRV was positively associated with LVM in a non-clinical sample of African Americans. These findings suggest that current assumptions regarding the meaning of higher HRV might not be universal, which might have implications for HRV as a risk marker among African Americans. Increased left ventricular mass (LVM) is an early precursor of target organ damage attributable to hypertension. Diminished parasympathetic cardiac control has been linked to both hypertension onset and left ventricular impairment; however, emerging evidence suggests that this pattern might be different in African Americans. The present study sought to determine whether race impacts the relationship between parasympathetic cardiac control and LVM. The LVM was assessed via echocardiography in a sample (n = 148) of African American and White adults (mean age 33.20 ± 5.71 years) with normal or mildly elevated blood pressure. Parasympathetic cardiac control was assessed by a measure of high-frequency heart rate variability (HF-HRV) determined from ECG recordings during 5 min of rest. In regression analysis, greater HF-HRV was associated with greater LVM among African Americans (P = 0.002) but was not related to LVM in Whites (P = 0.919). These are the first data to demonstrate that race moderates the relationship between HRV and LVM and further suggest that race might be an important factor in the association between parasympathetic cardiac control and other cardiovascular disease risk factors.

Examining the association between perceived discrimination and heart rate variability in African Americans.

OBJECTIVE: Previous research attempting to delineate the role of discrimination in racial/ethnic disparities in hypertension has focused largely on blood pressure, which is chiefly governed by the sympathetic branch of the autonomic nervous system. Consequently, few studies have considered the role of the parasympathetic branch and particularly its regulation of the heart via the vagus nerve. METHOD: In the present cross-sectional study, we employed hierarchical linear regressions to examine associations between perceived ethnic discrimination and resting heart rate variability (HRV), an important biomarker of parasympathetic cardiac modulation and overall health, in a sample (N = 103) of young, healthy African American participants (58% female, Mage = 19.94 years, SD = 2.84). RESULTS: After accounting for demographic factors and health status characteristics, lifetime discrimination emerged as an inverse predictor of HRV. When subdomains of discrimination were considered, discrimination attributable to threats or actual acts of aggression was also predictive of lower HRV. CONCLUSIONS: Our findings suggest that a greater lifetime burden of discrimination and discriminatory harassment and/or assault is associated with lower resting HRV in African Americans. The implications of these findings are discussed in the context of past, present and emerging research emphasizing biological linkages between discrimination and health. (PsycINFO Database Record

Ethnic differences in resting heart rate variability: a systematic review and meta-analysis.

BACKGROUND: Ethnic disparities in cardiovascular morbidity and mortality are widely documented in the literature. Recently, research has shown that decreased parasympathetic cardiac modulation is associated with the established and emerging risk factors for cardiovascular disease (CVD) and stroke. In consideration of the disproportionate CVD risk and disease profile of African Americans (AAs), it is plausible that decreased cardiac parasympathetic functioning may partially explain these disparities. In the present systematic review and meta-analysis, we assess the available evidence for a reliable ethnic difference in tonic vagally mediated heart rate variability (HRV), an indicator of parasympathetic cardiac modulation. METHODS: A systematic literature search was conducted yielding studies comparing tonic HRV in AAs and European Americans. Adjusted standardized effect sizes (Hedges g) were calculated using a mixed-effects model, with restricted maximum likelihood estimation for 17 studies containing appropriate measures of vagally mediated HRV. RESULTS: Meta-analysis results suggest that AAs have greater HRV than do European Americans (Hedges g = 0.93, 95% confidence interval = 0.25-1.62), even after consideration of several covariates including health status, medication use, and subgroup stratification by sex and age. CONCLUSIONS: These findings suggest that decreased vagally mediated HRV is not likely to account for the persistent health disparities experienced by AAs with respect to CVD risk and burden. These disparities underscore the need for continued research addressing socioethnic cardiovascular differences and the biobehavioral mechanisms involved.

Perceived Control Predicts Pulse Pressure in African American Men: The Baltimore Study of Black Aging.

OBJECTIVE: Poorer health profiles among African American men throughout the life course evince greater rates of cardiovascular disease (CVD) and significantly earlier mortality compared with other groups. Despite growing emphasis on identifying how psychosocial factors influence disparate disease risk, little of this research has focused intently on African American men. METHODOLOGY: Using hierarchical linear regression, we explored the additive influence of stress, depression, and perceived control on pulse pressure, an established marker of CVD risk, in a sample (N = 153) of African American men (mean age = 66.73 ± 9.29) from the Baltimore Study of Black Aging (BSBA). RESULTS: After accounting for age and health status indicators, perceived control emerged as a significant predictor of pulse pressure. DISCUSSION: These findings suggest that greater belief in one's own efficacy is a protective factor for cardiovascular health among African American men. Future research should examine whether enhancing perceived control can have an appreciable impact on the immense CVD burden in this and other at-risk populations.

Racial differences in baroreflex function: Implications for the cardiovascular conundrum.

Study objective: African Americans (AAs) show early signs of vascular dysfunction paired with elevated blood pressure (BP) and total peripheral resistance (TPR), which is thought to underlie their increased rates of cardiovascular health complications relative to European Americans (EAs). AAs paradoxically have higher cardiac vagal tone, indexed by heart rate variability (HRV), which is cardio-protective. This paradox has been termed the Cardiovascular Conundrum. The physiological mechanism underlying this phenomenon is not well understood. We examined race differences in baroreflex function, which might be an important mechanism underlying the Cardiovascular Conundrum. Design: Participants completed a 5-minute baseline period where resting cardiac metrics were assessed. Setting: Laboratory. Participants: 130 college-aged individuals (54 women, 57 AAs). Main outcome measures: Baroreflex function was indexed as baroreflex sensitivity (BRS; the magnitude of changes in cardiovascular activity in accordance with BP changes) and effectiveness (BEI; the ratio of BP changes that elicit changes in cardiovascular activity) in the cardiac, vascular, and myocardial limbs. Results and conclusions: Results showed AAs to have higher HRV and cardiac BRS in comparison to EAs, suggesting the baroreflex is more sensitive to correcting the heart period for changes in BP among AAs compared to EAs. However, AAs showed lower vascular BEI relative to EAs, suggesting less effective control of TPR. In sum, lower BEI in the vascular branch might be an important mechanism underlying the Cardiovascular Conundrum (i.e., higher HRV and BP) and by extension, health disparities in cardiovascular diseases between AAs and EAs.

Multi-ethnic variation in the ties that bind rumination and heart rate variability: Implications for health disparities.

Higher self-reported rumination, a common form of trait perseverative cognition, is linked with lower resting heart rate variability (HRV), which indicates poorer cardiac function and greater disease risk. A meta-analysis and systematic review indicated that in samples with fewer European Americans, the association of rumination with both heart rate and blood pressure was stronger. Thus, trait rumination may be more strongly associated with resting HRV among ethnically minoritized populations. The current study investigated whether differences in the association of self-reported rumination with resting HRV varied by ethnicity in a sample (N = 513; Mage  = 19.41; 226 Women) of self-identified African Americans (n = 110), Asian Americans (n = 84), and European Americans (n = 319). Participants completed a five-minute baseline period to assess resting HRV, followed by the Ruminative Responses Scale, which contains three facets of rumination including brooding, depressive, and reflective rumination. On average, Asian Americans reported higher levels of rumination relative to European Americans. African Americans had higher resting HRV than Asian Americans. Adjusting for covariates, higher self-reported rumination was significantly associated with lower resting HRV in both African and Asian Americans, but not significantly so in European Americans. This finding was consistent for brooding and reflective, but not depressive rumination. Overall, this study lends insight into a psychological mechanism-rumination-that may impact health disparities among ethnically minoritized individuals, contributing to an understanding of how stress gets under the skin among such minoritized populations.