Browsing by Author "Brummett, Beverly H"

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    A functional polymorphism in the 5HTR2C gene associated with stress responses also predicts incident cardiovascular events.
    (PLoS One, 2013) Brummett, Beverly H; Babyak, Michael A; Jiang, Rong; Shah, Svati H; Becker, Richard C; Haynes, Carol; Chryst-Ladd, Megan; Craig, Damian M; Hauser, Elizabeth R; Siegler, Ilene C; Kuhn, Cynthia M; Singh, Abanish; Williams, Redford B
    Previously we have shown that a functional nonsynonymous single nucleotide polymorphism (rs6318) of the 5HTR2C gene located on the X-chromosome is associated with hypothalamic-pituitary-adrenal axis response to a stress recall task, and with endophenotypes associated with cardiovascular disease (CVD). These findings suggest that individuals carrying the rs6318 Ser23 C allele will be at higher risk for CVD compared to Cys23 G allele carriers. The present study examined allelic variation in rs6318 as a predictor of coronary artery disease (CAD) severity and a composite endpoint of all-cause mortality or myocardial infarction (MI) among Caucasian participants consecutively recruited through the cardiac catheterization laboratory at Duke University Hospital (Durham, NC) as part of the CATHGEN biorepository. Study population consisted of 6,126 Caucasian participants (4,036 [65.9%] males and 2,090 [34.1%] females). A total of 1,769 events occurred (1,544 deaths and 225 MIs; median follow-up time = 5.3 years, interquartile range = 3.3-8.2). Unadjusted Cox time-to-event regression models showed, compared to Cys23 G carriers, males hemizygous for Ser23 C and females homozygous for Ser23C were at increased risk for the composite endpoint of all-cause death or MI: Hazard Ratio (HR) = 1.47, 95% confidence interval (CI) = 1.17, 1.84, p = .0008. Adjusting for age, rs6318 genotype was not related to body mass index, diabetes, hypertension, dyslipidemia, smoking history, number of diseased coronary arteries, or left ventricular ejection fraction in either males or females. After adjustment for these covariates the estimate for the two Ser23 C groups was modestly attenuated, but remained statistically significant: HR = 1.38, 95% CI = 1.10, 1.73, p = .005. These findings suggest that this functional polymorphism of the 5HTR2C gene is associated with increased risk for CVD mortality and morbidity, but this association is apparently not explained by the association of rs6318 with traditional risk factors or conventional markers of atherosclerotic disease.
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    A putatively functional polymorphism in the HTR2C gene is associated with depressive symptoms in white females reporting significant life stress.
    (PloS one, 2014-01) Brummett, Beverly H; Babyak, Michael A; Williams, Redford B; Harris, Kathleen Mullan; Jiang, Rong; Kraus, William E; Singh, Abanish; Costa, Paul T; Georgiades, Anastasia; Siegler, Ilene C
    Psychosocial stress is well known to be positively associated with subsequent depressive symptoms. Cortisol response to stress may be one of a number of biological mechanisms that links psychological stress to depressive symptoms, although the precise causal pathway remains unclear. Activity of the x-linked serotonin 5-HTR2C receptor has also been shown to be associated with depression and with clinical response to antidepressant medications. We recently demonstrated that variation in a single nucleotide polymorphism on the HTR2C gene, rs6318 (Ser23Cys), is associated with different cortisol release and short-term changes in affect in response to a series of stress tasks in the laboratory. Based on this observation, we decided to examine whether rs6318 might moderate the association between psychosocial stress and subsequent depressive symptoms. In the present study we use cross-sectional data from a large population-based sample of young adult White men (N = 2,366) and White women (N = 2,712) in the United States to test this moderation hypothesis. Specifically, we hypothesized that the association between self-reported stressful life events and depressive symptoms would be stronger among homozygous Ser23 C females and hemizygous Ser23 C males than among Cys23 G carriers. In separate within-sex analyses a genotype-by-life stress interaction was observed for women (p = .022) but not for men (p = .471). Homozygous Ser23 C women who reported high levels of life stress had depressive symptom scores that were about 0.3 standard deviations higher than female Cys23 G carriers with similarly high stress levels. In contrast, no appreciable difference in depressive symptoms was observed between genotypes at lower levels of stress. Our findings support prior work that suggests a functional SNP on the HTR2C gene may confer an increased risk for depressive symptoms in White women with a history of significant life stress.
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    Evaluating the precision of EBF1 SNP x stress interaction association: sex, race, and age differences in a big harmonized data set of 28,026 participants.
    (Translational psychiatry, 2020-10-20) Singh, Abanish; Babyak, Michael A; Sims, Mario; Musani, Solomon K; Brummett, Beverly H; Jiang, Rong; Kraus, William E; Shah, Svati H; Siegler, Ilene C; Hauser, Elizabeth R; Williams, Redford B
    In prior work, we identified a novel gene-by-stress association of EBF1's common variation (SNP rs4704963) with obesity (i.e., hip, waist) in Whites, which was further strengthened through multiple replications using our synthetic stress measure. We now extend this prior work in a precision medicine framework to find the risk group using harmonized data from 28,026 participants by evaluating the following: (a) EBF1 SNPxSTRESS interaction in Blacks; (b) 3-way interaction of EBF1 SNPxSTRESS with sex, race, and age; and (c) a race and sex-specific path linking EBF1 and stress to obesity to fasting glucose to the development of cardiometabolic disease risk. Our findings provided additional confirmation that genetic variation in EBF1 may contribute to stress-induced human obesity, including in Blacks (P = 0.022) that mainly resulted from race-specific stress due to "racism/discrimination" (P = 0.036) and "not meeting basic needs" (P = 0.053). The EBF1 gene-by-stress interaction differed significantly (P = 1.01e-03) depending on the sex of participants in Whites. Race and age also showed tentative associations (Ps = 0.103, 0.093, respectively) with this interaction. There was a significant and substantially larger path linking EBF1 and stress to obesity to fasting glucose to type 2 diabetes for the EBF1 minor allele group (coefficient = 0.28, P = 0.009, 95% CI = 0.07-0.49) compared with the same path for the EBF1 major allele homozygotes in White females and also a similar pattern of the path in Black females. Underscoring the race-specific key life-stress indicators (e.g., racism/discrimination) and also the utility of our synthetic stress, we identified the potential risk group of EBF1 and stress-induced human obesity and cardiometabolic disease.
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    Gene by stress genome-wide interaction analysis and path analysis identify EBF1 as a cardiovascular and metabolic risk gene.
    (European journal of human genetics : EJHG, 2015-06) Singh, Abanish; Babyak, Michael A; Nolan, Daniel K; Brummett, Beverly H; Jiang, Rong; Siegler, Ilene C; Kraus, William E; Shah, Svati H; Williams, Redford B; Hauser, Elizabeth R
    We performed gene-environment interaction genome-wide association analysis (G × E GWAS) to identify SNPs whose effects on metabolic traits are modified by chronic psychosocial stress in the Multi-Ethnic Study of Atherosclerosis (MESA). In Whites, the G × E GWAS for hip circumference identified five SNPs within the Early B-cell Factor 1 (EBF1) gene, all of which were in strong linkage disequilibrium. The gene-by-stress interaction (SNP × STRESS) term P-values were genome-wide significant (Ps = 7.14E-09 to 2.33E-08, uncorrected; Ps = 1.99E-07 to 5.18E-07, corrected for genomic control). The SNP-only (without interaction) model P-values (Ps = 0.011-0.022) were not significant at the conventional genome-wide significance level. Further analysis of related phenotypes identified gene-by-stress interaction effects for waist circumference, body mass index (BMI), fasting glucose, type II diabetes status, and common carotid intimal-medial thickness (CCIMT), supporting a proposed model of gene-by-stress interaction that connects cardiovascular disease (CVD) risk factor endophenotypes such as central obesity and increased blood glucose or diabetes to CVD itself. Structural equation path analysis suggested that the path from chronic psychosocial stress to CCIMT via hip circumference and fasting glucose was larger (estimate = 0.26, P = 0.033, 95% CI = 0.02-0.49) in the EBF1 rs4704963 CT/CC genotypes group than the same path in the TT group (estimate = 0.004, P = 0.34, 95% CI = -0.004-0.012). We replicated the association of the EBF1 SNPs and hip circumference in the Framingham Offspring Cohort (gene-by-stress term P-values = 0.007-0.012) as well as identified similar path relationships. This observed and replicated interaction between psychosocial stress and variation in the EBF1 gene may provide a biological hypothesis for the complex relationship between psychosocial stress, central obesity, diabetes, and cardiovascular disease.
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    Lack of Association of a Functional Polymorphism in the Serotonin Receptor Gene With Body Mass Index and Depressive Symptoms in a Large Meta-Analysis of Population Based Studies.
    (Frontiers in genetics, 2018-01) Brummett, Beverly H; Babyak, Michael A; Singh, Abanish; Hauser, Elizabeth R; Jiang, Rong; Huffman, Kim M; Kraus, William E; Shah, Svati H; Siegler, Ilene C; Williams, Redford B
    The serotonin receptor 5-HTR2C is thought to be involved in the function of multiple brain structures. Consequently, the HTR2C gene has been studied extensively with respect to its association with a variety of phenotypes. One coding variant in the HTR2C gene, Cys23Ser (rs6318), has been associated with depressive symptoms. and adiposity; however, these findings have been inconsistent. The reasons for this mixed picture may be due to low statistical power or due to other factors such as failure to account for possible interacting environmental factors, such as psychosocial stress. Further, the literature around this polymorphism is marked by limited inclusion of persons of African ancestry. The present study sought to overcome these limitations and definitively determine the relationship of this polymorphism with depressive and obesity phenotypes in a large sample meta-analysis. Thus, we harmonized individual level data from 10 studies including the Women's Health Initiative, CARDIA, ARIC, Framingham Offspring, and the Jackson Heart Study, resulting in a sample of 27,161 individuals (10,457 Black women, 2,819 Black men, 7,419 White women, and 6,466 White men). We conducted a random effects meta-analysis using individual level data to examine whether the Cys23Ser variant-either directly, or conditionally depending on the level of psychosocial stress-was associated with depressive symptoms and body mass index (BMI). We found that psychosocial stress was associated with both depression and BMI, but that Cys23Ser was not directly associated with, nor did it modify the associations of psychosocial stress with depression or BMI. Thus, in the largest study of this polymorphism, we have determined that rs6318 is not associated with depression, or BMI.
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    Relationship Between Psychosocial Stress and Blood Pressure: The National Heart, Lung, and Blood Institute Family Heart Study.
    (SAGE open nursing, 2022-01) Nwanaji-Enwerem, Uzoji; Onsomu, Elijah O; Roberts, Dionne; Singh, Abanish; Brummett, Beverly H; Williams, Redford B; Dungan, Jennifer R

    Introduction

    Various domains of psychosocial stress have been significantly related to blood pressure. However, ambiguity is present in how these relationships are defined in the literature.

    Objective

    To add to the existing literature and examine the relationship between psychosocial stress (financial strain and job strain) and other cofactors on blood pressure.

    Methods

    This secondary analysis is designed to analyze the relationship between levels of job and financial stress and blood pressure outcomes among participants in the National Heart, Lung, and Blood Institute (NHLBI) Family Heart Study 2004-2008. The descriptive, cross-sectional design uses data from a subset of study participants, 350 White and 195 Black (n = 545), 338 female (62%), and all aged 18-56 years. Psychosocial stress was measured using the Singh Stress Scale. Resting systolic (SBP) and diastolic (DBP) blood pressure values obtained on a stress reactivity protocol day in the primary study, as well as calculated mean arterial pressure (MAP) were used for this analysis. Multivariate linear regression analyses were used to explore the relationship between psychosocial stress and blood pressure.

    Results

    In this young cohort, self-report of either financial strain or job strain was associated with lower blood pressure levels than those of participants who reported neither stressor. Differential sex and race effects appear to contribute to these results. Blood pressure levels were not significantly associated with self-report of both stressors.

    Conclusion

    Understanding the effects of various forms of stress on blood pressure may inform more precise HTN risk-factor screening and interventions to improve BP management.
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    Systolic Blood Pressure and Socioeconomic Status in a large multi-study population.
    (SSM - population health, 2019-12) Brummett, Beverly H; Babyak, Michael A; Jiang, Rong; Huffman, Kim M; Kraus, William E; Singh, Abanish; Hauser, Elizabeth R; Siegler, Ilene C; Williams, Redford B
    The present study used harmonized data from eight studies (N = 28,891) to examine the association between socioeconomic status (SES) and resting systolic blood pressure (SBP). The study replicates and extends our prior work on this topic by examining potential moderation of this association by race and gender. We also examined the extent to which body mass index (BMI), waist circumference (WC), and smoking might explain the association between SES and SBP. Data were available from six race/gender groups: 9200 Black women; 2337 Black men; 7248 White women; 6519 White men; 2950 Hispanic women; and 637 Hispanic men. Multivariable regression models showed that greater annual household income was associated with lower SBP in all groups except Hispanic men. The magnitude and form of this negative association differed across groups, with White women showing the strongest linear negative association. Among Black men and Hispanic women, the association was curvilinear: relatively flat among lower income levels, but then negative among higher income ranges. Education also was independently, negatively related to SBP, though evidence was weaker for race and gender differences in the strength of the association. Higher BMI and WC were associated with higher SBP, and current smoking with lower SBP. Inclusion of these risk factors resulted in only a modest change in the magnitude of the SBP and SES relation, accounting on average about 0.4 mmHg of the effect of income and 0.2 mmHg of the effect of education-effects unlikely to be clinically significant. Further understanding of mechanisms underlying the association between SBP and SES may improve risk stratification in clinical settings and potentially inform interventions aimed at reductions in social disparities in health.