Publications by authors named "John C Barefoot"

After the publication of the original article, the Editor was notified by Duke University that they have determined the authorship to be incomplete. Consequently, Dr Edward Suarez has been added as a co-author to represent his contribution to the conception and design of the work and acquisition of the data.

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Objective: Central nervous system (CNS) serotonin (5-HT) exerts both excitatory and inhibitory effects on the sympathetic nervous system (SNS) in animals. In this study, we examine the effects of tryptophan enhancement and depletion on plasma catecholamine levels in humans.

Methods: The total sample consisted of 164 healthy men and women who were tested for 2 days.

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Chronic psychosocial stress adversely affects health and is associated with the development of disease [Williams, 2008]. Systematic epidemiological and genetic studies are needed to uncover genetic variants that interact with stress to modify metabolic responses across the life cycle that are the proximal contributors to the development of cardiovascular disease and precipitation of acute clinical events. Among the central challenges in the field are to perform and replicate gene-by-environment (G × E) studies.

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Background: Previous research has shown an association between hostility and fasting glucose in African American women. Central nervous system serotonin activity is implicated both in metabolic processes and in hostility related traits.

Purpose: The purpose of this study is to determine whether central nervous system serotonin influences the association between hostility and fasting glucose in African American women.

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Certain personality traits are likely to be associated with stress and distress through the lifespan, and as a consequence these traits may influence the rate of age-related cognitive decline. The present study uses data from the Glostrup 1914 cohort to analyze potential effects of personality on decline in general intelligence over a 30-year period. The Minnesota Multiphasic Personality Inventory was administered at a 50-year baseline exam, and from this inventory the Obvious Depression Scale and an abbreviated version of the Cook-Medley Hostility Scale were derived.

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Background: Expectations of patients regarding their prospects for recovery have been shown to predict subsequent physical and social functioning. Evidence regarding the impact of expectations on clinical outcomes is limited.

Methods: At the inpatient service of a tertiary care hospital, we evaluated beliefs of patients undergoing coronary angiography about their prognosis as predictors of long-term survival and 1-year functional status.

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Objective: To use measures of cerebrospinal fluid (CSF) 5-hydroxyindoleacetic acid (5HIAA) and genotype of a functional polymorphism of the monoamine oxidase A gene promoter (MAOA-uVNTR) to study the role of central nervous system (CNS) serotonin in clustering of hostility, other psychosocial, metabolic and cardiovascular endophenotypes.

Methods: In 86 healthy male volunteers, we evaluated CSF levels of the primary serotonin metabolite 5HIAA and MAOA-uVNTR genotype for association with a panel of 29 variables assessing hostility, other psychosocial, metabolic, and cardiovascular endophenotypes.

Results: The correlations of 5HIAA with these endophenotypes in men with more active MAOA-uVNTR alleles were significantly different from those of men with less active alleles for 15 of the 29 endophenotypes.

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Posttraumatic stress disorder (PTSD) can be a complex disorder, and some studies have found that samples of individuals with PTSD contain subtypes that may relate to health outcomes. The goals were to replicate previously identified PTSD subtypes and examine how subtype membership relates to mortality. Data from the Vietnam Experience Study and a clinical sample of Vietnam veterans were combined (n = 5248) to address these research questions.

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Background: Low socioeconomic status (SES) is associated with poor health. One potential pathway accounting for this relationship may be an association between low SES and personality characteristics that affect health.

Methods: Associations among parent's education, current SES (education and income), and personality were examined among 233 African Americans and Caucasian, male and female community volunteers.

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Objective: To examine whether the relationship of hostility (HOST) to fasting glucose indices is moderated by sex and race. HOST has been associated with abnormalities in glucose metabolism. Prior studies suggested that this association may be more prevalent in women and in African American (AA) individuals.

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The current study examines lifetime trauma exposure rates in 148 women with posttraumatic stress disorder (PTSD), major depressive disorder (MDD), or neither diagnosis and whether this is related to measures of PTSD, depression, hostility, health symptoms, and health care utilization. Findings indicate that multiple trauma exposures were prevalent in this sample, with 96% of those with PTSD and 79% of those with MDD reporting three or more trauma exposures compared to 46% in the comparison group. Controlling for diagnostic status, regression analysis for PTSD symptom severity reveals that the trauma exposure adult physical assault category was significantly associated with more severe PTSD and depressive symptoms, whereas the childhood violence category was most associated with increased hostility.

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Objective: To test the hypothesis that low socioeconomic status (SES) and the 5HTTLPR L allele are associated with increased cardiovascular reactivity (CVR) to stress in a larger sample and that SES and 5HTTLPR genotypes interact to enhance CVR to stress. CVR to mental stress has been proposed as one mechanism linking stress to the pathogenesis of cardiovascular disease. The more transcriptionally efficient long (L) allele of a polymorphism of the serotonin transporter gene promoter (5HTTLPR) has been found associated with increased risk of myocardial infarction.

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Aims: This study examined the association of hostility to drinking pattern and whether this association mediated the relation of hostility to mortality.

Participants And Design: Subjects were 3326 current drinkers from the Vietnam Experience Study cohort who were followed for vital status.

Setting: United States.

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Objective: To test the hypothesis that allelic variation in 5HTT gene-linked polymorphic region (5-HTTLPR) genotype was associated with sleep quality (Pittsburgh Sleep Quality Index, PSQI) as a main effect and as moderated by the chronic stress of caregiving. Serotonin (5HT) is involved in sleep regulation and the 5HT transporter (5HTT) regulates 5HT function. A common 44-base pair deletion (s allele) polymorphism in the 5-HTTLPR is associated with reduced 5HTT transcription efficiency and 5HT uptake in vitro.

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Objective: This study examined the associations of depressive symptoms with glucose concentrations and morning cortisol levels in 665 African-American and 4,216 Caucasian Vietnam-era veterans.

Research Design And Methods: Glucose level was measured as a three-level variable (diabetes, impaired glucose, and normal). Depressive symptoms were measured by the Obvious Depression Scale (OBD) from the Minnesota Multiphasic Personality Inventory.

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Objective: To examine the relationships among the variable number of tandem repeats in the monoamine oxidase-A linked polymorphic region allelic variation (MAOA-uVNTR) and the symptoms of depression and sleep quality. The monoamine oxidase-A (MAOA) gene, which plays a vital role in degradation of neurotransmitters such as serotonin, norepinephrine, and dopamine, contains a polymorphism in its promoter region (MAOA-uVNTR) that affects transcriptional efficiency. MAOA-uVNTR genotype has been associated with both psychological and physical measures.

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Objective: To examine the NEO Personality Inventory (NEO PI) Openness to Experience (O) domain and its facets as predictors of cardiac deaths and all-cause mortality.

Methods: The NEO PI was administered to a sample of 977 coronary catheterization patients with significant coronary artery disease. Over an average 15-year follow-up period, 266 cardiac deaths and 463 total deaths occurred.

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The role of information search in the attribution of physiological states was investigated by manipulating the subject's opportunity for information search following the presentation of false information about his heart-rate reactions to photographs of female nudes. Consistent with the self-persuasion hypothesis proposed by Valins, the rated attractiveness of the slides was not affected by the false heart-rate feedback for those subjects who were prevented from visually searching the slides. Those subjects who had ample opportunity to view the slides rated those slides accompanied by false information of a heart-rate change as more attractive than those slides which were not paired with a change in heart rate.

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Objective: A strong positive cross-sectional relationship between BMI and a sedentary lifestyle has been consistently observed in numerous studies. However, it has been questioned whether high BMI is a determinant or a consequence of a sedentary lifestyle.

Research Methods And Procedures: Using data from four follow-ups of the University of North Carolina Alumni Heart Study, we examined the prospective associations between BMI and sedentary lifestyle in a cohort of 4595 middle-aged men and women who had responded to questionnaires at the ages of 41 (standard deviation 2.

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Objective: Adverse neighborhood environments and caregiving for a relative with dementia are both stressors that have been associated with poor health. The present study examined the extent to which three self-report measures of neighborhood characteristics interact with caregiving status (caregiver versus noncaregiver) to modify an important stress related health outcome: plasma glucose.

Methods: The study sample consisted of 147 community recruited caregivers and 147 participants who did not have caregiving responsibilities.

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This study examined hostility as a predictor of survival in a sample of 1,328 patients who had documented coronary artery disease. After controlling for disease severity, there was a significant interaction between age and hostility. Hostility was significantly associated with poorer survival but only in younger (<61.

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Measures of various types of social contacts were used as predictors of ischemic heart disease events and total mortality in an age-stratified random sample of 9,573 adults enrolled in the Copenhagen City Heart Study (Copenhagen, Denmark). Baseline examinations were conducted in 1991-1994, and participants were followed until the end of 1997. Contacts with parents, children, family members, and friends were associated with better health.

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Background: An extensive body of research has demonstrated an association between negative affective states and health outcomes. Positive emotions may also influence physical health, however, their examination has received far less attention.

Methods: Positive and depressive emotion ratings were examined as independent and joint predictors of survival in a sample of 866 cardiac catheterization patients.

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Objective: Numerous studies have shown network assessments of social contact predict mortality in patients with coronary artery disease (CAD). Fewer studies have demonstrated an association between perceived social support and longevity in patient samples. It has been suggested that 1 of the mechanisms linking social support with elevated risk for mortality is the association between social support and other risk factors associated with decreased longevity such as smoking, failure to exercise, and depressive symptoms.

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