Biobehavioral basis of coronary-prone behavior in middle-age men. Part II: Serum cholesterol, the Type A behavior pattern, and hostility as interactive modulators of physiological reactivity

Parasympathetic Response Patterns are Associated with Metabolic Syndrome Among Older Women but Not Men

Background

Little is known about the role of physiological stress responses in metabolic syndrome (MetS).

Purpose

To examine whether patterns of autonomic response to psychological stress are associated with MetS and whether this association is moderated by sex

Methods

1121 men and women (M_age = 65.3 ± 6.77 years) with and without coronary artery disease (CAD) underwent an anger recall stressor task. Heart rate and heart-rate variability (HRV; HF, LF/HF) were assessed. Clusters of participants showing similar patterns of response across baseline, stress, and recovery periods were created using ACECLUS and FASTCLUS in SAS. Logistic regressions included clusters and interaction between clusters and sex as independent variables, controlling for relevant covariates. ANCOVAs were conducted in secondary analyses utilizing a continuous composite representation of MetS.

Results

Men and women showing greater tonic and phasic HR elevations were more likely to meet MetS criteria (OR = 1.45, [95% CI = 1.02–2.07], p = .037). HF-HRV cluster interacted significantly with sex (p < .001) to predict MetS. In women, those with significant parasympathetic withdrawal to stress and poor recovery were more likely to have MetS than women with a more moderate response (OR = 2.56, [95% CI = 1.23–5.41], p = .013). Women who displayed stress-related parasympathetic activation were also at greater risk of MetS (OR = 2.30, [95% CI = 1.30–4.07], p = .004). Results using a continuous measure of MetS were generally consistent with these findings.

Conclusion

Among older participants with CAD or other noncardiovascular disease, hyperreactivity to stress was associated with greater prevalence of MetS, particularly in women. Consistent with emerging literature, women who showed blunting or activation of parasympathetic responses to stress were similarly at greater risk.

Sympathetic arousal to a vestibular stressor in high and low hostile men

The aim of the present experiment was to extend the literature on hostility and a cerebral systems based model of sympathetic arousal to a vestibular-based stress. Several authors have concluded that autonomic stress reactivity in high hostile individuals must be interpersonally based, whereas healthy vestibular system functioning does not depend on interpersonal features. Utilizing a vestibular activation paradigm, skin conductance levels of 15 high hostile and 15 low hostile men were recorded after brief passive rotation about the vertical neuroaxis. It was expected that hostile individuals would exhibit higher skin conductance levels after rotation compared with low hostile individuals. The results confirmed expectations of heightened sympathetic tone among high hostiles subsequent to vestibular stress. Overall, the findings are interpreted to support a cerebral model of frontal region capacity limitation for regulation of vestibular stress that is independent of psychosocial mechanisms.

Physiological and cognitive effects of expressive dissonance

Emotional well-being depends in part on affect modulation. The present study extends research on emotion regulation by assessing the physiological and cognitive effects of a novel response-focused regulation strategy, termed 'expressive dissonance.' Expressive dissonance refers to the incongruence between an emotional state (e.g., sadness) and a behavioral expression (e.g., a smile). Fifty-five participants watched a series of sad film clips in which they were asked to either naturally watch or express the opposite of what they were feeling. Results suggest that persons using the expressive dissonant strategies evidenced greater sympathetic arousal and performed worse on subsequent memory tasks than persons in the natural-watch conditions.

Combined effect of the metabolic syndrome and hostility on the incidence of myocardial infarction (the Normative Aging Study)

A growing body of evidence suggests that the metabolic syndrome and hostility are independent risk factors for the development of coronary heart disease. However, few studies have examined the combined effect of the metabolic syndrome and hostility on the incidence of myocardial infarction (MI). We examined prospectively the relation among the metabolic syndrome, hostility, and the incidence of MI in healthy, older men (mean +/- SD 59.7 +/- 7.2 years) who participated in the Normative Aging Study. Seven hundred fifty-four men who were diagnosed as not having coronary heart disease and diabetes mellitus were included in the present study. Men were assigned to 1 of 4 risk-factor groups based on the presence or absence of the metabolic syndrome and low or high hostility. Hierarchical logistic regression was used to assess the multivariate risk of developing a MI. The incidence of MI was 11.3% (n = 85) over an average follow-up period of 13.8 years. After adjusting for potential covariates, risk-factor group significantly predicted the incidence of MI (odds ratio 1.59, 95% confidence interval 1.29 to 1.96, p <0.0001). The effect was strongest among patients who had the metabolic syndrome and high levels of hostility, with this subgroup showing a fourfold increase in the odds of developing a MI (odds ratio 4.21, 95% confidence interval 2.21 to 8.04, p = 0.0001). In conclusion, it appears that hostility may provide additional prognostic information to the assessment of coronary heart disease risk in patients with the metabolic syndrome and should routinely be evaluated as part of a comprehensive risk factor assessment.

Acute stressors and cortisol responses: a theoretical integration and synthesis of laboratory research

This meta-analysis reviews 208 laboratory studies of acute psychological stressors and tests a theoretical model delineating conditions capable of eliciting cortisol responses. Psychological stressors increased cortisol levels; however, effects varied widely across tasks. Consistent with the theoretical model, motivated performance tasks elicited cortisol responses if they were uncontrollable or characterized by social-evaluative threat (task performance could be negatively judged by others), when methodological factors and other stressor characteristics were controlled for. Tasks containing both uncontrollable and social-evaluative elements were associated with the largest cortisol and adrenocorticotropin hormone changes and the longest times to recovery. These findings are consistent with the animal literature on the physiological effects of uncontrollable social threat and contradict the belief that cortisol is responsive to all types of stressors.

Mental disorders as possible intrapsychic routes to remission. Part I: delusional and psychotic disorders

It is hypothesized in this article that delusional and psychotic disorder may be a route to survive and finally to remission when completed successful. The intrapsychic mechanism, or navigation system, that outlines this route takes into account (a) the mental and emotional limitations and vulnerabilities of the patients, and (b) hopelessness of the situation. It was speculated that cognitive and emotional capacities and associated neurobiological dysfunctions that are necessarily linked to delusional/psychotic disorders could be brought about by this intrapsychic mechanism in order to create an escape route which avoids the unbearable reality. When the patient has completed this traject successfully and the circumstances are favourable, the intrapsychic navigation system might restore his or her relevant cognitive and emotional abilities and related neurobiological functions so that the patient is ready for healthy development and remission.

Stress, inflammation and cardiovascular disease

Various psychosocial factors have been implicated in the etiology and pathogenesis of certain cardiovascular diseases such as atherosclerosis, now considered to be the result of a chronic inflammatory process. In this article, we review the evidence that repeated episodes of acute psychological stress, or chronic psychologic stress, may induce a chronic inflammatory process culminating in atherosclerosis. These inflammatory events, caused by stress, may account for the approximately 40% of atherosclerotic patients with no other known risk factors. Stress, by activating the sympathetic nervous system, the hypothalamic-pituitary axis, and the renin-angiotensin system, causes the release of various stress hormones such as catecholamines, corticosteroids, glucagon, growth hormone, and renin, and elevated levels of homocysteine, which induce a heightened state of cardiovascular activity, injured endothelium, and induction of adhesion molecules on endothelial cells to which recruited inflammatory cells adhere and translocate to the arterial wall. An acute phase response (APR), similar to that associated with inflammation, is also engendered, which is characterized by macrophage activation, the production of cytokines, other inflammatory mediators, acute phase proteins (APPs), and mast cell activation, all of which promote the inflammatory process. Stress also induces an atherosclerotic lipid profile with oxidation of lipids and, if chronic, a hypercoagulable state that may result in arterial thromboses. Shedding of adhesion molecules and the appearance of cytokines, and APPs in the blood are early indicators of a stress-induced APR, may appear in the blood of asymptomatic people, and be predictors of future cardiovascular disease. The inflammatory response is contained within the stress response, which evolved later and is adaptive in that an animal may be better able to react to an organism introduced during combat. The argument is made that humans reacting to stressors, which are not life-threatening but are "perceived" as such, mount similar stress/inflammatory responses in the arteries, and which, if repetitive or chronic, may culminate in atherosclerosis.

Effects of antisocial or social attitudes on neurobiological functions

Antisocial personality disorder is characterized by triats like a failure to conform to social norms, impulsivity, hostility, irritability and aggressiveness, recklessness, irresponsibility, criminality, a lack of guilt or remorse, and deceitfulness. A large number of investigations revealed that there is evidence for a neurobiological underpinning of antisocial behavior. The precise nature and causal aspects of the relationship between neurobiological abnormalities and antisocial behavior is still unknown. There is, however, some evidence that some antisocial patients are able to influence their neurobiological functions, which are related to sensation seeking, aggressiveness, impulsivity, criminality and a lack of fear (associated with an inability to learn from experiences). The author hypothesizes that a reduction of antisocial behavior/attitude, may consequently result in normalization of neurobiological functions, which are linked to specific attitudes and behavioral dimensions.

Psychologic factors as precursors to hypertension

The possibility that certain psychologic factors lead to hypertension has been considered by many investigators over the past 60 years, but prospective studies with suitable methods to evaluate this hypothesis were not available for analysis until the 1990s. There are now five large longitudinal studies demonstrating a relation between symptoms of anxiety or depression and subsequent hypertension incidence. Anger expression, long considered a major psychologic factor in hypertension, has been studied less extensively, and the findings to date are less consistent. While some evidence supports the biological plausibility of psychologic factors as risk factors for hypertension, biobehavioral mechanisms explaining the relationship have not been adequately explored. The results of these recent studies may lead to new intervention trials specifically selecting hypertensive patients with anxiety or depression for treatment with stress reduction or other appropriate psychologic therapies. Such studies would further contribute to the evaluation of anxiety and depression as risk factors for hypertension.

Sense of coherence buffers relationships of chronic stress with fasting glucose levels

Sense of coherence (SOC) was examined as a buffer of the relationship of chronic stress with fasting glucose and insulin levels. Spouse caregivers of persons with diagnoses of Alzheimer's disease (AD) (n = 73) were compared to controls [spouses of nondemented persons (n = 69)], group-matched on age/gender. After controlling for anger and coronary heart disease (CHD), interactions of SOC and gender explained variance in glucose (but not insulin) at study entry (T1) and 15-18 months later (T2). However, this occurred only in caregivers. At both times SOC and glucose were negatively related in men caregivers but not in women caregivers or in controls. In caregivers (but not controls), SOC at T1 predicted glucose at T2, independent of gender, anger, and glucose at T1; and hassles at T1 appeared to mediate this relationship. Future research should examine SOC as a buffer of other chronic stressors and metabolic variables.

Fatty acid mixture counters stress changes in cortisol, cholesterol, and impair learning

A mixture of linoleic and alpha-linolenic acids (free non-esterified unsaturated fatty acids) administered for 3 weeks prior to injection of cortisol (10 mg/kg), or prior to immersion of rats in a 10 degree C saline bath, prevented elevation of blood levels of cortisol and cholesterol and deficits in Morris water maze spatial learning that usually accompany such stressful conditions. Differences from controls on all behavioural and biochemical measures were statistically significant (P < .05). It is proposed that induction of intense stress, and the associated increase in cortisol, cholesterol and other corticosteroids may damage hippocampal structures and help account for the cognitive decline witnessed in Alzheimer's disease and other age-related conditions. The modulation of these consequences by the fatty acid mixture may provide an alternative strategy for the study of stress markers and for the development of other intervention options in humans.

Influence of cholesterol and fasting insulin levels on blood pressure reactivity

OBJECTIVE

This study examined how cholesterol and fasting insulin levels are related to blood pressure reactivity to behavioral stressors.

METHODS

Subjects (N = 116) were 20 to 52 years old, at 80% to 150% of ideal weight, and had an average fasting cholesterol level of 183 mg/dl. Stressor tasks included mirror star tracing and a videotaped speech task. Changes from baseline were calculated for systolic and diastolic blood pressure.

RESULTS

Neither cholesterol nor insulin was independently related to blood pressure change scores. However, after controlling for body mass, a two-way analysis of variance revealed a significant cholesterol-by-insulin interaction for change in diastolic blood pressure (p = .022). Subjects in the high-cholesterol/high-insulin group showed the greatest increase in diastolic blood pressure reactivity.

CONCLUSIONS

In a general population, people with a below-average cholesterol level experience only moderate cardiovascular reactivity to mental stressors regardless of their fasting insulin level. However, for people with an above-average cholesterol level, fasting insulin level is an important factor in determining potential reactivity to mental stressors. These findings highlight the importance of adequate sample size to allow for the analysis of such interactions in future studies of cholesterol, insulin, and blood pressure reactivity.

Serum cholesterol, suicidal tendencies, impulsivity, aggression, and depression in adolescent psychiatric inpatients

BACKGROUND

This study was undertaken to examine the relationship between serum cholesterol levels and suicidal behaviors in adolescent psychiatric inpatients. Any association between serum cholesterol and measures of suicidal behavior, impulsivity, aggression, anxiety, and depression was also examined.

METHODS

Consecutive admissions (n = 152) to an adolescent psychiatric inpatient unit were assessed using measures of suicidal behavior, violence, impulsivity, and depression. Serum cholesterol was compared between those admitted for reasons of suicidal tendencies and those for other reasons. Correlation between serum cholesterol and measures of suicidal behavior, violence, impulsivity, and depression were examined.

RESULTS

Serum cholesterol levels were significantly higher in adolescent patients who were currently suicidal than in nonsuicidal adolescents. Within the suicidal group, but not in the total inpatient group, serum cholesterol correlated negatively with the degree of suicidal behavior. No correlation between serum cholesterol levels and depression, violence, and impulsivity were detected. No significant differences were found in serum cholesterol levels between diagnoses or between suicidal and nonsuicidal patients within each diagnostic group.

CONCLUSIONS

The association between cholesterol and suicidal tendencies remains complex and may depend on several variables within the population studied. Its usefulness as a biologic risk factor in clinical samples remains to be determined.

Chronic and acute psychological risk factors for clinical manifestations of coronary artery disease

Psychological factors are known to affect biological processes involved in the progression of coronary artery disease. This article focuses on psychological risk factors for progression of coronary artery disease and its clinical manifestations. Recent research on the adverse cardiovascular consequences of feelings of exhaustion and acute psychological arousal is reviewed, and a classification of psychological risk factors is presented distinguishing (1) chronic psychological risk factors, such as hostility; (2) episodic risk factors, such as exhaustion, with a duration ranging from several months to 2 years; and (3) acute psychological triggers, including mental activity and anger. The distinctive pathophysiological mechanisms by which these psychological risk factors promote coronary disease progression and cardiac ischemia are described, including hemodynamic reactivity, blood clotting, and inflammatory processes.

Hostility-related differences in the associations between stress-induced physiological reactivity and lipid concentrations in young healthy women

We examined the relations of fasting lipid levels to stress-induced neuroendocrine and cardiovascular responses as a function of hostility in 36 healthy young women. Participants were women who scored above 17 (n = 23) or below 12 (n = 13) on the Cook-Medley Hostility (Ho) Inventory. Lipids were determined following an overnight fast. Individuals participated in a solvable anagram task, which evoked significant physiological responses in all participants. The Ho group by total serum cholesterol (TSC) and the Ho group by low-density lipoprotein (LDL) cholesterol interactions significantly predicted heart rate (HR) and norepinephrine (Ne) responses. For high Ho women, elevations in TSC and LDL cholesterol were associated with smaller HR responses and larger Ne responses. In contrast, for low Ho women, elevations in TSC and LDL cholesterol were associated with larger HR responses and smaller Ne responses. Results also indicated a significant Ho group by TSC to high density lipoprotein (HDL) cholesterol ratio interaction for cortisol. For high Ho women, larger cortisol responses were associated with a greater TSC to HDL cholesterol ratio. For low Ho women, larger cortisol responses were associated with a smaller TSC to HDL cholesterol ratio. Lastly, higher TSC and LDL cholesterol levels were significantly associated with larger epinephrine responses. The findings suggest that stress-induced physiological responses are differentially associated with fasting lipids as a function of hostility in healthy young women.

Feindseligkeit als koronarer Risikofaktor

Zusammenfassung. Das Persönlichkeitsmerkmal “Feindseligkeit” ist in den letzten Jahren insbesondere in US-Forschungsarbeiten zu den Risikofaktoren der koronaren Herzerkrankung stark beachtet worden. Dabei wurde zumeist die Cook-Medley Hostility Scale (Ho-Skala) zur Messung von Feindseligkeit verwandt, die im wesentlichen Zynismus erfaßt. Vorliegende empirische Studien legen nahe, daß Feindseligkeit mit einer erhöhten koronaren Morbidität bzw. Mortalität sowie der Schwere der Erkrankung verbunden ist. Hinsichtlich der zugrundeliegenden Mechanismen liegen Befunde zur kardiovaskulären Reaktivität sowie zum Zusammenhang zwischen Hostilität und dem gesundheitsbezogenen Lebensstil bzw. dem Risikofaktorenprofil (z.B. fehlende soziale Unterstützung) vor. Die Konsequenzen für weitere Forschung werden diskutiert.

The relation of hostility to lipids and lipoproteins in women: evidence for the role of antagonistic hostility

We examined the relation of antagonistic, neurotic, and cynical hostility to lipids and lipoproteins in 77 healthy women (aged 18-26) selected for having high (> 17) or low (< 12) scores on the Cook-Medley Hostility (Ho) scale. Fasting lipids were determined during the luteal phase of the menstrual cycle for oral contraceptive (OC) non-users (N = 41), and during pills 15-21 for OC users (N = 36). Factor scores for antagonistic and neurotic hostility were derived from a principal component of the Buss-Durkee Hostility Inventory, Spielberger's Anger Expression, and the NEO-Personality Inventory. High Ho scores were significantly associated with higher cholesterol. Antagonistic hostility significantly predicted cholesterol, low density lipoprotein cholesterol, triglycerides, and the ratio of cholesterol to high density lipoprotein cholesterol, with higher antagonistic hostility scores associated with higher levels. Neurotic hostility did not predict lipids. Results suggest a potential pathophysiological mechanism that may contribute to the association between hostility and coronary heart disease. Moreover, a measure of antagonistic hostility, relative to cynical and neurotic hostility, was the best predictor of lipid levels.

Relationships between the pituitary-adrenal hormones, insulin, and glucose in middle-aged men: moderating influence of psychosocial stress

We examined whether the relationships between the pituitary-adrenal hormones (corticotropin [ACTH) and cortisol), insulin, and glucose differ as a function of psychosocial stress defined in terms of vital exhaustion (VE) and depressive behavior (DB). The participants were 69 normotensive and 21 unmedicated borderline hypertensive (BH) middle-aged men whose work is stressful. Hormonal and metabolic variables were measured during an oral glucose tolerance test (OGTT), and the cortisol response to dexamethasone (DXM) suppression and intravenous ACTH stimulation was also measured. We found that the basal ACTH level during the OGTT was positively associated with the cortisol response to ACTH at 60 minutes, the fasting insulin level, and the insulin to glucose ratio among exhausted and high DB men, while the reverse was true for nonexhausted and low DB men. Also, a high cortisol response to ACTH, a low cortisol level during the OGTT, and a high ratio of these cortisol determinations (cortisol ratio) were associated with high fasting insulin and glucose levels, the summed insulin values, and the insulin to glucose ratio only among nonexhausted and low DB men; among exhausted and high DB men, these associations were less pronounced, absent, or in the opposite direction. The findings suggest that VE and DB have a moderating influence on the relationships among the hormonal and metabolic parameters studied. Psychosocial stress may affect the pituitary-adrenocortical system in complex ways, contributing thereby to insulin resistance, hyperinsulinemia, and coronary heart disease (CHD) risk.

Hostility is associated with increased platelet activation in coronary heart disease

OBJECTIVE

To determine whether Potential for Hostility is related to platelet activation (PA) among patients with coronary heart disease (CHD) and healthy controls. Increased PA has been associated with adverse secondary events after myocardial infarction or coronary angioplasty.

METHODS

We tested 32 CHD patients and 23 healthy men and women, aged 45 to 73 years, for PA by using whole blood flow cytometry. PA was measured in blood exiting a bleeding time wound (wound-induced platelet activation) and also in venous blood stimulated in vitro with collagen. Monoclonal antibodies were used to test for fibrinogen receptor activation and fibrinogen receptor binding. All subjects refrained from taking aspirin for at least 14 days before testing; CHD patients stopped nitrates and calcium channel blockers for 24 hours, while continuing to take lipid-lowering medications. Potential for Hostility was assessed, using the Type A Structured Interview.

RESULTS

Among the CHD patients only, all four of the wound-induced fibrinogen receptor activation indicators (activation and binding) were related to hostility; the relationships were significant for receptor activation at 2 minutes, and for receptor binding at 1 minute (r values = .46, p values = .02). Subjects on lipid-lowering medications had lower PA for most measures. Healthy subjects had higher wound-induced fibrinogen receptor activation at 2 minutes and fibrinogen receptor activation in vitro than the CHD patients (p = .04), but after statistical adjustment for lipid-lowering medications, there were no significant differences between the patients and controls.

CONCLUSIONS

PA was related to hostility among CHD patients, consistent with previous studies indicating a relationship between PA and psychological factors among CHD patients. However, PA was not increased in nonsmoking, nondepressed CHD patients relative to controls.

Serum lipid concentrations, hostility and cardiovascular reactions to mental stress

The objective of the present study was to determine whether serum lipid concentrations interact with hostility to affect cardiovascular responses to mental stress. One-hundred and seventy-four male subjects were screened with the Cook and Medley hostility scale (Ho), the anger expression inventory by Spielberger and a general health questionnaire. Subjects in the upper (n = 22) and lower (n = 22) quartile of the Ho score distribution were asked to take part in a laboratory experiment. Continuous measures of heart rate, blood pressure, respiration and electrodermal activity were taken while participants carried out a series of behavioral maneuvres, including mental arithmetic and mirror star tracing. Prior to the experiment fasting blood samples were taken for lipid determinations. The results show higher heart rate reactivity in high hostile than low hostile subjects. High hostile subjects also reported more anger and frustration in response to tasks. Hostility groups differed in lipid levels in that high hostiles had higher triglyceride and VLDL-c concentrations than low hostiles. Cholesterol levels showed an inverse association with cardiovascular reactivity but only in low hostile subjects. No such associations could be found in high hostiles. We conclude that there is partial support for both, the hyperreactivity and the health behavior model linking hostility and cardiovascular disorder.

Serum lipids and cardiovascular reactivity to stress

Several studies have reported an association between serum lipid levels and cardiovascular reactivity to laboratory stressors. Their findings, however, are equivocal. The inconsistencies may be due to shortcomings such as the small number of subjects, the inclusion of patient groups, no control for medication, and no control for age effects. Two studies are presented investigating the relationship in large groups of adolescent and middle-aged males and females. Cholesterol, triglycerides and HDL were measured. Subjects were exposed to mental stressors, and in one study also to a cold pressor test. In addition to heart rate and blood pressure, in one study impedance cardiography was used to measure pre-ejection period, stroke volume and total peripheral resistance. Canonical correlation analysis suggested an association between triglycerides and decreased cardiac reactivity to mental stressors in middle-aged females. Trends in the same direction were found in both middle-aged males and females with respect to reactivity to the cold pressor. These associations, however, were not confirmed when the extreme deciles of the triglyceride distributions were compared with respect to stress reactivity. The fact that associations were completely absent in youngsters but sometimes showed up in older persons suggested an age dependency of the association. In post hoc analyses, indeed, some evidence was found for stronger cardiac responsivity being associated with cholesterol specifically in relatively older males. In females, in contrast to this, the association between triglycerides and cardiac responsivity was stronger in the younger group. More detailed measurement techniques, of specifically vascular processes, may be needed to explore further the effects of sex and age on the association between lipids and stress reactivity.

Acute and chronic psychological risk factors for coronary syndromes: moderating effects of coronary artery disease severity

This article provides a selective review of the effects of psychosocial factors and responses to acute mental stress on the onset of acute coronary syndromes. The literature suggests that the relationship between the anatomical severity of coronary artery disease (CAD) and likelihood of subsequent cardiac events, such as myocardial infarction, is not linear. Furthermore, evidence will be provided that the age-dependent associations between psychosocial factors and risk of cardiac events is at least in part mediated through the severity of underlying CAD. Finally, research will be summarized that supports the importance of both chronic psychosocial factors (e.g., low socioeconomic status and/or high hostility) and episodic psychological distress syndromes, such as vital exhaustion and depression. In reviewing this literature, two perspectives will be focused on: (1) the relationship between psychosocial factors and progressive CAD; and (2) the evidence concerning underlying pathophysiological mechanisms.

The influence of dietary cholesterol on cardiac and hepatic Beta-adrenergic receptors in egyptian sand rats

We examined the effects of dietary cholesterol on cardiac and hepatic beta-adrenergic receptor functioning. Age-matched adult desert rodents (Psammomys obesus) were randomized to either a 5% cholesterol diet (CD, n = 20), or normal rabbit chow (RC, n = 18). After a 2-month exposure to the diets, animals were sacrificed and tissue from both heart and liver were retained for radioligand bindings studies. In heart tissue, cholesterol fed animals, relative to controls, showed an increased production of adenosine 3,5>-cyclic monophosphate (cAMP) in response to isoproterenol. Cholesterol supplementation was not associated with an increase in heart beta-adrenergic receptor number. Animals fed the 5% cholesterol diet showed significant increases in the number of beta-adrenergic receptor sites in hepatic tissue (M = 13.2 vs. 10.4 pmol/mg protein, CD and RC, respectively). The increased number of receptor sites in the liver was accompanied by a significant increase in isoproterenol-stimulated cAMP production. Results are supportive of the hypothesis that dietary cholesterol contributes to an upregulation of beta-adrenergic receptor function in cardiac, as well as hepatic tissue. These findings may be relevant to the observations of excessive stress-induced cardiovascular reactivity in persons with high cholesterol levels.

The impact of a relaxation technique on the lipid profile

The purpose of this research was to test the effect of a relaxation technique on blood lipid levels. Sixty outpatient males with known hyperlipidemia were recruited to the study. All participants were stabilized on an American Heart Association Step I diet for 8 weeks. After stabilization, participants were randomly assigned to relaxation or reading groups and received in-depth follow-up and support over another 8-week period. Monthly follow-up continued for an additional 8 months. Although both groups demonstrated decreased weight, total cholesterol, and triglycerides, no group differences were detected over time. This suggests that relaxation training may not be an effective technique for long-term clinical management of clients with dyslipidemias.

Psychologic characteristics associated with acute stressor-induced leukocyte subset redistribution

This study examined relationships between psychologic characteristics and enumerative immune responses to an acute laboratory stressor. Lymphocyte subsets were measured in 104 subjects at rest and following a 6-minute laboratory naturalistic speaking stressor. Multiple linear regression was utilized to assess relationships between immune reactivity (change scores) and anger expression, hostility, anxiety, depression, and stress. The task resulted in significant increases over baseline in WBC (p < 0.001), T-suppressor/cytotoxic CD8 cells (p = 0.010) natural killer CD56 cells (p < 0.0001), and CD57 (p < 0.0001) cells, and significant decreases in T-cells (p = 0.012), T-helper cells (p = 0.003), B-cells (p < 0.001), and the T-helper/suppressor ratio (p < 0.001). In general, the regression suggested that moderate associations exist between certain psychologic attributes and acute subset redistribution. For example, the increase in natural killer cell subsets was significantly negatively associated with anger expression, hostility, and depression. Suppressor/cytotoxic (CD8) cell reactivity was associated with baseline as well as with the task-induced changes in anxiety. B-cell (CD19) responses were related to the subject's age, expression of anger, and depression scores. As with the cardiovascular reactivity literature, these findings suggest that a relationship exists between certain psychologic characteristics such as anger and anxiety and immune reactivity to acute stress.

Menstrual cycle effects on catecholamine and cardiovascular responses to acute stress in black but not white normotensive women

This study examined cardiovascular and catecholamine responses to two standardized laboratory stressors in 33 healthy age- and weight-matched black and white normotensive women (mean age, 32 years) during two phases of the menstrual cycle. Subjects were studied in a randomized order at the same time of day on two separate occasions approximately six weeks apart, once during the follicular phase (days 7 to 10 after menses) and once during the luteal phase (days 7 to 10 after the leutenizing hormone surge) of the menstrual cycle. Black women has higher systolic (P=.01) and diastolic (P=.01) pressures compared with white women. Black women showed greater diastolic pressure (P <.01) and plasma epinephrine (P <.05) responses to stress during the follicular compared with the luteal phase of the menstrual cycle; white women showed no significant changes in these variables. The findings extend the literature on race differences in responsivity to stress and indicate that in contrast to white women, reproductive hormones do influence cardiovascular and catecholamine responsivity to stress in black women.

Type A behavior and metabolic syndrome precursors in young adults

The association between type A behavior and a cluster of parameters of the metabolic syndrome was studied in 919 randomly selected healthy young adults. Type A behavior was measured using the Type A Behavior Questionnaire for the Finnish Multicenter Study and the Hunter Wolf A-B Rating Scale. The results showed that type A men scored higher on the "Metabolic Syndrome Precursors Factor," representing a metabolic entity, than did non-type A men. In addition, type A behavior had a moderating effect on the relationship between parameters of the metabolic syndrome, that is, interdependence of these somatic factors was stronger in type A men than in non-type A men. These findings were not true of women. It is discussed whether type A behavior might affect bodily functions through increased activity along the pituitary-adrenal system resulting in insulin resistance, compensatory hyperinsulinemia, and other characteristics of the metabolic syndrome.

Effects of hostility on platelet reactivity to psychological stress in coronary heart disease patients and in healthy controls

Previous studies have demonstrated a potential relationship between psychological stress and platelet activation, which may serve as a link between stress and myocardial infarction (MI). However, the possibility that personality traits associated with coronary heart disease may affect platelet activation has not been adequately investigated. The effect of a laboratory stressor (Type A Structured Interview (SI) and speech task) on platelet activation was assessed in 14 stable post-MI patients and 15 age-matched healthy men, using a standardized method of measuring plasma beta-thromboglobulin (BTG) levels. BTG levels were increased after the stressor (average change = 2.0 ng/ml, p = .005). Increases in BTG with stress were related to higher SI ratings of Potential for Hostility (r = .53, p = .004) and Type A behavior (r = .43, p = .02) but not to Cook-Medley-rated hostility scores. Increases in norepinephrine levels and in diastolic blood pressure were nonsignificantly related to increases in BTG levels (ps < .10), whereas increases in epinephrine levels were unrelated. Despite ceasing aspirin and other platelet inhibitors for 10 days before testing, individuals taking platelet inhibitors before the study had less change in BTG with stress (p = .05). However, after statistical adjustment for this factor, SI ratings of Potential for Hostility were still strongly related to increases in BTG with stress (adjusted r = .56, p = .002). Contrary to expectations, healthy men tended to have greater change in BTG with stress than post-MI patients (p = .06). These results indicate that acute stress increases BTG levels and that hostility is related to greater platelet reactivity, independent of any long term effects of platelet inhibition.

Vital exhaustion, anger expression, and pituitary and adrenocortical hormones. Implications for the insulin resistance syndrome

This study was undertaken to examine whether there are psychological factors that can incline an individual toward coronary heart disease and that can in turn identify a pattern of pituitary and adrenocortical responses that is associated with the Insulin Resistance Syndrome (IRS). The study was performed with 69 normotensive and 21 unmedicated borderline hypertensive men (age range, 30 to 55 years). Type A behavior, hostility (defined as cynicism, pessimism, and paranoia), vital exhaustion, and anger expressions were the behavioral variables studied. Among these, only the vital exhaustion-anger-out factor identified the neuroendocrine pattern that predicted the IRS. This neuroendocrine pattern consisted primarily of an adrenal responsiveness to ACTH and secondarily of a high mean basal cortisol-to-mean basal ACTH ratio. The contribution of this last variable was, however, slightly questionable. Instead of the traditional coronary-prone factors, ie, type A behavior and hostility, the findings emphasize the significance of vital exhaustion and emotional distress. The findings have been discussed in terms of defeat reaction, hypocortisolemia, and visceral obesity.

Neuroimmunologic implications in coronary artery disease

In this review, the role of the macrophage in the pathophysiology of coronary artery disease (CAD) is examined. The central interaction of macrophage, endothelial cell and smooth muscle cell in the context of hyperlipidemia is considered. The macrophage appears to be at the beginning of a chain of events that starts with elevated low density lipoprotein (LDL). Stress, particularly in those with a core hostility, may be associated not only with higher catecholamine levels but also with higher serum lipid levels. These lipids will in turn be processed to oxidized LDL by macrophage and endothelial cells. Oxidized LDL molecules will contribute to atherosclerotic plaquing. A side effect of such plaque formation may be a diminished vasodilatory response to the nitric oxide (NO) produced by macrophages and endothelium. Indeed, paradoxical vasoconstriction occurs in atherosclerosis in response to neurotransmitters such as serotonin and acetylcholine, which under normal circumstances cause vasodilation. There also is evidence that both macrophages and endothelial cells can regulate NO production through a specific mu 3 morphine receptor, an effect that can be blocked by naloxone. The clinical effectiveness of morphine and nitroglycerin in CAD patients may relate to these mechanisms. More research will be needed to elucidate the neuroimmunologic basis for atherosclerosis with prospects for better treatment and management in future.

Psychosocial risk factors and nonfatal myocardial infarction

BACKGROUND

Numerous psychosocial factors have been hypothesized to play a role in coronary heart disease. However, existing studies have yielded inconsistent results.

METHODS AND RESULTS

The relations between type A personality as well as suppressed versus expressed anger and risk of nonfatal myocardial infarction (MI) were studied in 340 patients and 340 age-, sex-, and community-matched control subjects. Subjects were interviewed at home to assess behavioral and medical cardiovascular risk factors, and fasting blood samples were obtained. Type A personality was associated with nonfatal MI in crude matched-pair analysis (OR, 1.57; 95% CI, 1.12 to 2.20; P = .008). Adjusting for known cardiovascular risk factors (including treated hypertension, body mass index, treated diabetes, family history of premature MI, physical activity, smoking, alcohol, total calories per day, and saturated fat) did not substantially change the magnitude of the point estimate, although the finding was no longer statistically significant (OR, 1.43; 95% CI, 0.97 to 2.09; P = .069). Further adjustment for lipids, including total cholesterol, total HDL, its subfractions (HDL2, HDL3), LDL, VLDL, and triglycerides, markedly attenuated the association (OR, 1.12; 95% CI, 0.66 to 1.90; P = .687), an effect due almost entirely to HDL cholesterol. Suppressed anger was positively but not statistically significantly associated with increased risk of MI in crude matched-pair analysis (OR, 1.33; 95% CI, 0.98 to 1.81; P = .065), in analysis adjusted for behavioral and medical cardiovascular risk factors (OR, 1.26; 95% CI, 0.89 to 1.78; P = .193), or after adjustment for lipids (OR, 1.11; 95% CI, 0.67 to 1.82; P = .695).

CONCLUSIONS

These findings suggest a possible association of type A but not suppressed anger with risk of nonfatal MI that may be mediated by alterations in HDL cholesterol level. If decreases in HDL are not in the same causal pathway, then the apparent association between type A personality and risk of MI is due to confounding, principally by HDL.

The relationship between habitual anger coping style and serum lipid and lipoprotein concentrations

The relationship between habitual anger coping styles, especially anger expression in a socially assertive manner and serum lipid concentrations was examined in 86 healthy subjects. Habitual anger expression was measured by the Müller Anger Coping Questionnaire (MAQ) on four scales: Aggression, Controlled Affect, Guilt, and Social Inhibition. A positive correlation between serum cholesterol and Aggression was found, as was a negative correlation between LDL/HDL ratio and Controlled Affect. These correlations remained significant after adjustments for age, Body Mass Index (BMI), athletic activity, alcohol, nicotine and coffee consumption. After these adjustments, significant negative partial correlations between Controlled Affect and both total cholesterol and LDL were also found. We found no significant gender differences on any lipid measure. This study demonstrated that unfavourable lipid profiles are linked to a predominantly aggressive anger coping style, whereas favourable lipid profiles are associated with more socially assertive anger coping (Controlled Affect). Thus the expression of anger in a socially assertive manner can be seen as health promoting. The MAQ scales were better predictors of total serum cholesterol concentrations than the health related behaviors and characteristics. Results are discussed in terms of a psychophysiological risk model of inadequate anger coping.

Serum cholesterol and aggression in hospitalized male forensic patients

Human studies of the link between serum cholesterol and aggression have yielded equivocal results. Depending on the type of aggression studied (e.g., criminal violence or Type A hostility), investigators have found either a negative or a positive association between cholesterol and aggressive behavior. We conducted a retrospective analysis of aggressive incidents in a sample of hospitalized male forensic patients. The whole sample had lower cholesterol levels than the general population. Patients with low cholesterol levels (< 200 mg/dl) engaged in more frequent aggressive behavior but showed no difference in severity of aggression. They also showed no difference in verbal vs physical aggression. The relationship between cholesterol and frequency of aggression was curvilinear, with the most frequent acts of aggression committed by patients with moderately low cholesterol levels. Current research findings regarding the cholesterol-aggression association suggest the need for further clarification of the behavioral parameters under investigation.

Menopausal status influences ambulatory blood pressure levels and blood pressure changes during mental stress

BACKGROUND

Frequent and large cardiovascular and neuroendocrine responses to psychological stress are thought to enhance an individual's risk for cardiovascular diseases. Preliminary data suggest that levels of reproductive hormones affect the magnitude of stress responses, perhaps contributing to the protective effect of ovarian hormones on premenopausal women's rates of coronary heart disease.

METHODS AND RESULTS

Healthy middle-aged men and premenopausal and postmenopausal women performed a series of standardized mental and physical challenges while blood pressure, heart rate, plasma catecholamines, lipids, and lipoproteins were measured. Subjects then wore an ambulatory blood pressure monitor during two consecutive workdays. Results showed that postmenopausal women had larger mean +/- SEM stress-induced increases in systolic blood pressure (24.7 +/- 2.2 mm Hg) and diastolic blood pressure (14.3 +/- 1.0 mm Hg) compared with either premenopausal women (16.9 +/- 1.3 and 10.2 +/- 0.9 mm Hg) or men (17.7 +/- 1.5 and 10.9 +/- 1.1 mm Hg, respectively). Postmenopausal women and men had higher mean +/- SEM ambulatory diastolic blood pressure levels (75.5 +/- 3.2 and 76.4 +/- 1.8 mm Hg) than did premenopausal women (69.9 +/- 2.2 mm Hg). Large blood pressure responses during public speaking were associated with high cholesterol levels and low educational attainment.

CONCLUSIONS

Menopause is associated with enhanced stress-induced cardiovascular responses and elevated ambulatory blood pressure during the workday. These effects may contribute to the risk of cardiovascular morbidity and mortality after the menopause.

Psychological, situational, and gender predictors of cardiovascular reactivity to stress: a multivariate approach

This study examined whether relationships between anger expression, hostility, social evaluative anxiety, and a presumed mechanism for coronary heart disease development, cardiovascular reactivity (CVR) to stress, are moderated by stress situation and gender and whether such relationships are attenuated by inadequate assessments. Subjects (47 men, 47 women) were assigned randomly to either a Harassment or a Social Evaluation condition, under which they performed a reaction time task. SBP, DBP, and HR measures were recorded during baseline and task. Multiple regression analyses indicated that expressed anger was related to CVR only among men in the Harassment condition; that hostile men who express anger showed the most CVR across situations, and that the traits assessed here did not predict CVR among women. Results suggest that assessments of coronary-risk and interventions to reduce risk may need to take into account attitudes, styles of emotional expression, environmental factors, and gender.

Relationship of cardiovascular reactivity and anger expression to serum lipid concentrations in healthy young men

The relationship between behaviorally evoked cardiovascular reactivity, preferred mode of anger expression, and serum lipid concentrations was examined in 63 healthy, young adult males. Subjects derived from three studies, each evaluating cardiovascular response to laboratory stressors. All participants completed the Spielberger Anger Expression Scale and provided fasting blood samples for lipid determinations. A significant negative correlation, calculated by meta-analytic procedures, was noted between a baseline-free measure of heart rate reactivity and high density lipoprotein-cholesterol (HDL-C) concentrations (r = -0.26, p = 0.05). However, the previously reported relationship between cardiovascular reactivity and elevated total serum cholesterol (TSC) was not found. Additionally, men scoring high on a self-report measure of the tendency to express anger outwardly had significantly higher HDL-C concentrations than men scoring low on this measure (r = 0.30, p = 0.02); when subjects were stratified by level of cardiovascular reactivity, this relationship was apparent only among those showing the greatest magnitude of heart rate and blood pressure responses to acute mental stress.

Effects of demand and decision latitude on cardiovascular reactivity among coronary-prone women and men

According to the Job Strain Model, high demand/low decision latitude jobs may be associated with increased risk of developing coronary heart disease. In further analyses of a laboratory study, the authors hypothesized that Type A behavior and/or hostility moderate the effects of demand, decision latitude, and gender on cardiovascular reactivity, a putative mechanism for the development of coronary disease. With multiple regressions, it was found that scores on the Framingham Type A scale interacted with demand and decision latitude to affect diastolic blood pressure changes, such that Type Bs in the low demand/high decision latitude condition showed the smallest increases in diastolic blood pressure. Among men, hostility accounted significantly and positively for variance in systolic blood pressure changes in addition to that accounted for by high demand. These results suggest that coronary-prone traits may potentiate, or add to, the effects that stressful environments have on health outcomes.

Serum lipids, neuroendocrine and cardiovascular responses to stress in healthy Type A men

This study examined the relationship between serum lipid activity in healthy Type A men and cardiovascular and neuroendocrine responses to a behavioral stressor, mental arithmetic. Assessment of blood lipids included measures of total cholesterol (TC), low density lipoprotein cholesterol (LDLC), high density lipoprotein cholesterol (HDLC), and serum triglycerides. Cardiovascular (blood pressure and heart rate) and neuroendocrine (epinephrine, norepinephrine and cortisol) responses were recorded before (rest), during (stress) and after (recovery) the mental arithmetic test. Diastolic blood pressure, mean arterial pressure and, to a lesser extent, systolic blood pressure levels at rest, during stress, and at recovery correlated positively with TC levels. In addition, both diastolic and mean arterial pressure were positively correlated with the ratio of TC to HDLC and with triglycerides during stress and recovery. Heart rate did not correlate with any lipid measure. Cardiovascular stress-reactivity calculated as change from rest to stress did not correlate significantly with any lipid measure. Plasma norepinephrine during stress correlated positively with triglycerides; a similar trend was observed for the TC/HDLC ratio. Plasma cortisol at rest and during stress correlated positively with the TC/HDLC ratio and serum triglycerides, and negatively with HDLC. Plasma norepinephrine reactivity calculated as change from rest to stress correlated negatively with HDLC and positively with triglycerides. In addition, cortisol reactivity was positively correlated with triglycerides. It is suggested that the mechanisms mediating Type A behavior and coronary heart disease may include increased cardiovascular and neuroendocrine responses as well as unfavorable lipid profiles.

Lipids in psychological research: the last decade

We review the recent literature examining lipid changes during stressful experiences, and the psychological and constitutional differences that influence lipid levels at rest and that may modulate lipid response to stress. Mild forms of chronic or episodic stress are apparently not associated with alterations in lipids and lipoproteins, but severe forms of real or perceived stress do appear to alter lipid levels. Acute laboratory stress is frequently associated with short-term alterations in lipids and lipoproteins, but the significance of these changes is unclear. Several individual characteristics, such as heightened neuroendocrine or autonomic reactivity to stressors, Type A component behavior, and other aspects of personality, appear to be associated with an atherogenic lipid profile. Stress may influence lipid concentrations and metabolism through a variety of physiological and behavioral mechanisms, but none have been clearly elucidated. Future research should concentrate on understanding these mechanisms.