Lipid reactivity to stress: II. Biological and behavioral influences.

This study examined behavioral and physiological influences on lipid concentrations during acute and chronic stressors. One hundred men (n?=?92) and women (n?=?8) were tested during a chronic stressor and during 2 acute stressors. During chronic stress, diet, physical activity, exercise, and sleep were examined. During the acute stressors, catecholamines, cortisol, plasma volume, and cardiovascular responses were examined. None of the behavioral influences could explain the lipid response to chronic stress. Responses of the atherogenic lipids to acute stressors were not solely reflecting hemoconcentration of the plasma but were moderately correlated with cardiovascular, epinephrine, and cortisol reactivity. Diastolic blood pressure reactors to the acute stressors had larger lipid responses to the chronic stressor than did nonreactors. Elevations in blood lipids during stress are not artifacts and may be clinically significant. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cellular immune responses to acute stress in female caregivers of dementia patients and matched controls.

This study investigated whether the stress of caregiving alters cellular immune responses to acute psychological stressors. Twenty-seven women caring for a spouse with a progressive dementia (high chronic stress) and 37 controls matched for age and family income performed a 12-min laboratory stressor. Cellular immune function was assessed by both functional and quantitative measures taken before (low acute stress), immediately after (high acute stress), and 30 min after (recovery from stress) exposure to the laboratory stressors. The laboratory challenges were associated with diminished proliferative responses but elevated natural killer (NK) cell cytotoxicity; however, subsequent analyses suggested that this elevated cytotoxicity was largely attributable to an increase in the number of NK cells in peripheral blood. The results suggest that although the stress of caregiving diminishes cellular immune function, caregiving appears to have little effect on cellular immune responses to or recovery from brief psychological challenges. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chronic stress influences cardiovascular and neuroendocrine responses during acute stress and recovery, especially in men.

This study tests the influence of chronic stress on cardiovascular and neuroendocrine responses to and recovery from acute stressors and whether the effects are gender specific. Sixty-two healthy, middle-aged persons (50% women) performed mental-arithmetic and public-speaking tasks and relaxed thereafter for 1 hr while their cardiovascular and neuroendocrine functions were measured. Participants with higher levels of chronic stress showed lower systolic blood pressure (SBP) and epinephrine (E; men only) and marginally lower levels of norepinephrine (NE) responses to the tasks and showed lower levels of cortisol and marginally lower NE responses during recovery. Relative to women, men had high diastolic blood pressure (DBP) responses to the tasks and high SBP, DBP, and E responses during recovery. Gender differences in cardiovascular disease in midlife may be due to gender differences in inability to recover quickly, in addition to enhanced acute-stress response. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of the Transcendental Meditation program on adaptive mechanisms: changes in hormone levels and responses to stress after 4 months of practice

Stress has been implicated in both somatic and mental disorders. The mechanisms by which stress leads to poor health are largely unknown. However, studies in animals suggest that chronic stress causes high basal cortisol and low cortisol response to acute stressors and that such changes may contribute to disease. Previous studies of the Transcendental Meditation (TM) technique as a possible means of countering effects of stress have reported altered levels of several hormones both during the practice and longitudinally after regular practice of this technique. In this prospective, random assignment study, changes in baseline levels and acute responses to laboratory stressors were examined for four hormones-cortisol, growth hormone, thyroid-stimulating hormone and testosterone-before and after 4 months of either the TM technique or a stress education control condition. At pre- and post-test, blood was withdrawn continuously through an indwelling catheter, and plasma or serum samples were frozen for later analysis by radioimmunoassay. The results showed significantly different changes for the two groups, or trends toward significance, for each hormone over the 4 months. In the TM group, but not in the controls, basal cortisol level and average cortisol across the stress session decreased from pre- to post-test. Cortisol responsiveness to stressors, however, increased in the TM group compared to controls. The baselines and/or stress responsiveness for TSH and GH changed in opposite directions for the groups, as did the testosterone baseline. Overall, the cortisol and testosterone results appear to support previous data suggesting that repeated practice of the TM technique reverses effects of chronic stress significant for health. The observed group difference in the change of GH regulation may derive from the cortisol differences, while the TSH results are not related easily to earlier findings on the effects of chronic stress.     

The effects of presleep stress on sleep-onset insomnia.

10 sleep-onset (SO) insomniacs and 11 noninsomniacs (18–21 yrs old) slept undisturbed for 3 nights but were exposed to brief cognitive stressors before SO on the next 2 nights. Significant between-group differences were found in responses to the cognitive stressors on self-report but not objective measures of SO latency (SOL). Noninsomniac Ss evidenced an increase and insomniac Ss a decrease in SOL on stress nights. Insomniac Ss demonstrated a significantly higher mean heart-rate response before and after the stressors. A variable expressing the relationship between objective and subjective measures of SOL (pseudoidiopathic dimension) for each S was not significantly related to Ss' responses to stress. Results are inconsistent with the hypothesized role of presleep stress in SO insomnia but are consistent with other studies indicating higher levels of physiological arousal of insomniac vs noninsomniac Ss. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Potassium supplementation induces beneficial cardiovascular changes during rest and stress in salt sensitive individuals.

The typical American diet includes high salt and low potassium, a pattern linked to elevated blood pressure (BP) in cross-cultural studies. This study compared resting and stress cardiovascular responses on a high salt, low potassium diet to those observed during 2 interventions: salt restriction and potassium supplementation. Forty-seven percent of the primarily normotensive sample (n?=?67 adults) were salt sensitive, showing a decrease in mean arterial pressure ≥5 mmHg during low salt and equivalent reductions during high potassium. The equivalent benefits of the interventions were maintained, but not enhanced, during exposure to behavioral stress (i.e., no effect on reactivity). Salt resistants (SRs) exhibited no change in resting or stress BP across the diets. High salt increased cardiac index in both groups, whereas vascular tone was decreased only in the SR group. High potassium produced hemodynamic benefits similar to low salt, even with continued high salt intake. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associations between acute lipid stress responses and fasting lipid levels 3 years later.

The authors assessed the association between lipid responses to acute mental stress and fasting serum lipid levels 3 years later in 199 middle-aged men and women. Total cholesterol, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) cholesterol increased following moderately stressful behavioral tasks. LDL cholesterol, HDL cholesterol, and total:HDL ratio measured 3 years later were predicted by acute stress responses independent of gender, age, socioeconomic position, change in body mass, smoking, alcohol consumption, or hormone replacement therapy baseline lipid levels. The odds of clinically elevated cholesterol were significantly greater in the highest compared with the lowest stress tertile, independent of baseline levels and covariates. Acute lipid stress responsivity may reflect processes that contribute to the development of elevated blood cholesterol concentration. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Depressive symptomatology in new mothers: A stress and coping perspective.

The aim of the present research was to test the utility of a stress-coping model of postpartum depression. Data were collected during the last trimester of pregnancy (n?=?197) and twice after the birth (4 weeks, n?=?180, and approximately 5 months, n?=?163). Coping resources and depressive symptomatology were assessed at Time 1, stress and coping were assessed at Time 2, and depressive symptomatology and partner ratings of coping effectiveness were assessed at Times 2 and 3. After control of the effects of initial depression, there was evidence of significant effects of levels of stress and coping responses on the Time 2 and Time 3 outcome measures. There was also some evidence linking coping resources (particularly self-esteem and family support) to postpartum depressive symptomatology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychometric profile of posttraumatic stress disorder, anxious, and healthy Vietnam veterans: Correlations with psychophysiologic responses.

Three groups of Vietnam combat veterans, posttraumatic stress disorder (PTSD, n?=?25), anxious (n?=?7) and healthy (n?=?18), completed a battery of psychometric tests. Measurement of psychophysiologic responses to imagery of individualized combat experiences followed the psychometrics. The PTSD Ss differed significantly from the healthy Ss on almost all measures but showed fewer differences from the anxious Ss. The typical PTSD S was characterized as anxious, depressed, prone to dissociation, and external in locus of control. Correlations with the physiologic responses supported the validity of psychometric scales specifically designed to measure PTSD but cast doubt on the interpretation of traditional measures of overreporting or dissimulation in this disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Longitudinal patterns of risk for depression in dementia caregivers: Objective and subjective primary stress as predictors.

The present study examined how patterns of risk for depression over 1 year in 188 dementia caregivers (consistently asymptomatic, n ?=?88; consistently symptomatic, n ?=?40; changing risk, n ?=?60) could be predicted by objective (behavior problems of the relative) and subjective (role captivity and overload) primary stress. Results reveal that all primary stressors differentiated caregivers who remained at low levels of symptomatology over the course of 1 year from those who were at risk for experiencing a depressive disorder. In addition, caregivers' subjective experience of role captivity predicted the chronicity of risk. Findings extend prior caregiving research on patterns of depressive symptomatology by highlighting the relationship between subjective primary stressors and stability and change in caregivers' mental health. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relationship between acute stress disorder and posttraumatic stress disorder: A prospective evaluation of motor vehicle accident survivors.

Motor vehicle accident survivors (n?=?92) were assessed for acute stress disorder (ASD) within 1 month of the trauma and reassessed (n?=?71) for posttraumatic stress disorder (PTSD) 6 months posttrauma. ASD was diagnosed in 13% of participants, and a further 21% had subclinical levels of ASD. At follow-up, 78% of ASD participants and 60% of subclinical ASD participants met criteria for PTSD. The strong predictive power of acute numbing, depersonalization, a sense of reliving the trauma, and motor restlessness, in contrast to the low to moderate predictive power of other symptoms, indicates that only a subset of ASD symptoms is strongly related to the development of chronic PTSD. Although these findings support the use of the ASD diagnosis, they suggest that the dissociative and arousal clusters may require revision. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Moderators and mediators of the stress-aggression relationship: Executive function and state anger.

The present study examined the effects of executive function (i.e., EF) and anger/hostility on the relationship between stress (across individual stress domains, as well as at the aggregate level) and aggression. Two independent groups of participants—a college sample and a low-income community sample—were administered a battery of self-report measures concerning the subjective experience of stress, aggressive behaviors, and feelings of state anger and hostility in the last month, along with a battery of well-validated neuropsychological tests of EF. Across both samples, the stress domains that demonstrated the strongest associations with aggression were those involving chronic strains of daily living (e.g., job, financial, health) versus interpersonal stressors (e.g., family, romantic). In the community sample, analyses also revealed a significant interaction between perceived stress (aggregated across domains) and EF in predicting aggressive behavior. Specifically, participants with relatively low EF abilities, across different EF processes, showed a stronger relationship between different domains of stress and aggression in the last month. Similar effects were demonstrated in the college sample, although the interaction was not significant. In both samples, experiences of anger and hostility in the last month mediated the relationship between perceived stress (aggregate) and aggressive behavior among those low, but not high, in EF. These findings highlight the importance of higher-order cognitive processes in regulating appropriate affective and behavioral responses across different types of individuals, particularly among those experiencing high levels of stress. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Oral contraceptive use and hemodynamic, lipid, and fibrinogen responses to smoking and stress in women.

The effects of acute smoking and oral contraceptive (OC) use on cardiovascular, lipid, and fibrinogen stress responses were examined in 52 female smokers and nonsmokers, half of whom were using OCs. Women smoked or sham-smoked a cigarette and then performed 2 stressful tasks. Stress elicited increases in total and low-density lipoprotein cholesterol, and in triglycerides among women who smoked, and in fibrinogen among all women. Smokers who used OCs had greater blood pressure increases to smoking and to stress than did smokers who did not use OCs. OC use was also associated with enhanced total peripheral resistance stress responses among women who smoked and cardiac output stress responses among women who sham-smoked. Results suggest that OC use moderates cardiovascular reactivity in smokers but not nonsmokers, enhancing vascular responsivity to smoking combined with stress and myocardial responsivity to stress alone. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Discrimination, dispositions, and cardiovascular responses to stress.

Objective: Recent research suggests that past exposure to discrimination may influence perceptions of, and physiological responses to, new challenges. The authors examined how race and trait levels of hostility and optimism interact with past exposure to discrimination to predict physiological reactivity and recovery during an anger recall task. Design: A community sample of 165 normotensive Black and White adults participated in an anger recall task while having their cardiovascular function monitored. Main Outcome Measures: Blood pressure and heart rate indicators of physiological reactivity and recovery. Results and Conclusion: Participants had higher reactivity and slower recovery to the anger recall task when they had high past discrimination, low cynicism, or high optimism. The pattern of effects was similar for both racial groups, but Blacks had more acute reactivity and slower recovery than Whites. These results are consistent with the perspective of discrimination as a chronic stressor that is related to acute stress responses, particularly for Blacks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Vigilance and cardiovascular reactivity to subsequent stressors in men: A preliminary study.

Understanding moderators of acute responses to stress has implications for a variety of outcomes in health psychology. The present study investigated the role of sustained search for potential threat in acute cardiovascular stress responses. As a means of manipulating vigilance for threat in the laboratory, male participants (N?=?30) were randomly assigned to search, on a computer screen, for statements that were negative, positive, or occurring at known intervals. Relative to participants in the other search conditions, participants in the negative search condition had significantly higher systolic and diastolic blood pressure responses during subsequent stressors. These results encourage a closer look at the effects of vigilance for threat. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dispositional affect and work-related stress.

Trait negative affectivity (NA) has been asserted to be a factor that spuriously inflates relationships between self-reported stressors and self-reported strain outcomes. This hypothesis was tested with conventional work stress instrument responses and physiological assessments obtained from 311 fire and police department employees. Confirmatory factor analyses indicated that NA did not measure a factor in common with measures of subjective strain. Latent-variable structural equations analyses, however, found that estimating the effects of NA on strain significantly attenuated the effects of work stressors. NA had no correlation with physiological stress outcomes. Trait positive affectivity did not attenuate relationships between work stressors and either subjective or objective stress outcomes. Implications for work stress research methodology and recommendations are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Generation of stress in the course of unipolar depression.

The effect of stressful events on depression has been amply demonstrated, but the opposite relation is also important. The author examined event occurrence over 1 yr in 14 women with unipolar depression who were compared with demographically matched groups of women with bipolar disorder (n?=?11), chronic medical illness (n?=?13), or no illness or disorder (n?=?22). Interview assessments of life events, severity, and independence of occurrence confirmed the hypothesis that unipolar women were exposed to more stress than the normal women, had significantly more interpersonal event stress than all others, and tended to have more dependent events than the others. The implication is that unipolar women by their symptoms, behaviors, characteristics, and social context generate stressful conditions, primarily interpersonal, that have the potential for contributing to the cycle of symptoms and stress that create chronic or intermittent depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lipoprotein changes in patients with chronic hepatitis C treated with interferon-alpha

OBJECTIVE: The aim of this study was to evaluate the effects of interferon-alpha therapy on the lipid profile of patients with chronic hepatitis C. METHODS: In 36 consecutive patients with chronic hepatitis C, fasting lipoproteins were evaluated prospectively at baseline, 1, 3 and 6 months during interferon-alpha therapy and 3 months after the end of treatment. RESULTS: During interferon-alpha therapy, there was a progressive increase in total and very low density lipoprotein (VLDL)-triglycerides, VLDL-cholesterol and a sustained raise in apolipoprotein (apo) B. In parallel, there was a reduction in high density lipoprotein (HDL)-cholesterol and apo A1 levels. In contrast, total and low density lipoprotein (LDL)-cholesterol and lipoprotein (a) levels remained essentially unchanged during interferon-alpha therapy. Three patients developed chylomicronemia, two of them with severe hypertriglyceridemia, although none of them presented with pancreatitis. Chylomicronemia and severe hypertriglyceridemia were more common in patients with basal triglycerides above 200 mg/dl. Nineteen patients responded to interferon-alpha therapy, but their lipid profile did nor differ from that of nonresponders. Three months after the end of interferon-alpha therapy lipid changes subsided, although VLDL and HDL-cholesterol and apo B did not reach basal levels. CONCLUSION: In patients with chronic hepatitis C, interferon-alpha therapy is associated with an increase of total and VLDL-triglycerides, VLDL-cholesterol and apo B, and a decline of HDL-cholesterol and apo A1. The development of chylomicronemia and severe hypertriglyceridemia in some cases makes mandatory a close monitoring of triglycerides during interferon-alpha therapy, particularly among patients with increased triglycerides at baseline.     

Cigarette smoking and oral contraceptive use influence women's lipid, lipoprotein, and cardiovascular responses during stress.

Investigated the effects of behavioral stress and smoking cigarettes on the lipid, lipoprotein, neuroendocrine, and cardiovascular responses of 35 healthy female smokers (aged 18–30 yrs), 20 of whom used oral contraceptives (OCs). Ss relaxed, smoked, or sham smoked and then prepared, delivered, and reviewed a speech presented in front of a videocamera. Behavioral stress increased total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, triglyceride, and free fatty acid levels, with significant increases in cholesterol, LDL-C, and free fatty acids apparent only among women who smoked during the session. In addition, OC users exhibited larger increases in triglyceride and blood pressure responses during stress than did nonusers whether or not they smoked during the protocol. (PsycINFO Database Record (c) 2010 APA, all rights reserved)