Nicotine and acute stress: effects of nicotine versus nicotine withdrawal on stress-induced hemoconcentration and cardiovascular reactivity

This study was designed to assess the effects of nicotine and nicotine withdrawal on stress-induced hemoconcentration and cardiovascular reactivity during acute stress in smokers. Forty-six smokers (>or=10 cigarettes per day) were tested twice, once while wearing a 21 mg nicotine patch for 12h and once while wearing a placebo patch (nicotine withdrawal). Calculated plasma volume, hemoglobin, hematocrit, HR, SBP, DBP, cardiac output, stroke volume, and total peripheral resistance were assessed during a 10-min baseline period, 6-min Paced Auditory Serial-Addition Task (PASAT), and a 2-min cold pressor (CP). No differences between conditions were found for any of the hematological measurements. Participants demonstrated greater HR and SBP increases to the PASAT during the nicotine withdrawal condition. For CP, participants showed greater HR and DBP increases and SV decreases during the nicotine withdrawal condition. Data from affective state ratings indicated that participants reported more negative affect during the psychological challenges during nicotine withdrawal conditions. Negative affective state may further lead to enhanced cardiovascular reactivity. These results demonstrate that although nicotine and nicotine withdrawal significantly have differential effects on cardiovascular functioning, the same differential condition effects do not appear to exist for stress-induced hemoconcentration.     

Effects of menstrual phase and parental history of hypertension on cardiovascular response to cognitive challenge

The effects of parental history of hypertension and menstrual phase on systolic and diastolic blood pressure (SBP, DBP) and heart rate (HR) responses to two frustrating cognitive tasks were examined in 47 normotensive, young adult women. Subjects with and without a parental history of hypertension were scheduled to be tested during either the follicular (days 7-11 of a 28-day cycle) or luteal (days 17-22) phase of the menstrual cycle. During the laboratory session, HR, SBP, DBP, and self-report of affective states were measured while subjects performed two cognitive tasks (mental arithmetic and concept formation). Results indicated that the magnitude of SBP responses to the two tasks was significantly greater in subjects tested during the follicular phase than in subjects tested in the luteal phase of the menstrual cycle. No effect of parental hypertension was observed on cardiovascular response measures, though offspring of hypertensive parents reported experiencing significantly less anger during the tasks than subjects with normotensive parents.     

Social stressors and cardiovascular response: Influence of ambivalent relationships and behavioral ambivalence

Objective

The protective influence of social relationships on health is well documented; however, not all relationships are positive and negative aspects of relationships may be detrimental. Relatively less is known about the relationships characterized by both positivity and negativity (i.e., ambivalence). The goal of this study was to examine the relative influence of ambivalence in relationship quality and social behavior on cardiovascular response.

Methods

104 healthy young adults were randomly assigned to bring in either a supportive or ambivalent same-sex friend to the experiment. Participants were also randomly assigned to receive positive, negative, ambivalent or ambiguous feedback from their friend after giving a series of speeches. Cardiovascular response was obtained before, during, and after the social stressor (speech task).

Results

Results indicate a significant effect of relationship type before, during, and after the stressor task. Adjusting for baseline, heart rate reactivity and anxiety was significantly higher among those assigned to ambivalent friends relative to those assigned to supportive friends during the stressor task (ps < .05). There was also a significant effect of behavioral feedback during the speech task, such that those receiving ambivalent messages had the greatest systolic blood pressure (SBP) and diastolic blood pressure (DBP) reactivity (p < .05); however, there was no interaction between relationship and feedback conditions. Those in the ambivalent friend condition also exhibited significantly higher SBP, DBP, and anxiety during the baseline and recovery periods (ps < .05).

Conclusions

These findings suggest that both relationship quality and the actions of relationships may have a significant influence on health-relevant physiology.     

Mechanisms underlying hemodynamic and neuroendocrine stress reactivity at different phases of the menstrual cycle

This study examined the association of menstrual cycle phase with stress reactivity as well as the hormonal and neuroendocrine mechanisms contributing to cycle effects. Fifty‐seven women underwent a modified Trier Social Stress Test during the early follicular, late follicular, and luteal phases of the menstrual cycle. Greater increases in cardiac index (CI) and greater decreases in vascular resistance index (VRI) during speech were observed in the luteal phase relative to other phases, while greater increases in epinephrine (EPI) was observed during the late follicular and luteal phases compared to the early follicular phase. Luteal phase estradiol predicted luteal EPI reactivity but not CI or VRI reactivity, while luteal phase EPI reactivity predicted luteal phase CI and VRI reactivity. Thus, cycle‐related changes in EPI reactivity may be a stronger determinant of cycle effects on hemodynamic reactivity than sex hormones per se.     

Ambulatory blood pressure, heart rate, and neuroendocrine responses in women nurses during work and off work days.

OBJECTIVE: This study examined women's cardiovascular and neuroendocrine responsiveness to work. METHODS: Ambulatory blood pressure (BP) and heart rate (HR) were recorded over 24-hour periods on 2 work and 2 off days during the luteal and follicular phases of the menstrual cycle in 138 registered nurses, aged 25 to 50 years. Urinary catecholamines and cortisol were measured for day and night periods. RESULTS: During waking hours systolic BP (SBP), HR, and epinephrine were higher on work than off days. Diastolic BP (DBP) and HR were highest at work. Nurses scoring high on job demands had elevations in daytime SBP, daytime HR only on work days, and nighttime epinephrine on work days. Compared with those with short work histories, nurses employed longer had consistently higher norepinephrine levels during days and nights, and higher nighttime DBP during off days. In unmarried nurses compared with married nurses, nighttime cortisol was lower during all 4 days and norepinephrine was lower during days off. All findings were independent of actigraph-recorded activity. CONCLUSIONS: Although the work environment leads to increased activity of the cardiovascular and sympathoadrenal medullary system in healthy women, the effects are modified by the woman's domestic role, by the length of her employment, and by the demands of her job.     

Cardiovascular responses to psychological and physiological stressors during the menstrual cycle

Psychological and physical stress reactivity was studied in 15 females in two phases of the menstrual cycle (cycle days 5-7 and 24-26) and in 15 males. Each female was matched for age and time between sessions with a male. There was a significant phase-related difference in cardiovascular reactivity among the females. Females in the luteal phase reacted significantly more to the cold pressor but not to the mental arithmetic test. There were significant sex differences in systolic blood pressure, the males displaying higher levels during provocation, as well as during control conditions. The females were more reactive in heart rate to the mental stressor when changes from control conditions to stress were calculated. When the data were analyzed separately for smokers and non-smokers, there was a significant interaction between menstrual cycle phase and smoking. In the luteal phase, the female smokers were more reactive in systolic blood pressure than the non-smokers. The male smokers were more reactive than the non-smokers in diastolic blood pressure response to mental arithmetic, but not to the cold pressor test. Significantly higher levels of cortisol and aldosterone were found in the luteal phase as compared with the follicular phase. The cortisol levels were higher in the males than in the females in the follicular phase, whereas the female aldosterone concentrations in the luteal phase were higher than those of the males.     

Hydration status and cardiovascular function: effects of hydration enhancement on cardiovascular function at rest and during psychological stress.

This study examined the effects of a 3-day enhanced hydration regimen on resting cardiac function and reactivity to acute stress. Healthy volunteers (14 male, 14 female) were assigned to one of two groups: Enhanced Hydration and Normal Hydration Group. Participants in the Enhanced Group were given six 1-l bottles of water and instructed to drink two bottles a day in addition to normal fluid intake for 3 days preceding their laboratory session; no extra water was given to the Normal Group. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), cardiac output (CO), stroke volume (SV), and total peripheral resistance (TPR) were recorded during a 10-min baseline, 6-min Paced Auditory Serial Addition Test (PASAT), 5-min recovery, 5-min intermediate baseline, and 3-min Cold Pressor Test. Repeated-measures ANOVA revealed a significant Hydration GroupxTask interaction for DBP during the cold pressor (p<0.01) with the Enhanced Group exhibiting greater DBP reactivity to cold stress relative to the Normal Group. Analysis revealed significant Hydration GroupxGender interactions for SV and TPR (p<0.05) at rest and during both the PASAT and Cold Pressor Test. Females in the Enhanced Group displayed higher SV and lower TPR relative to Enhanced Group males, whereas females in the Normal Group displayed lower SV and greater TPR relative to Normal Group males. These results suggest that 3-day hydration enhancement influences blood pressure reactivity in both men and women, and that long-term hydration enhancement is related to resting gender differences in cardiac function.     

The Availability of Social Support Reduces Cardiovascular Reactivity to Acute Psychological Stress

The influence of the availability of social support on cardiovascular reactivity to acute psychological stress was examined. Twenty-eight men and twenty-one women performed a speech task either in a support availability or no support availability condition while measures of systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were assessed. Consistent with past research, the speech stressor was associated with significant increases in SBP, DBP, and HR. More important, the availability of social support moderated cardiovascular reactivity to the acute stressor: individuals in the support availability condition were characterized by lower SBP and DBP reactivity to the acute stressor compared to individuals in the no support availability condition. These data suggest that simply having potential access to support is sufficient to foster adaptation to stress in the absence of enacted support.     

Reproducibility of blood pressure and heart rate reactivity: A meta-analysis

Reproducibilities of blood pressure and heart rule (HR) reactivity reported in studies assessing responses to the same laboratory stressors across occasions were reviewed with meta-analytic techniques. Changes in HR had the greatest reproducibility (r =.555), followed by systolic blood pressure (SBP) (.407) and diastolic blood pressure (DBF) (.348), Both SBP and HR response reproducibility was higher at shorter lest-retest intervals, whereas DBP values varied unsystematically with length of test-retest interval Older samples exhibited higher SBP and DBP reproducibility to stressors. SBP and DBP reproducibilities were better for tasks that did not make speech demands. The reliability of reactivity assessment was higher when based on three or more measurements, On the basis of able evidence, the drop in stress reproducibility, as test-retest interval increases, places limits on the viability of BP reactivity as a strong marker or risk factor for coronary heart disease.     

Hormonal and behavioral responses to stress in lactating and non-lactating female common marmosets (Callithrix jacchus)

In several mammalian species, hypothalamic-pituitary-adrenal (HPA) and behavioral responses to stressors are down-regulated in lactating females, possibly preventing stress-induced disruptions of maternal care. Experimental elevations of HPA axis hormones have been found to inhibit maternal behavior in lactating common marmoset monkeys (Callithrix jacchus), raising the question of whether lactating female marmosets also have blunted endogenous responses to stress. Therefore, we compared HPA and behavioral responses to standardized stressors in reproductively experienced female common marmosets that were undergoing ovulatory cycles and that either were (N = 7) or were not lactating (N = 8). Each marmoset underwent (1) a restraint stressor during the early follicular phase of the ovarian cycle (approximately 5 weeks postpartum for lactating females) and (2) exposure to a simulated hawk predator during the early to mid-luteal phase (approximately 7 weeks postpartum for lactating females). Lactating females were tested in the presence of one of their infants. Blood samples were collected before, during, and immediately after each test for determination of plasma adrenocorticotropic hormone (ACTH) and cortisol concentrations. Both stressors caused significant elevations in plasma ACTH and cortisol levels, and significant decreases in cortisol:ACTH ratios; however, lactating and non-lactating females showed no significant differences in their endocrine or behavioral responses to either stressor, or in baseline ACTH or cortisol levels. These findings suggest that in contrast to several other mammalian species, lactating female marmosets maintain full behavioral and HPA responsiveness to stress, at least in the presence of their infants.     

Menstrual Cycle Phase is a Potential Confound in Psychophysiology Research

Effects of menstrual cycle phase on physiological levels and reactivity were studied in a withinsubject design with 20 women aged 18–30 years. Basal body temperature was monitored daily; follicular and luteal recording sessions occurred before and after the ovulatory temperature rise, respectively. The design consisted of task and rest periods, presented in counterbalanced order across phases. Half the subjects began during their follicular phase and half began during their luteal phase. Follicular and luteal phases were compared for differences between baseline resting levels, as well as for reactivity. The results showed menstrual phase differences in heart rate, pulse transit time, and EEG alpha, particularly during tasks, but no difference in reactivity. Habituation effects in the group that began during the follicular phase often masked luteal activation. In spite of the fact that not all statistical results achieved significance, the consistency of most trends supports the conclusion that physiological recording sessions with women might best be restricted to the follicular phase.     

Changes of respiratory sinus arrhythmia during the menstrual cycle depend on average heart rate

To evaluate the complex time course of changes in respiratory sinus arrhythmia (RSA) during the menstrual cycle, daily beat-to-beat morning recordings of heart rate (HR) were carried out in 26 healthy female subjects (age 20–29 years) during two menstrual cycles. For determination of fast, vagally mediated variations of HR we used a robust time-domain measure of RSA (logRSA). We found pronounced changes in HR during the menstrual cycle with a minimum in the early follicular phase and a maximum in the late luteal phase. There were large differences between individuals in the fluctuations of logRSA during the menstrual cycle that were related to average HR: subjects with a low HR exhibited higher values of logRSA in the luteal compared to the follicular phase, whereas the trend was reversed in subjects with a high HR. The difference of extreme points of logRSA fluctuations (early follicular and mid luteal phase) was correlated to average HR (r=–0.64, P<0.001). We conclude that different patterns of RSA fluctuations occur depending on the level of average HR. Electronic Publication     

Smoking cessation and cardiovascular reactivity to stress

Systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) reactivity to mental arithmetic and deep knee bends were monitored in a sample of smokers prior to and 6 months following smoking cessation. There was no reduction in cardiovascular reactivity to either stressor following cessation. However, heightened pretreatment DBP and HR reactivity to mental arithmetic and SBP reactivity to deep knee bends were associated with relapse by the 6-month follow-up. Demographic and smoking history variables and pretreatment nicotine dependence were not associated with treatment outcome. Further exploration of cardiovascular reactivity to stress among smokers may elucidate the process of relapse.This research was supported by funds from the American Lung Association (Nassau-Suffolk County, NY), the American Heart Association (Suffolk County), the Veteran's Administration, NIH Grants HL3142903, HL3426103, HL4036801, and CA 50108-02, Biomedical Research Support Grants RR0706721 and RR0536927, and Sigma Xi.     

Variations in dynamic knee valgus and gluteus medius onset timing in non-athletic females related to hormonal changes during the menstrual cycle

It has been suggested that activities of daily living could contribute to the occurrence of ACL injury in females. Currently, no studies have focused on the lower extremity behavior of a non-athletic population to compare or understand the lower extremity adeptness towards daily movements that mimic athletic tasks. Our hypothesis was that increased knee valgus angles would occur during the late follicular phase of the menstrual cycle accompanied by different onset timing of the gluteus medius muscle. In a controlled laboratory study, 23 non-athletic collegiate females participated and 15 subjects comprised the final sample for statistical analysis. Subjects performed a single leg drop landing maneuver while 3-D knee kinematics and gluteus medius muscle onset timing were assessed throughout three distinct phases of the menstrual cycle, confirmed by blood hormone analysis. In general, knee valgus angles were significantly less in the luteal phase compared to both follicular phases (p < 0.005), while differences were not observed for gluteus medius onset timing (p = 0.936). As a decreased knee joint valgus angle was observed during the luteal phase, it was hypothesized that the hormone progesterone could significantly influence knee kinematics during a dynamic task. However, such influence was not observed for gluteus medius EMG onset timing as a significant correlation between gluteus medius onset timing and knee valgus angle could not be determined.     

The role of menstrual cycle phase and anxiety sensitivity in catastrophic misinterpretation of physical symptoms during a CO2 challenge

The current study examined the interactive effects of anxiety sensitivity (AS; fear of anxiety and anxiety-related sensations) and menstrual cycle phase (premenstrual phase vs. follicular phase) on panic-relevant responding (i.e., cognitive and physical panic symptoms, subjective anxiety, and skin conductance level). Women completed a baseline session and underwent a 3-min 10?% CO₂-enriched air biological challenge paradigm during her premenstrual and follicular menstrual cycle phases. Participants were 55 women with no current or past history of panic disorder recruited from the general community (M _age?=?26.18, SD?=?8.9) who completed the biological challenge during both the premenstrual and follicular cycle phases. Results revealed that women higher on AS demonstrated increased cognitive panic symptoms in response to the challenge during the premenstrual phase as compared to the follicular phase, and as compared to women lower on AS assessed in either cycle phase. However, the interaction of AS and menstrual cycle phase did not significantly predict physical panic attack symptoms, subjective ratings of anxiety, or skin conductance level in response to the challenge. Results are discussed in the context of premenstrual exacerbations of cognitive, as opposed to physical, panic attack symptoms for high AS women, and the clinical implications of these findings.     

Ethnic differences in cardiovascular responses to laboratory stress: A comparison between asian and white americans

Compared to other ethnic groups, Asian Americans show significantly lower rates of cardiovascular disease (CVD). We tested the hypothesis that Asian Americans would show reduced cardiovascular responses to laboratory stressors than Caucasians. Forty-three Asians (18 men, 25 women) and 77 Caucasians (36 men, 41 women) with a mean age of 24 years (SD = 3.93) participated in a stress reactivity protocol consisting of four tasks (speech, serial subtraction, mirror tracing, handgrip) while heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were measured. Asian Americans demonstrated overall lower reactivity across tasks for SBP F(1,117 = 7.48, p < .01) and a trend toward lower HR response F(1,117 = 3.18, p < .10). A significant ethnicity by task interaction was observed for HR reactivity F(3,351 = 2.94, p < .05) such that Caucasians showed greater responses for the subtraction task.     

The Effects of Menstrual Cycle Phase on Cardiovascular and Pulmonary Responses to Behavioral and Exercise Stress

The present study was designed to compare the differential cardiopulmonary and hemodynamic responses of Type A and B women to an exercise and a psychological stressor. In addition, the effects of menstrual cycle phase on the resting and response levels of a wide range of physiological variables were explored. Thirty-two women participated in a progressive exercise stress test and a threat of shock video game during both the luteal and follicular phases of the menstrual cycle. Half of these subjects expressed the coronary-prone behavior pattern referred to as Type A, as assessed by the Jenkins Activity Survey. The remaining women were relatively free of these behaviors (Type B). Heart rate, oxygen consumption, carbon dioxide production, minute ventilation, and end-tidal carbon dioxide were monitored and recorded on a breath-by-breath basis. Systolic and diastolic blood pressure measures were taken at 2-min intervals. Results indicated similar baseline, exercise, and behavioral stress responses among Type A and B women. The stress responses were also the same between the follicular and luteal phases for all measured physiological variables. However, resting levels of heart rate, metabolism, and ventilation were all elevated at rest during the luteal phase. A regression analysis based on the exercise heart rate and oxygen consumption data demonstrated that a majority of subjects exhibited heart rate responses in excess of that expected during the psychological stressor. These data are discussed with special reference to possible mechanisms of the pathophysiology of cardiovascular disease.     

Sibling Similarities in Cardiovascular Reactivity to Stress

To examine the similarities of nun-twin sibling pairs in cardiovascular reactivity to stress, in terms of both individual parameters such as heart rate and general cardiovascular reactivity, 36 young adult sibling pairs were recruited. Members of 12 same-sex male, 12 same-sex female, and 12 opposite-sex pairs participated in a 66-min experimental protocol consisting of alternating stress and relaxation periods. Pour stressors were employed: a challenging conceptual task, mental arithmetic, isometric bund-grip, and the cold pressor test. Repeated measurements of systolic and diastolic blood pressure (SBP. DBF), heart rate (HR), ear pulse transit time (EPTT), and digital blood volume pulse (DBVP) were obtained. Pair members exhibited significant similarities in resting SBP, DBP, and HR. A number of significant similarities in reactivity to stress were observed. To examine the specificity of familial influences on different aspects of cardiovascular response to stress, a number of canonical and cross-correlations were computed. The cardiovascular reactions of one sibling were used to predict those of his/her brother or sister. Several of the correlations attained significance. Most interestingly, familial influences on SBP, DBP, and DBVP reactivity to the cold pressor test appear to exhibit some degree of overlap, possibly reflecting more fundamental familial influences on alpha-adrenergic reactivity. Joint familial influences on behavioral and cardiovascular reactivity to stress are discussed.     

Is the association between depression and blunted cardiovascular stress reactions mediated by perceptions of stress?

Symptoms of depression are related to blunted cardiovascular reactions to acute stress tasks. However, it is unclear what factors might mediate this association and whether blunted responses are specific to mental stress tasks or are also evident with other forms of stress. The present study assessed cardiovascular reactivity to both mental and postural stress and the role of background stress exposure and stress perception. Undergraduate students (N = 119, 81 females) were screened for depressive symptoms using the Beck Depression Inventory. Twenty-six participants with probable depression and 26 non-depressed controls underwent cardiovascular stress testing. Heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressure were measured at rest and in response to a 5 min orthostatic challenge and an 8 min mental arithmetic task. Stress exposure was measured using the Undergraduate Stress Questionnaire. Perceptions of general life stress were assessed using the Perceived Stress Scale (PSS) and perceptions of the stress task impact were measured using Threat Appraisal (TA). Symptoms of depression were associated with blunted HR, F(2,98) = 5.26, p = .010, η² = .097, and SBP, F(2,98) = 6.47, p = .008, η² = .117, reactions to the mental stress but not to postural challenge. HR reactions were mediated by PSS score, while both PSS score and TA emerged independently as mediators of SBP reactions. These results confirm a negative relationship between depressive symptoms and cardiovascular reactions to acute stress, suggest that this association may be stress task-specific, and may be mediated by perceptions of stress.     

Heart rate and autonomic response to stress after experimental induction of worry versus relaxation in healthy,high-worry,and generalized anxiety disorder individuals

Generalized anxiety disorder (GAD) is the most commonly occurring anxiety disorder and has been related to cardiovascular morbidity such as cardiac ischemia, sudden cardiac death, and myocardial infarction. Both GAD and its cardinal symptom – worry – have been shown to promote muted physiological reactivity in response to laboratory and ecological stressors. Importantly, no study to date has examined the concurrent and relative contributions of trait and state worry within healthy controls, (non-clinical) high trait-worry controls, and GAD participants. The present study examined heart rate (HR), respiratory sinus arrhythmia (RSA), and salivary alpha-amylase (sAA) responses to laboratory stress during and following the experimental induction of worry versus relaxation in healthy controls (n = 42), high trait worriers (n = 33) and participants with GAD (n = 76). All groups exhibited increased HR and decreased RSA in response to the stressor, with no differences by condition. Baseline sAA significantly moderated HR and RSA reactivity, such that higher sAA predicted greater increases in HR and decreases in RSA. There was a significant group by baseline sAA interaction such that in GAD, higher baseline sAA predicted decreased change in sAA during stress, whereas higher baseline sAA predicted greater sAA change in healthy controls. High-worry controls fell non-significantly between these groups. The present study provides additional evidence for the effect of worry on diminished HR stress response and points to possible suppression of adrenergic sympathetic stress responses in GAD.