Maternal blood pressure trajectories and associations with gestational age at birth: a functional data analytic approach

BACKGROUND

Research has revealed group-level differences in maternal blood pressure trajectories across pregnancy. These trajectories are typically constructed using clinical blood pressure data and multivariate statistical methods that are prone to bias and ignore the functional, dynamic process underlying a single blood pressure observation. The aim of this study was to use functional data analysis to explore blood pressure variation across pregnancy, and multivariate methods to examine whether trajectories are related to gestational age at birth.

METHODS

Clinical blood pressure observations were available from 370 women who participated in a longitudinal pregnancy cohort study conducted in Montreal, Quebec, Canada. Functional data analysis was used to smooth blood pressure data and then to conduct a functional principal component analysis to examine predominant modes of variation.

RESULTS

Three eigenfunctions explained greater than 95% of the total variance in blood pressure. The first accounted for approximately 80% of the variance and was characterized by a prolonged-decrease trajectory in blood pressure; the second explained 10% of the variance and captured a late-increase trajectory; and the third accounted for approximately 7% of the variance and captured a mid-decrease trajectory. The prolonged-decrease trajectory of blood pressure was associated with older, and late-increase with younger gestational age at birth.

CONCLUSION

Functional data analysis is a useful method to model repeated maternal blood pressure observations and many other time-related cardiovascular processes. Results add to previous research investigating blood pressure trajectories across pregnancy through identification of additional, potentially clinically important modes of variation that are associated with gestational age at birth.

The relationship of trait mindfulness to physical and psychological health during pregnancy

INTRODUCTION

Research on mindfulness has extended to the prevention of psychopathology and physical conditions during pregnancy. The purpose of this study was to investigate the relationship between trait mindfulness assessed in the first or early second trimester to health outcomes throughout pregnancy.

METHODS

A total of 510 women were recruited at McGill University-affiliated obstetrics clinics (average gestational age: 13.43 weeks, sd = 1.2). The Mindful Awareness and Attention Scale (MAAS) was administered at baseline. At three timepoints during pregnancy, participants completed the Perceived Stress Scale (PSS-10), the Edinburgh Postnatal Depression Scale (EPDS), the Prenatal Distress Questionnaire-revised (PDQR) and a measure of pregnancy symptom intensity and indicated whether they had been diagnosed with gestational diabetes or high blood pressure.

RESULTS

Higher MAAS scores predicted lower PSS, EPDS and PDQR scores and less severe physical discomforts throughout pregnancy. MAAS scores were a stronger predictor of PSS scores earlier in pregnancy. Logistic regressions found that trait mindfulness did not predict the presence of physical discomforts, diabetes or high blood pressure.

CONCLUSIONS

These results indicate that trait mindfulness is an important predictor of subjective stress, depression, anxiety and the severity of physical discomforts during pregnancy. These findings suggest that interventions earlier in pregnancy may increase the impact of mindfulness on maternal health.

Social Contagion of Vasovagal Symptoms in Blood Donors: Interactions With Empathy

BACKGROUND

Vasovagal reactions (VVRs) are commonly experienced in medical situations such as blood donation. Many believe that psychosocial contagion can contribute to the development of VVRs, but this is largely clinical lore.

PURPOSE

The goal of the present investigation was to examine the physiological effects of observing another experience a reaction, focusing on the potential moderating effects of empathy.

METHODS

This study was part of a randomized controlled trial of behavioral techniques on the prevention of VVRs in blood donors. The sample was composed of 530 healthy university students. Measures of symptoms were obtained with the Blood Donation Reactions Inventory (BDRI) and through observation. Physiological variables were measured using respiratory capnometry and a digital blood pressure monitor. The Affective and Cognitive Measure of Empathy was administered to 230 participants.

RESULTS

Donors who witnessed another experiencing a reaction were more likely to spontaneously report symptoms during the blood draw, to be treated for a reaction, to score higher on the BDRI, and to exhibit smaller compensatory heart rate increases. Donors with higher affective empathy reported more symptoms, exhibited hyperventilation, and were more likely to be treated. Donors with higher cognitive empathy were less likely to require treatment if they witnessed a reaction.

CONCLUSION

These results suggest that psychosocial contagion of physical symptoms can occur. The moderating effects of empathy differed depending on the subtype of empathy. Perhaps a better cognitive understanding of how other people are feeling functions as a coping response, whereas feeling sympathetic about others' distress increases one's own.

Vagal Tone Biofeedback: Respiratory and Non-respiratory Mediated Modulations of Vagal tone Challenged by Cold Pressor Test

Deficient parasympathetic activity to the heart has been hypothesized to underlie some forms of cardiovascular disease. Consequently, this experiment attempted to induce non- respiratory mediated increases in cardiac parasympathetic activity. Thirty-nine subjects were asked to increase their vagal tone using biofeedback, paced breathing, biofeedback plus paced breathing, or quiet sitting. The cold pressor test was used to examine the relative efficacy of vagal tone increase to mitigate cardiovascular reactivity. Repeated measures ANOVAs and t-tests revealed significant increases in vagal tone for the paced breathing, and biofeedback plus paced breathing groups, relative to controls. However, the quality of these increases could not be tested using the cold pressor test because the test failed to produce homogeneous cardiac 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.

The Association Between Pregnancy-Specific Anxiety and Exclusive Breastfeeding Status Early in the Postpartum Period

BACKGROUND

Exclusive breastfeeding is recommended for the first 6 months of life and has significant benefits for both mother and child. Pregnancy-specific anxiety is a distinct and definable syndrome that has been identified as a robust predictor of pregnancy outcomes, but whether it is associated with exclusive breastfeeding status has not been determined.

RESEARCH AIMS

To examine the association between pregnancy-specific anxiety in each trimester of pregnancy and exclusive breastfeeding status early in the postpartum period.

METHODS

Data were available from 412 women who participated in a longitudinal pregnancy cohort study. Pregnancy-specific anxiety and exclusive breastfeeding status were assessed using an online self-report questionnaire.

RESULTS

Logistic regression analyses showed that a one-unit increase in pregnancy-specific anxiety in the first (OR = 0.94, 95% CI [0.90, 0.98]) and third (OR = 0.95, 95% CI [0.91, 0.99]) trimester of pregnancy was associated with a 5-6% decrease in the odds of exclusive breastfeeding at 6-8 weeks postpartum.

CONCLUSIONS

Pregnancy-specific anxiety was associated with lower odds of exclusive breastfeeding at 6-8 weeks postpartum. Prenatal interventions designed to increase exclusive breastfeeding duration may benefit from the incorporation of strategies that help reduce worries and concerns unique to the pregnancy experience.

Expectancies mediate the relationship between perceived injustice and return to work following whiplash injury: A 1-year prospective study

BACKGROUND

Emerging evidence suggests that perceived injustice is a risk factor for work disability in individuals with whiplash injury. At present, however, little is known about the processes by which perceived injustice impacts on return to work. The purpose of this study was to examine whether expectancies mediated the relationship between perceived injustice and return to work in patients with whiplash injury.

METHOD

One hundred and fifty-two individuals (81 men, 71 women) with a primary diagnosis of whiplash injury completed self-report measures of pain intensity, perceived injustice and return-to-work expectancies following admission to a rehabilitation programme. Work status was assessed 1 year after discharge.

RESULTS

Consistent with previous research, high scores on a measure of perceived injustice were associated with prolonged work disability. Results indicated that high perceptions of injustice were associated with low return-to-work expectancies. Causal mediation analyses revealed that expectancies fully mediated the relationship between perceived injustice and return to work.

CONCLUSION

The findings suggest that intervention techniques designed to target expectancies could improve return-to-work outcomes in patients with whiplash injury. Discussion addresses the processes by which expectancies might impact on return-to-work outcomes and the manner in which negative return-to-work expectancies might be modified through intervention.

SIGNIFICANCE

The study confirms that expectancies are the mechanism through which perceived injustice impacts return to work following whiplash injury. The findings suggest that interventions designed to specifically target return-to-work expectancies might improve rehabilitation outcomes in patients with whiplash injury.

Respiratory and hemodynamic contributions to emotion-related pre-syncopal vasovagal symptoms

Vasovagal reactions are conventionally understood as resulting from systemic changes in cardiovascular activity; however, there exists a complementary perspective focused on specific changes in cerebral vasoconstriction associated with hyperventilation-induced hypocapnia. The present study investigated the role of cardiovascular and respiratory activity in self-reported pre-syncopal vasovagal reactions to a surgery video in a sample of 49 healthy women. Participants who indicated more previous real-life episodes of dizziness reported experiencing significantly more symptoms in the laboratory consistent with a vasovagal response. They also showed lower total peripheral resistance and higher pre-ejection period in general, suggesting lower sympathetic nervous system activity. Significant decreases in end-tidal carbon dioxide (P_ETCO₂) occurred during the surgery video among susceptible participants, without significant increases in respiration rate. Further, participants who experienced reductions from the neutral video in P_ETCO₂, systolic blood pressure, or both, reported vasovagal symptoms during the surgery video. The results suggest that patterns of respiration associated with decreases in P_ETCO₂ may contribute to vasovagal symptoms reported in non-clinical groups as well as those with blood-injection-injury phobia and are associated with susceptibility to dizziness.

Attitudes and Attributions Related to Psychological Symptomatology in Indian Immigrant Women

This study explored the patterns of attitudes and attributions associated with relatively high and low distress among a sample of (N = 104) immigrant women from India living in Montreal. Results showed the high distress group to be less satisfied with their roles in the home and in the job market, to be more in favor of modem sex roles, to want less to pass on traditional sex roles to their children, to attribute success and failure more to their own personal characteristics and less to destiny, and to perceive more racial discrimination in society. The findings underline the value of differentiating between aspects of immigration and incorporating social psychological variables in studies of possible links between immigration and distress.

The vasovagal response during confrontation with blood-injury-injection stimuli: the role of perceived control

The vasovagal response (VVR) is a common medical problem, complicating and deterring people from various procedures. It is an unusual stress response given the widespread decreases in physiological activity. Nevertheless, VVR involves processes similar to those observed during episodes of strong emotions and pain. We hypothesized that heightened perceived control would reduce symptoms of VVR. Eighty-two young adults were randomly assigned to perceived control or no perceived control conditions during exposure to a stimulus video of a mitral valve surgery, known to trigger VVR in non-medical personnel. Perceived control was manipulated by allowing some participants to specify a break time, though all received equivalent breaks. Outcomes included subjective symptoms of VVR, anxiety, blood pressure, heart rate, and other measures derived from impedance cardiography. Compared to participants with perceived control, participants with no perceived control reported significantly more vasovagal symptoms and anxiety, and experienced lower stroke volume, cardiac output, and diastolic blood pressure. Participants who were more fearful of blood were more likely to benefit from perceived control in several measures. Perceived control appears to reduce vasovagal symptoms. Results are discussed in terms of cognition and emotion in VVR.

The interaction between anxiety and depressive symptoms on brachial artery reactivity in cardiac patients

The association between anxiety, depression, and endothelial function (EF) was assessed in a sample of 295 cardiac outpatients (n=222 men; mean age=59). Patients were administered the Beck Depression Inventory-II and the State-Trait Anxiety Inventory, trait scale. EF was assessed through forearm hyperemic reactivity, a nuclear medicine variation of the flow-mediated dilatation technique, which calculates the rate of uptake ratio (RUR) between hyperaemic and non-hyperaemic arms. Neither effect of anxiety (F=1.40, p=.24) nor depression (F=2.66, p=.10) was found in a model predicting EF, however there was an interaction (F=4.11, p=.04). Higher anxiety and lower depressive symptoms were associated with superior RUR compared to lower anxiety and lower depressive symptoms. Anxiety had no influence on RUR in those patients with higher depressive symptoms, who generally displayed the lowest levels of RUR, i.e., poor function. It is speculative whether this potential protective role of anxiety may be guided by behavioral or physiological mechanisms.

Donor anxiety, needle pain, and syncopal reactions combine to determine retention: a path analysis of two-year donor return data

BACKGROUND

Efforts to expand the donor pool by recruiting younger donors have resulted in higher numbers of initial donations, but retention of young donors continues to be challenging.

STUDY DESIGN AND METHODS

Path analysis was used to examine the simultaneous relationships among syncopal reactions, donation anxiety, needle pain, donor satisfaction, and donation intention in predicting repeat donation. Participants included 421 first- and second-time donors recruited for a study comparing the effects of predonation water loading with and without the use of applied muscle tension during donation (52% female, 60.8% first-time donor, mean age 20.3 years). For this longitudinal follow-up study, donor database records were accessed 2 years after the index donation to assess repeat donation.

RESULTS

Results of a series of path analyses demonstrated the influential role of donor anxiety in shaping donor retention (final model χ(2) = 35.75, root mean square error of approximation 0.03, comparative fit index 0.98, weighted root mean square residual 0.74). First, anxiety exerted a direct negative influence on donation intention, the proximal and sole direct predictor of repeat donation. Second, anxiety increased the likelihood of donor-reported needle pain, adversely affecting donation satisfaction and, subsequently, donation intention. Finally, anxiety was associated with donor ratings of syncopal reactions through its impact on needle pain, which also contributed to decreased donation intention.

CONCLUSION

These results provide novel evidence that donation anxiety plays a central role in shaping future donation behavior. Individual differences in anxiety must be considered when developing and testing strategies to enhance blood donor retention.

Cognitive depressive symptoms associated with delayed heart rate recovery following interpersonal stress in healthy men and women

Among cardiac patients, research suggests that somatic depressive symptoms are more strongly associated with altered cardiovascular responses to stress than cognitive depressive symptoms. This study sought to determine whether this was also the case in healthy individuals. One hundred and ninety-nine adults from the community completed the Beck Depression Inventory II (BDI-II) and underwent psychological laboratory stressors while their blood pressure, heart rate, and heart rate variability were monitored. A cognitive-affective factor and somatic-affective factor were identified within the BDI-II, but only the cognitive factor was associated with reduced heart rate recovery following the stressors in multivariate analyses examining both factors simultaneously. This suggests that cognitive depressive symptoms may be more strongly related to altered stress physiology following psychological stressors.

The effects of blood-draw and injection stimuli on the vasovagal response

Vasovagal reactions (VVR) are common, complicating and deterring people from various medical procedures. A recent perspective (R. R. Diehl, ) suggests that VVR developed from the adaptive process of hemorrhagic fainting, perhaps as a means of preparing for anticipated blood loss. The primary goal of this study was to compare vasovagal symptoms during intravenous-injection and blood-draw videos. Sixty-two young adults watched the videos. Vasovagal symptoms were assessed with self-report, blood pressure, and heart rate variability. As predicted, participants reported more vasovagal symptoms and anxiety following the blood-draw video. Sympathetic nervous system activity (low- to high-frequency ratio) decreased during both videos but significantly more during the blood-draw video, although this could be reversed by the Applied Tension technique. Results are discussed in terms of the relevance of specific stimuli and emotions in VVR.

Relation between perceived blood loss and vasovagal symptoms in blood donors

INTRODUCTION/RESULTS: This study examined whether a belief of significant blood loss may be associated with vasovagal symptoms, irrespective of actual blood loss. Individual differences in vasovagal symptoms among blood donors who had an equivalent amount of blood withdrawn were significantly associated with their rating of perceived blood loss.

CONCLUSION

The anticipation or belief of blood loss, and perhaps more remotely associated ideas, may trigger processes similar to those induced by actual hemorrhage though further research is required to address other possibilities such as the inflation of ratings by vasovagal symptoms.

Applied tension and blood donation symptoms: the importance of anxiety reduction

OBJECTIVE

Despite being a voluntary activity, many blood donors experience anxiety, and fainting (syncope) is not unusual. The muscle-tensing technique applied tension (AT) has been found to be effective in reducing vasovagal symptoms and syncope. A series of studies was developed to investigate the role of AT on anxiety and fainting.

METHODS

The mechanisms of AT were examined in the laboratory and the blood donor clinic. In Study 1, 70 participants were assigned randomly to either a control group or an experimental group who learned AT before watching a video depicting blood draws. In Study 2, 667 volunteer blood donors completed similar questionnaires.

RESULTS

In Study 1, a significant Condition × Sex × Needle Fear interaction, F(1, 59) = 4.97, p = .03, indicated that AT reduced vasovagal symptoms in higher-fear women. Study 2 also found a significant Condition × Sex × Needle Fear effect on vasovagal symptoms, F(2, 653) = 3.95, p = .02, indicating that AT reduced symptoms but primarily among women with more pronounced fear of needles.

CONCLUSIONS

Analysis of the physiological data and self-reported anxiety supports the conclusion that the reduction in vasovagal symptoms was due more to decreased anxiety rather than exercise-related cardiovascular change. These results suggest that AT may provide a useful means of coping with invasive medical procedures in part by reducing anxiety.

Limbic response to psychosocial stress in schizotypy: a functional magnetic resonance imaging study

Psychological stress causes dopamine release in the striatum and is thought to play a role in susceptibility to psychotic illness. Previous work suggests that an elevated dopaminergic response to stress may index vulnerability to psychosis in certain individuals. With functional magnetic resonance imaging, we measured stress-induced changes in brain activity in healthy individuals at elevated risk of developing psychosis. Participants were 15 controls and 25 psychometric schizotypes: 12 with positive symptom schizotypy (perceptual aberrations) and 13 with negative symptom schizotypy (physical anhedonia), as determined by questionnaires (Chapman et al., 1976; Chapman and Chapman, 1978). In the scanner, participants performed the Montreal Imaging Stress Task and a matched sensory-motor control task. Measures of self-reported stress and salivary cortisol levels were taken throughout the experiment. All three groups showed significant increases in self-reported stress and significant fMRI signal change in the striatal, limbic and cortical regions. However, the Physical Anhedonia group showed greater stress-induced striatal and limbic deactivation than the other two groups. Deactivation in the striatum was significantly correlated with Physical Anhedonia score across all subjects. Our findings suggest the presence of abnormalities in striatal response to stress in negative symptom schizotypy.

Fear-related predictors of vasovagal symptoms during blood donation: it's in the blood

A recent theory proposes that emotional fainting developed from an earlier adaptive characteristic, fainting in response to hemorrhage. Despite potential loss of consciousness, a dramatic decrease in blood pressure improves chances of survival in animals with severe wounds by reducing blood loss and facilitating clotting. Humans may have developed the characteristic of emotional fainting as a response to anticipated blood loss. This idea suggests that people with stronger fears of blood should be especially susceptible to fainting and milder vasovagal symptoms such as dizziness and lightheadedness. Two samples of young adult blood donors (N = 276 and 663) who completed the Medical Fears Survey (MFS) were studied. Items from the MFS related to fears of blood, needles, and mutilation were used to predict self-reported dizziness and nurse-initiated treatment for vasovagal reactions. In both samples, fears of experiencing or seeing blood loss were more closely associated with both subjective and objective measures of vasovagal reactions, despite the fact that other fears (e.g., fears related to needles) were more common overall. Better understanding of the mechanisms of vasovagal reactions has both theoretical and clinical implications, such as improving means of coping with invasive medical procedures.

Applied tension may help retain donors who are ambivalent about needles

BACKGROUND

Vasovagal symptoms can discourage people who might otherwise give blood on many occasions. However, the effects of symptoms on donor retention as well as the effects of treatments to reduce vasovagal symptoms on donor retention are probably moderated by a person's confidence that they can tolerate the procedure.

METHODS

Data from a study on the effects of the muscle tensing technique applied tension (AT) on donor retention were examined to determine if (1) the degree of donor ambivalence about needles influenced the impact of vasovagal symptoms on subsequent return and (2) ambivalence about needles moderated the effect of learning AT on donor return. One-year follow-up data on 614 people who had previously given blood and were randomly assigned to either a no treatment, donation-as-usual condition or one of two conditions involving AT were obtained. Self-reported degree of needle ambivalence and vasovagal symptoms were assessed during the initial blood donation.

RESULTS

Among participants in the no treatment group, increases in vasovagal symptoms were associated with decreases in donor return but only among people who expressed some fear of blood draws. Similarly, among people who expressed no fear of needles, learning AT had no effect on post-donation estimate of the likelihood they would give blood again or return rate. However, among people with some fear of blood draws learning AT led to both a higher estimate that they would give blood again as well as actual return rate.

CONCLUSIONS

The experience of vasovagal symptoms may not deter people who are generally confident in their ability to tolerate blood donation. However, among people who are ambivalent about needles, symptoms may 'confirm' pre-existing doubts about their suitability for blood donation and lead to drop-out. Targeted interventions that give the uncertain volunteer a sense of confidence that they might be able to realize their goal and become a regular blood donor may be useful.

Predonation hydration and applied muscle tension combine to reduce presyncopal reactions to blood donation

BACKGROUND

A randomized controlled trial was conducted to test the effects of hydration and applied muscle tensing on presyncopal reactions to blood donation. Both interventions are designed to prevent the decreases in blood pressure that can contribute to such reactions, but due to the distinct physiologic mechanisms underlying their pressor responses it was hypothesized that a combined intervention would yield the greatest benefit.

STUDY DESIGN AND METHODS

Before blood donation, first- and second-time blood donors (mean age, 20.2 years; SD, 4.9) were randomly assigned to 1) standard donation, 2) placebo (leg exercise before venipuncture), 3) predonation water, or 4) predonation water and leg exercise during donation.

RESULTS

Main effects of group were observed for phlebotomist classification of vasovagal reactions (chi(2)(3) = 8.38, p < 0.05) and donor reports of presyncopal reactions (chi(2)(3) = 13.16, p < 0.01). Follow-up analyses of phlebotomist classifications revealed fewer reactions in the predonation water and predonation water and leg exercise groups relative to placebo but not standard donation. Follow-up analyses of self-reported reactions revealed that women, but not men, had lower scores in both the predonation water and the predonation water and leg exercise groups relative to both placebo and standard donation.

CONCLUSIONS

Predonation hydration and a combination of hydration and leg exercise may help attenuate presyncopal reactions in relatively novice donors, although future studies with larger samples are required to confirm this effect.

Effects of cardiopulmonary baroreceptor activation on pain may be moderated by risk for hypertension

Cardiopulmonary baroreceptor stimulation may modulate pain, though the literature is much smaller than research showing that sinoaortic baroreceptor stimulation can buffer pain. To examine the possibility that risk for established high blood pressure may moderate the effects of cardiopulmonary baroreceptor stimulation on pain, 22 borderline hypertensive and 18 normotensive men participated in a laboratory experiment. Group differences in blood pressure were documented by 24-h ambulatory blood pressure recording. Ratings of the intensity of acute heat pain were influenced by both group membership and leg position. Passive elevation of the legs, a technique that stimulates cardiopulmonary baroreceptors, reduced ratings of heat pain though only among borderline hypertensives. Alteration of pain sensitivity may reflect the development of the hypertensive process.

Dismantling applied tension: mechanisms of a treatment to reduce blood donation–related symptoms

BACKGROUND

Blood donation-related symptoms such as dizziness, nausea, and fainting are unpleasant for the donor and a significant disincentive for repeat donation. The muscle tensing technique of applied tension (AT) reduced symptoms in several studies.

STUDY DESIGN AND METHODS

This study was a randomized controlled trial of different components of AT. A total of 1209 donors were randomly assigned to one of six conditions involving tension of different muscle groups or donation as usual. Dependent measures included a symptom questionnaire and whether or not the donor's chair was reclined to treat a reaction.

RESULTS

Replicating previous findings, donors who practiced the "full" AT procedure reported significantly fewer symptoms, were less likely to require chair reclining, and rated their chances of giving blood again as greater than those in the donation-as-usual group. Of the component groups, donors who tensed only their lower body were most similar to the full-AT group. Upper-body tension in and of itself did not reduce symptoms though another condition involving upper body tension, which directed attention away from the arm with the needle in it had several significant effects.

CONCLUSION

The positive effects of AT on blood donation outcome appear to be mediated primarily by lower-body tension though distraction also probably contributes to its impact.

Health behaviors and endothelial function

An unhealthy lifestyle, including excess caloric intake, lack of exercise, smoking, and excessive alcohol consumption, increases one's risk of developing cardiovascular disease (CVD). However, the exact mechanisms by which these behaviors influence the development and progression of CVD have yet to be determined. Endothelial function (EF) has been shown to be a potent predictor of CVD, yet the effects of health behaviors on EF are not clear. The literature assessing the role of four health behaviors, obesity (a proxy of excess caloric intake), smoking, physical inactivity, and alcohol consumption, on the development of endothelial dysfunction is reviewed. Potential mechanisms through which these behaviors may influence EF are discussed. Smoking, being overweight or obese, and physical inactivity are all associated with decreased EF. A direct causal relationship between these measures and EF is suggested by the fact that improvements in these behaviors leads to parallel improvements in EF. The influence of alcohol consumption is somewhat more contentious, with some studies indicating a dose-response relationship such that those with greater consumption have poor EF. However, other studies have shown that those who drink moderately have the best EF. Although there is a growing body of literature implicating poor health behaviors in the development of endothelial dysfunction, more work is needed to establish the exact mechanisms by which this occurs. To our knowledge, there are no studies that have assessed the impact of multiple health behaviors or the interaction of health behaviors on EF.

Effects of opioid blockade on the modulation of pain and mood by sweet taste and blood pressure in young adults

Increased blood pressure and sweet taste are often associated with decreased pain sensitivity. Animal research suggests that endogenous opioids are involved in both these relationships. Fifty-eight healthy young adults (36 male, 22 female) participated in two sessions receiving a placebo tablet or 50mg of naltrexone on counterbalanced days. On each day, three cold-pressor tests were administered while the participant held a sweet solution, water, or nothing in their mouth when their hand was in the water. 2 Drug x 3 Solution x 2 Gender x Pre-Drug Resting Blood Pressure general linear models (GLM) were conducted separately for systolic (SBP) and diastolic (DBP) pressure. Consistent with previous research, significant main effects of SBP were observed in GLMs of pain tolerance and pain unpleasantness ratings. A main effect of solution on tolerance was seen in the GLM with DBP, which was qualified by an interaction of solution by blood pressure. Sweet taste increased pain tolerance among those with lower DBP across drug conditions. This suggests some overlap between mechanisms of sweet taste and blood pressure analgesia, without implicating opioid activity in sweet taste analgesia. However, the GLM of tolerance also produced a significant drug by DBP interaction suggesting that blood pressure-related analgesia is at least partially opioid-mediated. Also participants with higher DBP showed dampened mood reactivity to the experiment, which was partially reversible by naltrexone. These results are consistent with findings suggesting that endogenous opioid activity may contribute to generally reduced pain sensitivity, and perhaps mood reactivity, in those with higher BP.

Chest pain is inversely associated with blood pressure during exercise among individuals being assessed for coronary heart disease

Acute and chronic increases in blood pressure have been related to decreases in pain perception. This phenomenon has been studied primarily using acute experimental pain stimuli. To extend the literature to naturalistic pain and in particular the problem of silent cardiac ischemia, this study examined the relationship between blood pressure and chest pain during exercise stress testing. Nine hundred seven (425 men, 482 women) individuals undergoing exercise stress testing for diagnosis of possible myocardial ischemia completed the McGill Pain Questionnaire (MPQ) immediately afterward and other questionnaires before and after testing. Blood pressure was measured before, during, and after exercise. Systolic blood pressure at the end of exercise was inversely related to a number of measures of pain such as total score on the MPQ. The relationship could not be explained by individual differences in exercise duration, medication use, sex, or other measured variable. In sum, the inverse relationship between blood pressure and sensitivity to pain that has been observed in other populations in experimental and naturalistic conditions was observed for chest pain during exercise. Blood pressure may contribute to episodes of silent ischemia.

Short-term autonomic and cardiovascular effects of mindfulness body scan meditation

BACKGROUND

Recent research suggests that the Mindfulness-Based Stress Reduction program has positive effects on health, but little is known about the immediate physiological effects of different components of the program.

PURPOSE

To examine the short-term autonomic and cardiovascular effects of one of the techniques employed in mindfulness meditation training, a basic body scan meditation.

METHODS

In Study 1, 32 healthy young adults (23 women, 9 men) were assigned randomly to either a meditation, progressive muscular relaxation or wait-list control group. Each participated in two laboratory sessions 4 weeks apart in which they practiced their assigned technique. In Study 2, using a within-subjects design, 30 healthy young adults (15 women, 15 men) participated in two laboratory sessions in which they practiced meditation or listened to an audiotape of a popular novel in counterbalanced order. Heart rate, cardiac respiratory sinus arrhythmia (RSA), and blood pressure were measured in both studies. Additional measures derived from impedance cardiography were obtained in Study 2.

RESULTS

In both studies, participants displayed significantly greater increases in RSA while meditating than while engaging in other relaxing activities. A significant decrease in cardiac pre-ejection period was observed while participants meditated in Study 2. This suggests that simultaneous increases in cardiac parasympathetic and sympathetic activity may explain the lack of an effect on heart rate. Female participants in Study 2 exhibited a significantly larger decrease in diastolic blood pressure during meditation than the novel, whereas men had greater increases in cardiac output during meditation compared to the novel.

CONCLUSIONS

The results indicate both similarities and differences in the physiological responses to body scan meditation and other relaxing activities.

What is worse for asthma control and quality of life: depressive disorders, anxiety disorders, or both?

BACKGROUND

The high burden of asthma appears to be related to poor asthma control. Although previous studies have reported associations between depressive disorders (DDs) and anxiety disorders (ADs) and worse asthma control and quality of life, the relative impact of these disorders on asthma control and quality of life has not been explored. This study evaluated the relative impact of having a DD and/or AD on asthma control and quality of life.

METHOD

Five hundred four consecutive adults with confirmed, physician-diagnosed asthma underwent a brief, structured psychiatric interview using the Primary Care Evaluation of Mental Disorders. Asthma control and asthma-related quality of life were assessed using the Asthma Control Questionnaire (ACQ) and the Asthma Quality of Life Questionnaire (AQLQ). All patients underwent standard spirometry.

RESULTS

Thirty-one percent of patients (n = 157) met the diagnostic criteria for one or more psychiatric disorders (8% had DD only, 12% had AD only, and 11% had both). Analyses revealed independent effects for DDs on total ACQ scores (p < 0.01), and for DDs and ADs on total AQLQ scores and all four AQLQ subscales (p < 0.05). There were no interaction effects.

CONCLUSIONS

Results suggest that DDs and ADs are associated with worse asthma-related quality of life, but only DDs are associated with worse asthma control. Interestingly, having both a DD and an AD did not confer additional risk for worse asthma control or quality of life. Physicians may want to consider the differential impact of negative mood states when assessing levels of asthma control and quality of life.

The effects of applied tension on symptoms in French-speaking blood donors: a randomized trial

Blood-donation-related symptoms such as dizziness and weakness discourage people from participating in this important health-related activity. Four hundred sixty-seven young adult, French-speaking blood donors were randomly assigned to (a) a condition in which they learned a possible preventive technique called applied tension and were asked to practice it from the time they got on the donation chair until they were just about to get up, (b) a placebo condition in which they learned applied tension and were asked to practice it from the time they got on the chair until the insertion of the donation needle, or (c) a no-treatment control condition. Donors assigned to the treatment condition reported significantly fewer blood-donation-related symptoms than did donors assigned to the other conditions and rated their likelihood of returning to give blood again as greater than did those in the no treatment condition. Among donors whose chairs were not reclined, participants in the treatment condition had significantly smaller heart rate reactions to blood donation than did those in the other conditions.

Vasovagal symptoms mediate the relationship between predonation anxiety and subsequent blood donation in female volunteers

BACKGROUND

Although not universal, a certain amount of predonation anxiety is common and not surprising among inexperienced blood donors. Variations in predonation anxiety, however, may influence the donor's experience in several respects and might be related to the likelihood of subsequent donation even among those who do not report particularly high levels of anxiety.

STUDY DESIGN AND METHODS

A total of 671 inexperienced blood donors (zero or one prior donation) enrolled in a treatment study and completed questionnaires assessing anxiety before and after giving blood. Ratings of pain and blood donation-related symptoms were obtained after giving blood, as well as information from the nurses about the blood donation procedure. Follow-up information on number of additional visits to a blood collection clinic during the subsequent year was also obtained for most participants.

RESULTS

Predonation anxiety was positively related to ratings of blood donation-related symptoms and chair reclining by the nurses and negatively related to the donor's rating, obtained at the end of the procedure, of the likelihood that he or she would give blood again. Women, but not men, with higher predonation anxiety were significantly less likely to return to a blood clinic in the following year. The results of mediation analyses suggest that this was due to the association between anxiety and donation-related symptoms.

CONCLUSION

The results do not indicate whether or not it is feasible or useful to modify predonation anxiety, but highlight the relationships between the emotional state of inexperienced donors and several aspects of the donation experience, including subsequent donor return. Further study of the psychosocial aspects of blood donation and examination of related research (e.g., treatment of dental anxieties) may be worthwhile.

Neuropsychological characteristics of adolescent boys differing in risk for high blood pressure

BACKGROUND

Individuals with established hypertension have been found to display deficits in a number of neuropsychological abilities. In general, these are probably due to structural changes in the brain produced by sustained high blood pressure. However, a potentially important line of research suggests that some of these deficits may extend to younger individuals with less severe elevations of blood pressure, perhaps even children, and thus be related more to risk for hypertension than hypertension per se.

PURPOSE

The objective was to examine the relationships between neuropsychological function and risk for hypertension in children.

METHODS

Measurements of blood pressure and parental history of hypertension were obtained in 88 French-Canadian 14-year-old boys and used to predict performance on a neuropsychological battery.

RESULTS

Boys at greater risk of hypertension by virtue of having a parental history of high blood pressure and normatively elevated systolic blood pressure had significantly lower scores on a verbal learning factor score compared to boys at lower risk. Boys with normatively elevated systolic blood pressure also had significantly lower scores on a spatial learning and memory factor score compared to boys with lower blood pressure. The results could not be attributed to differences in family socioeconomic status.

CONCLUSIONS

Using a younger sample than typically employed in the area, the results support previous suggestions that some of the neuropsychological characteristics displayed by hypertensive individuals may predate the development of clinically elevated blood pressure and could be associated with risk for the disorder.

The role of ischaemia and pain in the blood pressure response to exercise stress testing in patients with coronary heart disease

Silent myocardial ischaemia is a common phenomenon in patients with coronary heart disease. However, very little is known about the underlying mechanisms of silent ischaemia. One potential pathway that may contribute to this absence of pain is increased blood pressure. The main aim of the current study was to assess the associations among blood pressure, pain and ischaemia in patients undergoing a standard exercise stress test. We hypothesized that patients who experienced chest pain during exercise would have lower baseline and peak blood pressures compared to those who did not experience chest pain. A total of 1,355 patients (418 women) who underwent a single-photon emission computed tomography treadmill exercise stress test and had not experienced a cardiac event in the past 2 weeks participated in the current study. Myocardial perfusion defects were assessed at rest and during the stress challenge. Systolic blood pressure (SBP), diastolic blood pressure, heart rate (HR) and rate pressure product (RPP) were assessed during rest and at peak exercise. There were no main effects of either pain or ischaemia on the baseline cardiovascular variables. Peak exercise data revealed main effects of pain on SBP, RPP and HR, and main effects of ischaemia on SBP and RPP, controlling for age, sex, baseline level, medication status and cardiac history. These findings suggest that acute rather than chronic increases in blood pressure may be one mechanism to explain the phenomena of silent myocardial ischaemia in cardiac patients, and may potentially provide a target for future treatment strategies.

Asthma self-efficacy, high frequency heart rate variability, and airflow obstruction during negative affect in daily life

BACKGROUND

Emotional stress has been considered an important asthma trigger for years, though the mechanisms by which stress may exacerbate asthma remain poorly understood. The stress-asthma morbidity association could occur through cognitive-behavioral pathways, such as decreased asthma self-efficacy and disorganized self-care, or through the more direct physiological effects of stress on autonomic (parasympathetic) nervous system activity. No study has examined how these two mechanisms may interact to contribute to greater airflow obstruction during emotional stress in daily life. This study investigated associations between peak expiratory flow rate (PEFR) and high frequency heart rate variability (HFHRV) during periods of negative affect and physical activity in daily life in patients with higher versus lower asthma self-efficacy scores.

METHODS

Fifty-three patients with mild to moderate asthma completed the Asthma Self-Efficacy Scale (ASES) and underwent a 15 h ambulatory assessment of daytime HFHRV and PEFR, while completing self-report diaries of their physical activities and affect.

RESULTS

In patients with lower asthma self-efficacy scores, increased levels of negative affect during daily life were associated with higher levels of HFHRV and decreased PEFR relative to patients with higher asthma self-efficacy scores. Increased levels of physical activity were associated with decreased levels of HFHRV irrespective of asthma self-efficacy scores.

CONCLUSIONS

Findings suggest that lower asthma self-efficacy may be associated with increased parasympathetic activity and airflow obstruction during periods of negative affect during daily life.

Higher BMI is associated with worse asthma control and quality of life but not asthma severity

Asthma and obesity tend to co-occur, but relatively few studies have linked obesity, measured using body mass index (BMI), to clinically relevant measures of asthma morbidity. This study assessed BMI in a Canadian sample of asthma outpatients, and evaluated associations between BMI and levels of asthma severity, asthma control, and asthma-related quality of life. A total of 382 adult asthma patients underwent demographic and medical history interviews on the day of their clinic visit. Patients' self-reported height and weight were used to calculate BMI (kg/m(2)). Asthma severity was classified according the GINA (2002) guidelines. Patients completed the Asthma Control (ACQ) and Asthma Quality of Life (AQLQ) Questionnaires and underwent standard pulmonary testing (spirometry). A total of 139 (36%) patients had a normal BMI; 149 (39%) patients were overweight; and 94 (25%) patients were obese. There was no relationship between BMI and asthma severity when controlling for age and sex. Patients with higher BMI scores had higher ACQ and lower AQLQ scores, independent of age, sex and asthma severity. Results identify higher BMI and obesity as potential behavioral factors related to worse asthma control and quality of life, but not asthma severity, and suggest important avenues for asthma management and control initiatives.

Airflow and autonomic responses to stress and relaxation in asthma: the impact of stressor type

The impact of stress on respiratory airflow in asthmatics is unclear. Part of the uncertainty may spring from the different physiological effects of different stressors. Given their potential to elicit increases in parasympathetic vagal activity, stressful situations that present few opportunities for coping (passive coping stressors) may be particularly problematic for people with asthma. Thirty-one adult asthmatics participated in a protocol including a widely used passive coping stressor (the cold pressor test), an active coping stressor (mental arithmetic), an interview about an upsetting asthma-related incident (viewed as a potential passive coping stressor given the exposure to unpleasant memories), and progressive muscle relaxation. Repeated measurements of airflow (via peak expiratory flow), vagal tone (via heart rate variability), and other variables were obtained. The cold pressor test, asthma interview and progressive muscle relaxation produced significant decreases in airflow compared to the baseline period. The cold pressor test and progressive muscle relaxation produced significant, complementary increases in vagal tone. These results suggest that passive coping stressors and other stimuli (e.g., certain forms of relaxation) that elicit increased vagal tone may be associated with poorer asthma control, a view consistent with a significant negative correlation between the participant's mean vagal tone response to the tasks and score on a measure of asthma self-efficacy.