Psychophysiological theories on sympathetic nervous system reactivity in the development of essential hypertension

Psychophysiological theories on the development of essential hypertension are reviewed and evaluated. Two interconnected theories that relate behavior to essential hypertension and account for individual differences in susceptibility to disease are the "hyperreactivity" theory and "the symptom specificity" theory. The "hyperreactivity" theory identifies individual differences in autonomic nervous system reactivity as the pathophysiological mechanism and the "symptom specificity" theory suggests that inflexible, stereotypical responding increases the risk to develop hypertension. Based on a literature review, these theories are examined. There exist both case/control and prospective studies on autonomic nervous system reactivity and the development of hypertension. It is concluded that a neurogenically mediated hyperreactivity to stress is a precursor and not an effect of hypertension. Tasks that call for active but not passive coping efforts are more efficient elicitors of reactivity differences between those at high and low risk to develop hypertension in case/control studies. In prospective studies, active tasks may also have a predictive advantage over passive with respect to blood pressure development. In the early phase of hypertension, an increased cardiovascular reactivity is accompanied by increased neuroendocrine activation. In the later phase, heightened reactivity is confined to the cardiovascular system. This does not prove but is consistent with the notion that transient episodes of increased cardiac output translate into essential hypertension by causing vascular hypertrophy. Case/control studies suggest that an increased "symptom specificity", with stereotypical responding across multiple stressors, is independent of cardiovascular reactivity and a precursor of hypertension. The literature lacks prospective studies on the clinical relevance of stereotypical responding. It is suggested that the presence of both hyperreactivity and symptom specificity in a single individual increases the risk to develop essential hypertension.     

Psychoneurocardiology: Psychosomatic and somatopsychic approaches to hypertension research

We introduce the field of psychoneurocardiology, and cite examples of research into psychosomatic and somatopsychic bases for hypertensive development. Beta-adrenergic hyperreactivity (a possible precursor of hypertension), as indexed by electrocardiographic T-wave amplitude suppression, was greater during active than passive coping tasks. The rise in tonic mean arterial blood pressure in normotensives over a 19-month period was a joint function of self-reported daily stress and baroreceptor-dependent pain dampening (as determined by the PRES method of noninvasive controlled carotid baroreceptor manipulation). The latter finding provides support for the learned model of hypertension. In this model, phasic blood pressure increases stimulate the baroreceptors, which in turn dampen pain and stress. The long-term effect of this relief is initially to increase the frequency of such phasic increases, and eventually to produce a tonic elevation in blood pressure.     

Cardiovascular reactivity and interpersonal influence: active coping in a social context

Previous studies have demonstrated that effortful attempts to secure positive outcomes or avoid negative outcomes produce significant increases in systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR). Although these effects of active coping on cardiovascular reactivity are central in current psychosomatic theories, virtually all of the research to date has used impersonal, asocial tasks. Our two studies examined the cardiovascular effects of effortful attempts to influence other people. In Study 1, male subjects attempting to influence the opinions of their discussion partner to improve their own chances of winning money displayed significantly greater SBP, DBP, and HR reactivity. In Study 2, we obtained similar effects on SBP and DBP reactivity in men and women, while both preparing an influence attempt and making that attempt. Furthermore, reactivity levels were larger as the magnitude of incentive for successful persuasion increased. Implications of this interpersonal equivalent of active coping for the development of cardiovascular disease are discussed.     

A comparison of coping strategies in patients with fibromyalgia,chronic neuropathic pain,and pain‐free controls

Patients suffering from chronic pain may benefit from learning adaptive coping strategies. Consensus on efficient strategies for this group of patients is, however, lacking, and previous studies have shown inconsistent results. The present study has examined coping strategies in two distinctly different groups of chronic pain patients and a group of healthy controls. Thirty neuropathic pain (NP) patients, 28 fibromyalgia (FM) patients, and 26 pain‐free healthy controls completed the Coping Strategy Questionnaire (CSQ‐48/27) and rated their daily pain. The results showed that FM and NP patients did not cope differently with pain. The only difference between the groups was that FM patients felt more in control of their pain than NP patients. Both patient groups used more maladaptive/passive coping strategies, but surprisingly also more adaptive/active coping strategies than healthy controls. However, FM patients with high levels of passive strategies felt less in control than FM patients with low levels of passive strategies. This was not seen in NP patients. An important implication for clinical practice is therefore that passive coping strategies should be restructured into active ones, especially for FM patients. Otherwise, the same psychological treatment model can be applied to both groups since they use similar coping styles.     

Humor As a Stress Moderator in the Prediction of Blood Pressure Obtained during Five Stressful Tasks

In five consecutive stressful tasks we examined the role of humor as a potential stress moderator using systolic and diastolic blood pressure as an indication of cardiovascular reactivity. In all five tasks, the Coping Humor Scale interacted with sex in the prediction of blood pressure. The same pattern was found in response to each of the five tasks: Females who were higher in coping humor exhibited lower systolic blood pressure than females scoring lower on coping humor, while the reverse characterized males; males who scored high on the coping humor scale exhibited higher systolic blood pressure than males scoring low on that scale. Similar though less robust results were found when the Situational Humor Response Questionnaire was used as the measure of humor. In the Cold Pressor Task, which involves pain and endurance, interactions were found between humor, sex, and trials indicating a stress-moderator effect. The absence of interactions indicating stress moderation in most of the analyses with the other four stress tasks suggests that humor may play more of a role in moderating the impact of uncontrollable and passively experienced stressors. Tasks requiring more active, problem-solving behavior may be less amenable to the beneficial effects of humor. The findings do not clearly resolve the questions about the role of humor in effecting responses to stress. However, they do suggest that the subjects' sex may be an important consideration when evaluating the impact of humor as a stress moderator.     

高血压患者应激反应特点及行为人格的关系研究

为了解高血压患者心血管反应的特征及与健康人群的差异,使用实验和问卷调查的方法对高血压患者和健康居民进行研究。结果显示,两组在任务期和恢复期的心血管反应差异显著（P〈0．05）;病例组的健康实践行为和消极应对方式水平较高,积极应对方式有待提升;健康实践行为和恢复期舒张压呈负相关,积极应对方式和任务期收缩压呈正相关（P〈0...     

Psychological stress tasks in the prediction of blood pressure level and need for antihypertensive medication: 9-12 years of follow-up.

Increased blood pressure (BP) reactivity to subtypes of psychological stimuli may differentially predict the development of future BP elevation or hypertension. The authors present the 9-12-year follow-up results of 82 (86%) of 95 male participants with different BP levels. They were healthy, untreated, and age-matched volunteers from a routine health checkup carried out on all 35-, 40-, and 45-year-olds from a medium-sized city. Intra-arterial systolic blood pressure (SBP) during the psychological tasks improved the prediction of future casual SBP and noninvasive 24-hr ambulatory SBP compared with predictions from casual diagnostic measurements. Diastolic blood pressure (DBP) was very useful when added to casual DBP in predicting the need for antihypertensive medication. Reactivity to active tasks especially predicts the need for antihypertensive medication.     

High blood pressure and marital discord: not being nasty matters more than being nice

Theories linking anger and blood pressure (BP) reactivity to cardiovascular disease must be able to identify naturally occurring stressors that arouse emotion with sufficient frequency to cause chronic physiologic stress. We examine the impact of normal family arguments on 43 patients (24 women, 19 men) with essential hypertension. Patients and their partners discussed a threatening disagreement for 10 min while BP and conversation were recorded. Discussing problems increased BP, but the causal pathways differed by sex. In women, hostile interaction and marital dissatisfaction were associated with increased BP; "supportive" or "neutral" exchanges were unrelated to BP. In men, BP fluctuations were related only to the patient's speech rate. These findings are consistent with other research on sex differences in communication and social problem-solving styles and implicate different mechanisms (frequent anger, active coping) through which marital discord could increase risk. Implications for intervention are considered.     

Age-related changes in cardiovascular response as a function of a chronic stressor and social support.

The effects of aging, chronic stress, and social support on cardiovascular functioning were examined using a cross-sectional design. Thirty-six family caregivers of Alzheimer's disease victims and 34 control Ss performed 2 active coping tasks while continuous noninvasive measures of cardiovascular activity were monitored. Results revealed that caregivers high in social support displayed typical age-related decreases in heart-rate reactivity, whereas caregivers low in social support displayed age-related increases in heart-rate reactivity. Analyses further indicated that only Ss with low social support were characterized by age-related increases in systolic blood pressure. These results suggest that social support can moderate age-related changes in cardiovascular functioning, particularly in Ss exposed to a chronic stressor.     

Vigilance, active coping, and cardiovascular reactivity during social interaction in young men.

This study of 72 undergraduate men examined the effects of two determinants of cardiovascular response-active coping and vigilance-on blood pressure and heart rate responses to social stressors. Observation of a future debate partner (i.e., vigilance) evoked larger increases in blood pressure than did observation of a less relevant person, apparently through the combination of increases in cardiac output and vascular resistance. Preparation and enactment of efforts to exert social influence (i.e., active coping) evoked heightened blood pressure and heart rate responses through increased cardiac contractility and output. Thus, both vigilance and active coping in social contexts increased cardiovascular reactivity, but apparently through different psychophysiological processes.     

The correlation between coping with stress and blood pressure reaction]

This study explored the relationship between individual strategies of coping and blood pressure responses during and after mental stress. Blood pressure behavior was measured noninvasively and continuously before, during and after a mental stress situation in 27 normotensive subjects. Coping strategies were assessed with the Stressverarbeitungsfragebogen (SVF; coping with stress inventory). Two extreme groups were formed on the basis of the scores in the SVF. Results were: (a) Individuals who used coping strategies characterized by controlling the situation directly and constructively, in contrast to probands not using these strategies, exhibited lower blood pressure during the stress situation and a faster return to baseline levels after cessation of stress. (b) Subjects using a coping behavior characterized by the use of defense mechanisms such as suppression and denial, also showed lower blood pressure during stress but a significantly delayed return to baseline levels of blood pressure after stress was concluded.     

Cardiovascular reactivity to and recovery from psychological challenge as predictors of 3-year change in blood pressure.

The authors examined whether cardiovascular reactivity to and recovery from psychological challenge predict 3-year change in blood pressure (BP) among 216 initially normotensive, community-dwelling adults. Clinic BP assessments were conducted at baseline and follow-up. BP and heart rate (HR) readings were obtained before, during, and after 5 psychological tasks at baseline. Following adjustment for traditional predictors of BP and lifestyle factors, poorer systolic BP recovery across the tasks was associated with greater 3-year increases in clinic systolic and diastolic BP. Both diastolic BP recovery and HR recovery were also related to 3-year change in clinic BP, though cardiovascular reactivity measures were not. These findings suggest that the duration of stress-related cardiovascular responses may be important for predicting longitudinal changes in BP.     

Cardiovascular responses of embarrassment and effects of emotional suppression in a social setting.

The cardiovascular effects of embarrassment and of attempts to suppress embarrassment were examined. In 2 studies, embarrassment was associated with substantial increases in systolic and diastolic blood pressure, which monotonically increased over a 2-minute embarrassment period. In contrast, heart rate (HR) rose significantly during the 1st minute of embarrassment but returned to baseline levels during the 2nd minute. This pattern of reactivity may be distinctive. The effects of trying to suppress emotion in an interpersonal situation were also tested. Relative to the no-suppression group, suppression participants showed greater blood pressure during embarrassment and during posttask recovery. Suppression did not significantly affect HR. Possible mechanisms for these results, including passive coping, are discussed. Nonverbal behavior was also examined.     

Beneficial effects of docosahexaenoic acid on active avoidance performance in 1K-1C hypertensive rats

The present study evaluated the role of chronic docosahexaenoic acid (DHA) supplementation on active avoidance learning task performance in experimental hypertension. Male Wistar rats were randomly divided into five experimental groups as follows: control, sham, DHA treated, 1K-1C hypertensive, and 1K-1C hypertensive+DHA treated. Hypertension was induced in 1K-1C rats via placing a silver clip (0.20-mm ID) around the left renal artery following a right uninephrectomy. DHA (36 mg/kg/day) was given to the treatment groups for 60 days by gastric gavage. Arterial blood pressure was measured by using the tail-cuff method. Active avoidance responses were determined by an automated shuttle-box. In brain (cerebrum) and hippocampus tissues, thiobarbituric acid reactive substances (TBARS) and nitrite levels were measured by fluorometric methods. DHA supplementation decreased blood pressure in hypertensive rats. Data from active avoidance training indicated that performance of active avoidance learning tasks were significantly impaired in 1K-1C hypertensive rats, but was completely restored by DHA supplementation. Increased cerebrum TBARS levels in 1K-1C rats were abolished by DHA administration. Cerebrum nitrite levels were lower in the DHA, 1K-1C and 1K-1C+DHA treated groups compared to controls. Hippocampus nitrite levels were lower in DHA treated and 1K-1C hypertensive rats compared to controls and higher in 1K-1C+DHA treated rats compared to the 1K-1C group. Our data indicates that DHA supplementation improves the performance of active avoidance learning tasks which is impaired in experimental hypertension. These affirmative changes might be due to a DHA-induced decrease in lipid peroxidation which may in turn limit the consumption of nitric oxide (NO) which promotes active avoidance learning.     

Depression: avoidance learning and physiological correlates in clinical and analog populations

The behavioral and physiological components of depression were investigated in two experiments comparing eight student and seven non-student depressed females with an equal number of students and non-student controls on avoidance tasks and electrodermal responsivity to an aversive audiotape. Avoidance behavior was assessed in both active and passive paradigms where the correct response or response suppression, respectively, function to avoid a noxious buzzer. Physiological activity and reactivity were compared using measurements of skin resistance level and SRR fluctuations during resting and aversive tape periods. It was found that the depressed groups showed inferior active and superior passive avoidance learning as compared to controls. Depressed subjects were also more emotionally responsive (showed a greater number of SRR) during presentation of the audiotape. A passive avoidance model for depression is suggested for the explanation of the phenomena observed. A distinct difference was also found between student and non-student populations. The utility of college student analogs for depression is questioned.     

Behavioral hyperreactivity in the spontaneously hypertensive rat compared to its normotensive progenitor

The spontaneously hypertensive rat (SHR) is an excellent model of essential hypertensive disease. Hyperreactivity has been postulated as a contributing factor in the development of high blood pressure in the SHR and in man. In the maturing organism recurring hypertensive stress responses may promote permanent vascular changes and result in a fixed hypertension. Simple behavioral activity and emotionality rating scales were used to compare a large number of SHR with equally large groups of closely-related and distantly-related normotensive rats. As predicted, the SHR were clearly more active and emotional than their ancestral Wistar Kyoto (WKY) strain. However, the distantly-related normotensive Wistars did not differ from the SHR in either activity or emotionality. These results indicate that behavior and hypertension are not necessarily related in the rat. Nonetheless, the behavioral differences between the SHR and their closest genetic match, the WKY, suggest that arousal and blood pressure levels may be causally linked in this case of naturally occurring hypertension.     

Verbal processing deficits in schizophrenia

The authors reported that a subgroup of schizophrenic patients performed well on a tone serial position task but was impaired on an auditory word serial position task (Wexler, Stevens, Bowers, Cerniak, & Goldman-Rakic, 1998). This study assessed 30 schizophrenic and 32 controls (matched for comparable tone discrimination) on 4 versions of the verbal serial position tasks and 2 tone serial position tasks. Patients performed poorly on all verbal tasks but performed comparably to controls when tones served as stimuli. Proactive interference and visual presentation further compounded the verbal deficits. Deficits persisted with pronounceable nonword stimuli. These findings provide evidence of specific deficits in language-related processing, although the authors could not rule out the possibility that the differential effects that were observed between the tone and word tasks, and particularly among the verbal tasks, may result from differing discriminating power of the different tests.     

Anger management style and emotional reactivity to noxious stimuli among chronic pain patients and healthy controls: the role of endogenous opioids.

OBJECTIVE: Previous work suggests that elevated trait anger-out exacerbates pain responses in part through endogenous opioid dysfunction. The authors examined whether this opioid dysfunction affects not only perceived pain intensity, but also emotional responses to being hurt. DESIGN: 79 chronic low back pain (LBP) patients and 46 healthy controls received opioid blockade (8 mg naloxone i.v.) and placebo in randomized, counterbalanced order in separate sessions. During each session, participants sequentially experienced finger pressure pain and ischemic forearm pain tasks, with emotional state assessed at baseline and postpain. MAIN OUTCOME MEASURES: Blockade effects indexing opioid modulation of emotional reactivity were derived by subtracting placebo from blockade condition emotional reactivity. RESULTS: Significant Participant Type x Anger-Out interactions on blockade effects indicated that in LBP participants but not in controls, greater anger-out was associated with deficient opioid modulation of anxiety, anger, and fear reactivity to noxious stimulation. Across participant types, greater anger-in was associated with impaired opioid modulation of anxiety and fear reactivity. Anger-in opioid effects were partially due to overlap with general negative affect. CONCLUSIONS: Opioid dysfunction associated with trait anger-out may affect not only perceived pain intensity, but also pain-related suffering in individuals with chronic pain conditions. Implications for understanding the health effects of anger management styles are discussed.     

Cardiovascular reactivity to psychological stress in aerobically trained versus untrained mild hypertensives and normotensives

Cardiovascular reactivity to video game and mental arithmetic stressors was compared among three groups of men: aerobically trained mild hypertensives, untrained mild hypertensives, and a comparison group of untrained normotensives. Relative to the untrained hypertensives, the trained hypertensives reacted to the video game with marginally smaller systolic blood pressure and diastolic blood pressure, but there were no significant differences between these groups in reactivity during the mental arithmetic task. Comparisons between each hypertensive group and the normotensive group showed that blood pressure (BP) reactivity of normotensives during the video game was generally similar to that of trained hypertensives but smaller than that of untrained hypertensives. These results indicate that aerobic training, which has been found to reduce resting BP in mild hypertensives, may also exert a favorable impact in reducing cardiovascular reactivity of hypertensives during some stressful situations.     

Greater pressor reactivity in women with pre-eclampsia is not related to specific psychological or emotional stressors

To investigate whether emotional or psychosocial factors could be significantly related with the development of pre-eclampsia, 15 pregnant women with early diagnosis of pre-eclampsia and 15 normotensive pregnant controls of comparable age (23-37 yr.), gestational age (10-37 wk.), parity (70% primiparous), amount of instruction, and marital status underwent a blood pressure monitoring during a specific psychological assessment based on a semistructured interview followed by the administration of three different questionnaires: the Symptom Checklist 90-Revised, the Perceived Stress Questionnaire-Recent, and the Questionnaire about Social Relationships. Systolic and diastolic blood pressure and heart rate were measured at 2-min. intervals by an automatic device both during the interview and the questionnaires' administration. Both systolic and diastolic responses were significantly increased in both groups during the interview (deltaSBP = 15 vs. 10%; deltaDBP=28 vs. 15.8%), whereas no differences were observed in blood pressure while answering questionnaires. Conversely, differences in questionnaire responses between groups were not statistically significant. Present results confirm a greater pressor reactivity in these women with pre-eclampsia but does not specifically support that this was related to psychological or emotional stress.