Elevated sympathetic nervous system activity in patients with recently diagnosed rheumatoid arthritis with active disease

OBJECTIVE

To investigate sympathetic (SNS) and parasympathetic (PNS) nervous system activity in patients with recently diagnosed rheumatoid arthritis (RA), and to analyze the association between activity of these systems and disease activity, and complaints that frequently occur in RA, viz., pain, fatigue, negative mood, and stiffness.

METHODS

To assess sympathetic and parasympathetic nervous activity, the Pre-Ejection-Period (PEP) and Respiratory Sinus arrhythmia (RSA) were measured on two consecutive nights in a real-life environment in 25 patients with RA [19 female (f), 6 male (m), mean age 55.2 years) and 28 healthy controls (20f, 8m, mean age 55.8 years].

RESULTS

Patients showed a significantly shorter PEP (reflecting elevated SNS activity) compared to healthy controls, an effect that was most pronounced in those with active disease. RSA and the heart period did not differ between patients and healthy controls. The heart period was significantly associated with stiffness, but neither PEP nor RSA were associated with pain, fatigue, mood, or stiffness.

CONCLUSION

Our study showed that cardiac sympathetic nervous system activity is elevated in RA, whereas cardiac parasympathetic activity remains at a normal level. Our results suggest that inflammatory stress rather than the common symptoms of RA challenge the SNS.

Biopsychosocial mediators and moderators of stress-health relationships in patients with recently diagnosed rheumatoid arthritis

OBJECTIVE

To investigate the mediating and moderating roles of social support, coping, and physiological variables in the relationship between life events and health status.

METHODS

Psychological and biological measurements were taken in 54 patients (38 women, 16 men, mean age +/- SD 56 +/-14.4 years) with recently diagnosed rheumatoid arthritis (RA).

RESULTS

Life events were correlated with psychological distress, but not with disease activity. No mediators for the relationship of life events with psychological well-being and disease activity were observed. In 40 tests, 4 moderators were found: Problem-focused coping, perceived support, diastolic blood pressure, and total number of lymphocytes were moderators of the relationship between daily hassles and health status (P < or = 0.05).

CONCLUSION

Our study provides limited support for the notion that the interactions of life stress with biopsychosocial variables have an impact on health. None of these variables were found to be crucial mediators of stress-health associations in recently diagnosed patients with RA, but some provocative evidence was given that biopsychosocial variables may have a minor impact on stress-health relationships.

Cortisol secretion throughout the day, perceptions of the work environment, and negative affect

The effects of explanatory variables derived from a work stress model (the effort-reward imbalance model) on salivary cortisol were assessed. A multilevel analysis was used to distinguish the effects of single occasion and multiple occasion measurements of work stress and effect on cortisol. The single (or cross-sectional) factors include Effort-Reward Imbalance (ERI), need for control, negative affect, and other enduring factors (type of occupation, gender, and smoking). The multiple occasion measurements include momentary negative mood, Momentary Demand-Satisfaction Ratio (MD-SR), sleep quality, work load (workday versus day off), at work (versus not being at the workplace), and lunch. The effect of time of day on cortisol was controlled for before the effects of these variables were determined. Momentary negative mood but not trait negative affect was positively associated with ambulatory measured cortisol. The variables from the work stress model--effort, reward, need for control, and the multiple occasion measurements of demand and satisfaction--did not affect cortisol. As could be expected, time of day had an effect on cortisol, but a hypothesised interaction with momentary negative mood was not found. Additionally, the results show that the time course of cortisol differs between individuals and that the effect of sleep quality on cortisol can vary from person to person. This points to the necessity of continued efforts to single out sources of individual variability. The finding that variables derived from the effort-reward imbalance model are not related with cortisol does not support the hypothesis that ERI leads to short-term changes in cortisol, indicating no relation with hypothalamic-pituitary-adrenal (HPA) axis activity. On the other hand, the present results invite further qualification of negative affect as a potential determinant of HPA activity, at least, as far as can be deduced from cortisol measurements.

Experimentally challenged reactivity of the hypothalamic pituitary adrenal axis in patients with recently diagnosed rheumatoid arthritis

OBJECTIVE

There is evidence that the hypothalamic pituitary adrenal (HPA) axis is subresponsive in patients with rheumatoid arthritis (RA). We assessed HPA axis responses to experimental stressors mimicking daily life challenges in patients with RA to determine whether HPA axis activity is associated with Th1 and Th2 activity.

METHODS

ACTH and cortisol responses in reaction to the succession of a bicycle ergometer task, a cold pressor task, and a computerized Stroop Color-Word interference test, as well as basal Th1 and Th2 cell activity, were assessed in 29 patients (21 female, 8 male) with recently diagnosed RA (mean disease duration 29 wks, range 5-69), mean age 55.7 years, none receiving glucocorticoid treatment, and 30 (20 female, 10 male) healthy age and sex matched controls (mean age 54.1 yrs).

RESULTS

Mean ACTH and cortisol levels did not differ between the groups (p > 0.10). Patients tended to have a less pronounced ACTH response (F2.50 = 2.7, p = 0.08) and had a significantly smaller cortisol response (P F2.50 = 6.1, p < 0.01) than healthy controls in reaction to the stressors. This difference in cortisol response was reduced, but remained significant when ACTH responsiveness was accounted for by entering it as a covariate (P F2.49 = 3.7, p = 0.03). ACTH and cortisol levels and responses were not associated (all p > 0.19) with basal interferon-gamma and interleukin 4 as reflections of Th1 and Th2 cell activity, respectively. HPA axis activity was not linked to current disease activity.

CONCLUSION

Our findings show reduced HPA axis responsiveness in RA patients with recent diagnosis receiving longterm medication that is suggested to be located both at a hypothalamic/pituitary and at an adrenal level. It appears that common HPA axis activity accomplishes low amounts of cortisol release, which makes it difficult to determine an influence of endogenous cortisol changes on the Th1/Th2 balance.

Vagal cardiac control throughout the day: the relative importance of effort-reward imbalance and within-day measurements of mood, demand and satisfaction

The effects of variables derived from a work stress theory (the effort-reward imbalance theory) on the power in the high frequency (HF_HRV) band of heart rate (0.14-0.40 Hz) throughout a work day, were determined using multilevel analysis. Explanatory variables were analysed at two levels: at the lowest level (within-day level), the effects of positive mood, negative mood, demand, satisfaction, demand-satisfaction ratio, and time of day were assessed. At the highest level (the subject level), the effects of sleep quality, effort, reward, effort-reward imbalance, need for control, type of work (profession), negative affectivity, gender and smoking on HF_HRV were assessed. Need for control has a negative effect on HF_HRV after controlling for time of day effects, i.e. subjects with a high need for control have a lower vagal control of the heart. In the long run, these subjects may be considered to be at increased health risk, because they have less of the health protective effects of vagal tone. The interaction between effort-reward imbalance and time of day has a positive effect on HF_HRV, i.e. the cardiac vagal control of subjects with a high effort-reward imbalance increases as the day progresses. It is discussed that this probably reflects reduced effort allocation, ensuing from disengagement from the work demands.

The validity and reliability of the Dutch Effort-Reward Imbalance Questionnaire

The reliability and validity of the Effort-Reward Imbalance Questionnaire were tested in 775 blue- and white-collar workers in the Netherlands. Cronbach's alpha revealed sufficient internal consistency of all subscales except Need for Control. With exploratory probabilistic scaling (Mokken) analysis, the psychometric qualities of the Need for Control scale were improved. With confirmatory factor analysis, the factorial validity of the Extrinsic Effort and Reward subscales was confirmed. A model with 3 separate dimensions for reward (status control, esteem reward, and monetary gratification) proved adequate, emphasizing the importance of distinguishing subscales. The congruent validity of the subscales and a hypothesized relationship with an external construct, health functioning, were confirmed.

The validity and reliability of the Dutch Effort-Reward Imbalance Questionnaire

The reliability and validity of the Effort-Reward Imbalance Questionnaire were tested in 775 blue- and white-collar workers in the Netherlands. Cronbach's alpha revealed sufficient internal consistency of all subscales except Need for Control. With exploratory probabilistic scaling (Mokken) analysis, the psychometric qualities of the Need for Control scale were improved. With confirmatory factor analysis, the factorial validity of the Extrinsic Effort and Reward subscales was confirmed. A model with 3 separate dimensions for reward (status control, esteem reward, and monetary gratification) proved adequate, emphasizing the importance of distinguishing subscales. The congruent validity of the subscales and a hypothesized relationship with an external construct, health functioning, were confirmed.

Immune responses to experimental stress: effects of mental effort and uncontrollability

OBJECTIVE

Two important determinants of physiological stress responses have been identified, uncontrollability of the stressor and amount of effort involved in coping with the stressor. In the present experiment, we tried to identify the specific contributions of effort and uncontrollability to immune system responses to stress.

METHODS

In a 2 x 2 design, effort and uncontrollability were manipulated independently of each other. Subjects participated in one of four experimental conditions, and their endocrine, immune, and sympathetic nervous system responses to the task were assessed.

RESULTS

Effort had a stimulating effect on enumerative immunological parameters (CD8 and CD16+ cells) and on natural killer cell activity. The effect occurred immediately after the stressor and was transient. Regression models indicated that this effort effect may have been mediated by activation of the sympathetic nervous system. Uncontrollability influenced in vitro production of the cytokine interleukin-6, leading to decreased production 15 and 30 minutes after the stressor. Uncontrollability also led to an increased level of cortisol, but no evidence was found that the decrease in cytokine production was mediated by cortisol release.

CONCLUSION

The results suggest that two major stressor characteristics, effort and uncontrollability, may have differential effects on the immune system.

High-density assessment of the IHS classification criteria for migraine without aura: a prospective study

Fifty-six adult female patients with the clinical diagnosis of MwoA kept a diary 6 times per day for 10 consecutive weeks to record the occurrence, pain characteristics, and accompanying symptoms of headache. In order to avoid bias due to retrospection or expectancy the diary was programmed into palmtop computers which signaled the patients with a beep to enter the diary with a random-fixed time schedule: two signals occurred in, respectively, the morning, the afternoon, and the evening, but at different times for each day. The palmtop computers also warranted flawless data storage and automatic computations of response delay and missing values. Of the 339 attacks, 75% had a duration of 4-72 h and 94% confirmed the International Headache Society classification criteria for MwoA concerning pain characteristics and accompanying symptoms. Our results obtained for attacks in treated patients are highly comparable with the results of Rasmussen, Jensen, and Olesen (1991) obtained in the general population with unknown treatment of headache. Together, both studies support the IHS classification criteria for MwoA. The electronic Experience Sampling Method also allowed for an unbiased description of the course of treated MwoA attacks: 67% subsided in the first day. In the 16 attacks the characteristics and accompanying symptoms were present in 60-80% of the attacks at the first assessment (9.30 a.m.) with the exception of moderate to severe pain intensity (37%) and nausea or vomiting (31%). A waxing and waning of characteristics and symptoms over the day remained in about 30-40% of the attacks with a tendency towards increases in the evening (7.30 p.m. and 10 p.m.). The method is there for a replication of this study in untreated MwoA patients.

Experimentally induced stress in rheumatoid arthritis of recent onset: effects on peripheral blood lymphocytes

OBJECTIVE

To examine the effects of experimentally-induced stress on the mobilization of peripheral blood lymphocytes (PBL) in patients with rheumatoid arthritis (RA) of recent onset.

METHODS

Twenty-two (16 F, 6 M) patients (mean age 57.6 yrs.) and 23 (15 F, 8 M) healthy subjects (mean age 54.7 yrs.) were subjected to experimental stressors. The numbers of T-cells, B-cells, and NK-cells were determined before and after the completion of tasks inducing physical and mental effort.

RESULTS

The change in PBL in response to stress was about equal for patients and healthy subjects (p > 0.75 in all PBL subsets). In patients as well as in healthy subjects, the correlations between PBL and cortisol changes in response to stress tended to be positive, while the correlations between PBL and cardiovascular changes were positive in healthy subjects, but zero or negative in patients. Moderate to high (0.32 < or = r < or = 0.55) correlations between PBL changes and pain were observed.

CONCLUSION

Experimentally-induced changes in PBL (as well as cortisol) are normal in patients with early RA who are receiving long term medication, but correlations between these changes and autonomic nervous system responses are zero or negative. This apparent shift in the control of the change in PBL in response to stress is observed in particular in patients with more pain. The pathophysiological significance of these findings should be clarified in longitudinal studies.

Results of aortic screening in the brothers of patients who had elective aortic aneurysm repair

BACKGROUND

Brothers of patients with an abdominal aortic aneurysm (AAA) are at high risk. In the present study brothers of patients who underwent elective AAA surgery were invited for aneurysm screening and the psychological consequences studied.

METHODS

All brothers over the age of 50 years were invited for abdominal ultrasonography. They were asked to complete a standard psychological well-being questionnaire both before, and 3 months after screening.

RESULTS

Some 571 brothers were identified: 251 were dead, 35 lived abroad, 16 could not be contacted for other reasons, 46 refused to participate and 13 were already known to have an AAA. Some 210 subjects (37.8 per cent) accepted the offer of screening. A new AAA was detected in 26 (12.3 per cent, 95 per cent confidence interval 8-18 per cent) of the men screened resulting in an overall prevalence of 18 per cent (95 per cent confidence interval 13-26 per cent). Eight (3.8 per cent) aneurysms were 5 cm or more in diameter and elective surgery was performed in five patients (2.4 per cent). The psychological dimensions of well-being (depression, anxiety, energy, and positive well-being) had not changed significantly 3 months after screening.

CONCLUSION

The prevalence of AAA in brothers of patients with AAA is far higher than in the overall male population of the same age. Screening does not seem to have a negative influence on psychological well-being.

Cardiovascular and immune responses to acute psychological stress in young and old women: a meta-analysis

OBJECTIVE

To describe the relationships between cardiovascular and natural killer (NK) cell number changes on acute psychological stress in women.

METHOD

Data from eight different studies were analyzed. A total of 128 healthy female subjects, 85 younger (18-45 years) and 43 older (49-87 years), had been subjected to a speech stressor (N = 80) or a mental effort stressor (N = 48), mental arithmetic, or the Stroop test. Correlations between changes in NK cell numbers, systolic (SBP) and diastolic (DBP) blood pressure, and heart rate (HR) were computed. Meta-analysis programs were used to study correlations across studies and to examine whether correlations differed with stressors or age.

RESULTS

In all studies, significant increases over baseline were observed for each variable. Across studies, the mean weighted r between changes in HR, DBP, and SBP was medium (rw = .25) to large (rw = .64). A medium to large average correlation between HR and NK changes (rw = .37) was observed, whereas average correlations of changes in NK cell numbers with blood pressure changes were small to medium (rw < or = .23). Correlations between changes in NK cell numbers and cardiovascular variables were homogeneous across studies, whereas mutual correlations between cardiovascular variables were heterogeneous. One moderator variable showed itself: correlations between HR and DBP reactions were larger in studies with older than younger subjects.

CONCLUSION

NK cell changes and HR responses induced by acute stress in women are regulated, to some extent, by the same mechanisms. Neither the type of stressor nor age seem to be very important when considering correlations between NK cell and cardiovascular changes. This study integrates information about NK cell and cardiovascular responses in women that can be used as reference material in future studies.

Experimental stress and immunological reactivity: a closer look at perceived uncontrollability

OBJECTIVE

Although stressor uncontrollability has been shown to suppress immune responses in animals and for human subjects, the results have been inconsistent. We reanalyzed results of our previous study regarding stress-related immune deviation in man, to establish whether perceived uncontrollability of an acute stressor acts as a co-determinant in the observed changes in immunological parameters.

METHOD

Three types of cognitive reactions to an acute interpersonal stressor were assessed: "motivation," "uncontrollability," and "guiltiness." Stress-induced changes in the number of several types of immune cells in peripheral blood and proliferative responses of lymphocytes to antigens and mitogens were assessed.

RESULTS

In comparison with control subjects and with subjects perceiving high control over the experimental stress situation, the subject perceiving low control showed a stressor-induced decrease in the number of T helper cells. Reversely, subjects perceiving high control showed an increase in the number of B cells as opposed to the other two groups. The effects of perceived uncontrollability could not be accounted for by mood changes, but they were related to previously experienced life stress.

CONCLUSIONS

Perceived uncontrollability of an acute stressor can have immuno-modulating effects over and above those of the stressor per se.

Cardiovascular and endocrine responses to experimental stress: effects of mental effort and controllability

The objective of the study was to investigate the unique and interactive effects of the controllability of a task and mental effort required by that task on cardiovascular and endocrine reactivity, when both were manipulated independently. A 2 x 2 factorial design was used, with two levels of mental effort and two levels of control. Twenty-four healthy male subjects participated in each experimental condition. Heart rate, blood pressure, catecholamine and cortisol responses were determined. High effort lead to greater increases in heart rate, blood pressure and norepinephrine levels. Uncontrollability lead to higher cortisol, blood pressure and norepinephrine responses. In addition, there was an effort x control interaction effect on the diastolic blood pressure response. In conclusion, effort has clear sympathetic effects, whereas control influences both the sympathetic nervous system and the release of cortisol. Having control seems to be most beneficial in high effort situations, at least with respect to sympathetic reactivity.

Diminished autonomic nervous system responsiveness in rheumatoid arthritis of recent onset

OBJECTIVE

To investigate responsiveness of the autonomic nervous system in rheumatoid arthritis (RA) of recent onset.

METHODS

21 patients (17 women, mean age 55.7 years) and 20 healthy controls (16 women, mean age 52.7 years) were subjected to 4 tasks eliciting divergent autonomic reactions: film watching, mild physical exercise, cognitive discrimination, and the Stroop color-word interference test. Changes in heart rate, diastolic (DBP) and systolic (SBP) blood pressure, and skin conductance relative to pretask baseline values were computed and related to erythrocyte sedimentation rate, pain, mobility, and dexterity.

RESULTS

Mean autonomic levels of patients were normal, as well as autonomic responses to film watching and mild physical exercise. Diminished autonomic responses were observed during cognitive discrimination and during the Stroop test. Blood pressure responses were negatively related to pain severity, but positively to impaired dexterity.

CONCLUSION

Diminished autonomic nervous system response is observed in RA of recent onset, most clearly in patients with more severe pain. This suggests that it is associated with primary pathophysiological mechanisms.

Relationships between cardiovascular and immunological changes in an experimental stress model

To investigate the relationships between cardiovascular variables (SBP, DBP, and HR) and circulating natural killer (NK) cell numbers, 70 male volunteers were subjected to a rest condition (N = 30) or a stressful laboratory task (N = 40). At baseline, no significant relationships could be demonstrated between the number of NK cells and the cardiovascular variables. Analysis of covariance showed that the stressor induced increases in the number of NK cells, SBP, DBP, and HR. Changes in Nk cell numbers were highly correlated to changes in cardiovascular variables in both the task and the no-task group. These results indicate that there is no relationship between the number of circulating NK cells and cardiovascular levels per se, but that changes in these variables, either stress-induced or under rest conditions, are regulated by a common mechanism.

Influence of life stress on immunological reactivity to mild psychological stress

This study investigated the effects of self-reported life stress and locus of control on reactivity of several immune parameters to a mild and short-lasting interpersonal stressor. Subjects were 86 male teachers aged 24 to 55 years. Immune reactivity was defined as changes in numbers of monocytes. T-lymphocytes and subsets, HLA-DR+ cells, and NK cells as well as changes in (in vitro) proliferative responses of peripheral blood lymphocytes to the antigens PHA and PWM. Multiple regression analysis was used to study the interaction effects of life stress and locus of control by experimental condition on immune reactivity. Life stress, but not locus of control, influences reactivity of the immunological parameters to the stressor. In particular, high numbers of daily hassles were associated with stressor-induced decreases in numbers of T cells and NK cells in peripheral blood. On the other hand, numbers of HLA-DR+ cells in high life stress scorers decreased only slightly during the stressor, whereas they increased in the control condition. The findings suggest that accumulated life stress is related to reactivity of immunological parameters to subsequent experimental stress. Possible physiological explanations and implications of these effects are discussed.

Effects of beta-adrenergic blockade on immunologic and cardiovascular changes induced by mental stress

BACKGROUND

Acute mental stress evokes responses in the cardiovascular and the immune systems. In particular, the subset of natural killer (NK) cells is found to be responsive to mental stress. The role of beta-adrenergic mechanisms in these processes in the subject of this investigation.

METHODS AND RESULTS

Healthy male volunteers (n = 31) were subjected to two consecutive mental tasks. Subjects were randomly assigned to a beta-blocker (propranolol 40 mg) or a placebo group. The capsules were ingested 1 hour before the tasks. The tasks evoked sympathetic responses, as indicated by an increase in heart rate and a decrease in the preejection period. These effects were abolished under beta-blockade, indicating that effective beta-blockade was achieved. In the immune system, significant increases were found for the number of NK cells and NK cell activity in the placebo group; these increases were absent in the propranolol group. In addition, an increase in all lymphocyte subsets was observed in subjects who had ingested propranolol. This increase, however, was also observed in subjects who had received propranolol but had not performed the tasks, indicating that these non-subset-specific increases in lymphocytes were a side effect of the beta-blocker.

CONCLUSIONS

Mental stress induces activation of the sympathetic nervous system, with concomitant increases in the number of NK cells in the circulation. These changes were inhibited by propranolol, indicating that stress-induced increases in the number and activity of NK cells in the circulation are controlled by a beta-adrenergic mechanism.

Chronic stress affects immunologic but not cardiovascular responsiveness to acute psychological stress in humans

This study deals with the effect of chronic stress on physiological responsiveness to an acute psychological stressor in male high school teachers. Chronic stress was operationalized as the self-reported number of everyday problems. Twenty-seven subjects reporting extremely low or high numbers of everyday problems were exposed to an acute psychological stressor, and changes in immunologic, endocrine, and cardiovascular parameters were monitored. The stressor included a learning process followed by a teaching session in which a confederate to the researchers was involved. Twenty subjects served as controls. The stressor had no effect on the endocrine variables measured but induced increases in heart rate and blood pressure, which were similar in both chronic stress groups. Analysis of subsets of blood lymphocytes revealed differences in natural killer (NK) and T cell responses in the low and the high stress groups. It is concluded that 1) immunologic responsiveness to an acute psychological stressor is related to problems experienced in daily life, and that 2) chronic stress differentially modifies the sensitivity of biological systems to mild acute stressors.

Effects of experimental psychological stress on distribution and function of peripheral blood cells

Fifty male subjects (aged 24 to 55 years) were subjected to a mild and potentially uncontrollable interpersonal stress situation. They were asked to solve a difficult puzzle. Subsequently they were requested to explain their solution to "another subject," actually a confederate to the researchers. The confederate frustrated the subjects' explanation efforts. Care was taken that neither solving nor explaining of the puzzle was successful. The experimental situation induced mild psychological strain as documented by mood changes in the experimental group when compared with a control group of 36 male subjects. Peripheral blood was drawn by an indwelling catheter just before, directly after, 15 minutes after, and 30 minutes after the stress situation. Numbers of leukocytes, lymphocytes, monocytes, T-cell subsets, natural killer (NK) cells, and B-cells were determined. As functional assays we used in vitro proliferative responses of T- and B-cells to mitogenic stimulation (PHA and PWM) and to an antigen cocktail. The potential influences of health- and biobehavioral variables were taken into account in the analyses, as well as incidental differences in initial mood or immunological baseline. The results replicated and expanded on previous research. In contrast to controls, experimental subjects showed a significant increase in numbers of NK cells after the stress-period, returning to baseline values after 15 minutes of rest. A similar effect was shown on T-suppressor/cytotoxic cells and, inversely, on T-helper/suppressor ratio, but these effects could be attributed to changes in the numbers of CD8+CD57+ cells. No effects were observed on proliferation. From the results we conclude that the effects of a short lasting mild psychological stressor are mainly restricted to cells of the NK cell population.

Tachistoscopic and questionnaire methods for the measurement of psychological defences

Only few attempts have been made to compare different methods aiming at quantifying defensive strategies. In this study the tachistoscopic Defence Mechanism Test (Kragh, 1960b and 1985) is compared to paper-and-pencil tests of defence. There were virtually no correlations between the DMT and the other measures of defence. This may indicate that the concept of defence is a highly complex one. It is suggested that the Defence Mechanism Test may be measuring primary defence while defence questionnaires may be assessing more secondary forms of defence. The two questionnaires used for assessing defence correlated significantly, while a scale for social desirability showed no correlation with DMT or the two defence questionnaires.