Is reduced health-related quality of life a primary manifestation of fibromyalgia? A comparative study with Rheumatoid arthritis.

BACKGROUND: Fibromyalgia syndrome (FMS) is a chronic pain condition associated with a significant reduction in health-related quality of life (HRQoL). This study compared the different components of HRQoL between FMS and rheumatoid arthritis (RA) patients, and evaluated the relationships between HRQoL and clinical and emotional factors in FMS and RA patients. METHOD: Women with FMS (n = 80), RA (n = 43) and healthy women (n = 67) participated in the study. HRQoL was assessed by the SF-36 survey. Associations between HRQoL and symptom severity were assessed by correlation and multiple linear regression analyses. RESULTS: FMS patients displayed lower values for all SF-36 variables than RA patients and healthy participants, while RA patients showed lower values for all SF-36 variables than healthy participants. These group differences persisted after statistically controlling for demographic, clinical and emotional variables. Clinical and emotional factors were inversely associated with SF-36 scores in the overall FMS + RA sample. Depression and fatigue were the strongest negative predictors. However, after the statistical control of the effect of diagnosis (FMS vs. RA) in the regression analysis, most of the associations disappear. CONCLUSIONS: The fact that group differences in HRQoL remained highly significant after statistically controlling of group differences in clinical symptom severity, and that associations between clinical symptoms and HRQoL disappear when the type of diagnosis was considered in the regression analysis, suggest that impairment of HRQoL could be considered a primary feature of FMS.

Longitudinal associations of physical fitness and affect with depression, anxiety and life satisfaction in adult women with fibromyalgia.

PURPOSE: This study analysed the longitudinal associations of physical fitness and affect with depression, anxiety and life satisfaction at 2- and 5-year follow-up. METHODS: In 312 adult women with fibromyalgia, physical fitness was measured by performance-based tests and affect, depression, anxiety and life satisfaction were self-reported using the Positive and Negative Affect Schedule (PANAS), Beck Depression Inventory-second edition (BDI-II), State Trait Anxiety Inventory-I (STAI) and Satisfaction with Life Scale (SWLS), respectively. We conducted sequential linear regression analyses adjusted for baseline levels of depression, anxiety, life satisfaction, age, body fat percentage and education. RESULTS: At the 2-year follow-up, all the associations under study were significant. At the 5-year follow-up, a number of associations remained significant. First, lowering negative affect was independently associated with lower depression, anxiety and higher life satisfaction (ß's from 0.14 to 0.31). Second, favourable changes in positive affect were independently associated with lower anxiety (ß = 0.21) and higher life satisfaction (ß = 0.28). Third, enhancing physical fitness was related to higher life satisfaction (ß = 0.16). CONCLUSION: Reductions in negative affect were associated with more favourable depression, anxiety and life satisfaction at the 2- and 5-year follow-up. Improvements in positive affect were associated with more favourable anxiety and life satisfaction and enhancements in physical fitness were associated with higher life satisfaction. If corroborated in clinical-experimental research, these findings may guide the development of interventions that are tailored to the levels of physical fitness, affect and the outcome of interest (i.e. depression, anxiety or life satisfaction) in women with fibromyalgia.

Slowly repeated evoked pain (SREP) as a central sensitization marker in episodic migraine patients.

Migraine headache is a pain condition characterized by severe and recurrent unilateral head pain. Among other mechanisms, central pain sensitization processes seem to be involved in the disorder. An experimental protocol based on slowly repeated evoked pain (SREP) has been shown to indicate pain sensitization in fibromyalgia patients and differentiate these patients from healthy individuals and rheumatoid arthritis patients. This study examined SREP sensitization in migraine patients and explored its potential usefulness as a central sensitization marker. The SREP protocol was administered to 40 episodic migraine (EM) patients not currently experiencing a headache and 40 healthy controls. SREP consisted of a series of 9 suprathreshold painful pressure stimuli of 5 s duration and a 30 s interstimulus interval. SREP sensitization was indexed by the increase in pain ratings across the stimuli. Pain threshold, pain tolerance and temporal summation of pain were also assessed. SREP sensitization was observed in EM, but not in healthy individuals (p < .001). SREP differentiated between EM and healthy individuals with up to 75% diagnostic accuracy. Pain threshold, pain tolerance and temporal summation of pain did not show significant discriminative ability. An SREP index value of 0.5 was the most sensitive cut-off for detecting central pain sensitization when prioritizing diagnostic sensitivity (0.88). Results provide evidence for SREP as a possible central sensitization marker with potential clinical utility in migraine patients. Inclusion of SREP in Quantitative Sensory Testing protocols may enhance the assessment of altered pain modulation in different pain conditions.

Pain catastrophizing mediates the negative influence of pain and trait-anxiety on health-related quality of life in fibromyalgia.

BACKGROUND: Patients with fibromyalgia syndrome (FMS) usually display a decrease in health-related quality of life (HRQoL). This decrease in HRQoL is related to clinical pain, anxiety, and depression. This cross-sectional study analyzes the mediating role of pain-coping strategies (especially catastrophizing) in the negative relationships of pain, anxiety, depression, and HRQoL in FMS. METHODS: One hundred and thirteen women with FMS and 63 healthy women were assessed using the Short-Form Health Survey (SF-36). Participants completed self-report questionnaires to evaluate clinical pain, anxiety, depression, and pain-coping strategies. RESULTS: Pain catastrophizing was inversely associated with the physical function, general health perception, vitality, emotional role, mental health, the physical and mental general components, and the global index of HRQoL, with percentages of variance explained ranging between 9 and 18%. Cognitive distraction showed a positive association with the physical function, general health perception, vitality, emotional role, mental health, physical component, and global index of HRQoL, with percentages of variance explained ranging between 4 and 7%. Mediation analysis showed that catastrophizing mediates the negative influence of clinical pain and trait-anxiety on the physical function, general health perception, vitality, mental health, and global index of HRQoL. No mediating effect of pain catastrophizing on the relation between depression and HRQoL was observed. CONCLUSIONS: Patients with FMS exhibited markedly lower HRQoL than healthy individuals. While pain catastrophizing was inversely related to several domains of HRQL, associations were positive for cognitive distraction. Catastrophizing mediates the negative influence of clinical pain and trait-anxiety on HRQoL. Therefore, cognitive behavioral treatments focused on adaptive management and control of catastrophizing and negative emotional states may be helpful.

Addition of Slowly Repeated Evoked Pain Responses to Clinical Symptoms Enhances Fibromyalgia Diagnostic Accuracy.

OBJECTIVE: Fibromyalgia is a chronic pain syndrome characterized by central sensitization. A novel protocol based on slowly repeated evoked pain (SREP) appears to be a useful marker of pain sensitization in fibromyalgia patients. Whether SREP enhances diagnostic accuracy beyond key clinical symptoms that characterize fibromyalgia has not been examined. METHODS: Fifty fibromyalgia patients, 30 rheumatoid arthritis patients, and 50 healthy individuals were evaluated to assess clinical pain, as well as fatigue, insomnia, pain catastrophizing, and negative mood. The SREP protocol consisted of a series of nine low-intensity painful pressure stimuli of five seconds' duration with 30-second interstimulus intervals. SREP sensitization was indexed by increases in pain intensity ratings across stimuli. RESULTS: SREP sensitization was observed in fibromyalgia but not in rheumatoid arthritis or healthy individuals. As expected, fibromyalgia patients exhibited a more negative psychosocial profile than did rheumatoid arthritis patients and healthy individuals. SREP was positively associated with clinical pain, fatigue, insomnia, and catastrophizing, but not with negative mood. SREP discriminated fibromyalgia cases from rheumatoid arthritis and healthy individuals even when current clinical pain was included in the analysis. Combining fatigue, insomnia, and SREP led to near perfect diagnostic accuracy (99%) in differentiating fibromyalgia from healthy individuals and 86.3% accuracy in discriminating fibromyalgia from rheumatoid arthritis. CONCLUSIONS: These results provide further evidence of SREP as a marker of pain sensitization in fibromyalgia and suggest that it captures aspects of fibromyalgia not fully captured by clinical features. Combining SREP with assessment of clinical features could potentially improve fibromyalgia diagnosis.

Body dissatisfaction and mirror exposure: evidence for a dissociation between self-report and physiological responses in highly body-dissatisfied women.

BACKGROUND: Weight and shape concerns are widespread in the general population. Mirror exposure has been used to reduce body dissatisfaction but little is known about the mechanisms which underlie this therapeutic technique. The present study examined emotional, cognitive, and psychophysiological responses, in women with high and low levels of body dissatisfaction, exposed to their own bodies in a mirror. METHOD: Forty-two university-attending women (21 high body-dissatisfied (HBD) and 21 low body-dissatisfied (LBD)), were confronted with their own body during four 5-min trials in which participants were instructed to focus their attention on different parts of their body under standardized conditions. Emotional and cognitive measures were taken after each exposure trial. Heart rate (HR) and skin conductance (SC) were recorded continuously. RESULTS: HBD women experienced more negative emotions and cognitions following body exposure compared to LBD women but, conversely, showed a reduced physiological reaction in terms of HR and SC. In both groups greater physiological responses were observed looking at the thighs, buttocks, and abdomen. Extent of negative emotions and cognitions were positively associated with HR and/or SC in LBD women but no associations were observed in HBD women. CONCLUSION: The dissociation between self-report and psychophysiological measures in HBD women supports the existence of a passive-behavioral inhibited coping style in HBD women and suggests deficiencies in the generation of physiological correlates of emotion related to body dissatisfaction.

Comparison of baroreceptor cardiac reflex sensitivity estimates from inter-systolic and ECG R-R intervals.

Baroreceptor reflex sensitivity (BRS) is frequently evaluated using the spontaneous sequence method. Many of these studies use the inter-systolic interval (ISI) derived from a blood pressure monitor (e.g., Finapres) as interbeat interval measure instead of the traditionally recommended R-R series derived from the ECG. In this study, we examine possible differences between estimates of BRS from ISI and ECG R-R intervals. BRS was evaluated in 35 participants under three conditions: rest, mental arithmetic, and recovery periods. Although correlations between the two estimates are very high (all rs>.9), small but significant differences were found: the measures from ISI systematically yield higher BRS values and result in the detection of a greater number of reflex sequences. The higher BRS values from measures of ISI are due to the effects of pulse transit time fluctuations associated with the sequences of change in blood pressure.

Tonic blood pressure modulates the relationship between baroreceptor cardiac reflex sensitivity and cognitive performance.

This study explored the effects of tonic blood pressure on the association between baroreceptor cardiac reflex sensitivity and cognitive performance. Sixty female participants completed a mental arithmetic task. Baroreceptor reflex sensitivity was assessed using sequence analysis. An interaction was found, indicating that the relationship between baroreceptor reflex sensitivity and cognitive performance is modulated by blood pressure levels. Reflex sensitivity was inversely associated to performance indices in the subgroup of participants with systolic blood pressure above the mean, whereas the association was positive in participants with systolic values below the mean. These results are in accordance with the findings in the field of pain perception and suggest that tonic blood pressure modulates the inhibitory effects of baroreceptor stimulation on high central nervous functions.

Relationships between features of autonomic cardiovascular control and cognitive performance.

The study investigated relationships between autonomic cardiovascular control and attentional performance. In 60 healthy subjects R-wave to pulse interval (RPI), respiratory sinus arrhythmia (RSA), heart rate variability in the mid-frequency (MF) band and sensitivity of the cardiac baroreflex (BRS) were assessed at rest and during a visual attention test. All parameters decreased markedly during test execution. Lower values of resting BRS predicted increased performance. On-task RPI, RSA, MF power and BRS were inversely related to attentional functioning, with RSA accounting for the largest portion of test score variance. The inverse association between resting BRS and performance is discussed as reflecting the bottom-up modulation of cerebral function by baroreceptor activity. The results concerning the on-task measures suggest that a pattern of cardiovascular adjustment including enhanced sympathetic and reduced vagal cardiovascular influences, as well as baroreflex inhibition may induce an adaptive state associated with improved cognitive-attentional functioning.

Increased sensitivity to heat pain in chronic low blood pressure.

While in elevated blood pressure reduced sensitivity to acute pain has been well established, little is known about possible alterations in pain perception within the lower range of blood pressure. In this study, sensitivity to heat pain was assessed in 40 subjects with chronic hypotension (mean blood pressure 96.5/57.7 mmHg) and 40 normotensive control persons (mean blood pressure 121.8/77.2 mmHg). Employing a contact thermode, heat stimuli were applied to the forearm. Pain threshold and tolerance were determined. Participants furthermore rated subjective intensities and unpleasantness of tonic heat stimuli (45.5-47.5 degrees C) on visual analogue scales and in a questionnaire. Possible confounding of sensitivity to heat pain with skin temperature, temperature sensitivity and mood was controlled for. In addition to blood pressure, functional features of the arterial baroreceptor system were related to pain experience. Therefore, estimates for the input on the baroreceptors, as well as baroreflex sensitivity were obtained. Hypotensive individuals exhibited markedly reduced pain threshold and pain tolerance, as well as increased sensory and affective pain experience. The measures related to the baroreceptor system were not associated with pain experience, suggesting that no significant modulation of heat pain occurs through this system. The results of this study complete the findings on hypertension-related hypoalgesia and suggest an inverse relationship between blood pressure and pain sensitivity across the whole blood pressure spectrum. Furthermore, increased proneness of hypotensive individuals to clinical pain may be discussed.

Modification of baroreceptor cardiac reflex function by biofeedback.

Baroreceptor sensitivity (BRS) is considered a powerful prognostic factor in cardiovascular health. This study investigated the possibility of modifying the baroreflex cardiac function through biofeedback. Thirty-two psychology students underwent 3 biofeedback sessions, with four 5-min trials each, in which they had to increase and decrease baroreflex function. BRS was assessed by a system that analyzed baroreflex cardiac function on-line using a noninvasive spontaneous sequence method in the time domain. Baroreceptor parameters were differentiated in terms of blood pressure increases ("up" sequences) or blood pressure decreases ("down" sequences). BRS in the "up" sequences increased during the Increase Condition and decreased during the Decrease Condition. BRS in the "down" sequences decreased during the Decrease Condition but was unchanged during the Increase Condition. The increase in BRS during the Increase Condition was associated with a significant reduction in blood pressure and increase in heart period. The opposite cardiovascular changes were observed during the Decrease Condition. Suggestions for future research were discussed.