Fibromyalgia Group Research Articles

Cloninger's psychobiological model of personality and psychological distress in fibromyalgia.

Personality can play an important role in the clinical symptoms of fibromyalgia (FM). The aim of this study is to identify personality profiles in FM patients and the possible presence of personality disorder (PD) from the Temperament and Character Inventory-Revised (TCI-R), and to assess whether personality dimensions are related to psychological distress in FM. The sample consisted of 42 patients with FM and 38 healthy controls. The TCI-R, Hospital Anxiety and Depression Scale, State-Trait Anxiety Inventory, Short-Form-36 Health Survey, Fibromyalgia Impact Questionnaire and McGill Pain Questionnaire were administered. The personality profile of the FM group based on the TCI-R is defined by high Harm Avoidance (HA), low Novelty Seeking (NS), and low Self-Directedness (SD). Only one-third of patients with FM present a possible psychometric PD, principally from Cluster C. In the FM group, HA and SD are associated positively and negatively, respectively, with indicators of emotional distress. Patients with higher HA present higher perceived pain intensity rated via a verbal-numerical scale while Determination (SD2) reduced the perceived level of pain induced by the stimulus. NS is negatively related to the number of work absences caused by FM. The study suggests that HA and SD play an important role in psychological distress in FM. The fact that SD is prone to modification and has a regulatory effect on emotional impulses is a key aspect to consider from the psychotherapeutic point of view.

Cognitive dysfunction in fibromyalgia: slow access to the mental lexicon.

Lexical access speed, the time needed for the brain to access the catalogue of words in long-term memory, is assumed to provide a foundation for a broad array of cognitive operations. It was hypothesized that deficits in lexical speed are likely to play a central role in deficiencies in cognitive performance of patients with fibromyalgia, who as a group show deficits in lexical speed. This was tested in a sample of 209 patients with fibromyalgia and in 72 control patients with memory deficits. Participants completed the Stroop word-naming measure of lexical access speed and 12 neurocognitive measures. Deficit in lexical access speed occurred at approximately twice the frequency (48.3% vs 25.0%) in fibromyalgia. The average delay in speed of lexical access was 171 msec. in fibromyalgia and 163 msec. in controls. Those with deficits in lexical access speed displayed deficiencies on 10 of 12 cognitive measures in the fibromyalgia group, and on 8 of 12 cognitive measures in the control group. The premise that lexical access speed is disproportionately present in fibromyalgia and serves as a foundation for a wide array of cognitive operations is supported.

Vitamin D Levels in Women with Fibromyalgia and Relationship between Pain, Depression, and Sleep

Objective: Fibromyalgia (FM) is a chronic syndrome characterized by widespread musculoskeletal pain, associated with sleep disorders and depression. There are several studies suggesting a possible relationship between musculoskeletal pain and vitamin D deficiency. In this study, we aimed to compare serum 25-hydroxyvitamin D (25(OH)D) levels between FM patients and control groups and determine the relationship between 25(OH)D levels and pain, depression, and sleep disturbance. Material and Methods: This study enrolled 60 fibromyalgia women who fulfilled the American College of Rheumatology (ACR) 1990 criteria (mean age 41.9±9.8 and mean duration of disease 27.3±17.3 months) and 30 healthy women (mean age 38.8±12.7). All subjects were evaluated with biochemical markers, including 25(OH)D and parathyroid hormone. The patients were divided into three groups based on their serum 25(OH) D levels (normal, insufficient, deficient). In addition, the fibromyalgia impact questionnaire (FIQ), visual analog scale (VAS), Beck depression inventory (BDI), and Epworth sleepiness scale (ESS) were applied to the patients with FM. Results: Mean serum 25(OH)D levels were lower in the FM group than in the controls (16.7±9.5 ng/mL vs. 21.6±5.9 ng/mL, p=0.004). As patients were classified according to the levels of 25(OH)D, no significant difference was found between the groups in terms of pain and sleep disorder VAS, FIQ, BDI, and ESS scores (p>0.05). Also, there was no statistically significant correlation between vitamin D levels and clinical scales (p>0.05). Conclusion: In this study, mean serum 25(OH)D levels were lower in patients with fibromyalgia, and no association was demonstrated between serum 25(OH)D levels and severity of pain, sleep disorder, and depression.

Altered white matter integrity in the corpus callosum in fibromyalgia patients identified by tract-based spatial statistical analysis.

Although recent imaging studies of fibromyalgia (FM) have converged on a dysfunction of central pain processing as the primary pathophysiologic cause of the disorder, microstructural changes of the white matter (WM) suggestive of abnormalities in the anatomic connectivity of the brain have not been extensively examined. The aim of this study was to investigate WM integrity and its possible relationship to pain symptoms in women with FM. Nineteen FM patients and 21 age-, sex-, and education-matched healthy control subjects were included in the study and underwent diffusion-weighted imaging. Group differences in WM integrity, which were assessed via fractional anisotropy (FA), was investigated by applying tract-based spatial statistics. As compared with the healthy control group, the FM group showed a single cluster with lower FA in the left body of the corpus callosum, which was found to be connected to the bilateral sensorimotor cortices (P < 0.05, corrected for multiple comparisons). Furthermore, FA values in the cluster were negatively associated with sensory pain, as measured by the Short-Form McGill Pain Questionnaire, as well as with the relative magnitude of sensory pain versus affective pain (calculated by dividing the sensory score by the affective score). Findings of the current study demonstrated that patients with FM had disrupted WM microstructure in the body of the corpus callosum, which was associated with clinical pain intensity. Our results suggest that abnormal interhemispheric transfer might contribute to the heightened pain perception. Our findings further strengthen the hypothesis of centrally augmented pain processing in patients with FM.

Hypervigilance for innocuous tactile stimuli in patients with fibromyalgia: an experimental approach.

Hypervigilance, i.e., excessive attention, is often invoked as a potential explanation for the observation that many individuals with fibromyalgia show a heightened sensitivity to stimulation in various sensory modalities, such as touch and hearing. Compelling evidence for this assumption is, however, lacking. The aim of the present study was to investigate the presence of somatosensory hypervigilance in patients with fibromyalgia. Fibromyalgia patients (n = 41) and a matched control group (n = 40) performed a tactile change detection task in which they had to detect whether there was a change between two consecutively presented patterns of tactile stimuli presented to various body locations. The task was performed under two conditions: in the unpredictable condition, tactile changes occurred equally often at all possible body locations; in the predictable condition, the majority of tactile changes occurred at one specific body location. It was hypothesized that the fibromyalgia group would show better tactile change detection in the unpredictable condition and when changes ocurred at unexpected locations in the predictable condition. The results did not support this hypothesis. In neither condition was the fibromyalgia group better than the control group in detecting tactile changes. No evidence was found to support the claim that patients with fibromyalgia display somatosensory hypervigilance. This finding challenges the idea of hypervigilance as a static feature of fibromyalgia and urges for a more dynamic view in which hypervigilance emerges in situations when bodily threat is experienced.

18. Stress, pain and monocytes in fibromyalgia

Several lines of evidence implicate an immunological contribution to symptoms associated with fibromyalgia (FM). However, a clear picture of how immunological disturbances could drive these symptoms remains elusive. This preliminary study was performed to explore whether or not FM-related symptoms could be associated with differences in circulating monocyte subpopulations. A mixed-methods design was used to assess the relationship between specific symptoms found in FM (n = 19) and patterns of monocytes phenotypes as compared to healthy age- and gender-matched controls (n = 19). All participants provided a blood sample for monocyte phenotyping and completed questionnaires assessing pain, stress, fatigue, positive/negative affect, depression, sleep, and disease impact (FM group only). Monocyte populations were assessed for expression of CD14 and CD16 using flow cytometry, and data was expressed as percentages of CD45 positive cells (i.e. all leukocytes). There was no association of symptoms with any monocyte subpopulation in the control group. However, in the FM group, symptoms of pain and stress were significantly correlated with reduced percentages of “classical” and “intermediate” monocyte populations. Although the mechanisms driving these differences cannot be determined from this study, the strong correlation of stress with increased ratings of pain and depression, concomitant with lower percentages of classic and intermediate monocytes in FM suggests that stress may play a mediating role in symptom levels in FM.

Gait characteristics of women with fibromyalgia: a premature aging pattern

BackgroundFibromyalgia is a condition which involves chronic pain. Middle-aged individuals with fibromyalgia seem to exhibit changes in gait pattern, which may prematurely expose them to a gait pattern which resembles that found in the elderly population. ObjectiveTo determine the 3D spatial (linear and angular) gait parameters of middle-aged women with fibromyalgia and compare to elderly women without this condition. Methods25 women (10 in the fibromyalgia group and 15 in the elderly group) volunteered to participate in the study. Kinematics was performed using an optoelectronic system, and linear and angular kinematic variables were determined. ResultsThere was no difference in walking speed, stride length, cadence, hip, knee and ankle joints range of motion between groups, except the pelvic rotation, in which the fibromyalgia group showed greater rotation (P<0.05) compared to the elderly group. Also, there was a negative correlation with pelvic rotation and gluteus pain (r = - 0.69; P<0.05), and between pelvic obliquity and greater trochanter pain (r = - 0.69; P<0.05) in the fibromyalgia group. ConclusionMiddle-aged women with fibromyalgia showed gait pattern resemblances to elderly, women, which is characterized by reduced lower limb ROM, stride length and walking speed.

Do Comorbid Fibromyalgia Diagnoses Change After a Functional Restoration Program in Patients With Chronic Disabling Occupational Musculoskeletal Disorders?

A retrospective study of prospectively collected data. To determine whether comorbid fibromyalgia, identified in patients with chronic disabling occupational musculoskeletal disorders (CDOMDs), resolves with a functional restoration program (FRP). Fibromyalgia involves widespread bodily pain and tenderness to palpation. In recent studies, 23% to 41% of patients with CDOMDs entering an FRP had comorbid fibromyalgia, compared with population averages of 2% to 5%. Few studies have examined whether fibromyalgia diagnoses resolve with any treatment, and none have investigated diagnosis responsiveness to an FRP. A consecutive cohort of patients with CDOMDs (82% with spinal disorders and all reporting chronic spinal pain) and comorbid fibromyalgia (N = 117) completed an FRP, which included quantitatively directed exercise progression and multimodal disability management. Diagnosis responsiveness, evaluated at discharge, created 2 groups: those who retained fibromyalgia and those who did not. These groups were compared with chronic regional lumbar pain only patients (LO group, n = 87), lacking widespread pain and fibromyalgia. Of the patients with comorbid fibromyalgia, 59% (n = 69) retained the fibromyalgia diagnosis (RFM group) and 41% (n = 48) lost the fibromyalgia diagnosis (LFM group) at discharge. Although all 3 groups reported decreased pain intensity, disability, and depressive symptoms from admission to discharge, RFM patients reported higher symptom levels than the LFM and LO groups at discharge. The LFM and LO groups were statistically similar. At 1-year follow-up, LO patients demonstrated higher work retention than both fibromyalgia groups (P < 0.03). Despite a significant comorbid fibromyalgia prevalence in a cohort of patients with CDOMDs entering an FRP, 41% of patients with an initial fibromyalgia diagnosis no longer met diagnostic criteria for fibromyalgia at discharge and were indistinguishable from LO patients on pain, disability, and depression symptoms. However, both fibromyalgia groups (LFM and RFM) had lower work retention than LO patients 1 year later, suggesting that an FRP may suppress symptoms of fibromyalgia in a subset of patients, but prolonged fibromyalgia-related disability may be more difficult to overcome. 2.

The role of depression, anxiety, fatigue, and fibromyalgia on the evaluation of the remission status in patients with rheumatoid arthritis.

To investigate the effect of depression, anxiety, fatigue, and fibromyalgia (FM) on the remission status in patients with rheumatoid arthritis (RA), defined according to the 28-joint count Disease Activity Score (DAS28)-erythrocyte sedimentation rate (ESR) and the Boolean-based new American College of Rheumatology/European League Against Rheumatism remission criteria. The subjects were patients with RA who participated in a hospital-based observational cohort. Patients who met the DAS28-ESR remission criteria at their latest visit were invited to participate in our study. The patient groups fulfilling or not fulfilling the Boolean remission criteria were identified and compared with each other with regard to the presence of depression, anxiety, fatigue (0-50), and FM. The relationship between psychosocial factors and Simplified Disease Activity Index (SDAI) remission, which is the index-based definition of remission in RA, was also investigated. A total of 87 out of 428 patients (20%) with RA met the DAS28-ESR remission criteria and 32 (37%) of these also met the Boolean remission criteria, while 55 (63%) did not. Forty patients were also in SDAI remission. In the Boolean remission group, 2 patients had depression and 2 had anxiety (p = 0.004). In the Boolean nonremission group, 19 patients had depression and 13 had anxiety (p = 0.04). Continuous scales of anxiety (3.34 ± 3.76 vs 5.83 ± 4.70, p = 0.012) and depression (2.18 ± 2.75 vs 4.63 ± 4.10, p = 0.001) were also lower in the Boolean remission group in comparison with the nonremission group. Though FM syndrome was detected in only 1 patient of the Boolean remission group and in 7 patients of the Boolean nonremission group (p = 0.249), patients' polysymptomatic distress scores of FM in the Boolean remission group were significantly lower than those of the nonremission group (3.12 ± 3.25 vs 6.27 ± 5.19, p = 0.001). The mean fatigue scores were 9.5 ± 10.6 in the Boolean remission group and 16.8 ± 12.8 in the Boolean nonremission group (p = 0.006). In multivariate analysis, patient's global assessment (PtGA) and depression were found as the independent discriminators of Boolean-based definition. Similar relationships were also observed between psychosocial factors and SDAI remission. In patients with RA who do not fulfill the Boolean remission criteria, to avoid overtreatment, assessment of anxiety, fatigue, FM, and especially depression must be considered if PtGA scores and disease activity variables are significantly different.

Características da marcha de mulheres com fibromialgia: um padrão prematuro de envelhecimento

BackgroundFibromyalgia is a condition which involves chronic pain. Middle‐aged individuals with fibromyalgia seem to exhibit changes in gait pattern, which may prematurely expose them to a gait pattern which resembles that found in the elderly population. ObjectiveTo determine the 3D spatial (linear and angular) gait parameters of middle‐aged women with fibromyalgia and compare to elderly women without this condition. Methods25 women (10 in the fibromyalgia group and 15 in the elderly group) volunteered to participate in the study. Kinematics was performed using an optoelectronic system, and linear and angular kinematic variables were determined. ResultsThere was no difference in walking speed, stride length, cadence, hip, knee and ankle joints range of motion between groups, except the pelvic rotation, in which the fibromyalgia group showed greater rotation (P<0.05) compared to the elderly group. Also, there was a negative correlation with pelvic rotation and gluteus pain (r = –0.69; P<0.05), and between pelvic obliquity and greater trochanter pain (r = –0.69; P<0.05) in the fibromyalgia group. ConclusionMiddle‐aged women with fibromyalgia showed gait pattern resemblances to elderly, women, which is characterized by reduced lower limb ROM, stride length and walking speed.

Mapping the body distribution of pain perception in fibromyalgia

Background. Fibromyalgia is a syndrome characterized for persistent and debilitating disorder marked by chronic widespread pain. Objec­tive. We aim to create a virtual body representation of peripheral pain to pressure in fibromyalgia patients. Method. Fifty adult subjects, aged 32-71 years, who fulfill the American College of Rheumatol­ogy (ACR) criteria for fibromyalgia and forty-two healthy volunteers, were recruited. Pain sensitivity was performed on the 18 points iden­tified by ACR. Algometry was carried out to record threshold and tolerance to pain quantified in kg/cm2. Functionality was evaluated by Fibromyalgia Impact Questionnaire (FIQ). Differences in percent were used to enlarge the correspondent body part in fibromyalgia group using a 3D MAX® Software. Results. Significant difference be­tween FIQ (p&lt;0.0001), pain threshold (fibromyalgia 1.8±0.4; control 4.7±1.2) and tolerance (fibromyalgia 2.52±0.5; control 5.91±1.5) was found between the groups (p&lt;0.0001). The body pain representation in fibromyalgia group is different than control, showing that pain perception increases is mainly in cervical, thoracic, arms, gluteus and over the knees. Conclusion. It is possible to create a virtual body pain image of fibromyalgia using algometry. This may contribute to build a specific body representation of this syndrome and to contribute to better information for clinical management and diagnosis.

Mapping the body distribution of pain perception in fibromyalgia

Background. Fibromyalgia is a syndrome characterized for persistent and debilitating disorder marked by chronic widespread pain. Objec­tive. We aim to create a virtual body representation of peripheral pain to pressure in fibromyalgia patients. Method. Fifty adult subjects, aged 32-71 years, who fulfill the American College of Rheumatol­ogy (ACR) criteria for fibromyalgia and forty-two healthy volunteers, were recruited. Pain sensitivity was performed on the 18 points iden­tified by ACR. Algometry was carried out to record threshold and tolerance to pain quantified in kg/cm2. Functionality was evaluated by Fibromyalgia Impact Questionnaire (FIQ). Differences in percent were used to enlarge the correspondent body part in fibromyalgia group using a 3D MAX® Software. Results. Significant difference be­tween FIQ (p&lt;0.0001), pain threshold (fibromyalgia 1.8±0.4; control 4.7±1.2) and tolerance (fibromyalgia 2.52±0.5; control 5.91±1.5) was found between the groups (p&lt;0.0001). The body pain representation in fibromyalgia group is different than control, showing that pain perception increases is mainly in cervical, thoracic, arms, gluteus and over the knees. Conclusion. It is possible to create a virtual body pain image of fibromyalgia using algometry. This may contribute to build a specific body representation of this syndrome and to contribute to better information for clinical management and diagnosis.

AB0862 Qt Dispersion and P Wave Dispersion in Fibromyalgia

BackgroundFibromyalgia syndrome is a chronic disease with unknown etiology, characterized by widespread pain. QT dispersion represents a general repolarization abnormality and autonomic dysfunction. Longer QT dispersion is associated with higher...

AB1168-HPR Physical Inacivity in Adults with Rheumatic Diseases

BackgroundPhysical inactivity is a frequent complication of rheumatic diseases, and also common in the general population. However, there is surprisingly little research available comparing daily life physical activity between patients...

Altered Resting State Connectivity of the Insular Cortex in Individuals With Fibromyalgia

The insular cortex (IC) and cingulate cortex (CC) are critically involved in pain perception. Previously we demonstrated that fibromyalgia (FM) patients have greater connectivity between the insula and default mode network at rest, and that changes in the degree of this connectivity were associated with changes in the intensity of ongoing clinical pain. In this study we more thoroughly evaluated the degree of resting-state connectivity to multiple regions of the IC in individuals with FM and healthy controls. We also investigated the relationship between connectivity, experimental pain, and current clinical chronic pain. Functional connectivity was assessed using resting-state functional magnetic resonance imaging in 18 FM patients and 18 age- and sex-matched healthy controls using predefined seed regions in the anterior, middle, and posterior IC. FM patients exhibited greater connectivity between 1) right mid IC and right mid/posterior CC and right mid IC, 2) right posterior IC and left CC, and 3) right anterior IC and left superior temporal gyrus. Healthy controls displayed greater connectivity between left anterior IC and bilateral medial frontal gyrus/anterior cingulate cortex; and left posterior IC and right superior frontal gyrus. Within the FM group, greater connectivity between the IC and CC was associated with decreased pressure-pain thresholds. PerspectiveThese data provide further support for altered resting-state connectivity between the IC and other brain regions known to participate in pain perception/modulation, which may play a pathogenic role in conditions such as FM. We speculate that altered IC connectivity is associated with the experience of chronic pain in individuals with FM.

Effects of 12-week combined exercise therapy on oxidative stress in female fibromyalgia patients

The aims of this study were to investigate the effect of exercise therapy on the oxidative stress in fibromyalgia patients and relationship between oxidative stress and fibromyalgia symptoms. Thirty women diagnosed with fibromyalgia according to the American College of Rheumatology preliminary criteria, and 23 healthy women whose age- and weight-matched women were enrolled the study. Pain intensity with visual analog scale (VAS), the number of tender points, the fibromyalgia impact questionnaire (FIQ), the Beck depression inventory (BDI) were evaluated. The oxidative stress parameters thiobarbituric acid reactive substances, protein carbonyls, and nitric oxide, and antioxidant parameters thiols and catalase were investigated in patients and control group. After, combined aerobic and strengthen exercise regimen was given to fibromyalgia group. Exercise therapy consisted of a warming period of 10 min, aerobic exercises period of 20 min, muscle strengthening exercises for 20 min, and 10 min cooling down period. Therapy was lasting 1 h three times per week over a 12-week period. All parameters were reevaluated after the treatment in the patient group. The oxidative stress parameters levels were significantly higher, and antioxidant parameters were significantly lower in patients with fibromyalgia than in the controls. VAS, FIQ, and BDI scores decreased significantly with exercise therapy. The exercise improved all parameters of oxidative stress and antioxidant parameters. Also, all clinical parameters were improved with exercise. We should focus on oxidative stress in the treatment for fibromyalgia with the main objective of reducing oxidative load.

Perceived injustice in fibromyalgia and rheumatoid arthritis

This is a pilot study to compare levels of perceived injustice via the Injustice Experience Questionnaire in patients with fibromyalgia or rheumatoid arthritis. Two cohorts of patients, one with fibromyalgia (FM), one with rheumatoid arthritis (RA), completed the Injustice Experience Questionnaire, a visual analogue pain scale, and the Hospital Anxiety and Depression Scale (HADS). Inferential statistics were then used to determine whether participants in the two diagnostic groups had significantly different scores on the Perceived Injustice Questionnaire. This was done univariately using t tests and after adjusting for potential confounders using ANCOVA. We also examined crude associations between the variables using Pearson correlation coefficients, then examined the adjusted association between diagnostic group and perceived injustice using multivariable linear regression. Our final models were built in a blocked fashion by initially entering diagnostic category into the model, then entering other variables simultaneously using a stepwise strategy (p-to-enter ≤.05, p-to-remove ≥.10). A total of 126 participants (64 FM, 62 RA) completed all questionnaires. The FM group had a greater percentage of female participants, more severe pain, more severe anxiety and more severe depression. In unadjusted analysis, the FM group had higher Injustice Experience Questionnaire scores. When the RA and FM group scores for the Injustice Experience Questionnaire are adjusted for pain levels, there is no statistically significant difference between groups. Adjustment for HADS anxiety and HADS depression does not significantly affect the Injustice Experience Questionnaire scores after adjustment for pain. Fibromyalgia is associated with a higher level of perceived injustice than is seen with rheumatoid arthritis. This difference appears to be associated with higher levels of pain reported by fibromyalgia patients, and therefore may not be specific to the diagnosis. Prospective studies may help to resolve this issue.

Fibromyalgia: is there association between balance and pain? a pilot study

Studies of balance and risk factors for falling typically focus on the elderly population or on individuals with musculoskeletal pain. Although fibromyalgia is associated with intrinsic factors that predispose to falls (pain, depression, fatigue), few studies have researched balance and falls in this syndrome. The aim of this study was to verify the association between balance, balance self-efficacy and pain in women with and without fibromyalgia, and verify the association between Berg Balance Scale and Activities-specific Balance Confidence Scale (ABC Scale). The sample consisted of 48 women aged between 40 and 59 years, divided into two groups: Fibromyalgia group (n=22) and Control group (n=26) with asymptomatic people. Balance was assessed by Berg Balance Scale, balance self-efficacy by the ABC Scale and pain by the visual analog scale. Mean scores for pain, Berg and ABC Scale were 5.4 cm (SD 2.6), 55 (interquartile range 54-56), and 54.6 (SD 26.6) respectively for Fibromyalgia group, and 0 cm, 56 (interquartile range 55-56), and 89.4 (SD 14.4) respectively for Control group. Statistically significant differences were found in balance on comparing both groups (p=0.000 for Berg Balance Scale and 0.009 for ABC Scale) with lower values for Fibromyalgia group. In Fibromyalgia group, pain was negatively correlated with balance (r=-0.48, p=0.020) and balance self-efficacy (rs=-0.56, p=0.006). Correlation between Berg Balance Scale and ABC Scale was found only in the Fibromyalgia group (rs =0.55, p=0.007). There are associations between poor balance and pain, and poor balance and decreased balance self-efficacy in women with fibromyalgia. There is an association between scales in the Fibromyalgia group.

Mean platelet volume in patients with fibromyalgia

Fibromyalgia is a syndrome characterised by chronic widespread pain at multiple tender points, as well as joint stiffness and systemic symptoms. The aetiology and pathogenesis of fibromyalgia still remain unclear, although many contributory factors have been suggested. The presence of some common features between fibromyalgia and cardiovascular risk factors (e.g. depression and sleep disturbance) led to question of whether there is there a relationship between fibromyalgia and cardiovascular disease and/or atherosclerosis. Mean platelet volume, which is a determinant of platelet activation, is a newly emerging independent risk factor for cardiovascular disease.The present study was designed to evaluate levels of mean platelet volume in patients with fibromyalgia; the study population consisted of 283 individuals with this syndrome, who were compared with 72 healthy controls. Erythrocyte sedimentation rate, C-reactive protein, white blood cell count, platelet count and mean platelet volume levels were retrospectively recorded via the computerised patient database. The levels of mean platelet volume were significantly higher in the fibromyalgia group than in the control group (8.09 ± 0.84 fl and 7.73 ± 0.65 fl, respectively, p < 0.001). There were no statistical differences between groups with regard to platelet count and other parameters. These results suggest that an early atherosclerosis marker, mean platelet volume, is elevated in patients with fibromyalgia. This indicates increased platelet activation and therefore a higher risk of future cardiovascular disease.

Hyperexcitable C nociceptors in fibromyalgia

To test the hypothesis that peripheral C nociceptor function may be abnormal in fibromyalgia and that C nociceptor dysfunction may contribute to the symptoms reported by these patients. Microneurography was used to record C nociceptors of 30 female patients meeting criteria for fibromyalgia and compared with recordings from 17 female patients with small-fiber neuropathy and 9 female controls. We obtained stable recordings of 186 C nociceptors in the fibromyalgia group, 114 from small-fiber neuropathy patients, and 66 from controls. The mechanosensitive nociceptors in the fibromyalgia patients behaved normally, but the silent nociceptors in 76.6% of fibromyalgia patients exhibited abnormalities. Spontaneous activity was detected in 31% of silent nociceptors in fibromyalgia, 34% in small-fiber neuropathy, and 2.2% in controls. Sensitization to mechanical stimulation was found in 24.2% of silent nociceptors in fibromyalgia, 22.7% in small-fiber neuropathy, and 3.7% in controls. Abnormally high slowing of conduction velocity when first stimulated at 0.25Hz was more common in fibromyalgia. We show for the first time that the majority of fibromyalgia patients have abnormal C nociceptors. Many silent nociceptors exhibit hyperexcitability resembling that in small-fiber neuropathy, but high activity-dependent slowing of conduction velocity is more common in fibromyalgia patients, and may constitute a distinguishing feature. We infer that abnormal peripheral C nociceptor ongoing activity and increased mechanical sensitivity could contribute to the pain and tenderness suffered by patients with fibromyalgia.