Scand J Gastroenterol 2006 Jun; 41(6): 650-6 (Read article online)

Vandvik PO, Lydersen S, Farup PG

Objective. To study the prevalence of irritable bowel syndrome (IBS) and its comorbidity in a Norwegian adult population.Material and methods. In 2001, 11,078 inhabitants (aged 30-75 years) in Oppland County were invited to take part in a public health survey. A total of 4622 subjects (42%) completed the questionnaires on symptoms of IBS (Rome II criteria), comorbidity, health-care visits and medications. The impact of comorbidity on global health, working disability and use of health-care resources in subjects with IBS was explored by stepwise logistic regression.Results. The population prevalence of IBS was 388/4622 (8.4% (95% CI: 7.6-9.4%)) with a female predominance and an age-dependent decrease. The proportion who had consulted for IBS ranged from 51% among 30-year-olds to 79% in 75-year-olds (p=0.05). IBS was associated with musculoskeletal complaints (OR = 2.4-3.4 for six different items), fibromyalgia (OR = 3.6 [2.7-4.8]), mood disorder (OR = 3.3 (2.6-4.3)), reduced global health (OR = 2.6 (2.1-3.2)), working disability (OR = 1.6 (1.2-2.1)), more frequent health-care visits and use of medications (OR 1.7-2.3). When controlling for comorbidity, reduced global health (OR = 1.5 (1.1-2.0)) and use of alternative health care (OR = 1.7 (1.3-2.4)) remained associated with IBS. Severity of abdominal pain/discomfort was a predictor of having to seek a physician for IBS (OR = 1.3 (1.2-1.5)).Conclusions. Symptoms of IBS were reported by 8% of Norwegian adults and had resulted in consultations with physicians for the majority in the long run. Subjects with IBS in the community were characterized by frequent somatic and psychiatric comorbidity. Their observed reduced health, working disability and increased use of health resources were largely explained by comorbid symptoms and disorders.

CMAJ 2006 May 23; 174(11): 1589-94 (Read article online)

Furlan AD, Sandoval JA, Mailis-Gagnon A, Tunks E

BACKGROUND: Chronic noncancer pain (CNCP) is a major health problem, for which opioids provide one treatment option. However, evidence is needed about side effects, efficacy, and risk of misuse or addiction. METHODS: This meta-analysis was carried out with these objectives: to compare the efficacy of opioids for CNCP with other drugs and placebo; to identify types of CNCP that respond better to opioids; and to determine the most common side effects of opioids. We searched MEDLINE, EMBASE, CENTRAL (up to May 2005) and reference lists for randomized controlled trials of any opioid administered by oral or transdermal routes or rectal suppositories for CNCP (defined as pain for longer than 6 mo). Extracted outcomes included pain, function or side effects. Methodological quality was assessed with the Jadad instrument; analyses were conducted with Revman 4.2.7. RESULTS: Included were 41 randomized trials involving 6019 patients: 80% of the patients had nociceptive pain (osteoarthritis, rheumatoid arthritis or back pain); 12%, neuropathic pain (postherpetic neuralgia, diabetic neuropathy or phantom limb pain); 7%, fibromyalgia; and 1%, mixed pain. The methodological quality of 87% of the studies was high. The opioids studied were classified as weak (tramadol, propoxyphene, codeine) or strong (morphine, oxycodone). Average duration of treatment was 5 (range 1-16) weeks. Dropout rates averaged 33% in the opioid groups and 38% in the placebo groups. Opioids were more effective than placebo for both pain and functional outcomes in patients with nociceptive or neuropathic pain or fibromyalgia. Strong, but not weak, opioids were significantly superior to naproxen and nortriptyline, and only for pain relief. Among the side effects of opioids, only constipation and nausea were clinically and statistically significant. INTERPRETATION: Weak and strong opioids outperformed placebo for pain and function in all types of CNCP. Other drugs produced better functional outcomes than opioids, whereas for pain relief they were outperformed only by strong opioids. Despite the relative shortness of the trials, more than one-third of the participants abandoned treatment.

Osteoporos Int 2006 May 23; (Read article online)

Erkal MZ, Wilde J, Bilgin Y, Akinci A, Demir E, Bödeker RH, Mann M, Bretzel RG, Stracke H, Holick MF

INTRODUCTION: The aim of the study was to determine the prevalence of vitamin D deficiency, secondary hyperparathyroidism (sHPT), generalized bone pain and predictors of vitamin D deficiency in a cohort of 994 healthy adult urban residents (589 males, 405 females; age range: 16-69 years) consisting of 101 Germans, 327 Turkish residents of Turkey and 566 Turkish immigrants living in Germany. METHODS: The mean (+/- standard deviation) for 25-hydroxyvitamin D [25(OH)D] and biointact parathyroid hormone (BioPTH) for the German men and women was 68.4 nmol/l and 26.7 pg/ml, respectively. Turkish residents of Turkey had a mean 25(OH)D and BioPTH of 40.6 nmol/l and 27.5 pg/ml, respectively, whereas Turkish residents of Germany had a 25(OH)D of 38.1 nmol/l and a BioPTH of 35.6 pg/ml. RESULTS: Vitamin D insufficiency was common among Turkish nationals independent of whether they lived in Turkey or Germany; 75% had 25(OH)D levels of <50 nmol/l. Turkish females had a higher prevalence of 25(OH)D deficiency (<25 nmol/l) than Turkish males: 30 and 19% of Turkish females living in Germany and Turkey were severely vitamin D deficient compared to 8% and 6% of Turkish males living in Germany and Turkey, respectively. With respect to BioPTH levels, 31% of Turkish females and 21% of Turkish males had elevated BioPTH levels in contrast to only 15% of females and 4% of males living in Turkey. Unconditional logistic regression analysis identified the most important predictors for low 25(OH)D levels as sex, body mass index, lack of sun exposure and living at a higher latitude. Additionally, wearing a scarf and number of children were found to be an independent risk factor for vitamin D deficiency in Turkish women living in Turkey and Germany. A strong correlation between low 25(OH)D levels and higher rates and longer duration of generalized bone and/or muscle aches and pains (often diagnosed as fibromyalgia) was observed. CONCLUSION: Secondary hyperparathyroidism and vitamin D deficiency was found to be common among Turkish immigrants living in Germany, especially in veiled women. Therefore, the monitoring of vitamin D status - i.e. 25(OH)D and PTH - in Turkish immigrants is warranted and once a deficiency is identified, it should be appropriately treated.

Int J Behav Med 2006; 13(2): 101-8 (Read article online)

Dobkin PL, De Civita M, Abrahamowicz M, Baron M, Bernatsky S

Although cross-sectional studies have identified correlates of dysfunction in fibromyalgia (FM) patients (e.g., psychological distress and pain), predictors of health status have not been previously investigated using a longitudinal research design. We gathered data from 156 women who met American College of Rheumatology criteria for primary FM recruited from both tertiary care and community settings. Stepwise multiple linear regression analysis indicated that poorer health status (p < .0001) and more comorbidity (p = .0089) at baseline were predictors of poorer health status 6 months later. After controlling for these covariates, psychological distress contributed significantly to the model (p = .01). There was a trend indicating that palliative coping styles (i.e., self-care, energy conservation) altered the impact of pain on 6-month health status (p = .06). These findings highlight the need for multidisciplinary interventions that target psychological distress, coping, and comorbidity in patients with FM.

Neurosci Lett 2006 May 19; (Read article online)

Lund I, Lundeberg T, Carleson J, Sönnerfors H, Uhrlin B, Svensson E

The purpose of this preliminary study was to evaluate the relationship between a possible biochemical marker of stress, 24-h urinary concentrations of Corticotropin Releasing Factor-Like Immunoreactivity (CRF-LI), and ratings of stress-related symptoms like depression and anxiety, as well as to evaluate pain and emotional reactions in patients with fibromyalgia (FM). Another purpose was to study the effects of massage and guided relaxation, with respect to change in the same variables. Urine sampling and ratings were performed before treatments, after and 1 month after completed treatments. Concentrations of CRF-LI was analysed with radioimmnoassay technique. For the assessment of depression, anxiety and pain the CPRS-A questionnaire was used and for rated pain and emotional reactions the NHP questionnaire was used. The 24-h urinary concentration of the CRF-LI was found to be related to depression, mood and inability to take initiative. After treatment the urinary CRF-LI concentrations and the rated levels of pain and emotional reactions were found to have decreased. In conclusion, the 24-h urinary CRF-LI concentration may be used as a biochemical marker of stress-related symptoms such as depression in patients with FM and possibly also other conditions characterized by chronic pain. Therapies such as massage and guided relaxation may be tried for the amelioration of pain and stress but further studies are required.

Pain 2006 May 13; (Read article online)

Arguelles LM, Afari N, Buchwald DS, Clauw DJ, Furner S, Goldberg J

Previous studies of the association between posttraumatic stress disorder (PTSD) and chronic widespread pain (CWP) or fibromyalgia have not examined the role of familial or genetic factors. The goals of this study were to determine if symptoms of PTSD are related to CWP in a genetically informative community-based sample of twin pairs, and if so, to ascertain if the association is due to familial or genetic factors. Data were obtained from the University of Washington Twin Registry, which contains 1042 monozygotic and 828 dizygotic twin pairs. To assess the symptoms of PTSD, we used questions from the Impact of Events Scale (IES). IES scores were partitioned into terciles. CWP was defined as pain located in 3 body regions lasting at least 1 week during the past 3 months. Random-effects regression models, adjusted for demographic features and depression, examined the relationship between IES and CWP. IES scores were strongly associated with CWP (P<0.0001). Compared to those in the lowest IES tercile, twins in the highest tercile were 3.5 times more likely to report CWP. Although IES scores were associated with CWP more strongly among dizygotic than among monozygotic twins, this difference was not significant. Our findings suggest that PTSD symptoms, as measured by IES, are strongly linked to CWP, but this association is not explained by a common familial or genetic vulnerability to both conditions. Future research is needed to understand the temporal association of PTSD and CWP, as well as the physiological underpinnings of this relationship.

Pain 2006 May 12; (Read article online)

Raphael KG, Janal MN, Nayak S, Schwartz JE, Gallagher RM

Prior studies of careseeking fibromyalgia (FM) patients often report that they have an elevated risk of psychiatric disorders, but biased sampling may distort true risk. The current investigation utilizes state-of-the-art diagnostic procedures for both FM and psychiatric disorders to estimate prevalence rates of FM and the comorbidity of FM and specific psychiatric disorders in a diverse community sample of women. Participants were screened by telephone for FM and MDD, by randomly selecting telephone numbers from a list of households with women in the NY/NJ metropolitan area. Eligible women were invited to complete physical examinations for FM and clinician-administered psychiatric interviews. Data were weighted to adjust for sampling procedures and population demographics. The estimated overall prevalence of FM among women in the NY/NJ metropolitan area was 3.7% (95% CI=3.2, 4.4), with higher rates among racial minorities. Although risk of current MDD was nearly 3-fold higher in community women with than without FM, the groups had similar risk of lifetime MDD. Risk of lifetime anxiety disorders, particularly obsessive compulsive disorder and post-traumatic stress disorder, was approximately 5-fold higher among women with FM. Overall, this study found a community prevalence for FM among women that replicates prior North American studies, and revealed that FM may be even more prevalent among racial minority women. These community-based data also indicate that the relationship between MDD and FM may be more complicated than previously thought, and call for an increased focus on anxiety disorders in FM.

Arthritis Res Ther 2006 Apr 24; 8(3): 208 (Read article online)

Staud R

ABSTRACT : Fibromyalgia (FM) pain is frequent in the general population but its pathogenesis is only poorly understood. Many recent studies have emphasized the role of central nervous system pain processing abnormalities in FM, including central sensitization and inadequate pain inhibition. However, increasing evidence points towards peripheral tissues as relevant contributors of painful impulse input that might either initiate or maintain central sensitization, or both. It is well known that persistent or intense nociception can lead to neuroplastic changes in the spinal cord and brain, resulting in central sensitization and pain. This mechanism represents a hallmark of FM and many other chronic pain syndromes, including irritable bowel syndrome, temporomandibular disorder, migraine, and low back pain. Importantly, after central sensitization has been established only minimal nociceptive input is required for the maintenance of the chronic pain state. Additional factors, including pain related negative affect and poor sleep have been shown to significantly contribute to clinical FM pain. Better understanding of these mechanisms and their relationship to central sensitization and clinical pain will provide new approaches for the prevention and treatment of FM and other chronic pain syndromes.

Clin Rheumatol 2006 May 3; (Read article online)

Fengler RK, Jacobs JW, Bac M, van Wijck AJ, van Meeteren NL

OBJECTIVES: Action potential simulation (APS) is becoming a popular method of pain reduction. Nevertheless, little is known about the efficacy of this relatively new treatment. The aim of this study was to investigate whether APS helps to reduce pain, improves patients' perception of daily functioning and social participation in patients with fibromyalgia syndrome (FMS). MATERIALS AND METHODS: Ten patients with FMS according to the American College of Rheumatology (ACR) criteria entered this double blind crossover single-case study. In a period of 20 weeks, the patients underwent two treatment periods of 4 weeks, one with verum and one with placebo, at random, in a double blind fashion. Outcome measures were evaluated on a weekly basis. Primary outcome measure was pain measured with the Fibromyalgia Impact Questionnaire (FIQ) questions 4 and 5, the number of tender points and the total tender point pain intensity score. Both visual inspection and statistical analysis were done to analyse the data from this single-subject design. RESULTS: Performing visual inspection and statistical analysis, no positive results of the APS treatment were found in this study. Remarkable is the fact that placebo APS had significantly better results than verum APS. CONCLUSIONS: In this single-case study with ten patients (all female), APS was not a helpful method to reduce pain, to improve patients' perception of daily functioning and social participation in patients with FMS.

Int J Obes (Lond) 2006 Apr 25; (Read article online)

Hooper MM, Stellato TA, Hallowell PT, Seitz BA, Moskowitz RW

Objective:To determine the point prevalence of painful musculoskeletal (MSK) conditions in obese subjects before and after weight loss following bariatric surgery.Design:Longitudinal, interventional, unblended.Subjects:Forty-eight obese subjects (47 women, one man, mean age 44+/-9 years; mean body mass index (BMI) 51+/-8 kg/m(2)) recruited from an academic medical center bariatric surgery program.Measurements:Comorbid medical conditions; MSK findings; BMI; Western Ontario McMaster Osteoarthritis Index (WOMAC) for pain, stiffness and function; and SF-36((R)) for quality of life.Methods:Consecutive subjects were recruited from the University Hospitals of Cleveland Bariatric Surgery Program. Musculoskeletal signs and symptoms and non-MSK comorbid conditions were documented at baseline and at follow-up. Subjects completed the SF-36((R)) and the WOMAC questionnaires. Analyses were carried out for each MSK site, fibromyalgia syndrome (FMS) and for the cumulative effect on the spine, upper and lower extremities. The impact of change in comorbid medical conditions, BMI, physical and mental health domains of the SF-36((R)) on the WOMAC pain subscale score was evaluated. SF-36((R)) outcomes were compared to normal published controls.Results:Forty-eight subjects were available for baseline and a follow-up assessment 6-12 months after gastric bypass surgery. They lost an average of 41+/-15 kg and the mean BMI decreased from 51+/-8 to 36+/-7 kg/m(2). Baseline comorbid medical conditions were present in 96% before surgery and 23% after weight loss. There was an increased prevalence of painful MSK conditions at baseline compared to general population frequencies. Musculoskeletal complaints had been present in 100% of obese subjects before, and 23% after weight loss. The greatest improvements occurred in the cervical and lumbar spine, the foot and in FMS (decreased by 90, 83, 83 and 92%, respectively). Seventy-nine percent had upper extremity MSK conditions before and 40% after weight loss. Before surgery, 100% had lower extremity MSK conditions and only 37% did after weight loss. The WOMAC subscale and composite scores all improved significantly, as did the SF-36((R)). Change in BMI was the main factor impacting the WOMAC pain score.Conclusion:There was a higher frequency of multiple MSK complaints, including non-weight-bearing sites compared to historical controls, before surgery, which decreased significantly at most sites following weight loss and physical activity. These benefits may improve further, as weight loss may continue for up to 24 months. The benefits seen with weight loss indicate that prevention and treatment of obesity can improve MSK health and function.International Journal of Obesity advance online publication, 25 April 2006; doi:10.1038/sj.ijo.0803349.

J Behav Med 2006 May 6; (Read article online)

Reich JW, Johnson LM, Zautra AJ, Davis MC

Fibromyalgia syndrome (FMS) is a chronic musculoskeletal pain condition poorly understood in terms of etiology and treatment by both physicians and patients. This condition of "uncertainty of illness" was examined as a variable involved in the adjustment of FMS patients, relating it to their depression, anxiety, affect, and coping styles. Fifty-one community-residing FMS patients provided self-report information on subsets of adjustment variables. Both cross-sectional and more dynamic longitudinal analyses showed that illness uncertainty was significantly associated with anxiety, negative affect, and avoidant and passive coping. Its positive relationship with depression was eliminated when a control variable, pain helplessness, was included as a covariate. Longitudinally, illness uncertainty interacted with interpersonally stressful daily events in predicting reports of reduced positive affect, suggesting that illness uncertainty acts as a risk factor for affective disturbances during stressful times. Implications of these results for therapeutic interventions are discussed.

Chronic Dis Can 2006; 27(1): 9-16 (Read article online)

McNally JD, Matheson DA, Bakowsky VS

Fibromyalgia (FM) is a poorly understood condition characterized by chronic diffuse musculoskeletal pain. This study describes the self-reported epidemiology of FM in Canada using data collected from the Canadian Community Health Survey, Cycle 1.1 (2000). FM prevalence rates with corresponding 95 percent confidence intervals were calculated. The Canadian prevalence rate was 1.1 percent with a female-to-male ratio of six to one. In women, rates increased with age up to 65 years, declining thereafter. Data collected on-ageat- diagnosis is presented and demonstrates a surprising number of newly diagnosed FM cases among people in their 20s and 30s, signifying that FM is a problem for people of all ages. The association with FM and a number of sub-populations was also investigated. With respect to geography and environment, the FM prevalence rate in women was shown to be approximately two percent in all Canadian regions except Quebec, where it was 1.1 percent. Further analysis by language suggested that geographical and cultural differences might best explain this observation. Finally, an association with a number of behavioral and socioeconomic determinants of health, including weight, is presented. Key words: Canada, epidemiology, fibromyalgia, prevalence.

Clin Occup Environ Med 2005 May; 5(2): 455-469 (Read article online)

Hayden RJ, Louis DS, Doro C

Fibromyalgia and myofascial pain syndromes are terms used to describe a constellation of complaints ranging from generalized aches to specific tender trigger points often accompanied by fatigue, depression, and sleep disturbances. In the past 5 years, research has been directed primarily at determining the pathophysiology of fibromyalgia and myofascial pain syndromes and the treatment of patients' comorbidities to alleviate their symptomatology. Controversy exists as to whether fibromyalgia and myofascial pain syndromes represent a specific pathology or are merely terms to describe clinical conditions that provide patients with the reassurance that their symptoms are real and help clinicians with therapeutic direction. In the occupational health setting, this uncertainty can lead to significant difficulty in determining short- and long-term disability and assigning culpability to an individual's work environment.

BMC Musculoskelet Disord 2006 May 4; 7(1): 40 (Read article online)

Hagen K, Pettersen E, Stovner LJ, Skorpen F, Zwart JA

ABSTRACT: Background The Catechol-O-methyltransferase (COMT) gene contains a functional polymorphism, Val158Met, that has been found to influence human pain perception. In one study fibromyalgia was less likely among those with Val/Val genotype. Methods In the 1995-97 Nord-Trondelag Health Study (HUNT), the association between Val/Met polymorphism at the COMT gene and chronic musculoskeletal complaints (MSCs) was evaluated in a random sample of 3017 individuals. Results The distribution of the COMT Val158Met genotypes and alleles were similar between controls and the twelve different chronic MSCs groups. Even when the Met/Met and Val/Met genotypes were pooled, the distribution of the Val/Val genotype and other genotypes were similar between controls and the chronic MSCs groups. Conclusions In this population-based study, no significant association was found between Val/Met polymorphism at the COMT gene and chronic MSCs.

J Rheumatol 2006 May 1; (Read article online)

Tishler M, Levy O, Maslakov I, Bar-Chaim S, Amit-Vazina M

OBJECTIVE: To investigate whether whiplash injury may be a trigger for the onset of fibromyalgia (FM). METHODS: One hundred fifty-three patients presenting to the emergency room with the diagnosis of whiplash injury were examined. The control group included 53 patients hospitalized with fractures of the limbs, spine, and ribs due to road accident. The study and control groups were interviewed shortly after presenting and then followed prospectively. Patients complaining of musculoskeletal symptoms during followup were examined and a count of 18 tender points was conducted. FM was diagnosed if the patient fulfilled currently accepted 1990 American College of Rheumatology criteria. RESULTS: The mean followup period for the study and control groups was 14.5 months (range 12-18) and 9 months (range 6-14), respectively. There were no differences between the groups with regard to age, sex, marital, education, or employment status. During the followup period only one patient in the study group and no patients in the control group developed signs and symptoms of FM. Three patients in the study group (2%) and 15 patients in the control group (16%) filed insurance claims; none was associated with FM. CONCLUSION: Whiplash injury and road accident trauma were not associated with an increased rate of FM after more than 14.5 months of followup.

Dig Dis Sci 2006 Mar; 51(3): 454-60 (Read article online)

Kurland JE, Coyle WJ, Winkler A, Zable E

The purpose of this study was to determine the point prevalence of depressive symptoms, using the PRIME-MD questionnaire, and irritable bowel syndrome (IBS), while comparing the Rome II to the Rome I criteria, in patients with fibromyalgia (FM) and rheumatologic controls in an outpatient setting. The prevalence of IBS in FM patients (n = 105) was 63% by Rome I and 81% by Rome II criteria. The prevalence of IBS in controls (n = 62) was 15% by Rome I and 24% by Rome II criteria (FM vs. control; P < 0.001). Depressive symptoms were met in 40% of FM patients and 8% of controls (P < 0.001). The coexistence of IBS and depressive symptoms in the FM patients was 31% (Rome I) and 34% (Rome II). The prevalence of IBS and depressive symptoms was higher in FM patients compared to the control population. Identification of IBS and depressive symptoms in FM patients might enable clinicians to better meet the needs of this patient population.

Arthritis Rheum 2006 Mar 30; 54(4): 1334-1339 (Read article online)

Valkeinen H, Häkkinen A, Hannonen P, Häkkinen K, Alén M

OBJECTIVE: To examine heavy-resistance exercise-induced acute neuromuscular fatigue, blood lactate concentration, and muscle pain in elderly women with fibromyalgia (FM) and in healthy controls before and after a period of strength training. METHODS: Thirteen elderly women with FM (mean +/- SD age 60 +/- 2 years) and 10 healthy women (mean +/- SD age 64 +/- 3 years) performed a heavy-resistance fatiguing protocol (5 sets of leg presses with 10 repetitions maximum) before and after a 21-week strength training period. Maximal isometric force and electromyography (EMG) activity of leg extensors and blood lactate concentration were measured during the loading. Pain was assessed by visual analog scale. RESULTS: The strength training led to large increases in maximal force and EMG activity of the muscles and contributed to the improvement in loading performance (average load/set) at week 21. The fatiguing loading sessions typically applied in strength training before and after the experimental period caused remarkable and comparable acute decreases in maximal force and increases in blood lactate concentration in both groups. Acute exercise-induced muscle pain increased similarly in both groups, and the pain level in women with FM was lowered after the 21-week training period. CONCLUSION: The increased strength in women with FM improved high-load performance and also seemed to attenuate perceived pain. Acute exercise-induced neuromuscular changes and the time course of muscle pain in women with FM were comparable with findings in healthy controls, which suggests a typical fatiguing process and a similar trainability of the muscles in elderly women with FM.

Pain Med 2006 Mar-Apr; 7(2): 115-8 (Read article online)

Sampson SM, Rome JD, Rummans TA

ABSTRACT Objective. Evidence suggests that fibromyalgia (FM) is a centrally mediated pain disorder. Antidepressants, including electroconvulsive therapy, provide some symptomatic relief in FM and other pain disorders. Repetitive transcranial magnetic stimulation (rTMS) is a new antidepressant treatment, which may also be useful in treating chronic pain. Design. As part of a larger study, four women with depression, FM, and borderline personality disorder received 1-Hz rTMS applied to the right dorsolateral prefrontal cortex. Subjects rated pain using an 11-point Likert scale. Results. Pretreatment pain averaged 8.2 (7-9.5) and reduced to 1.5 (0-3.5) after treatment (P < 0.009). All had improvement in pain, and two had complete resolution of pain. Only one of the four subjects had an antidepressant response. Conclusions. These preliminary findings suggest a possible role for rTMS in treating FM.

Joint Bone Spine 2006 Mar 15; (Read article online)

Auvinet B, Bileckot R, Alix AS, Chaleil D, Barrey E

OBJECTIVES: The objective of this study was to compare gait in patients with fibromyalgia and in matched controls. METHODS: Measurements must be obtained in patients with fibromyalgia, as the evaluation scales for this disorder are semi-quantitative. We used a patented gait analysis system (Locometrix(TM) Centaure Metrix, France) developed by the French National Institute for Agricultural Research. Relaxed walking was evaluated in 14 women (mean age 50+/-5 years; mean height 162+/-5 cm; and mean body weight 68+/-13 kg) meeting American College of Rheumatology criteria for fibromyalgia and in 14 controls matched on sex, age, height, and body weight. RESULTS: Gait during stable walking was severely altered in the patients. Walking speed was significantly diminished (P<0.001) as a result of reductions in stride length (P<0.001) and cycle frequency (P<0.001). The resulting bradykinesia (P<0.001) was the best factor for separating the two groups. Regularity was affected in the patients (P<0.01); this variable is interesting because it is independent of age and sex in healthy, active adults. CONCLUSION: Measuring the variables that characterize relaxed walking provides useful quantitative data in patients with fibromyalgia.

Arthritis Rheum 2006 Apr 27; 54(5): 1682-1686 (Read article online)

Kato K, Sullivan PF, Evengård B, Pedersen NL

OBJECTIVE: To estimate the relative importance of genetic and environmental factors in chronic widespread pain, and to assess whether there are sex differences in the type or magnitude of these influences. METHODS: Data were collected from a national sample of twins >/=42 years of age, all of whom were participants in the Swedish Twin Registry. The presence of chronic widespread pain was assessed via computer-assisted telephone interviews, which were conducted between 1998 and 2002, using the American College of Rheumatology criteria for fibromyalgia. No clinical examinations were performed. In preliminary analyses, probandwise concordance rates and tetrachoric correlations were calculated. Structural equation modeling was then performed to estimate additive genetic, shared environmental, and nonshared environmental sources of variability in susceptibility for the development of chronic widespread pain. RESULTS: Of 61,355 eligible twins, 44,897 individuals (73.2%) responded to the interview. Both members of 15,950 pairs responded to the items regarding pain symptoms; of these pairs, 4,170 were monozygotic, 5,881 were same-sex dizygotic, and 5,755 were opposite-sex dizygotic. The prevalence of chronic widespread pain was 4.1%, and the ratio of women to men was 3.3 to 1. Probandwise concordance rates and tetrachoric correlations suggested modest genetic influences for both women and men. Genetic and shared environmental influences explained approximately half of the total variance, with no indication of sex differences in either the type or magnitude of these influences. CONCLUSION: Individual differences in the likelihood of developing chronic widespread pain reflect modest genetic influences. There are no significant sex differences in the type or expression of the genes responsible for chronic widespread pain or in the magnitude of the relative importance of these influences on chronic widespread pain.