IntroductionFibromyalgia (FM) is characterized by persistent widespread pain, increased pain sensitivity and tenderness. Muscle strength in women with FM is reduced compared to healthy women. The aim of this study was to examine the effects of a progressive resistance exercise program on muscle strength, health status, and current pain intensity in women with FM.MethodsA total of 130 women with FM (age 22–64 years, symptom duration 0–35 years) were included in this assessor-blinded randomized controlled multi-center trial examining the effects of progressive resistance group exercise compared with an active control group. A person-centred model of exercise was used to support the participants’ self-confidence for management of exercise because of known risks of activity-induced pain in FM. The intervention was performed twice a week for 15 weeks and was supervised by experienced physiotherapists. Primary outcome measure was isometric knee-extension force (Steve Strong®), secondary outcome measures were health status (FIQ total score), current pain intensity (VAS), 6MWT, isometric elbow-flexion force, hand-grip force, health related quality of life, pain disability, pain acceptance, fear avoidance beliefs, and patient global impression of change (PGIC). Outcomes were assessed at baseline and immediately after the intervention. Long-term follow up comprised the self-reported questionnaires only and was conducted after 13–18 months. Between-group and within-group differences were calculated using non-parametric statistics.ResultsSignificant improvements were found for isometric knee-extension force (p = 0.010), health status (p = 0.038), current pain intensity (p = 0.033), 6MWT (p = 0.003), isometric elbow flexion force (p = 0.02), pain disability (p = 0.005), and pain acceptance (p = 0.043) in the resistance exercise group (n = 56) when compared to the control group (n = 49). PGIC differed significantly (p = 0.001) in favor of the resistance exercise group at post-treatment examinations. No significant differences between the resistance exercise group and the active control group were found regarding change in self-reported questionnaires from baseline to 13–18 months.ConclusionsPerson-centered progressive resistance exercise was found to be a feasible mode of exercise for women with FM, improving muscle strength, health status, and current pain intensity when assessed immediately after the intervention.Trial registrationClinicalTrials.gov identification number: NCT01226784, Oct 21, 2010.

The aims of this study were to compare circulating cytokines between FM and healthy controls and to investigate the effect on cytokine levels by 15 weeks of progressive resistance exercise or relaxation therapy in FM. Baseline plasma cytokine levels and clinical data were analyzed in 125 women with FM and 130 age-matched healthy women. The FM women were then randomized to progressive resistance exercise (n = 49) or relaxation (n = 43). Baseline IL-2, IL-6, TNF-α, IP-10, and eotaxin were higher in FM than in healthy controls (P < 0.041), whereas IL-1β was lower (P < 0.001). There were weak correlations between cytokine levels and clinical variables. After both interventions, IL-1ra had increased (P = 0.004), while IL-1β had increased in the relaxation group (P = 0.002). Changes of IFN-γ, IL-2, IL-4, IL-6, IL-8, and IL-17A were weakly correlated with changes of PPT, but there were no significant correlations between changes of cytokine and changes in other clinical variables. The elevated plasma levels of several cytokines supports the hypothesis that chronic systemic inflammation may underlie the pathophysiology of FM even if the relation to clinical variables was weak. However, 15 weeks of resistance exercise, as performed in this study, did not show any anti-inflammatory effect on neither FM symptoms nor clinical and functional variables. This trial is registered with ClinicalTrials.gov NCT01226784, registered October 21, 2010. The first patient was recruited October 28, 2010.

Fibromyalgia (FM) is a syndrome characterized by chronic pain without known peripheral causes. Previously, we have reported dysfunctional pain inhibitory mechanisms for FM patients during pain administration. In this study we employed a seed correlation analysis, independent component analysis (ICA), and an analysis of fractional amplitude of low frequency fluctuations (fALFF) to study differences between a cohort of female FM patients and an age-and sex-matched healthy control group during a resting-state condition. FM patients showed decreased connectivity between thalamus and premotor areas, between the right insula and primary sensorimotor areas, and between supramarginal and prefrontal areas. Individual sensitivity to painful pressure was associated with increased connectivity between pain-related regions (e.g., insula and thalamus) and midline regions of the default mode network (including posterior cingulate cortex and medial prefrontal cortex) among patients and controls. However, neither ICA nor fALFF revealed any group differences. Our findings suggest that abnormal connectivity patterns between pain-related regions and the remaining brain during rest reflect an impaired central mechanism of pain modulation in FM. Weaker coupling between pain regions and prefrontal-and sensorimotor areas might indicate a less efficient system level control of pain circuits. Moreover, our results show that multiple, complementary analytical approaches are valuable for obtaining a more comprehensive characterization of deviant resting-state activity. In conclusion, our findings show that FM primarily is associated with decreased connectivity, for example, between several pain-related areas and sensorimotor regions, which could reflect a deficiency in pain regulation.

BackgroundFibromyalgia (FM) affects approximately 1–3 % of the general population. Fatigue limits the work ability and social life of patients with FM. A few studies of physical exercise have included measures of fatigue in FM, indicating that exercise can decrease fatigue levels. There is limited knowledge about the effects of resistance exercise on multiple dimensions of fatigue in FM. The present study is a sub-study of a multicenter randomized controlled trial in women with FM. The purpose of the present sub-study was to examine the effects of a person-centered progressive resistance exercise program on multiple dimensions of fatigue in women with FM, and to investigate predictors of the potential change in fatigue.MethodsA total of 130 women with FM (age 22–64 years) were included in this assessor-blinded randomized controlled multicenter trial examining the effects of person-centered progressive resistance exercise compared with an active control group. The intervention was performed twice a week for 15 weeks. Outcomes were five dimensions of fatigue measured with the Multidimensional Fatigue Inventory (MFI-20). Information about background was collected and the women also completed several health-related questionnaires. Multiple linear stepwise regression was used to analyze predictors of change in fatigue in the total population.ResultsA higher improvement was found at the post-treatment examination for change in the resistance exercise group, as compared to change in the active control group in the MFI-20 subscale of physical fatigue (resistance group Δ –1.7, SD 4.3, controls Δ 0.0, SD 2.7, p = 0.013), with an effect size of 0.33. Sleep efficiency was the strongest predictor of change in the MFI-20 subscale general fatigue (beta = −0.54, p = 0.031, R2 = 0.05). Participating in resistance exercise (beta = 1.90, p = 0.010) and working fewer hours per week (beta = 0.84, p = 0.005) were independent significant predictors of change in physical fatigue (R2 = 0.14).ConclusionsPerson-centered progressive resistance exercise improved physical fatigue in women with FM when compared to an active control group.Trial registrationClinicalTrials.gov NCT01226784. Registered 21 October 2010.

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