Anette Larsson

Resistance exercise improves muscle strength, health status and pain intensity in fibromyalgia—a randomized controlled trial

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.

Comparison of the Levels of Pro-Inflammatory Cytokines Released in the Vastus Lateralis Muscle of Patients with Fibromyalgia and Healthy Controls during Contractions of the Quadriceps Muscle – A Microdialysis Study

Objective Fibromyalgia is associated with central hyperexcitability, but it is suggested that peripheral input is important to maintain central hyperexcitability. The primary aim was to investigate the levels of pro-inflammatory cytokines released in the vastus lateralis muscle during repetitive dynamic contractions of the quadriceps muscle in patients with fibromyalgia and healthy controls. Secondarily, to investigate if the levels of pro-inflammatory cytokines were correlated with pain or fatigue during these repetitive dynamic contractions. Material and Methods 32 women with fibromyalgia and 32 healthy women (controls) participated in a 4 hour microdialysis session, to sample IL-1β, IL-6, IL-8, and TNF from the most painful point of the vastus lateralis muscle before, during and after 20 minutes of repeated dynamic contractions. Pain (visual analogue scale; 0–100) and fatigue Borg’s Rating of Perceived Exertion Scale; 6–20) were assessed before and during the entire microdialysis session. Results The repetitive dynamic contractions increased pain in the patients with fibromyalgia (P < .001) and induced fatigue in both groups (P < .001). Perceived fatigue was significantly higher among patients with fibromyalgia than controls (P < .001). The levels of IL-1β did not change during contractions in either group. The levels of TNF did not change during contractions in patients with fibromyalgia, but increased in controls (P < .001) and were significantly higher compared to patients with fibromyalgia (P = .033). The levels of IL-6 and IL-8 increased in both groups alike during and after contractions (P’s < .001). There were no correlations between pain or fatigue and cytokine levels after contractions. Conclusion There were no differences between patients with fibromyalgia and controls in release of pro-inflammatory cytokines, and no correlations between levels of pro-inflammatory cytokines and pain or fatigue. Thus, this study indicates that IL-1β, IL-6, IL-8, and TNF do not seem to play an important role in maintenance of muscle pain in fibromyalgia.

PERCEIVED EXERTION AT WORK IN WOMEN WITH FIBROMYALGIA: EXPLANATORY FACTORS AND COMPARISON WITH HEALTHY WOMEN

OBJECTIVE To investigate perceived exertion at work in women with fibromyalgia. DESIGN A controlled cross-sectional multi-centre study. SUBJECTS AND METHODS Seventy-three women with fibromyalgia and 73 healthy women matched by occupation and physical workload were compared in terms of perceived exertion at work (0-14), muscle strength, 6-min walk test, symptoms rated by Fibromyalgia Impact Questionnaire (FIQ), work status (25-100%), fear avoidance work beliefs (0-42), physical activity at work (7-21) and physical workload (1-5). Spearmans correlation coefficient and linear regression analysis were conducted. RESULTS Perceived exertion at work was significantly higher in the fibromyalgia group than in the reference group (p = 0.002), while physical activity at work did not differ between the groups. Physical capacity was lower and symptom severity higher in fibromyalgia compared with references (p < 0.05). In fibromyalgia, perceived exertion at work showed moderate correlation with physical activity at work, physical workload and fear avoidance work beliefs (rs = 0.53-0.65, p < 0.001) and a fair correlation with anxiety (rs = 0.26, p = 0.027). Regression analysis indicated that the physical activity at work and fear avoidance work beliefs explained 50% of the perceived exertion at work. CONCLUSION Women with fibromyalgia perceive an elevated exertion at work, which is associated with physical work-related factors and factors related to fear and anxiety.

Gene-to-gene interactions regulate endogenous pain modulation in fibromyalgia patients and healthy controls—antagonistic effects between opioid and serotonin-related genes

Abstract Chronic pain is associated with dysfunctional endogenous pain modulation, involving both central opioid and serotonergic (5-HT) signaling. Fibromyalgia (FM) is a chronic pain syndrome, characterized by widespread musculoskeletal pain and reduced exercise-induced hypoalgesia (EIH). In this study, we assessed the effects of 3 functional genetic polymorphisms on EIH in 130 patients with FM and 132 healthy controls. Subjects were genotyped regarding the mu-opioid receptor (OPRM1) gene (rs1799971), the serotonin transporter (5-HTT) gene (5-HTTLPR/rs25531), and the serotonin-1a receptor (5-HT1a) gene (rs6296). The patients with FM had increased pain sensitivity and reduced EIH compared with healthy controls. None of the polymorphisms had an effect on EIH on their own. We found significant gene-to-gene interactions between OPRM1 x 5-HTT and OPRM1 x 5-HT1a regarding activation of EIH, with no statistically significant difference between groups. Better EIH was found in individuals with genetically inferred strong endogenous opioid signaling (OPRM1 G) in combination with weak 5-HT tone (5-HTT low/5-HT1a G), compared with strong 5-HT tone (5-HTT high/5-HT1a CC). Based on the proposed mechanisms of these genetic variants, the findings indicate antagonistic interactions between opioid and serotonergic mechanisms during EIH. Moreover, despite different baseline pain level, similar results were detected in FM and controls, not supporting an altered interaction between opioid and 5-HT mechanisms as the basis for dysfunction of EIH in patients with FM. In summary, our results suggest that, by genetic association, the mu-opioid receptor interacts with 2 major serotonergic structures involved in 5-HT reuptake and release, to modulate EIH.

OP0286-HPR Resistance Exercise Improves Multidimensional Fatigue in Women with Fibromyalgia. A Randomized Controlled Trial

Background Fibromyalgia (FM) affects approximately 1-3% of the general population. Fatigue limits the work ability as well as the 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. Objectives 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 for the potential change in fatigue. Methods A total of 130 women with FM (age 22-64 years) were included in this assessor-blinded randomized controlled multi-center 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 gathered collected and the women also completed several health-related questionnaires. Multivariable stepwise regression was used to analyze predictors of change in fatigue in the total population. Results A 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 for the MFI-20 subscales General fatigue (Resistance Δ-1.3 SD 3.1, Controls Δ-0.5 SD 2.6, p=0.031), Physical fatigue (Resistance Δ-1.7, SD 4.3, Controls Δ0.0, SD 2.7, p=0.013) and Mental fatigue (Resistance Δ-1.6 SD 3.4, Controls Δ-0.1 SD 2.5, p=0.008). Sleep efficiency was found to be the strongest predictor for change in the MFI-20 subscales General Fatigue (rs = -0.21, p=0.049) and for change in Reduced Motivation (rs = -0.22, p=0.037). Participating in resistance exercise (beta =1.90, p=0.010) and working less hours per week (beta =0.84, p=0.005) was independent significant predictors for change in Physical Fatigue (R2=0.14). Participating in resistance exercise was the strongest predictor for change in Mental Fatigue (p=0.008). Conclusions Person-centered progressive resistance exercise improved multiple dimensions of fatigue in women with FM when compared to an active control group. Participating in resistance exercise, reporting poorer sleep efficiency and working less hours per week at baseline predicted improvement in multidimensional fatigue in women with FM. Disclosure of Interest None declared

Controlled, cross-sectional, multi-center study of physical capacity and associated factors in women with fibromyalgia

BackgroundHealth and physical capacity are commonly associated with disease, age, and socioeconomic factors. The primary objective of this study was to investigate the degree to which physical capacity, defined as muscle strength and walking ability, is decreased in women with fibromyalgia (FM), as compared to healthy women, who are matched for age and level of education. The secondary aim was to investigate whether muscle strength and walking ability are associated with age, symptom duration, activity limitations and, Body Mass Index (BMI) in women with FM and control subjects.MethodsThis controlled, cross-sectional, multi-center study comprised 118 women with FM and 93 age- and education-level-matched healthy women. The outcome measures were isometric knee-extension force, isometric elbow-flexion force, isometric hand-grip force, and walking ability. Differences between the groups were calculated, and for the women with FM analyses of correlations between the measures of physical capacity and variables were performed.ResultsThe women with FM showed 20% (p < 0.001) lower isometric knee-extension force, 36% (p < 0.001) lower isometric elbow-flexion force, 34% (p < 0.001) lower isometric hand-grip force, and 16% lower walking ability (p < 0.001), as compared to the healthy controls. All measures of muscle strength in women with FM showed significant weak to moderate relationship to symptom duration (rs = − 0.23–0.32) and walking ability (rs = 0.25–0.36). Isometric knee-extension force correlated with activity limitations, as measured using the SF-36 Physical function subscale (rs=0.23, p = 0.011).ConclusionsPhysical capacity was considerably decreased in the women with FM, as compared to the age- and education-level-matched control group. All measures of physical capacity showed a significant association with symptom duration. Knee-extension force and walking ability were significantly associated with activity limitations, age, and BMI. It seems important to address this problem and to target interventions to prevent decline in muscle strength. Assessments of muscle strength and walking ability are easy to administer and should be routinely carried out in the clinical setting for women with FM.Trial registrationClinicalTrials.gov identification number: NCT01226784, Oct 21, 2010.

AB0832-HPR Resistance exercise training for women with fibromyalgia

Background Studies show that women with fibromyalgia (FM) are less physically active, have lowered physical capacity and experience limitations in daily activities compared to healthy women. Many patients with FM experience exercise-related pain. This often results in reduced confidence in the ability to be physically active. Currently, we have little knowledge of the effects of specific physiotherapy treatments on fibromyalgia symptoms. It is important to identify safe and effective treatments for these patients. For optimal individualized treatment different training options are needed. Low intensity exercise has shown to be a safe mode of exercise not increasing pain. However, only a few studies have investigated the effect of resistance exercise training in patients with FM. Objectives The aim of this study is to investigate the effect of progressive resistance exercise training compared to relaxation exercise training on physical capacity, pain, experience of physical activity and exercise self-efficacy. Methods A randomized controlled multicenter trial comparing the effects of resistance exercise training and relaxation exercise training. Both interventions are conducted twice a week for 15 weeks. Participants are examined at baseline and after 15 weeks intervention with a battery of questionnaires and functional tests of physical capacity. A total of 120 women will be recruited to the study. Outcomes are analysed according to intent-to-treat design, implying that all patients are invited to post-test and examined accordingly. Data collection is not yet completed at all centres. Results A total of 88 women have so far been recruited, and 69 of them have completed the intervention, resistance exercise training (n=37) or relaxation exercise training (n=32). The mean age of the study population was 51 years (SD 9.5). The mean duration of symptoms was 7.5 years (SD 5.8). The mean number of tender points was 16 (SD 1.7) and the mean pain at baseline (FIQ pain) was 64.2 (SD 19.7). There were no significant differences in baseline characteristics between the two groups. Significant improvement was found in the resistance exercise training group compared to the relaxation exercise training group regarding physical capacity as measured by Six-Minute Walk Test (p=0.032) and isometric quadriceps force (Steve Strong)(p<0.05). Significant differences in favour of the resistance exercise training group were also found regarding experience of physical activity measured by Experience of Physical Activity-questionnaire subscale Activity Habits (p<0.001) and Exercise Self Efficacy Scale (p=0.025). No significant between-group differences were found regarding global pain measured by Visual Analogue Scale. Conclusions The resistance exercise training significantly improved physical capacity, activity habits and exercise self efficacy. The participants were able to exercise at high loads without increased pain. This shows that individually adjusted, progressively increased resistance exercise training is a feasible mode of exercise for women with FM. Disclosure of Interest None Declared

Plasma Cytokine Levels in Fibromyalgia and Their Response to 15 Weeks of Progressive Resistance Exercise or Relaxation Therapy

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.

PAIN AND FEAR AVOIDANCE PARTIALLY MEDIATE CHANGE IN MUSCLE STRENGTH DURING RESISTANCE EXERCISE IN WOMEN WITH FIBROMYALGIA

OBJECTIVES Resistance exercise results in health benefits in fibromyalgia. The aim of this study was to determine the factors that mediate change in muscle strength in women with fibromyalgia as a result of resistance exercise. METHODS Sixty-seven women with fibromyalgia (age range 25-64 years) were included. Tests of muscle strength and questionnaires related to pain, fear avoidance and physical activity were carried out. Multivariable stepwise regression was used to analyse explanatory factors for change and predictors for final values of knee-extension force, elbow-flexion force and hand-grip force. RESULTS Change in knee-extension force was explained by fear avoidance beliefs about physical activity at baseline, together with change in pain intensity, knee-extension force at baseline, age and body mass index (BMI) (R2=0.40, p = 0.013). Change in elbow-flexion force was explained by pain intensity at baseline, together with baseline fear avoidance beliefs about physical activity, BMI and elbow-flexion force at baseline (R2 = 0.32, p = 0.043). Change in hand-grip force was explained by hand-grip force at baseline, change in pain intensity and baseline fear avoidance (R2 = 0.37, p = 0.009). Final muscle strength was predicted by the same variables as change, except pain. CONCLUSION Pain and fear avoidance are important factors to consider in rehabilitation using resistance exercise for women with fibromyalgia.

OP0260-HPR Higher satisfaction with activity-related symptoms after 15-week resistance exercise in women with fibromyalgia

Background Physical exercise is troublesome for most patients with fibromyalgia (FM) due to activity-induced pain. A reason for activity-induced pain is a low pain threshold. In the present study we investigated if experience of physical activity changed after 15-week progressive person-centred resistance exercise. The control group participated in 15-week relaxation program. Objectives To investigate how experience of physical activity changed after 15-week resistance exercise in women with FM, and if experiences correlated with pain threshold. Methods 130 women (age 22–64 years, symptom duration 0–35 years) with FM were randomized to 15-week resistance exercise or to a parallel relaxation program. The participants completed Experience of physical activity scale (EPA) comprising five subscales (0–7), assessing how exercise was perceived in terms of Physical relaxation (PR), Well-being (WB), Activity beliefs (AB), Activity-related symptoms (ARS), and Activity Habits (AH) (1). A lower score indicates a higher satisfaction. Pain threshold was investigated with algometer. Within-group and between-group analyses were conducted by non-parametric statistics. Correlations between algometry and ratings on EPA were investigated by Spearman correlation coefficient. ResultsTable 1. Baseline and post-test ratings of EPA in the two groups EPA subscales Resistance exercise Relaxation Baseline (n=67) 15 weeks (n=56) Baseline (n=63) 15 weeks (n=49) PR 3.9±1.1 3.6±1.0* 4.1±1.3 3.9±1.2 WB 2.9±1.5 2.5±1.2* 2.7±1.3 2.7±1.4 AB 2.0±1.0 1.9±1.2 2.1±1.3 2.0±1.2 ARS 4.7±1.2 4.1±1.1* 4.9±1.1 4.8±1.1 AH 4.1±1.3 3.1±1.5* 3.7±1.3 3.6±1.4 Within-group changes (p<0.05) are marked with *. The resistance exercise group scored significantly higher satisfaction at posttest than before the intervention in their ratings on how they experienced exercise in terms of PR, WB, ARS and AH (p<0.05), Table 1. Between-group analyses showed that the resistance exercise group scored significantly higher satisfaction in ARS subscale (p<0.006) after the intervention when compared to the relaxation group. Significant correlations were found between algometry and PR (rs -0.32, p=0.017) as well as ARS (-0.33, p=0.015) at post-test in the resistance exercise group. Conclusions Women with FM experienced a higher satisfaction with activity-related symptoms after having participated in a person-centered resistance exercise program, which is an important knowledge for health care professionals when motivating patients for exercise. Correlations between algometry and ratings on PR and ARS indicate that activity-related symptoms are partly associated with the pain threshold. References Mannerkorpi K, Rivano-Fischer M, Ericsson A, Nordeman L, Gard G. Experience of physical activity in patients with fibromyalgia and chronic widespread pain. Disabil Rehabil 2008;30 (3):213–21. Disclosure of Interest None declared