Pain catastrophizing is associated with pain thresholds for heat, cold and pressure in women with chronic pelvic pain

Background and aims Psychological traits such as pain catastrophizing may play a role in the development of chronic pelvic pain (CPP). Pain catastrophizing is the tendency to amplify negative cognitive and emotional pain processes. The Pain Catastrophizing Scale (PCS) assesses elements of pain catastrophizing divided into three subgroups of factors (rumination, helplessness and magnification). Previous studies have shown associations between CPP and increased pain sensitivity, widespread generalized hyperalgesia, and decreased pain thresholds, but the relation between pain catastrophizing and specific pain thresholds has not yet been widely examined in this patient group. The aims of this study were (a) to determine if catastrophizing is increased in women with CPP compared with pain-free women, (b) to assess the importance of pain catastrophizing, psychological distress variables, and subjective pain sensitivity for pain thresholds of heat, cold and pressure in these two groups, and (c) to determine whether psychological variables or pain thresholds best contribute to the differentiation between CPP and controls. Methods Thirty-seven women with chronic pelvic pain who underwent diagnostic laparoscopy on the suspicion of endometriosis participated along with 55 healthy and pain-free controls. All underwent quantitative sensory testing on six locations on the body to determine heat (HPT), cold (CPT) and pressure (PPT) pain thresholds. The PCS, the Pain Sensitivity Questionnaire (PSQ), the Hospital Anxiety Depression Scale, (HADS) demographics and clinical data were collected prospectively. Principal component analysis and orthogonal partial least square regressions were used to assess the associations between PCS scores and pain thresholds. Results The women with CPP scored significantly higher on PCS than the healthy controls. PCS-helplessness, PCS-rumination and HADS-depression were significantly associated with pain thresholds for the whole group. In the CPP group, PCS-rumination, body mass index and PSQ were significant regressors for HPT and CPT. The PCS and the HADS subscales were strongly intercorrelated in women with CPP and were stronger regressors of group membership than the three pain thresholds. In the group of healthy control women, no relationships were found to be significant. The psychological variables were somewhat stronger significant regressors than pain thresholds (also significant) for group membership. Conclusions Women with CPP have significantly higher pain catastrophizing scores than women without CPP. The pain catastrophizing rumination factor is significantly associated with pain thresholds of heat and cold in CPP women. PCS and HADS are strongly intercorrelated and PSQ correlates positively with these variables. It seems that the psychological variables are important for group differentiation. Implications The results clearly indicate the need for a multimodal assessment (bio-psycho-social) of CPP patients including psychological symptoms such as catastrophizing, anxiety and depression. The registration of semi-objective pain thresholds captures both specific pain sensitivity information (mechanical pressure, cold or heat) and the degree of wide spread pain hypersensitivity. There is a need for future larger studies investigating whether certain profiles in the clinical presentations (including pain thresholds and psychological variables) are associated with outcomes after different types of interventions.

Predictive association between immigration status and chronic pain in the general population: results from the SwePain cohort

Background

Previous studies suggest that immigration may influence the experience of pain.

Objective

This population-based study examines whether immigration status is associated with chronic pain (CP), chronic widespread pain (CWSP), and severe CP at a two-year follow-up. We also tested mediation by mood status (i.e., anxiety and depression).

Methods

15, 563 participants from a representative stratified random sample of 34,000 individuals living in south-eastern Sweden completed a postal survey, during 2013–2015, that included the following data: immigration status; presence of CP (pain lasting at least 3 months) and CWSP (a modified classification of widespread pain for use in epidemiological studies); severity of CP based on a numeric rating scale; and depression, anxiety, economic situation, and sociodemographic information. We applied logistic regressions using the generalized estimating equations (GEE), with Swedish-born as the reference group and path analyses models.

Results

Compared to the Swedish-born participants (n = 14,093;90%), the immigrants (n = 1470;10%) had an elevated risk of all pain outcomes (CP: odds ratio [OR] = 1.18; 95% confidence interval [CI = 1.04–1.33, CWSP: OR = 1.39; 95% CI: 1.15–1.69 and severe CP: 1.51; 95% CI: 1.23–1.87) after adjustments. Path analyses showed that baseline age, immigrant status, and financial hardship had a significant influence on chronic pain outcomes at follow-up with baseline mood status as the mediator. Immigration status was also associated with age and financial hardship.

Conclusion

Immigrants may have increased risk of chronic pain, widespread pain, and severe pain and this risk is mediated by mood status. Targeted interventions better tailored to the socio-economic and psychological status of immigrants with chronic pain are warranted.

Facing obesity in pain rehabilitation clinics: Profiles of physical activity in patients with chronic pain and obesity-A study from the Swedish Quality Registry for Pain Rehabilitation (SQRP)

Background

The obesity epidemic has influenced pain rehabilitation clinics. To date, little is known about baseline level of physical activity (PA) in patients referred to pain rehabilitation clinics. We aimed to investigate the PA levels of patients referred to pain rehabilitation clinics and to evaluate the effect of excess weight on PA level.

Methods and findings

Data were obtained from the Swedish Quality Registry for Pain Rehabilitation between 2016 and 2017. These data included PA time (everyday PA and physical exercise per week), Body Mass Index (BMI), sociodemographic factors, chronic pain and psychological aspects (e.g., pain intensity, depressive and anxiety symptoms and insomnia problems). Insufficient PA was defined as less than 150 minutes per week. We performed logistic regressions as well as orthogonal partial least square regression to estimate the effects of excess weight on PA. Over one-fourth of the patients were classified as obese (BMI ≥30 kg/m², 871/3110, 25.3%) and nearly one-third of these patients were classified as severely obese (BMI ≥35 kg/m², 242/871, 27.8%). Time estimations for physical exercise varied among the BMI groups, but patients in the higher BMI category were more likely to spend less time on everyday PA. Compared to normal weight, mild obesity [odds ratio (OR) 0.65, 95% confidence interval (CI) 0.53–0.81] and severe obesity (OR 0.56, 95% CI 0.42–0.74) were associated with less PA. Mild obese patients had an elevated risk of 65% and severe obese patients had an elevated risk of 96% for insufficient PA. Increased pain intensity was positively related to insufficient PA (OR 1.17, 95% CI 1.06–1.29) among the obese patients.

Conclusion

Having low PA is very common for patients referred to pain rehabilitation clinics, especially for those with comorbid obesity. As a first step to increase PA, obese patients need to be encouraged to increase the intensity and amount of less painful daily PA.

Reported Outcomes in Published Systematic Reviews of Interdisciplinary Pain Treatment: Protocol for a Systematic Overview

BACKGROUND

Interdisciplinary pain treatment (IPT) is a complex intervention; its outcomes are very diverse, as are the methodologies for handling those outcomes. This diversity may hamper evidence-based decision making. Presently, there is no gold standard recommendation of how to select reported outcomes in published systematic reviews and meta-analyses to explicitly demonstrate the effectiveness of IPT.

OBJECTIVE

In this systematic overview, we aim to evaluate the reported outcome domains and measurements across published systematic reviews and meta-analyses and to identify any methods, considerations, and discussion regarding the handling of the chosen outcome domains and measurements.

METHODS

This article describes the protocol for a systematic overview of the outcomes reported in published systematic reviews and meta-analyses of randomized control trials for the effectiveness of IPT versus any control. To this end, we searched the PubMed, Cochrane Library, and Epistemonikos databases from inception to December 2019. Two independent investigators screened the titles, the abstracts of the identified records, and the full texts of the potentially eligible systematic reviews and meta-analyses, performed data extraction according to predefined forms, and rated the quality of the included systematic reviews and meta-analyses. The quality of the included systematic reviews and meta-analyses will be rated with AMSTAR (A MeaSurement Tool to Assess systematic Reviews) 2. Data will be analyzed descriptively and stratified by AMSTAR 2.

RESULTS

We introduced the rationale and design of a systematic overview to summarize and map the chosen IPT outcome domains and the methods of handling these outcomes reported in published systematic reviews and meta-analyses. As of December 2019, we collected 5229 systematic reviews, of which 147 (2.81%) were examined in-depth for eligibility. Topline results are anticipated by September 2020.

CONCLUSIONS

The results of this study will be published as soon as they are available. Our results will fill a gap in the related literature and will be used to inform the development of a set of recommendations that can be applied in systematic reviews and hopefully serve as a gold standard.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/17795.

Pain intensity and pressure pain thresholds after a light dynamic physical load in patients with chronic neck-shoulder pain

Background

To investigate the development of pain intensity and pressure pain thresholds during and 24 h after a light dynamic physical load among patients with chronic neck-shoulder pain.

Methods

Twenty-six patients with chronic neck-shoulder pain and 12 healthy controls were included. The participants arm-cycled on an ergometer. Effort was rated with the Borg Rating of Perceived Exertion scale (RPE), and pain intensity with an numeric rating scale (NRS). Pressure pain thresholds were measured by an algometer. Participants started a pain diary 1 week before the physical exercise and continued until 1 week after. Pain intensity was assessed before, during and the following two evenings after arm-cycling. Pressure pain thresholds were assessed before, 15 min after, 105 min after and 24 h after.

Results

The chronic pain group showed increased pain intensity during, and the following two evenings after the arm cycling, and decreased pain thresholds immediately after the arm cycling involving painful regions. In the patient group there were no impact on pain thresholds in the neck the following day.

Conclusions

Patients with chronic neck-shoulder pain reported increased pain intensity during and in the evenings after a light dynamic load involving painful regions. In addition, they showed decreased pain thresholds close to the exercise, indicating mechanical hyperalgesia.

Factors Associated with Life Satisfaction in Older Adults with Chronic Pain (PainS65+)

Background

Chronic pain in later life is a worldwide problem. In younger patients, chronic pain affects life satisfaction negatively; however, it is unknown whether this outcome will extend into old age.

Objective

This study examines which factors determine life satisfaction in older adults who suffer from chronic pain with respect to socio-demographics, lifestyle behaviors, pain, and comorbidities.

Methods

This cross-sectional study recruited a random sample of people ≥65 years old living in south-eastern Sweden (N= 6611). A postal survey addressed pain aspects and health experiences. Three domains from the Life Satisfaction Questionnaire (LiSat-11) were used to capture the individual’s estimations of overall satisfaction (LiSat-life), somatic health (LiSat-somhealth), and psychological health (LiSat-psychhealth).

Results

Respondents with chronic pain (2790, 76.2±7.4 years old) rated lower on life satisfaction than those without chronic pain, with medium effect size (ES) on LiSat-somhealth (r = 0.38, P < 0.001) and small ES on the other two domains (r < 0.3). Among the respondents with chronic pain, severe pain (OR 0.29–0.59) and pain spreading (OR 0.87–0.95) were inversely associated with all three domains of the LiSat-11. Current smoking, alcohol overconsumption, and obesity negatively affected one or more domains of the LiSat-11. Most comorbidities were negatively related to LiSat-somhealth, and some comorbidities affected the other two domains. For example, having tumour or cancer negatively affected both LiSat-life (OR 0.62, 95% CI 0.44–0.88) and LiSat-somhealth (OR 0.42, 95% CI 0.24–0.74). Anxiety or depression disorders had a negative relationship both for LiSat-life (OR 0.54, 95% CI 0.38–0.78) and LiSat-psychhealth (OR 0.10, 95% CI 0.06–0.14).

Conclusion

Older adults with chronic pain reported lower life satisfaction but the difference from their peers without chronic pain was trivial, except for satisfaction with somatic health. Pain management in old age needs to consider comorbidities and severe pain to improve patients’ life satisfaction.

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Enzymatic Determination of Lactose and Galactose in Foods: NMKL Collaborative Methods Performance Study

Enzymes are widely used in food chemistry as analytical tools. An enzymatic method for determining lactose and galactose in foods was evaluated in an interlaboratory methods performance study by 12 laboratories in 4 countries. The method is based on enzymatic hydrolysis of lactose and enzymatic oxidation of the hydrolysis products. The exchange of the coenzyme in the second reaction is the basis of quantitation. The method may be used for various types of foods, such as liquid and solid milk products, meat products, cereal products, fats, dressings, sweets, chocolate, and foods for special dietary uses. It is also applicable to lactose-free foods but not to products in which lactose has been partially hydrolyzed enzymatically to glucose and galactose. Six commonly used foodstuffs with lactose concentrations ranging from 0.4 g/100 g to 40 g/100 g and galactose concentrations up to 0.7 g/100 g were analyzed: crisp rye bread, milk chocolate, sausage, cheese, margarine, and baby food containing milk powder. They were distributed to the 12 participants as 12 randomly numbered test samples, representing blind duplicates of the 6 materials. The relative standard deviations for reproducibility (RSDR) were between 2.3-11% for lactose and 6.8-50% for galactose.

Are patient education and self-care advantageous for patients with head and neck cancer? A feasibility study

AIM

This study evaluates whether patient education and individually self-care reduces pain and improves QoL, mood and sleep during and after radiotherapy treatment for patients with head and neck cancer.

DESIGN

A longitudinal, two-armed feasibility study design was performed.

METHODS

Sixty-four participants with curative intent were included in the study. All participants answered questions about pain three times a week and completed a survey questionnaire about pain, QoL, psychological aspects and barriers towards pain management at baseline, at 4 weeks and at 10 weeks. Thirty-four of the participants attended in two education sessions on pain based on their beliefs about pain and received individualized self-care instructions based on their weekly rating of pain.

RESULT

This study did not find any significant group differences for the pain, QoL, mood and sleep.

Maintenance of quality of life improvement for patients with chronic pain and obesity after interdisciplinary multimodal pain rehabilitation - A study using the Swedish Quality Registry for Pain Rehabilitation

BACKGROUND

Throughout the world many people have both obesity and chronic pain, comorbidities that decrease Health-Related Quality of Life (HRQoL). It is uncertain whether patients with comorbid obesity can maintain improved HRQoL after Interdisciplinary Multimodal Pain Rehabilitation (IMMPR).

METHODS

Data from 2016, 2017, and 2018 were obtained from a national pain database for Swedish specialized pain clinics and collected at three time points: Pre-IMMPR; Post- IMMPR; and 12-month follow-up (FU-IMMPR). Participants (N = 872) reported body weight, height, pain aspects, and HRQoL (RAND 36-Item Health Survey). Severe obesity (Body Mass Index, BMI ≥35 kg/m² ) was defined according to WHO classifications. We used linear mixed regression models to examine BMI group differences in HRQoL over time.

RESULTS

More than 25% of patients (224/872) were obese and nearly 30% (63/224) of these were severely obese. All BMI groups improved significantly in both physical and mental composites of HRQoL after IMMPR (Pre- vs. Post-IMMPR, p < .001). The improvements were maintained at a 12-month follow-up (Post- vs. FU-IMMPR, p > .05). The severe obesity group had the lowest physical health score and least improvement (pre- vs. FU-IMMPR, Cohen's d = o.422, small effect size). Severe obesity had negative impact on physical health (β = -4.39, p < .05) after controlling for sociodemographic factors and pain aspects.

CONCLUSION

Improvements in HRQoL after IMMPR were achieved and maintained across all weights, including patients with comorbid obesity. Only severe obesity was negatively associated with physical health aspects of HRQoL.

SIGNIFICANCE

Patients with chronic pain and comorbid obesity achieve sustained Health-Related Quality of Life (HRQoL) improvements from Interdisciplinary Multimodal Pain Rehabilitation (IMMPR). This finding suggests that rehabilitation professionals should consider using IMMPR for patients with comorbid obesity even though their improvement may not reach the same level as for non-obese patients.

Moderate and Stable Pain Reductions as a Result of Interdisciplinary Pain Rehabilitation-A Cohort Study from the Swedish Quality Registry for Pain Rehabilitation (SQRP)

Few studies have investigated the real-life outcomes of interdisciplinary multimodal pain rehabilitation programs (IMMRP) for chronic pain. This study has four aims: investigate effect sizes (ES); analyse correlation patterns of outcome changes; define a multivariate outcome measure; and investigate whether the clinical self-reported presentation pre-IMMRP predicts the multivariate outcome. To this end, this study analysed chronic pain patients in specialist care included in the Swedish Quality Registry for Pain Rehabilitation for 22 outcomes (pain, psychological distress, participation, and health) on three occasions: pre-IMMRP, post-IMMRP, and 12-month follow-up. Moderate stable ES were demonstrated for pain intensity, interference in daily life, vitality, and health; most other outcomes showed small ES. Using a Multivariate Improvement Score (MIS), we identified three clusters. Cluster 1 had marked positive MIS and was associated with the overall worst situation pre-IMMRP. However, the pre-IMMRP situation could only predict 8% of the variation in MIS. Specialist care IMPRPs showed moderate ES for pain, interference, vitality, and health. Outcomes were best for patients with the worst clinical presentation pre-IMMRP. It was not possible to predict who would clinically benefit most from IMMRP.

Longitudinal Associations between Anatomical Regions of Pain and Work Conditions: A Study from The SwePain Cohort

We investigated the time-based associations between workload (physical and mechanical), psychosocial work stressors (demands, control, and support), and the number of anatomical regions with pain (ARP). This population-based study with a two-year follow-up included 11,386 responders (5125 men, 6261 women; mean age: 48.8 years; SD: 18.5) living in south-eastern Sweden. Predictive associations were assessed through generalised linear models, and changes over time were examined using a generalised estimating equation. The results of both models were reported as parameter estimates (B) with 95% confidence interval (CIs). Mean changes in the number of ARP, workload, and psychosocial work stressors were stable over time. High mechanical workload and job demands were likely associated with the number of ARP at the two-year follow-up. In the reverse prospective model, we found that the number of ARP was also associated with high physical and mechanical workload and low job control and support. In the two time-based models of changes, we found a reciprocal association between number of ARP and mechanical workload. Our results add epidemiological evidence to the associations between work conditions and the extent of pain on the body. Components of work conditions, including job demands and mechanical strain, must be considered when organisations and health policy makers plan and employ ergonomic evaluations to minimise workplace hazards in the general population.

A Meta-Epidemiological Appraisal of the Effects of Interdisciplinary Multimodal Pain Therapy Dosing for Chronic Low Back Pain

Using a meta-analysis, meta-regression, and a meta-epidemiological approach, we conducted a systematic review to examine the influence of interdisciplinary multimodal pain therapy (IMPT) dosage on pain, disability, return to work, quality of life, depression, and anxiety in published randomised controlled trials (RCTs) in patients with non-specific chronic low back pain (CLBP). We considered all RCTs of IMPT from a Cochrane review and searched PubMed for additional RCTs through 30 September 2018. A subgroup random-effects meta-analysis by length, contact, and intensity of treatment was performed followed by a meta-regression analysis. Using random and fixed-effect models and a summary relative odds ratio (ROR), we compared the effect sizes (ES) from short-length, non-daily contact, and low-intensity RCTs with long-length, daily contact, and high-intensity RCTs. Heterogeneity was quantified with the I² metric. A total of 47 RCTs were selected. Subgroup meta-analysis showed that there were larger ES for pain and disability in RCTs with long-length, non-daily contact, and low intensity of treatment. Larger ES were also observed for quality of life in RCTs with short-length, non-daily contact, and low intensity treatment. However, these findings were not confirmed by the meta-regression analysis. Likewise, the summary RORs were not significant, indicating that the length, contact, and intensity of treatment did not have an overall effect on the investigated outcomes. For the outcomes investigated here, IMPT dosage is not generally associated with better ES, and an optimal dosage was not determined.

Predictors of chronic pain intensity, spread, and sensitivity in the general population: A two-year follow-up study from the SWEPAIN cohort

OBJECTIVE

To determine whether the intensity, spread and sensitivity of chronic pain can be predicted using demographic features, socioeconomic conditions and comorbidities.

DESIGN

A longitudinal study design was employed. Data was collected at baseline and at 2-year follow-up.

SETTING

General population in south-eastern Sweden.

SUBJECTS

A representative stratified random sample of 34,000 individuals, between 18 and 85 years of age, selected from a sampling frame of 404,661 individuals based on the Swedish Total Population Register.

METHODS

Eligible individuals were sent postal surveys in 2013 and 2015. The 2 surveys included the same questions about basic demographic data, comorbidities, and chronic pain intensity, spread and sensitivity.

RESULTS

Several socio-demographic features and comorbidities at baseline were significant predictors of characteristics of pain (intensity, spread and sensitivity) at the 2-year follow-up. When characteristics of pain at baseline were included in the regression analyses they were relatively strong significant predictors of characteristics of pain after 2 years. After this adjustment there were fewer socio-demogra-phic and comorbidity predictors; the effect estimates for those significant predictors had decreased.

CONCLUSION

Clinical assessment should focus on several characteristics of pain and include a broad medical screening to capture the overall burden of pain in adults from a longitudinal perspective.

Positive psychological well-being predicts lower severe pain in the general population: a 2-year follow-up study of the SwePain cohort

BACKGROUND

Positive psychology indicators like well-being and life satisfaction may play a pivotal role in pain-related outcomes. In this study, we aimed to examine the prospective associations of positive well-being and life satisfaction with pain severity.

METHODS AND SUBJECTS

This longitudinal study, with a follow-up of 2 years, included 9361 participants (4266 males, 5095 females; mean age: 52.5 years; SD: 17.5) without and with chronic pain (CP) at baseline. All analyses were stratified by the two sub-cohorts-participants without CP (sub-cohort 1) and participants with CP (sub-cohort 2) at baseline. The predictive associations, assessed using ordinal regression in a Generalized Linear Model, were adjusted for baseline potential confounders and reported as odds ratios (ORs) with corresponding 95% confidence intervals (CIs).

RESULTS

After adjustments, in sub-cohort 1 positive well-being at baseline was associated with lower severe pain at follow-up compared to participants with severe distress (OR: 0.64; 95% CI 0.49-0.84; p < 0.001). In sub-cohort 2, both positive well-being and life satisfaction at baseline were associated with lower severe pain at follow-up compared to participants with severe distress and not satisfied with life (OR: 0.80; 95% CI 0.65-0.98; p = 0.031 and OR: 0.82; 95% CI 0.69-0.96; p = 0.014, respectively).

CONCLUSIONS

Positive well-being is predictive of lower pain severity both among participants without and with CP at baseline, whereas life satisfaction was found predictive of lower pain severity only for subjects with CP. Future research should emphasize implementing treatments associated with promoting and maintaining positive well-being and life satisfaction in patients who suffer from chronic pain and in risk populations.

Is excess weight a burden for older adults who suffer chronic pain?

Background

Obesity and chronic pain are common comorbidities and adversely influence each other. Advanced age is associated with more comorbidities and multi-morbidities. In this study, we investigated the burden of overweight/obesity and its comorbidities and their associations with chronic pain in a random population sample of Swedish older adults.

Methods

The cross-sectional analysis involved a random sample of a population ≥ 65 years in south-eastern Sweden (N = 6243). Data were collected from a postal questionnaire that addressed pain aspects, body mass index (BMI), and health experiences. Chronic pain was defined as pain during the previous three months. According to the 0–10 Numeric Rating Scale, pain scored ≥7 corresponds to severe pain. Binary logistic regression was used to determine the variables associated to pain aspects.

Results

A total of 2633 (42%) reported chronic pain. More obese older adults (BMI ≥30 kg/m²) experienced chronic pain (58%) than those who were low-normal weight (BMI < 25 kg/m², 39%) or overweight (25 ≤ BMI < 30 kg/m², 41%). Obese elderly more frequently had pain in extremities and lower back than their peers. In the multivariate model, obesity (Odds Ratio (OR) 1.59, 95% Confidence Interval (CI) 1.33–1.91) but not overweight (OR 1.08, 95% CI 0.95–1.22) was associated with chronic pain. Obesity (OR 1.53, 95% CI 1.16–2.01) was also significantly related to severe pain. We also found other comorbidities – i.e., traumatic history (OR 2.52, 95% CI 1.99–3.19), rheumatic diseases (OR 5.21, 95% CI 4.54–5.97), age ≥ 85 years (OR 1.66, 95% CI 1.22–2.25), and depression or anxiety diagnosis (OR 1.83, 95% CI 1.32–2.53) – showed stronger associations with pain aspects than weight status. Conclusion: In older adults, excess weight (BMI 30 or above) is a potentially modifiable factor but not the only risk factor that is associated with chronic pain and severe pain. Future studies should investigate the effectiveness of interventions that treat comorbid pain and obesity in older adults.

Percutaneous Treatment with a Mucopolysaccharide Polysulphate of Experimentally Induced Subcutaneous Haematomas in Man

In a double blind trial on ten healthy volunteers, the efficacy of a topically applied mucopolysaccharide polysulphate* in the treatment of subcutaneous haematomas was assessed. Standardized haematomas were induced by subcutaneous injection of a mixture of autogenous blood and 125I-fibrinogen. The absorption of the haematoma, expressed as the removal of the labelled fibrin(ogen), could thus be objectively measured by the decrease in radioactivity.

The results show an exponential absorption of these haematomas. The absorption time was reduced to about half compared with placebo, when treated topically with mucopolysaccharide polysulphate. The difference is statistically highly significant and is also considered clinically relevant.

Experiences and attitudes about physical activity and exercise in patients with chronic pain: a qualitative interview study

Purpose

The purpose of this study was to describe how patients with chronic pain experience physical activity and exercise (PA&E).

Method

This qualitative interview study included 16 women and two men suffering from chronic pain and referred to a multimodal pain rehabilitation program. Semi-structured interviews were conducted and qualitative content analysis was used to analyze the interviews.

Results

One main theme emerged: "To overcome obstacles and to seize opportunities to be physically active despite chronic pain." This main theme was abstracted from five themes: "Valuing a life with physical activity," "Physical activity and exercise - before and after pain," "A struggle - difficulties and challenges," "The enabling of physical activity," and "In need of continuous and active support."

Conclusion

Although these participants valued PA&E, they seldom achieved desirable levels, and performance of PA&E was undermined by difficulties and failure. The discrepancy between the intention to perform physical activity and the physical activity accomplished could be related to motivation, self-efficacy, and action control. The participants desired high-quality interaction with healthcare providers. The findings can be applied to chronic pain rehabilitation that uses PA&E as treatment.

Association of insomnia severity with well-being, quality of life and health care costs: A cross-sectional study in older adults with chronic pain (PainS65+)

BACKGROUND

Insomnia is one of the most common complaints in chronic pain. This study aimed to evaluate the association of insomnia with well-being, quality of life and health care costs.

METHODS

The sample included 2790 older individuals (median age = 76; interquartile range [IQR] = 70-82) with chronic pain. The participants completed a postal survey assessing basic demographic data, pain intensity and frequency, height, weight, comorbidities, general well-being, quality of life and the insomnia severity index (ISI). Data on health care costs were calculated as costs per year (€ prices) and measured in terms of outpatient and inpatient care, pain drugs, total drugs and total health care costs.

RESULTS

The overall fraction of clinical insomnia was 24.6% (moderate clinical insomnia: 21.9% [95% CI: 18.8-23.3]; severe clinical insomnia: 2.7% [95% CI: 1.6-3.2]). Persons who reported clinical insomnia were more likely to experience pain more frequently with higher pain intensity compared to those reported no clinically significant insomnia. Mean total health care costs were € 8469 (95% CI: €4029-€14,271) for persons with severe insomnia compared with € 4345 (95% CI: €4033-€4694) for persons with no clinically significant insomnia. An association between severe insomnia, well-being, quality of life, outpatient care, total drugs costs and total health care costs remained after controlling for age, sex, pain intensity, frequency, body mass index and comorbidities using linear regression models.

CONCLUSIONS

Our results determine an independent association of insomnia with low health-related quality of life and increased health care costs in older adults with chronic pain.

SIGNIFICANCE

The concurrence and the severity of insomnia among older adults with chronic pain were associated with decreased well-being and quality of life, and increased health care costs to society.

Distinctive subgroups derived by cluster analysis based on pain and psychological symptoms in Swedish older adults with chronic pain - a population study (PainS65+)

Background

Improved knowledge based on clinical features of chronic pain in older adults would be valuable in terms of patient-orientated approaches and would provide support for health care systems in optimizing health care resources. This study identifies subgroups based on pain and psychological symptoms among Swedish older adults in the general population and compares derived subgroups with respect to socio-demographics, health aspects, and health care costs.

Methods

This cross-sectional study uses data collected from four registers and one survey. The total sample comprised 2415 individuals ≥65 years old. A two-step cluster analysis was performed. Data on pain intensity, number of pain sites, anxiety, depression, and pain catastrophizing were used as classification variables. Differences in socio-demographics, quality of life, general health, insomnia, and health care costs among the clusters were investigated. Association of the clusters with the above parameters was further evaluated using multinomial logistic regression.

Results

Four major clusters were identified: Subgroup 1 (n = 325; 15%) – moderate pain and high psychological symptoms; Subgroup 2 (n = 516; 22%) – high pain and moderate psychological symptoms; Subgroup 3 (n = 686; 30%) – low pain and moderate psychological symptoms; and Subgroup 4 (n = 767; 33%) – low pain and low psychological symptoms. Significant differences were found between the four clusters with regard to age, sex, educational level, family status, quality of life, general health, insomnia, and health care costs. The multinomial logistic regression analysis revealed that Subgroups 1 and 2, compared to Subgroup 4, were significantly associated with decreased quality of life, decreased general health, and increased insomnia. Subgroup 3, compared to Subgroup 4, was associated with decreased general health and increased insomnia. In addition, compared to Subgroup 4, Subgroups 1 and 2 were significantly associated with higher health care costs.

Conclusions

Two high risk clusters of older adults suffering from chronic pain; one mainly based on psychological symptoms and one mainly on pain intensity and pain spread, associated with decreased quality of life and health and increased health care costs were identified. Our findings indicate that subgroup-specific treatment will improve pain management and reduce health care costs.

Electronic supplementary material

The online version of this article (10.1186/s12877-017-0591-4) contains supplementary material, which is available to authorized users.

A cross-sectional study of factors associated with the number of anatomical pain sites in an actual elderly general population: results from the PainS65+ cohort

BACKGROUND

Several studies have illustrated that multisite pain is more frequent than single pain site, and it is associated with an array of negative consequences. However, there is limited knowledge available about the potential factors associated with multisite pain in the elderly general population.

OBJECTIVE

This cross-sectional study examines whether the number of anatomical pain sites (APSs) is related to sociodemographic and health-related factors in older adults including oldest-old ages using a new method (APSs) to assess the location of pain on the body.

MATERIALS AND METHODS

The sample came from the PainS65+ cohort, which included 6,611 older individuals (mean age = 76.0 years; standard deviation [SD] = 7.4) residing in southeastern Sweden. All the participants completed and returned a postal survey that measured sociodemographic data, total annual income, pain intensity and frequency, general well-being, and quality of life. The number of pain sites (NPS) was marked on a body manikin of 45 sections, and a total of 23 APSs were then calculated. Univariable and multivariable models of regression analysis were performed.

RESULTS

Approximately 39% of the respondents had at least two painful sites. The results of the regression analysis showed an independent association between the APSs and the age group of 75-79 years, women, married, high pain intensity and frequency, and low well-being and quality of life, after adjustments for consumption of analgesics and comorbidities. The strongest association was observed for the higher frequency of pain.

CONCLUSION

Our results suggest that APSs are highly prevalent with strong relationships with various sociodemographic and health-related factors and concur well with the notion that multisite pain is a potential indicator of increased pain severity and impaired quality of life in the elderly. Our comprehensive method of calculating the number of sites could be an essential part of the clinical presentation, assessment, and treatment of multisite pain.

Quality of life during early radiotherapy in patients with head and neck cancer and pain

BACKGROUND

Patients with head and neck cancer (HNC) have a potentially severe diagnosis and often suffer from tumor-related pain as well as from adverse side effects of treatment such as radiotherapy (RT). Knowledge about quality of life (QoL) during early RT in this group is limited and should be assessed in relation to diagnosis and treatment.

PURPOSE

The purpose of this cross-sectional study was to identify potential factors that may influence QoL in patients with HNC during the early stages of RT (no later than two weeks of ongoing RT). We hypothesized that pain intensity, pain interference, catastrophizing, and mood disturbances are associated with QoL during early RT.

PATIENTS AND METHODS

In this study, 54 patients (53% of eligible patients) diagnosed with HNC were consecutively recruited from the regular flow to the Pain and Rehabilitation Center at Linköping University. The patients completed self-reported questionnaires on sociodemographics, pain intensity, pain interference, anxiety, depression, pain catastrophizing, and QoL.

RESULTS

The patients in this study scored high for QoL, low for pain intensity, and low for pain interference. The patients reported minor depressive symptoms and anxiety symptoms. Regression analyses showed that pain intensity and depressive symptoms negatively influenced QoL.

CONCLUSION

No later than two weeks of RT, pain intensity and depression negatively influenced QoL in patients with HNC. Early screening for pain and depression in a targeted preventive strategy might maintain QoL during the course of the RT for patients with HNC. This assumption needs to be further investigated.

Illness beliefs among patients with chronic widespread pain - associations with self-reported health status, anxiety and depressive symptoms and impact of pain

Background

Chronic widespread pain (CWP) is a disabling condition associated with a decrease in health. Illness beliefs are individual and are acquired during life. Constraining beliefs may prevent patients from regaining health. Understanding these patients’ illness beliefs may be a way to improve the health care they are offered. The aim of this study was to describe illness beliefs among patients with CWP and associations with self-reported health, anxiety and depressive symptoms, and impact of pain.

Method

In this cross-sectional study, questionnaires were sent by mail to 330 patients including socio-demographic information, the Illness Perception Questionnaire (IPQ-R), the Short-Form General Health Survey (SF-36) and the Hospital Anxiety and Depression Scale (HADS). Data were analysed using descriptive statistics, non-parametric tests and linear regression analyses.

Results

Patients experienced and related a high number of symptoms to CWP (mean (SD) 9 (3)). The patients believed their illness to be long lasting, to affect their emotional well being, and to have negative consequences for their lives. Some 72% reported having severe or very severe pain, and impact of pain according to SF-36 was negatively correlated to several illness beliefs dimensions, anxiety- and depressive symptoms. In regression analyses, the Identity, Consequences and Personal control dimensions of IPQ-R and Anxiety- and Depressive symptoms explained 32.6–56.1% of the variance in the two component scores of SF-36.

Conclusion

Constraining illness beliefs in patients with CWP are related to worse health status, especially in cases of high number of physical or mental symptoms, beliefs of negative consequences or the illness affecting them emotionally. Identification and understanding of these beliefs may reduce patients’ suffering if they are taken into consideration in rehabilitation programs and in development of new evidence-based interventions aimed at increasing health in patients with CWP.

Using education and support strategies to improve the way nurses assess regular and transient pain – A quality improvement study of three hospitals

Background and aims

Systematic and regular pain assessment has been shown to improve pain management. Well-functioning pain assessments require using strategies informed by well-established theory. This study evaluates documented pain assessments reported in medical records and by patients, including reassessment using a Numeric Rating Scale (NRS) after patients receive rescue medication.

Methods

Documentation surveys (DS) and patient surveys (PS) were performed at baseline (BL), after six months, and after 12 months in 44 in-patient wards at the three hospitals in Östergötland County, Sweden. Nurses and nurse assistants received training on pain assessment and support. The Knowledge to Action Framework guided the implementation of new routines.

Results

According to DS pain assessment using NRS, pain assessment increased significantly: from 7% at baseline to 36% at 12 months (p < 0.001). For PS, corresponding numbers were 33% and 50% (p < 0.001). According to the PS, the proportion of patients who received rescue medication and who had been reassessed increased from 73% to 86% (p = 0.003). The use of NRS to document pain assessment after patients received rescue medication increased significantly (4% vs. 17%; p < 0.001).

Conclusions

After implementing education and support strategies, systematic pain assessment increased, an encouraging finding considering the complex contexts of in-patient facilities. However, the achieved assessment levels and especially reassessments related to rescue medication were clinically unsatisfactory. Future studies should include nursing staff and physicians and increase interactivity such as providing online education support. A discrepancy between documented and reported reassessment in association with given rescue medication might indicate that nurses need better ways to provide pain relief.

Implications

The fairly low level of patient-reported pain via NRS and documented use of NRS before and 12 months after the educational programme stresses the need for education on pain management in nursing education. Implementations differing from traditional educational attempts such as interactive implementations might complement educational programmes given at the work place. Standardized routines for pain management that include the possibility for nurses to deliver pain medication within well-defined margins might improve pain management and increase the use of pain assessments. Further research is needed that examines the large discrepancy between patient-reported pain management and documentation in the medical recording system of transient pain.

Different DHEA-S Levels and Response Patterns in Individuals with Chronic Neck Pain, Compared with a Pain Free Group-a Pilot Study

Objective

To test, in this pilot study, whether DHEA-S (Dehydroepiandrosterone, sulfated form) plasma levels are lower among persons with chronic neck pain, compared to control persons, and to investigate the DHEA-S response after a physical exercise.

Subjects

Included were 12 persons with chronic neck pain and eight controls without present pain, all 18 and 65 years of age. Exclusion criteria for both groups were articular diseases or tendinosis, fibromyalgia, systemic inflammatory and neuromuscular diseases, pain conditions due to trauma, or severe psychiatric diseases.

Design and methods

The participants arm-cycled on an ergometer for 30 minutes. Blood samples were taken before, 60 minutes, and 150 minutes after this standardized physical exercise.

Results

The estimated plasma DHEA-S levels at baseline were 2.0 µmol/L (95% confidence interval [CI] 1.00; 4.01) in the pain group and 4.1 µmol/L (95% CI2.0; 8.6) in the control group, adjusted for sex, age, body mass index (BMI), and Shirom-Melamed Burnout Questionnaire (SMBQ), with a ratio of 0.48 ( P  = 0.094).

Conclusions

In this pilot study, the plasma DHEA-S levels appeared to be lower among the persons with chronic neck pain, compared with the control group. It was indicated that DHEA-S decreased during the physical exercise in the control group, and either increased or was unaffected in the chronic pain group.

Insomnia severity and its relationship with demographics, pain features, anxiety, and depression in older adults with and without pain: cross-sectional population-based results from the PainS65+ cohort

BACKGROUND

Insomnia is a major cause of concern in the elderly with and without pain. This study set out to examine the insomnia and its correlates in a large sample of community adults aged ≥65 years.

METHODS

A cross-sectional postal survey was completed by 6205 older individuals (53.8% women; mean age = 76.2 years; SD = 7.5). The participants also completed the Insomnia Severity Index (ISI) and questionnaires assessing pain intensity, pain spreading, anxiety, depression, and basic demographic information. The sample was divided into three groups based on the presence and duration of pain: chronic pain (CP; n = 2790), subacute pain (SP; n = 510), and no pain (NP; n = 2905).

RESULTS

A proportion of each of the groups had an ISI score of 15 or greater (i.e., clinical insomnia): CP = 24.6%; SP = 21.3%; and NP = 13.0%. The average scores of ISI differed significantly among CP, SP, and NP groups (p < 0.001). Stratified regression analyses showed that pain intensity, pain spreading, anxiety, and depression were independently related to insomnia in the CP group. Anxiety and depression were independently related to insomnia in the SP group, but only anxiety was significantly associated with insomnia in the NP group. Age and sex were not associated with insomnia.

CONCLUSIONS

This study confirms that insomnia is not associated with chronological aging per se within the elderly population. Although the possible associations of insomnia with pain are complex, ensuing from pain intensity, pain spreading, anxiety, and depression, our results highlighted that anxiety was more strongly associated with insomnia in all groups than the depression and pain characteristics. Therapeutic plans should consider these relations during the course of pain, and a comprehensive assessment including both pain and psychological features is essential when older people are seeking primary health care for insomnia complaints.

Prevalence of different pain categories based on pain spreading on the bodies of older adults in Sweden: a descriptive-level and multilevel association with demographics, comorbidities, medications, and certain lifestyle factors (PainS65+)

Background and objective

There is limited knowledge about the prevalence of pain and its relation to comorbidities, medication, and certain lifestyle factors in older adults. To address this limitation, this cross-sectional study examined the spreading of pain on the body in a sample of 6611 subjects ≥65 years old (mean age = 75.0 years; standard deviation [SD] = 7.7) living in southeastern Sweden.

Methods

Sex, age, comorbidities, medication, nicotine, alcohol intake, and physical activity were analyzed in relation to the following pain categories: local pain (LP) (24.1%), regional pain medium (RP-Medium) (20.3%), regional pain heavy (RP-Heavy) (5.2%), and widespread pain (WSP) (1.7%).

Results

RP-Medium, RP-Heavy, and WSP were associated more strongly with women than with men (all p<0.01). RP-Heavy was less likely in the 80–84 and >85 age groups compared to the 65–69 age group (both p<0.01). Traumatic injuries, rheumatoid arthritis/osteoarthritis, and analgesics were associated with all pain categories (all p<0.001). An association with gastrointestinal disorders was found in LP, RP-Medium, and RP-Heavy (all p<0.01). Depressive disorders were associated with all pain categories, except for LP (all p<0.05). Disorders of the central nervous system were associated with both RP-Heavy and WSP (all p<0.05). Medication for peripheral vascular disorders was associated with RP-Medium (p<0.05), and hypnotics were associated with RP-Heavy (p<0.01).

Conclusion

More than 50% of older adults suffered from different pain spread categories. Women were more likely to experience greater spreading of pain than men. A noteworthy number of common comorbidities and medications were associated with increased likelihood of pain spread from LP to RP-Medium, RP-Heavy, and WSP. Effective management plans should consider these observed associations to improve functional deficiency and decrease spreading of pain-related disability in older adults.

A 3-Year Follow-Up of Headache Diagnoses and Symptoms in Swedish Schoolchildren

Information is sparse concerning the incidence and prognosis of headache in children from the general population, especially of tension-type headache. In this study, headache diagnoses and symptoms were reassessed in 122 out of 130 schoolchildren after 3 years. Nearly 80± of those with headache at first evaluation still reported headache at follow-up. Although the likelihood of experiencing the same headache diagnosis and symptoms was high, about one-fifth of children with tension-type headache developed migraine and vice versa. Female gender predicted migraine and frequent headache episodes predicted overall headache at follow-up. The estimated average annual incidence was 81 and 65 per 1000 children, for tension-type headache and migraine, respectively. We conclude that there is a considerable risk of developing and maintaining headache during childhood. Headache diagnoses should be reassessed regularly and treatment adjusted. Girls and children with frequent headache have a poorer prognosis and therefore intervention is particularly important in these groups.

Increased Interstitial Concentrations of Glutamate and Pyruvate in Vastus Lateralis of Women with Fibromyalgia Syndrome Are Normalized after an Exercise Intervention - A Case-Control Study

BACKGROUND

Fibromyalgia syndrome (FMS) is associated with central alterations, but controversies exist regarding the presence and role of peripheral factors. Microdialysis (MD) can be used in vivo to study muscle alterations in FMS. Furthermore for chronic pain conditions such as FMS, the mechanisms for the positive effects of exercise are unclear. This study investigates the interstitial concentrations of algesics and metabolites in the vastus lateralis muscle of 29 women with FMS and 28 healthy women before and after an exercise intervention.

METHODS

All the participants went through a clinical examination and completed a questionnaire. In addition, their pressure pain thresholds (PPTs) in their upper and lower extremities were determined. For both groups, MD was conducted in the vastus lateralis muscle before and after a 15-week exercise intervention of mainly resistance training of the lower limbs. Muscle blood flow and interstitial muscle concentrations of lactate, pyruvate, glutamate, glucose, and glycerol were determined.

RESULTS

FMS was associated with significantly increased interstitial concentrations of glutamate, pyruvate, and lactate. After the exercise intervention, the FMS group exhibited significant decreases in pain intensity and in mean interstitial concentrations of glutamate, pyruvate, and glucose. The decrease in pain intensity in FMS correlated significantly with the decreases in pyruvate and glucose. In addition, the FMS group increased their strength and endurance.

CONCLUSION

This study supports the suggestion that peripheral metabolic and algesic muscle alterations are present in FMS patients and that these alterations contribute to pain. After an exercise intervention, alterations normalized, pain intensity decreased (but not abolished), and strength and endurance improved, all findings that suggest the effects of exercise are partially peripheral.

Associations between psychological factors and the effect of home-based physical exercise in women with chronic neck and shoulder pain

Background:

Exercise is often used in the treatment of chronic neck and shoulder muscle pain. It is likely that psychological aspects have an impact on the results of exercise-based treatments.

Objectives:

(1) To examine the associations between psychological factors and the effect of a home-based physical exercise intervention. (2) To examine differences in psychological factors at baseline between (a) subjects who continued in the trial and those who did not and (b) subjects who completed the intervention and those who did not.

Method:

A total of 57 women with chronic neck and shoulder pain were included in a home-based exercise intervention trial. Pain intensity, disability, and psychological factors (anxiety and depression symptoms, catastrophizing, fear-avoidance beliefs, self-efficacy, and pain acceptance) were measured at baseline, after 4–6 months, and after 1 year of exercise. Associations between the psychological factors and changes in pain intensity and disability were analysed, as well as differences in psychological factors at baseline between subjects who continued in and completed the intervention, and those who did not.

Results:

Associations between positive changes in pain intensity and disability were found for low fear-avoidance beliefs and low-pain self-efficacy at baseline. In addition, fear-avoidance beliefs at baseline were higher in the subjects who dropped out of the intervention than in those who continued. Pain acceptance at baseline was higher in the subjects who completed the intervention at the end of the trial.

Conclusion:

Particularly, fear-avoidance beliefs and pain self-efficacy should be taken into consideration when implementing home-based physical exercise as treatment for chronic neck pain. In addition, high pain acceptance might improve the adherence to prescribed exercise.

Contrast Enhancement of Pathologic Lymph Nodes Demonstrated by Computed Tomography

Enlarged mediastinal, retroperitoneal and pelvic lymph nodes are often difficult to differentiate from vascular structures. Contrast medium is therefore used to help to discriminate arteries and veins from lymph nodes. This study was undertaken to investigate the degree to which pathologic lymph nodes become enhanced after an intravenous bolus injection of contrast medium. Computed tomography was performed in 25 patients with enlargement of retroperitoneal lymph nodes due to primary lymphoproliferative disease or metastases. A dynamic sequence of a well delineated lymph node was obtained over a period of two minutes. Contrast enhancement was seen in all lymph nodes, but of varying degree. The enhancement was correlated to that observed in the inferior vena cava. Most examined lymph nodes showed slight or moderate enhancement, but in five instances strong enhancement, more than 75 per cent of that of the vena cava, was found. These nodes could possibly have been misinterpreted as blood vessels.

Circulating cartilage oligomeric matrix protein in juvenile idiopathic arthritis

OBJECTIVES

Raised serum cartilage oligomeric matrix protein (sCOMP) has been reported to predict erosive disease in early rheumatoid arthritis (RA). In juvenile idiopathic arthritis (JIA), subnormal sCOMP levels have been associated with ongoing inflammation and growth retardation. In this study we aimed to assess sCOMP, C-reactive protein (CRP), and insulin-like growth factor (IGF)-1 in children/adolescents with JIA and in referents.

METHOD

We enrolled 52 JIA patients at planned outpatient visits and 54 inpatients with ongoing infection ('infection referents'). A total of 120 referents testing negative for immunoglobulin (Ig)E-mediated allergy ('IgE referents') served as controls. All serum samples were analysed for COMP, IGF-1, and CRP.

RESULTS

The average sCOMP level was highest among the IgE referents and lowest among the infection referents. In the JIA patients, the level of sCOMP was not associated with the level of CRP or with clinical signs of disease activity.

CONCLUSIONS

The results of this study do not support routine clinical analysis of sCOMP levels in patients with JIA.

Prevalence of Different Pain Categories Based on Pain Spreading in Older Adults in Sweden: A Multilevel Association With Socio-Demographic Characteristics, Comorbidities and Drug Consumption (Pain S65+)

Introduction

Understanding of factors related to chronic pain in elderly is limited.

Objectives and aims

To estimate the prevalence of pain categories based on spreading of pain on the body and to investigate how such spreading is related to demographic variables, pain intensity, comorbidities and medication in an elderly general population in southeastern Sweden.

Methods

A total of 6611 adults aged ≥ 65 years participated (mean age = 76.2; SD = 7.4). Pain categories were assessed by a self-reported postal questionnaire covering 45 anatomical predefined pain regions along with demographics, pain intensity during previous seven days, comorbidities and medication. Poisson regression models with robust error variance were used for data analyzing.

Results

The prevalence of pain spreading categories was: chronic local pain (CLP) 16%; chronic regional pain medium (CRP-Medium) 17%; chronic regional pain heavy (CRP-Heavy) 5% and chronic widespread pain (CWSP) 2%. Overall, increased prevalence for CRP-Heavy and CWSP in subjects 75–79 years old compared to those 65–69, 70–74, 80–84 and ≥ 85 years were revealed. In men, 75–79 years old, CRP-Heavy was more common than in the other pain categories. In women, 75–79 years old CWSP, was more common than in the other pain categories. Pain intensity was strongly associated with all pain categories (P < 0.001). CLP was associated with trauma, rheumatoid arthritis, cancer, prescribed and non-prescribed analgesics. CRP-Medium was associated with rheumatoid arthritis, CRP-Heavy with rheumatoid arthritis and lung diseases and CWSP with rheumatoid arthritis and prescribed analgesics (P < 0.001).

Conclusions

Our findings elucidate heterogeneity of pain in elderly which has to be further investigated.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Plasma pro-inflammatory markers in chronic neuropathic pain: A multivariate, comparative, cross-sectional pilot study

BACKGROUND

Caused by a lesion or disease of the somatosensory system, neuropathic pain is notoriously difficult to treat with conventional analgesics. It has been suggested that inflammatory cytokines play a role in the development and maintenance of neuropathic pain. But human studies of these substances are relatively few and partly contradictory.

OBJECTIVES

To simultaneously investigate the plasma levels of chemokine interleukin 8 (IL-8) and the cytokines IL-6, IL-1β, and Granulocyte macrophage colony-stimulating factor (GM-CSF) in patients with peripheral neuropathic pain (most of whom due to failed back surgery syndrome) (n=14) compared to controls (n=17).

RESULTS

IL-6 was significantly higher in patients than in controls (0.92±0.12pg/ml vs. 0.57±0.08pg/ml, p=0.012). IL-1β, IL-8, and GM-CSF levels did not differ between the two groups. A multivariate analysis showed a tendency for patients also to have higher GM-CSF plasma levels than controls.

CONCLUSIONS

This study found an increased level of IL-6 in plasma in patients with neuropathic pain, but not for the other pro-inflammatory substances investigated. There are several possible confounders not registered or controlled for in this and other studies of neuropathic pain.

IMPLICATIONS

Larger studies that take several possible confounders into consideration are needed to further investigate the levels of plasma cytokines in different pain conditions.

Comorbidities, intensity, frequency and duration of pain, daily functioning and health care seeking in local, regional, and widespread pain - a descriptive population-based survey (SwePain)

Background

The clinical knowledge of factors related to the spread of pain on the body has increased and understanding these factors is essential for effective pain treatment. This population-based study examines local (LP), regional (RP), and widespread pain (WSP) on the body regarding comorbidities, pain aspects, and impact of pain and elucidates how the spread of pain varies over time.

Material and methods

A postal questionnaire that addressed pain aspects (intensity, frequency, duration and anatomical spreading on a body manikin), comorbidities and implications of pain (i.e., work situation, physical activity, consumption of health care and experience of hospitality and treatment of health care) was sent to 9000 adults living in southeastern Sweden. Of these, 4774 (53 %) completed and returned the questionnaire. After 9 weeks, a follow-up questionnaire was sent to the 2983 participants who reported pain in the first questionnaire (i.e. 62 % of 4774 subjects). Of these, 1940 completed and returned the questionnaire (i.e. 65 % of 2983 subjects). The follow-up questionnaire included the same items as the first questionnaire.

Results

This study found differences in intensity, frequency and duration of pain, comorbidities, aspects of daily functioning and health care seeking in three pain categories based on spreading of pain: LP, RP and WSP. Compared to the participants with RP and LP, the participants with WSP had lower education and worse overall health, including more frequent heart disease and hypertension. In addition, participants with WSP had more intense, frequent, and long-standing pain, required more medical consultations, and experienced more impact on work. The participants with RP constituted an intermediate group regarding frequency and intensity of pain, and impact on work. The participants with LP were the least affected group regarding these factors. A substantial transition to RP had occurred by the 9-week follow-up.

Conclusions

This study shows an association between increased spread of pain and prevalence of heart disease, hypertension, more severe pain characteristics (i.e., intensity, frequency and duration), problems with common daily activities and increased health care seeking. The WSP group was the most affected group and the LP group was the least affected group. Regarding these factors, RP was an obvious intermediate group. The transitions between the pain categories warrant research that broadly investigates factors that increase and decrease pain.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-015-0631-1) contains supplementary material, which is available to authorized users.

Accumulation of substances with melanin affinity to the internal ear. Therapeutic or ototoxic mechanism?

The capacity of the melanin in the internal ear to accumulate and retain labelled lidocaine, bupivacaine and chlorpromazine after intravenous and intraperitoneal injection was examined by whole-body autoradiography. Both young pigmented hooded rats and albino rats were studied. In the pigmented rats chlorpromazine showed the greatest accumulation, which was more pronounced in the cochlea than in the vestibular portion. The other two substances were evenly distributed in the internal ear. After a single injection of chlorpromazine and of bupivacaine these substances were still bound to the melanin of the internal ear after 14 days, which was the longest survival time. Lidocaine, on the other hand, had disappeared after only 4 days. In albino animals there was very weak, transient uptake of chlorpromazine and bupivacaine, but not of lidocaine, in the internal ear. In studies in vitro on isolated bovine eye melanin there was considerably greater adsorption of chlorpromazine than of lidocaine and bupivacaine.

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). Spearman's 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.

Algogenic substances and metabolic status in work-related Trapezius Myalgia: a multivariate explorative study

BACKGROUND

This study compares the levels of algesic substances between subjects with trapezius myalgia (TM) and healthy controls (CON) and explores the multivariate correlation pattern between these substances, pain, and metabolic status together with relative blood flow changes reported in our previous paper (Eur J Appl Physiol 108:657-669, 2010).

METHODS

43 female workers with (TM) and 19 females without (CON) trapezius myalgia were - using microdialysis - compared for differences in interstitial concentrations of interleukin-6 (IL-6), bradykinin (BKN), serotonin (5-HT), lactate dehydrogenas (LDH), substance P, and N-terminal propeptide of procollagen type I (PINP) in the trapezius muscle at rest and during repetitive/stressful work. These data were also used in multivariate analyses together with previously presented data (Eur J Appl Physiol 108:657-669, 2010): trapezius muscle blood flow, metabolite accumulation, oxygenation, and pain development and sensitivity.

RESULTS

Substance P was significantly elevated in TM (p=0.0068). No significant differences were found in the classical algesic substances (p: 0.432-0.926). The multivariate analysis showed that blood flow related variables, interstitial concentrations of metabolic (pyruvate), and algesic (BKN and K+) substances were important for the discrimination of the subjects to one of the two groups (R2: 0.19-0.31, p<0.05). Pain intensity was positively associated with levels of 5-HT and K+ and negatively associated with oxygenation indicators and IL-6 in TM (R2: 0.24, p<0.05). A negative correlation existed in TM between mechanical pain sensitivity of trapezius and BKN and IL-6 (R2: 0.26-0.39, p<0.05).

CONCLUSION

The present study increased understanding alterations in the myalgic muscle. When considering the system-wide aspects, increased concentrations of lactate, pyruvate and K+ and decreased oxygenation characterized TM compared to CON. There are three major possible explanations for this finding: the workers with pain had relatively low severity of myalgia, metabolic alterations preceded detectable alterations in levels of algesics, or peripheral sensitization and other muscle alterations existed in TM. Only SP of the investigated algesic substances was elevated in TM. Several of the algesics were of importance for the levels of pain intensity and mechanical pain sensitivity in TM. These results indicate peripheral contribution to maintenance of central nociceptive and pain mechanisms and may be important to consider when designing treatments.

Effects of two different specific neck exercise interventions on palmitoylethanolamide and stearoylethanolamide concentrations in the interstitium of the trapezius muscle in women with chronic neck shoulder pain

PURPOSE

Chronic neck/shoulder pain (CNSP) is one of the most common pain conditions. The understanding of mechanisms, including the peripheral balance between nociceptive and antinociceptive processes, is incomplete. N-acylethanolamines (NAEs) are a class of endogenous compounds that regulate inflammation and pain. The aim of this study was to investigate the levels of two NAEs: the peroxisome proliferator-activated receptor type-α ligand palmitoylethanolamide (PEA) and stearoylethanolamide (SEA) in the muscle interstitium of the trapezius muscle in women with CNSP randomized to two different neck specific training programs and in a healthy pain-free control group (CON).

MATERIALS AND METHODS

Fifty-seven women with CNSP were randomized to strength + stretch or stretch alone exercise programs. Twenty-nine subjects underwent microdialysis procedure before and after 4-6 months of exercise. Twenty-four CON subjects underwent microdialysis procedure before and after 4-6 months without any intervention in between. Microdialysate samples were collected from the trapezius muscle and analyzed by mass spectrometry for PEA and SEA levels.

RESULTS

PEA and SEA levels were significantly higher in CNSP patients compared with CON. PEA was significantly higher in CNSP than in CON after both training programs. SEA was significantly higher in CNSP than in CON after stretch alone but not after strength + stretch training. A significant positive correlation was found between changes in pain intensity and in SEA levels in the strength + stretch group, but not in the stretch alone group.

CONCLUSION

Our results indicate that exercise interventions differentially affect the levels of the bioactive lipids PEA and SEA in the interstitium of the trapezius muscle in women with CNSP.

Comparative metabolomics of muscle interstitium fluid in human trapezius myalgia: an in vivo microdialysis study

Purpose

The mechanisms behind trapezius myalgia are unclear. Many hypotheses have been presented suggesting an altered metabolism in the muscle. Here, muscle microdialysate from healthy and myalgic muscle is analysed using metabolomics. Metabolomics analyse a vast number of metabolites, enabling a comprehensive explorative screening of the cellular processes in the muscle.

Methods

Microdialysate samples were obtained from the shoulder muscle of healthy and myalgic subjects that performed a work and stress test. Samples from the baseline period and from the recovery period were analysed using gas chromatography—mass spectrometry (GC–MS) together with multivariate analysis to detect differences in extracellular content of metabolites between groups. Systematic differences in metabolites between groups were identified using multivariate analysis and orthogonal partial least square discriminate analysis (OPLS-DA). A complementary Mann–Whitney U test of group difference in individual metabolites was also performed.

Results

A large number of metabolites were detected and identified in this screening study. At baseline, no systematic differences between groups were observed according to the OPLS-DA. However, two metabolites, l-leucine and pyroglutamic acid, were significantly more abundant in the myalgic muscle compared to the healthy muscle. In the recovery period, systematic difference in metabolites between the groups was observed according to the OPLS-DA. The groups differed in amino acids, fatty acids and carbohydrates. Myristic acid and putrescine were significantly more abundant and beta-d-glucopyranose was significantly less abundant in the myalgic muscle.

Conclusion

This study provides important information regarding the metabolite content, thereby presenting new clues regarding the pathophysiology of the myalgic muscle.