Prevalence Of Chronic Widespread Pain Research Articles

Prevalence and the correlations of chronic widespread pain among loaders (Nattami) in Pettah, Sri Lanka

Introduction: Chronic widespread pain (CWP) is a cardinal symptom of fibromyalgia, which is a non-inflammatory condition of the musculoskeletal system. It has become a highly prevalent condition and a major health problem in the community and working population. Loaders are a vulnerable group of people engage in an occupation that has a higher risk of developing musculoskeletal pain. Psychological distress is also associated with CWP. The main aim of this study was to identify the prevalence and associated factors of CWP among loaders in Pettah, Sri Lanka. Further, the association of psychological distress and the health-seeking behaviors of loaders with CWP was assessed in this study.Methods: A cross sectional study was carried out in a convenience sample of 174 loaders in the main bazaar, Pettah, Sri Lanka. A criterion given in the “Manchester Definition” for CWP was used for the identification of CWP. Data were collected using a self-administered structured questionnaire and Perceived Stress Scale was used to identify the psychological distress. Descriptive and inferential statistics were used to analyze the data with SPSS version 21.Results: The mean age (SD) of the study participants was 42.65 (±12.21)ranged between 19 and 66 years. The level of education of the majority (61.5%) were between grade 6-11. The mean working years as a loader was 20.84 years and the mean weight that the participants carried per turn was 62kg. The prevalence of CWP was 18.4% (n=32) and the lower back pain was the most prevalent (64%) individual problem. High level of stress was perceived by 51.7% of the study participants. Age and the perceived stress were significantly associated with the CWP (p<0.05). Most of the participants (88%) used substances and among them 29.6 % used substances to relieve pain. High level of perceived stress was found in 51.7% of loaders.Conclusion: CWP is a significant occupational health issue which is associated with high level of stress among loaders in Pettah, Sri Lanka.

Temporomandibular Disorders and Fibromyalgia Prevalence: A Systematic Review and Meta-Analysis.

To evaluate the prevalence of chronic widespread pain (CWP) and fibromyalgia syndrome (FMS) in TMD patients and the prevalence of TMDs in patients with FMS. A systematic search was performed in electronic databases. Studies published in English examining the prevalence of comorbid TMDs and CWP/FMS were included. The Newcastle-Ottawa Scale was used to assess study quality, and meta-analyses using defined diagnostic criteria were conducted to generate pooled prevalence estimates. Nineteen studies of moderate to high quality met the selection criteria. Meta-analyses yielded a pooled prevalence rate (95% CI) for TMDs in FMS patients of 76.8% (69.5% to 83.3%). Myogenous TMDs were more prevalent in FMS patients (63.1%, 47.7% to 77.3%) than disc displacement disorders (24.2%, 19.4% to 39.5%), while a little over 40% of FMS patients had comorbid inflammatory degenerative TMDs (41.8%, 21.9% to 63.2%). Almost a third of individuals (32.7%, 4.5% to 71.0%) with TMDs had comorbid FMS, while estimates of comorbid CWP across studies ranged from 30% to 76%. Despite variable prevalence rates among the included studies, the present review suggests that TMDs and CWP/FMS frequently coexist, especially for individuals with painful myogenous TMDs. The clinical, pathophysiologic, and therapeutic aspects of this association are important for tailoring appropriate treatment strategies.

Comparison of chronic widespread pain prevalence with different criteria in two cohorts of rheumatoid arthritis

ObjectiveThis study aims to investigate chronic widespread pain with the 1990 (CWP1990) and 2019 (CWP2019) definitions 6 years after the onset of rheumatoid arthritis (RA), in one patient cohort with tight controls and one conventional cohort, and factors associated with reporting CWP1990 and CWP2019, respectively.MethodsA cohort of 80 RA patients with monthly visits to the physician the first 6 months was compared to a cohort of 101 patients from the same clinic with conventional follow-up. Both cohorts had early RA (< 13 months). The prevalence of CWP1990 and the more stringent CWP2019 were in a 6-year follow-up investigated with a questionnaire, including a pain mannequin and a fear-avoidance beliefs questionnaire.ResultsIn the tight control cohort, 10% reported CWP2019 after 6 years compared to 23% in the conventional cohort (p = 0.026). There was no difference when using the CWP1990 definition (27% vs 31%, p = 0.546). When adjusted for important baseline data, the odds ratio for having CWP2019 was 2.57 (95% CI 1.02–6.50), in the conventional group compared to the tight control group (p = 0.046). A high level of fear-avoidance behaviour towards physical activity was associated with CWP2019, OR 10.66 (95% CI 1.01–112.14), but not with CWP1990 in the tight control cohort.ConclusionA more stringent definition of CWP identifies patients with a more serious pain condition, which potentially could be prevented by an initial tight control management. Besides tight control, caregivers should pay attention to fear-avoidance behaviour and tailor treatment.Key Points• CWP2019 is a more stringent definition of chronic widespread pain and identifies patients with a more serious pain condition.• Patients with a serious pain condition could be helped by frequent follow-ups.• This study suggests that a special attention of fear-avoidance behaviour towards physical activity in patients with RA is needed.

Pressure pain thresholds in individuals with knee pain: a cross-sectional study

BackgroundKnee osteoarthritis (KOA), chronic widespread pain (CWP) and overweight/obesity are public health problems that often coincide, and there is a multifactorial and unclear relationship between them. The study aimed to (1) investigate pain sensitivity, assessed by pressure pain thresholds (PPTs), among women and men with knee pain and (2) associations with, respectively, radiographic KOA (rKOA), CWP, and overweight/obesity.MethodsBaseline data from an ongoing longitudinal study involving 280 individuals with knee pain in the 30–60 age group. Pain sensitivity was assessed by PPTs on eight different tender points using a pressure algometer. The participants’ knees were x-rayed. Self-reported CWP and number of pain sites were assessed with a pain figure, and overweight/obesity was measured using body mass index (BMI), visceral fat area (VFA), and body fat percentage, assessed with a bioimpedance. Associations were analysed using regression analyses.ResultsWomen reported lower PPTs than men (p < 0.001), but no PPTs differences were found between those with and without rKOA. Low PPTs was associated with female sex, more pain sites, CWP, and a higher VFA and body fat percentage. The tender points second rib and the knees were most affected. The prevalence of CWP was 38 %.ConclusionsThe modifiable factors, increased VFA, and body fat could be associated with increased pain sensitivity among individuals with knee pain. Longitudinal studies are needed to further investigate the associations.

Chronic widespread pain in children and adolescents presenting in primary care: prevalence and associated risk factors.

A significant proportion of children/adolescents report chronic widespread pain (CWP), but little is known about clinically relevant CWP or what factors lead to onset in this population. Objectives were to report the primary care consultation prevalence of CWP and investigate risk factors associated with onset. A validated algorithm for identifying CWP status from primary care electronic healthcare records was applied to a child or adolescent population (aged 8-18 years). The algorithm records patients who have recurrent pain consultations (axial skeleton and upper or lower limbs) or those with a nonspecific generalised pain disorder (eg, fibromyalgia). Prevalence was described, and a nested case-control study was established to identify risk factors associated with CWP onset using logistic regression producing odds ratios (ORs) and 95% confidence intervals (95% CIs). Two hundred seventy-one children or adolescents were identified with CWP, resulting in a 5-year consultation prevalence of 3.19%. Risk factors significantly associated with CWP onset were as follows: mental health (eg, anxiety/neurosis consultations), neurological (eg, headaches), genitourinary (eg, cystitis), gastrointestinal (eg, abdominal pain), and throat problems (eg, sore throats). Children or adolescents with 1 or 2 risk factors (OR 2.15, 95% CI 1.6-2.9) or 3 or more risk factors (OR 9.17, 95% CI 5.9-14.3) were at significantly increased odds of CWP onset compared with those with none. Findings show a significant proportion of the child or adolescent primary care population has CWP. Most risk factors involved pain-related conditions, suggesting potential pathways of pain development. Further work is now needed to better understand the development of CWP in children and adolescents.

Heme attenuates beta-endorphin levels in leukocytes of HIV positive individuals with chronic widespread pain

The prevalence of chronic widespread pain (CWP) in people with HIV is high, yet the underlying mechanisms are elusive. Leukocytes synthesize the endogenous opioid, β-endorphin, within their endoplasmic reticulum (ER). When released into plasma, β-endorphin dampens nociception by binding to opioid receptors on sensory neurons. We hypothesized that the heme-dependent redox signaling induces ER stress, which attenuates leukocyte β-endorphins levels/release, thereby increasing pain sensitivity in people with HIV. Results demonstrated that HIV positive individuals with CWP had increased plasma methemoglobin, erythrocytes membrane oxidation, hemolysis, and low plasma heme scavenging enzyme, hemopexin, compared to people with HIV without CWP and HIV-negative individuals with or without pain. In addition, the leukocytes from people with HIV with CWP had attenuated levels of the heme metabolizing enzyme, heme oxygenase-1, which metabolizes free heme to carbon-monoxide and biliverdin. These individuals also had elevated ER stress, and low β-endorphin in leukocytes. In vitro, heme exposure or heme oxygenase-1 deletion, decreased β-endorphins in murine monocytes/macrophages. Treating cells with a carbon-monoxide donor or an ER stress inhibitor, increased β-endorphins. To mimic hemolytic effects in a preclinical model, C57BL/6 mice were injected with phenylhydrazine hydrochloride (PHZ). PHZ increased cell-free heme and ER stress, decreased leukocyte β-endorphin levels and hindpaw mechanical sensitivity thresholds. Treatment of PHZ-injected mice with hemopexin blocked these effects, suggesting that heme-induced ER stress and a subsequent decrease in leukocyte β-endorphin is responsible for hypersensitivity in people with HIV.

Chronic Pain in HIV.

The evolution of therapeutics for and management of human immunodeficiency virus-1 (HIV-1) infection has shifted it from predominately manifesting as a severe, acute disease with high mortality to a chronic, controlled infection with a near typical life expectancy. However, despite extensive use of highly active antiretroviral therapy, the prevalence of chronic widespread pain in people with HIV remains high even in those with a low viral load and high CD4 count. Chronic widespread pain is a common comorbidity of HIV infection and is associated with decreased quality of life and a high rate of disability. Chronic pain in people with HIV is multifactorial and influenced by HIV-induced peripheral neuropathy, drug-induced peripheral neuropathy, and chronic inflammation. The specific mechanisms underlying these three broad categories that contribute to chronic widespread pain are not well understood, hindering the development and application of pharmacological and nonpharmacological approaches to mitigate chronic widespread pain. The consequent insufficiencies in clinical approaches to alleviation of chronic pain in people with HIV contribute to an overreliance on opioids and alarming rise in active addiction and overdose. This article reviews the current understanding of the pathogenesis of chronic widespread pain in people with HIV and identifies potential biomarkers and therapeutic targets to mitigate it.

Chronic widespread pain and its associations with quality of life and function at a 20- year follow-up of individuals with chronic knee pain at inclusion

ObjectiveTo study the prevalence of chronic widespread pain (CWP) and chronic regional pain (CRP), and their association to quality of life, pain, physical function at a 20-year follow-up in a population based cohort with chronic knee pain at inclusion.Methods121 individuals (45% women, mean age 64 years, range 54–73) with chronic knee pain from a population-based cohort study, answered a questionnaire and had radiographic knee examination at a 20-year follow-up. The responders were divided into three groups according to reported pain; individuals having no chronic pain (NCP), chronic widespread pain (CWP) and chronic regional pain (CRP). Pain and physical function were assessed using Knee injury and Osteoarthritis Outcome Score (KOOS). Health related quality of life (HRQL) was assessed with Euroqol-5D-3 L (EQ5D) and Short form 36 (SF36). The associations between pain groups and KOOS, EQ5D, and SF36 were analysed by multiple logistic regression, controlled for age, gender and radiographic changes indicating knee osteoarthritis (OA).ResultsThe prevalence of CWP was 30%, and CWP was associated to worse scores in all KOOS subscales, controlled for age, gender and radiographic changes. CWP was also associated to worse scores in EQ-5D and in seven of the SF-36 subgroups, controlled for age, gender and radiographic changes.ConclusionOne third of individuals with chronic knee pain met the criteria for CWP. CWP was associated with patient reported pain, function and HRQL. This suggest that it is important to assess CWP in the evaluation of patients with chronic knee pain, with and without radiographic knee OA.

Chronic Pain And Health-Related Quality Of Life In Women With Autism And/Or ADHD: A Prospective Longitudinal Study.

PurposeTo investigate the prevalence of chronic pain and its association with health-related quality of life (HRQoL) in a group of women, diagnosed with autism spectrum disorder (ASD) and/or attention deficit hyperactive disorder (ADHD) in childhood.Patients and methodsProspective longitudinal 16–19 years follow-up study of 100 Swedish females diagnosed with ASD and/or ADHD in childhood/adolescence. Seventy-seven of the women were included in the current sub-study, using validated measures of pain perception and quality of life.ResultsA large majority of the women (76.6%) reported chronic pain. HRQoL was low overall and lower still for those reporting chronic pain. Women with ADHD who had ongoing treatment with stimulants reported a significant lower prevalence of chronic widespread pain (CWP) than those not treated.ConclusionComorbidity with chronic pain is common in women with ASD and/or ADHD and important to address in the clinic since it is associated with an already low HRQoL. Treatment for ADHD might reduce the pain in some cases.

Risk factors for development and persistence of chronic widespread pain in spondyloarthritis: a population-based two-year follow-up study

Objective: To study chronic widespread pain (CWP) over time in patients with spondyloarthritis (SpA), and to identify risk factors for development and persistence of CWP.Methods: In this cohort study with baseline and 2.5 year follow-up postal surveys, patients with ankylosing spondylitis (AS) and undifferentiated spondyloarthritis (USpA) (47% women) answered questions regarding pain, and were categorized as no chronic pain (NCP), chronic regional pain (CRP), or CWP. For each risk factor candidate (disease duration, body mass index, smoking, and patient-reported outcome measures), logistic regression analyses with CWP as the main outcome were performed separately, together with a basic model including age, gender, and SpA subgroup.Results: Altogether, 644 patients could be categorized at both time-points, yielding similar prevalence estimates at baseline and follow-up, although 38% transitioned between pain groups. Risk factors (odds ratio; 95% confidence interval) for development of CWP included more pain regions (1.36; 1.20‒1.53), higher pain intensity (1.35; 1.20‒1.52), worse fatigue (1.25; 1.13‒1.38), and worse global health (1.35; 1.19‒1.54). Persistent CWP was reported by 72%. In addition to factors predicting development of CWP, higher age (1.02; 1.00‒1.04), female gender (1.82; 1.06‒3.10), and anxiety (1.07; 1.00–1.14) also predicted persistence.Conclusion: The prevalence of CWP remained high over time, but with individual transitions between the pain groups. The development and persistence of CWP were predicted by more pain and worse health, with the addition of female gender and higher age for persistent CWP. Special attention and treatment alternatives for patients with SpA and concomitant CWP are essential in the clinic.

Prevalence of chronic widespread pain in a population-based cohort of patients with spondyloarthritis \u2013 a cross-sectional study

BackgroundChronic pain, regional or widespread, is a frequent and multidimensional symptom in arthritis. There is still limited information on chronic pain in spondyloarthritis, which is important to recognize for adequate diagnosis and treatment. Our objective was to study differences in prevalence of chronic widespread pain in two spondyloarthritis subgroups: ankylosing spondylitis (AS) and undifferentiated spondyloarthritis (USpA).MethodsA population-based postal survey involving questions on the duration, distribution, and intensity of pain was answered by 940 patients with AS (ICD-10 M45.9) or USpA (ICD-10 M46.1-0, M46.8-9). The patients were categorized as having chronic widespread pain, chronic regional pain, or no chronic pain, and prevalence estimates for the pain groups were calculated, including age- and sex-adjusted prevalence.ResultsThe prevalence of chronic widespread pain was 45.3% in AS vs. 49.3% in USpA, and that of chronic regional pain was 17.7% vs. 21.9% (p = 0.033). More women than men reported having chronic widespread pain (54.1% vs. 41.2%, p ≤ 0.001), while the sex distribution for chronic regional pain was equal. Reports of pain intensity were equal in AS and USpA, with no significant difference in pain intensity between women and men who had chronic regional pain or chronic widespread pain. In the multiple logistic regression analysis, chronic widespread pain was associated to female sex, being an ever-smoker, and having a higher body mass index, controlled for SpA subgroup and disease duration.ConclusionsThe prevalence of chronic widespread pain in patients with AS and USpA is high, and with a female predominance, but with no difference in pain intensity between women and men. Chronic pain can complicate the clinical evaluation in patients with SpA, and highlights the need for a thorough clinical examination, including evaluation of inflammation and an accurate pain analysis, to individualize non-pharmacological and pharmacological treatment decisions.

Chronic widespread pain prevalence in the general population: A systematic review.

This systematic review and meta-analysis updates the current global CWP prevalence by examining the population-level (e.g. age, gender) and contextual (e.g. country development status; survey style; reporting and methodologic quality) factors associated with CWP prevalence. This analyses provides evidence to support higher levels of CWP in countries with a lower socioeconomic position relative to countries with a higher socioeconomic position.

Systemic alterations in plasma proteins from women with chronic widespread pain compared to healthy controls: a proteomic study.

Chronic widespread pain (CWP) is a complex pain condition that is difficult to treat. The prevalence of CWP approximates ~10% of the general population, with higher prevalence in women. Lack of understanding of molecular mechanisms has been a challenge for diagnosis and treatment of chronic pain. The aim of this study was to explore the systemic protein changes in CWP compared to those in healthy controls (CON). By applying 2-dimensional gel electrophoresis, we analyzed the protein pattern of plasma samples from women with CWP (n=16) and healthy women (n=23). The proteomic data were analyzed using multivariate statistical models, and altered proteins were identified using mass spectrometry. The proteome analysis was further validated by gel-free Western blot. Multivariate statistical data analysis of quantified proteins revealed 22 altered proteins in women with CWP, compared to CON group. Many of the identified proteins are previously known to be involved in different parts of the complement system and metabolic and inflammatory processes, e.g., complement factor B, vitamin D-binding protein, ceruloplasmin, transthyretin and alpha-2-HS-glycoprotein. These results indicate that important systemic protein differences exist between women with CWP and healthy women. Further, this study illustrates the potential use of proteomics to detect biomarkers that may provide new insights into the molecular mechanism(s) of chronic pain. However, further larger investigations are required in order to confirm these findings before it will be possible to identify proteins as potential pain biomarkers for clinical use.

Is alcohol consumption related to likelihood of reporting chronic widespread pain in people with stable consumption? Results from UK biobank.

Studies have suggested that alcohol consumption is strongly related to reduced reporting of chronic widespread pain (CWP) and level of disability in people with CWP or fibromyalgia. Direction of causality has not been established, that is whether the association is due to people's health influencing their alcohol consumption or vice versa. UK Biobank recruited over 500,000 people aged 40 to 69 years, registered at medical practices nationwide. Participants provided detailed information on health and lifestyle factors including pain and alcohol consumption. Total units consumed per week were calculated for current drinkers. Information was also collected on changes in alcohol consumption and reasons for such changes. Analysis was performed with logistic regression expressed as odds ratios (ORs) with 95% confidence intervals, then adjusted for a large number of potential confounding factors (adjORs). In males who reported drinking the same as 10 years previously, there was a U-shaped relationship between amount drunk and odds of reporting CWP (nondrinkers CWP prevalence 2.4%, 19.1-32.1 units/wk 0.4%, >53.6 units/wk 1.0%; adjORs 2.53 95% confidence intervals [1.78-3.60] vs 1 vs 1.52 [1.05-2.20]). In females, there was a decrease in the proportion reporting CWP up to the modal category of alcohol consumption with no further change in those drinking more (nondrinkers CWP prevalence 3.4%, 6.4-11.2 units/wk 0.7%, >32.1 units/wk 0.7%; adjORs 2.11 [1.67-2.66] vs 1 vs 0.86 [0.54-1.39]). This large study has shown a clear relationship between alcohol consumption and reporting of pain even in people who had not reported changing consumption because of health concerns, after adjustment for potential confounding factors.

All Cause Chronic Widespread Pain is Common in Patients with Symptomatic Peripheral Arterial Disease and is Associated with Reduced Health Related Quality of Life

Invasive treatment of peripheral arterial disease (PAD) does not always lead to improvement, as concomitant diseases might affect walking ability and health related quality of life (HRQoL). Patients with chronic widespread pain (CWP) report worse outcome when treated for cancer and rheumatic diseases. The aim of the present study was to evaluate the prevalence of CWP and its potential association with reduced HRQoL in patients treated for PAD. This was a longitudinal cohort study conducted between May 2011 and April 2014, including patients with planned invasive treatment of symptomatic PAD at two vascular clinics in Sweden. In 240 patients with planned treatment of PAD, HRQoL and pain distribution were assessed using the Short Form 36 Health Survey (SF-36), EuroQoL 5 dimensions (EQ5D), Walking Impairment Questionnaire (WIQ), and a questionnaire concerning musculoskeletal pain (Epipain manikin) before and 12 months after treatment. HRQoL was compared in patients with no chronic pain (NCP), with chronic regional pain (CRP), and with CWP. The SF-36 subscales PF, VT, and MH, representing important aspects of HRQoL (physical function, vitality, and mental health), were the main outcome measures. Before treatment 22 (10%) patients reported NCP, 133 (61%) CRP, and 64 (29%) CWP. These proportions did not differ between patients with intermittent claudication (IC) and critical limb ischemia (CLI, p=.150). CWP was more common in women than in men (36% vs. 24%, p=.035.) HRQoL improved significantly after treatment in all groups, but was still significantly reduced in CWP patients. CWP predicted worse outcome in HRQoL after treatment. CWP is common and is strongly associated with reduced HRQoL in patients with PAD. Treatment led to significant improvement, but patients with CWP still had significantly reduced HRQoL after treatment. CWP measured by a pain manikin should therefore be taken into account when evaluating disease severity, treatment options, and effect of treatment in PAD.

Complexity, comorbidity, and health care costs associated with chronic widespread pain in primary care.

The objective was to estimate the prevalence of chronic widespread pain (CWP) and compare the quality-of-life (QoL), cardiovascular risk factors, comorbidity, complexity, and health costs with the reference population. A multicenter case-control study was conducted at 3 primary care centers in Barcelona between January and December 2012: 3048 randomized patients were evaluated for CWP according to the American College of Rheumatology definition. Questionnaires on pain, QoL, disability, fatigue, anxiety, depression, and sleep quality were administered. Cardiovascular risk and the Charlson index were calculated. We compared the complexity of cases and controls using Clinical Risk Groups, severity and annual direct and indirect health care costs. CWP criteria were found in 168 patients (92.3% women, prevalence 5.51% [95% confidence interval: 4.75%-6.38%]). Patients with CWP had worse QoL (34.2 vs 44.1, P < 0.001), and greater disability (1.04 vs 0.35; P < 0.001), anxiety (43.9% vs 13.3%; P < 0.001), depression (27% vs 5.8%; P < 0.001), sleep disturbances, obesity, sedentary lifestyle, high blood pressure, diabetes mellitus, and number of cardiovascular events (13.1% vs 4.8%; P = 0.028) and higher rates of complexity, severity, hospitalization, and mortality. Costs were &OV0556;3751 per year in patients with CWP vs &OV0556;1397 in controls (P < 0.001). In conclusion, the average patient with CWP has a worse QoL and a greater burden of mental health disorders and cardiovascular risk. The average annual cost associated with CWP is nearly 3 times higher than that of patients without CWP, controlling for other clinical factors. These findings have implications for disease management and budgetary considerations.

Resilience moderates the association between chronic pain and depressive symptoms in the elderly.

Chronic pain is frequent in elderly people and, especially if widespread, associated with poor mental health. We investigated whether a resilient personality protects older adults against the adverse effects of chronic pain. Pain status [no pain, chronic local pain (CLP) and chronic widespread pain (CWP)] was determined using the American College of Rheumatologists' criteria for widespread pain in a cross-sectional sample of 724 participants aged 68-92years drawn from the population-based KORA-Age study in Southern Germany. Depressive symptoms and resilience were assessed via the scales GDS-15 and RS-5. The relation between pain, resilience and depressive symptoms was modelled using logistic and quantile regression. CLP prevalence and CWP prevalence were 57.5% and 12.3%, respectively. Confounder-adjusted logistic regression indicated a fourfold risk of depressed mood (GDS-15≥5) in CWP, vs. no pain (OR=4.08, 95% CI 1.90-8.74). However, in quantile regression, the adverse effect of CWP was significantly attenuated by resilience when looking at the GDS-15 score lower quartile (p=0.011) and median (p=0.011). This effect appeared to be mainly driven by participants aged 75-84years. Confounder adjustment reduced the effect of CLP on depressive symptoms to non-significance, and effect modification by resilience was undetectable in regression models of CLP. Resilience was protective in the association of CWP with depressive symptoms in this analysis. Older adults with CWP may potentially benefit from interventions supporting resilience. Prospective research should investigate the protective role of resilience in the potentially self-perpetuating relation between chronic pain and depressed affect. WHAT DOES THIS STUDY ADD?: The association of chronic widespread pain with depressive symptoms in the elderly population is attenuated by resilience.

A systematic review and meta-analysis of the prevalence of chronic widespread pain in the general population.

Chronic widespread pain (CWP) is common and associated with poor general health. There has been no attempt to derive a robust prevalence estimate of CWP or assess how this is influenced by sociodemographic factors. This study therefore aimed to determine, through a systematic review and meta-analysis, the prevalence of CWP in the adult general population and explore variation in prevalence by age, sex, geographical location, and criteria used to define CWP. MEDLINE, Embase, CINAHL, and AMED were searched using a search strategy combining key words and related database-specific subject terms to identify relevant cohort or cross-sectional studies published since 1990. Included articles were assessed for risk of bias. Prevalence figures for CWP (American College of Rheumatology criteria) were stratified according to geographical location, age, and sex. Potential sources of variation were investigated using subgroup analyses and meta-regression. Twenty-five articles met the eligibility criteria. Estimates for CWP prevalence ranged from 0% to 24%, with most estimates between 10% and 15%. The random-effects pooled prevalence was 10.6% (95% confidence intervals: 8.6-12.9). When only studies at low risk of bias were considered pooled, prevalence increased to 11.8% (95% confidence intervals: 10.3-13.3), with reduced but still high heterogeneity. Prevalence was higher in women and in those aged more than 40 years. There was some limited evidence of geographic variation and cultural differences. One in 10 adults in the general population report chronic widespread pain with possible sociocultural variation. The possibility of cultural differences in pain reporting should be considered in future research and the clinical assessment of painful conditions.

Chronic widespread pain: clinical comorbidities and psychological correlates.

Recent studies have provided consistent evidence for a genetic influence on chronic widespread pain (CWP). The aim of this study was to investigate (1) the etiological structure underlying CWP by examining the covariation between CWP and psychological comorbidities and psychoaffective correlates and (2) the decomposition of the covariation into genetic and environmental components. A total of 3266 female twins (mean age 56.6 years) were subject to multivariate analyses. Using validated questionnaires to classify twins as having CWP, the prevalence of CWP was 20.8%. In the multivariate analysis, the most suitable model was the common pathway model. This model revealed 2 underlying latent variables, one common to anxiety, emotional intelligence, and emotional instability (f1) and the other common to depression and CWP (f2), the latter being highly heritable (86%). Both latent variables (f1 and f2) shared an additive genetic and a nonshared environmental factor. In addition, a second additive genetic factor loading only on f2 was found. This study reveals the structure of genetic and environmental influences of CWP and its psychoaffective correlates. The results show that the clustering of CWP and depression is due to a common, highly heritable, underlying latent trait. In addition, we found evidence that CWP, anxiety, emotional instability, and emotional intelligence are influenced by different underlying latent traits sharing the same genetic and nonshared environmental factors. This is the first study to reveal the structure and relative importance of genetic and environmental influences on complex etiological mechanisms of CWP and its correlates.

Neuropathic pain as part of chronic widespread pain: environmental and genetic influences.

Chronic widespread pain (CWP) has complex aetiology and forms part of the fibromyalgia syndrome. Recent evidence suggests a higher frequency of neuropathic pain features in those with CWP than previously thought. The aim of this study was to determine the prevalence of neuropathic pain features in individuals with CWP and to estimate the influence of genetic and environmental factors on neuropathic pain in CWP. Validated questionnaires (the London Fibromyalgia Screening Study questionnaire and PainDETECT questionnaire) were used to classify twins as having CWP and neuropathic pain, respectively. The prevalence of CWP was 14.7% (n = 4324), and of the 1357 twins invited to complete neuropathic pain screening, 15.9% of those having CWP demonstrated features of neuropathic pain. Neuropathic pain was found to be heritable (A = 37%; 95% confidence interval [CI]: 23%-50%) with unique environmental factors accounting for 63% (95% CI: 49%-79%) of the variance. Heritability of neuropathic pain and CWP were found to be correlated, 0.54 (95% CI: 0.42-0.65). Increasing age, raised body mass index, female gender, and smoking were all risk factors for neuropathic pain (P < 0.05), and CWP (P < 0.05). High socioeconomic status showed negative correlation with neuropathic pain (P = 0.003) and CWP (P = 0.001). Bivariate analysis of the 2 pain traits revealed that genetic predisposition to neuropathic pain is shared with that for CWP. This is the first study to provide formal heritability estimates for neuropathic pain in CWP. The findings suggest that at least some of the genetic factors underlying the development of neuropathic pain and CWP are the same.