Mortality rate and causes of death in women with self-reported musculoskeletal pain: Results from a 17-year follow-up study

Is the relationship between chronic pain and mortality causal? A propensity score analysis

ABSTRACT

Chronic pain is a serious and prevalent condition that can affect many facets of life. However, uncertainty remains regarding the strength of the association between chronic pain and death and whether the association is causal. We investigate the pain-mortality relationship using data from 19,971 participants aged 51+ years in the 1998 wave of the U.S. Health and Retirement Study. Propensity score matching and inverse probability weighting are combined with Cox proportional hazards models to investigate whether exposure to chronic pain (moderate or severe) has a causal effect on mortality over a 20-year follow-up period. Hazard ratios (HRs) with 95% confidence intervals (CIs) are reported. Before adjusting for confounding, we find a strong association between chronic pain and mortality (HR: 1.32, 95% CI: 1.26-1.38). After adjusting for confounding by sociodemographic and health variables using a range of propensity score methods, the estimated increase in mortality hazard caused by pain is more modest (5%-9%) and the results are often also compatible with no causal effect (95% CIs for HRs narrowly contain 1.0). This attenuation highlights the role of confounders of the pain-mortality relationship as potentially modifiable upstream risk factors for mortality. Posing the depressive symptoms variable as a mediator rather than a confounder of the pain-mortality relationship resulted in stronger evidence of a modest causal effect of pain on mortality (eg, HR: 1.08, 95% CI: 1.01-1.15). Future work is required to model exposure-confounder feedback loops and investigate the potentially cumulative causal effect of chronic pain at multiple time points on mortality.

Association of Foot Symptoms With Decreased Time to All-Cause Mortality: The Johnston County Osteoarthritis Project

OBJECTIVE

Adults with foot symptoms (ie, pain, aching, or stiffness) may be at increased risk of reduced time to all-cause mortality. The purpose of this study was to evaluate whether foot symptoms are independently associated with all-cause mortality in older adults.

METHODS

We analyzed longitudinal data from 2613 participants from the Johnston County Osteoarthritis Project, a longitudinal population-based cohort of adults 45 years of age and older. Participants completed questionnaires at baseline to determine presence of foot symptoms and covariable status. Baseline walking speed was measured via an 8-foot walk test. To examine the association of foot symptoms with time to mortality, hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox regression models, adjusted for potential confounders.

RESULTS

We observed 813 deaths over 4 to 14.5 years of follow-up. At baseline, 37% of participants had foot symptoms, mean age was 63 years, mean body mass index was approximately 31 kg/m2 , 65% were women, and 33% were Black. Moderate to severe foot symptoms were associated with reduced time to mortality after adjustment for demographics, comorbidities, physical activity, and knee and hip symptoms (HR = 1.30, 95% CI 1.09-1.54). Importantly, this association was not modified by walking speed or diabetes.

CONCLUSION

Individuals with foot symptoms had an increased hazard of all-cause mortality compared with those with no foot symptoms. These effects were independent of key confounders and were not moderated by walking speed. Effective interventions to identify and manage at least moderate foot symptoms may reduce the risk of decreased time to mortality.

Worse health‐related quality of life, impaired functioning and psychiatric comorbidities are associated with excess mortality in patients with severe chronic pain

Background

Severe chronic pain that interferes with daily activities is associated with an increased risk of mortality. We assessed the overall mortality of tertiary chronic pain patients in comparison with the general population, with a special aim to analyse the association of health‐related quality of life (HRQoL) and its dimensions with the risk of death.

Methods

In this prospective observational follow‐up study, patients with non‐cancer chronic pain attended an outpatient multidisciplinary pain management (MPM) episode in a tertiary pain clinic in 2004–2012 and were followed until May 2019. Mortality between the patients and the general population was compared with standardized mortality ratios (SMR) in different age groups. Causes of death and comorbidities were compared among the deceased. Association of mortality and HRQoL and its dimensions, measured with the 15D instrument, was studied with Cox proportional hazards model.

Results

During a mean of 10.4‐year follow‐up of 1498 patients, 296 died. The SMR in the youngest age group (18–49 years) was significantly higher than that of the general population: 2.6 for males and 2.9 for females. Even elderly females (60–69 years) had elevated mortality (SMR 2.3). Low baseline HRQoL at the time of MPM, as well as poor ratings in the psychosocial dimensions of HRQoL, was associated with an increased risk of death.

Conclusions

Our results support the role of HRQoL measurement by a validated instrument such as the 15D in capturing both the physical and the psychological symptom burden, and consequently, an elevated risk of death, in patients with chronic pain.

Significance

Severe chronic pain is associated with elevated mortality. In patients in chronic pain under 50 years old, the mortality was 2.5–3 times higher than in the general population. Psychological distress appears to contribute to the increased mortality. Regular follow‐up by health‐related quality of life (HRQoL) measurement could be useful in identifying patients in chronic pain who are in need of intensive symptom management and to prevent early death.

Pain and mortality among older adults in Korea

OBJECTIVES

With the increasing elderly population with chronic disease, understanding pain and designing appropriate policy interventions to it have become crucial. While pain is a noted mortality risk factor, limited studies exist due to the various causes of pain and the subjectivity of pain expression. This study aimed to examine the relationship between pain and mortality, controlling for other diseases and socio-cultural factors.

METHODS

We analyzed 6,258 individuals aged 45 years or older, the population with the highest prevalence of pain, using the Korean Longitudinal Study of Aging (2006-2016) data and the Cox proportional-hazards model. Further subgroup analyses were conducted by sex and education level to examine differences in the relationship between pain and mortality.

RESULTS

The adjusted hazard ratios of mortality were 1.16 (95% confidence interval [CI], 1.00 to 1.34, model 1) and 1.12 (95% CI, 0.97 to 1.29, model 2) for the individuals in pain depending on the models used, where additional socio-cultural factors were accounted for in model 2. For individuals in severe pain, ratios were significantly higher with 1.23 (95% CI, 1.08 to 1.41, model 1) and 1.16 (95% CI, 1.02 to 1.32, model 2). Further subgroup analyses showed that severe pain was more associated with mortality for males and more educated individuals, with adjusted hazard ratios of 1.29 (95% CI, 1.08 to 1.55, model 2) and 1.62 (95% CI, 1.15 to 2.28, model 2), respectively.

CONCLUSIONS

Pain showed a statistically significant relationship with mortality risk. Family members or medical staff should pay proper attention to pain, particularly severe pain in males and highly educated individuals.

Pain Characteristics, Cardiovascular Risk Factors, and Cardiovascular Disease

BACKGROUND

There is unclear evidence that chronic pain may increase the risk of cardiovascular disease (CVD) incidence and mortality. This work evaluated the association between chronic pain, incidence of CVD and changes in CVD risk factors.

METHODS

Cohort of 1091 community-dwelling individuals ≥60years, free from CVD at baseline, followed up for 6 years. Data on psychosocial factors and CVD risk factors was obtained through validated questionnaires and laboratory measurements. A pain scale ranging from 0 (no pain) to 6 (worst pain) was created according to pain frequency, location and intensity.

RESULTS

The cumulative incidence of CVD was 4.2% at 3 years, and 7.7% at 5-years of follow-up. Compared to individuals without pain in the first 3 years (2012-2015), those with maintained scores ≥2 showed a mean reduction of 3.57 (-5.77,-1.37) METs-h/week in recreational physical activity; a 0.38-point (0.04,0.73) increase in psychological distress; and a 1.79 (1.03,3.11) higher odds of poor sleep. These associations held in the second follow-up period, when individuals with maintained pain also worsened their diet quality. A 1-point increase in the pain scale in 2012 was associated with a 1.21 (1.03,1.42) and 1.18 (0.97,1.44) increased CVD incidence in 2015 and 2017, respectively; none of the studied factors mediated this relationship.

CONCLUSIONS

Older adults with chronic pain show important reductions in recreational physical activity and deterioration in mental health, sleep and diet quality, which may well aggravate pain. Future studies should evaluate whether these factors mediate the increased risk of CVD observed in older adults with chronic pain.

The effect of the anti-diabetic drug metformin on musculoskeletal pain: A cross-sectional study with 21,889 individuals from the UK biobank

BACKGROUND

Although there is growing evidence of metformin's pleiotropic effects, including possible effects on pain, there is a lack of studies investigating the association of metformin with the prevalence of musculoskeletal pain among a large cohort with type 2 diabetes cohort.

METHODS

Cross-sectional analyses were conducted with UK Biobank data from 21,889 participants with type 2 diabetes. Type 2 diabetes, metformin use and musculoskeletal (back, knee, hip and neck/shoulder) pain were self-reported. Participants reported musculoskeletal pain that had interfered with their usual activities in the last month (recent pain), and for more than 3 months (chronic pain). We performed logistic regression analyses for recent and chronic pain for each site and for multisite pain among participants with diabetes who did or did not take metformin.

RESULTS

Participants using metformin had lower odds of musculoskeletal pain for back [recent OR 0.91, 95%CI 0.85 to 0.97; chronic OR 0.87, 95%CI 0.81 to 0.93], knee [recent OR 0.91, 95%CI 0.85 to 0.97; chronic OR 0.87, 95%CI 0.81 to 0.94] and neck/shoulder regions [chronic OR 0.92, 95%CI 0.85 to 0.99] but not hip pain. Participants using metformin also had lower odds of reporting chronic multisite musculoskeletal pain. The associations were generally stronger among women.

CONCLUSIONS

People with diabetes taking metformin were less likely to report back, knee, neck/shoulder and multisite musculoskeletal pain than those not taking metformin. Therefore, when treating these patients, clinicians should be aware that metformin may contribute to fewer reports of musculoskeletal pain. These effects should be investigated in future studies.

SIGNIFICANCE

People with type 2 diabetes taking metformin are less likely to present with musculoskeletal pain than those not taking metformin. Metformin may have a protective effect for musculoskeletal pain, which appears to be stronger among women than men.

Mortality among persons experiencing musculoskeletal pain: a prospective study among Danish men and women

Background

Musculoskeletal (MSK) pain affects many people worldwide and has a great impact on general health and quality of life. However, the relationship between MSK pain and mortality is not clear. This study aimed to investigate all-cause and cause-specific mortality in relation to self-reported MSK pain within the last 14 days, including spread of pain and pain intensity.

Methods

This prospective cohort study included a representative cohort of 4806 men and women aged 16+ years, who participated in a Danish MSK survey 1990–1991. The survey comprised questions on MSK pain, including spread of pain and pain intensity. These data were linked with the Danish Register of Causes of Death to obtain information on cause of death. Mean follow-up was 19.1 years. Cox regression analyses were performed with adjustment for potential confounders.

Results

In the study population (mean age 44.5 years; 47.9% men), 41.0% had experienced MSK pain within the last 14 days and 1372 persons died during follow-up. For both sexes, increased all-cause mortality with higher spread and intensity of MSK pain was observed; a high risk was observed especially for men with strong pain (HR = 1.66; 95% CI:1.09–2.53) and women with widespread pain (HR = 1.49; 95% CI:1.16–1.92). MSK pain within last 14 days yielded c-statistics of 0.544 and 0.887 with age added. Moreover, persons with strong MSK pain had an increased cardiovascular mortality, persons with moderate pain and pain in two areas had an increased risk of cancer mortality, and persons with widespread pain had an increased risk of respiratory mortality.

Conclusions

Overall, persons experiencing MSK pain had a higher risk of mortality. The increased mortality was not accounted for by potential confounders. However, when evaluating these results, it is important to take the possibility of unmeasured confounders into account as we had no information on e.g. BMI etc.

Significance

The present study provides new insights into the long-term consequences of MSK pain. However, the discriminatory accuracy of MSK pain was low, which indicates that this information cannot stand alone when predicting mortality risk.

Hip symptoms are associated with premature mortality: the Johnston County Osteoarthritis Project

OBJECTIVE

To investigate the impact of hip osteoarthritis (OA) and/or hip symptoms on excess mortality.

DESIGN

We analyzed data from 3,919 individuals in a community-based prospective cohort of African Americans and Caucasians age ≥45 years. Women ≥50 years of age and all men underwent supine anteroposterior pelvic radiography at baseline, with the participant's feet in 15 degrees of internal rotation. Hip radiographic (rOA) was defined as a Kellgren-Lawrence grade of ≥2 in at least one hip. Participants completed questionnaires at baseline to determine presence of hip symptoms and covariate status. Participants with symptomatic hip rOA (SxOA) are a subset of individuals with hip rOA and symptoms in the same hip. Multiple imputation was used to impute missing values of covariates. Mortality was determined through 2015 and follow-up time was calculated from baseline assessment until death or censoring which took place when a participant was lost to follow-up or reached the end of study period. Cox proportional hazards regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI). We carried out additional analyses stratified by sex, race, age and obesity.

RESULTS

Mean follow-up time was 14.2 years during which 1762 deaths occurred. There were 29.9% participants in our population with hip rOA at baseline. Compared to those with neither hip rOA nor hip symptoms, we observed an increased risk of all-cause mortality in participants with hip symptoms alone (HR = 1.28, 95% CI = 1.13-1.46), but no association for hip rOA either with or without symptoms. In stratified analyses we observed increased associations for hip symptoms alone and hip sxOA in those <65 years (43% and 39% increase, respectively) and in Caucasians (34% and 21% increase, respectively).

CONCLUSIONS

Individuals who had hip symptoms without hip rOA had an increased risk of mortality. These effects were particularly strong for those who were <65 years of age and Caucasians. Effective interventions to identify those with hip pain in order to lessen it could reduce premature mortality.

All-cause and cause-specific mortality in persons with fibromyalgia and widespread pain: An observational study in 35,248 persons with rheumatoid arthritis, non-inflammatory rheumatic disorders and clinical fibromyalgia

PURPOSE

Studies of the relation of fibromyalgia (FM) and widespread pain (WSP) to mortality have differed as to the presence or absence of an association and the extent of cause-specific mortality. However, no studies have investigated which definitions of FM and WSP associate with mortality, nor of FM mortality in other diseases. We investigated these issues and the meaning of mortality in patients with FM.

METHODS

We used Cox regression to study 35,248 rheumatic disease patients with up to 16 years of mortality follow-up in all patients and separately in those with diagnoses of rheumatoid arthritis (RA) (N = 26,458), non-inflammatory rheumatic disorders (NIRMD) (N = 5,167) and clinically diagnosed FM (N = 3,659). We applied 2016 FM criteria and other FM and WSP criteria to models adjusted for age and sex as well as to models that included a full range of covariates, including comorbid disease and functional status. We estimated the degree of explained of variance (R2) as a measure of predictive ability.

RESULTS

We found positive associations between al`l definitions of FM and WSP and all-cause mortality, with relative risks (RR)s ranging from 1.19 (95%CI 1.15-1.24) for American College of Rheumatology (ACR) 1990 WSP to 1.38 (1.31-1.46) in age and sex adjusted revised 2016 criteria (FM 2016). However, in full covariate models the FM 2016 RR reduced further to 1.15 (1.09-1.22). The association with mortality was noted with RA (1.52 (1.43-1.61)), NIRMD (1.43 (1.24-1.66)) and clinical FM (1.41 (1.14-1.75) - where 37% of FM diagnosed patients did not satisfy FM 2016 criteria. In the all-patient analyses, the age and sex explained variation (R2) was 0.255, increasing to 0.264 (4.4%) when FM 2016 criteria were added, and to 0.378 in a full covariate model. Death causes related to FM 2016 status included accidents, 1.45 (1.11-1.91); diabetes 1.78 (1.16-2,71); suicide, 3.01 (1.55-5.84) and hypertensive related disorders, 3.01 (1.55-5.84). Cancer deaths were less common 0.77 (0.68-0.88).

CONCLUSIONS

FM is weakly associated with mortality within all criteria definitions of FM and WSP examined (3.4% of explained variance), and across all diseases (RA, NIRMD, clinical FM) equally. Clinical and criteria-defined FM had different mortality outcomes. We found no evidence for a positive association of cancer and FM or WSP.

Does symptomatic knee osteoarthritis increase the risk of all-cause mortality? Data from four international population-based longitudinal surveys of aging

OBJECTIVE

This study aimed at examining the association between symptomatic knee osteoarthritis and all-cause mortality based on four population-based longitudinal surveys.

METHOD

Data were retrieved from the English Longitudinal Study of Aging (ELSA), the Survey of Health, Aging and Retirement in Europe (SHARE), the Korean Longitudinal Study of Aging (KLoSA), and the Indonesian Family Life Survey (IFLS). The association between symptomatic knee osteoarthritis and all-cause mortality over the 8- to 12-year follow-up period was assessed using Cox-proportional hazard models.

RESULTS

In the entire sample of 59,522 participants (4823 with symptomatic knee osteoarthritis; 54,699 without symptomatic knee osteoarthritis [control group]; mean age: 61.8 years; female percentage: 55.3%), 8375 died (937 in the symptomatic knee osteoarthritis group, 7438 in the control group) during the follow-up period. Patients with symptomatic knee osteoarthritis had a higher risk of all-cause mortality than control group without adjusting for potential confounders in each survey, and the unadjusted hazard ratios (HRs) of all-cause mortality were 1.32 (95% confidence interval [CI] 1.18 to 1.47) in ELSA, 1.40 (95%CI 1.24 to 1.56) in SHARE, 1.25 (95%CI 1.06 to 1.47) in KLoSA, and 1.65 (95%CI 1.31 to 2.07) in IFLS. However, with adjustment of potential confounders, the corresponding HRs dropped to 1.07 (95%CI 0.94 to 1.20) in ELSA, 1.08 (95%CI 0.97 to 1.22) in SHARE, 0.91 (95%CI 0.77 to 1.08) in KLoSA, and 0.89 (95%CI 0.66 to 1.21) in IFLS, respectively.

CONCLUSIONS

In these four population-based longitudinal studies, no association between symptomatic knee osteoarthritis and increased risk of all-cause mortality was observed after adjusting for potential confounders. Key Points • This study evaluated the association between symptomatic knee OA and the risk of all-cause mortality among the participants retrieved from four large population-based longitudinal studies across the world. • No association between symptomatic knee osteoarthritis and increased risk of all-cause mortality was observed after considering potential confounders, and our findings were consistent with the results derived from four independent longitudinal studies. • The present study included four international population-based longitudinal studies, comprising both developed and developing areas, which allowed the findings to be interpreted under larger circumstance.

Do incident musculoskeletal complaints influence mortality? The Nord-Trøndelag Health study

Background

Musculoskeletal complaints (MSC) are common in the general population, causing a major disease burden to the individual and society. The association between MSC and mortality is still unclear. To our knowledge, no study has hitherto evaluated the association between MSC onset within the last month (incident MSC) on the one hand, and all-cause and cause-specific mortality on the other.

Methods

This prospective population-based cohort study was done using data from the second Nord-Trøndelag Health Study (HUNT2) linked with data from a comprehensive national registry of cause of death. A total of 25,931 participants at risk for incident MSC were included. Hazard ratios (HR) of mortality were estimated for participants with incident MSC using Cox regression based on a mean of 14.1 years of follow-up.

Results

Participants who reported incident MSC did not have an excess mortality compared to those with no MSC in the analyses of all-cause mortality (HR 0.99, 95% CI 0.89–1.10) and cause specific mortality. This was true also after adjustment for several potential confounding factors. No clear association between the number of MSC body sites and mortality was found.

Conclusion

Incident MSC were not associated with an increased mortality, neither for all-cause mortality, nor cause-specific mortality.

Cause-specific mortality of patients with severe chronic pain referred to a multidisciplinary pain clinic: a cohort register-linkage study

Background and aims

Almost 20% of the adult population suffers from chronic pain. Chronic pain may be linked to an elevated mortality; however, results from previous studies are inconsistent. Some studies find similar mortality levels in chronic pain patients and pain-free controls while other studies show elevated mortality levels among chronic pain patients, primarily with respect to cancer, diseases of the circulatory and respiratory systems, and suicide. These conflicting results are potentially due to different population samples and different operational definitions of chronic pain. Further research on overall and cause-specific mortality in patients with severe chronic pain is needed to inform clinical practice. The objective of this register-linkage study was to investigate whether patients with severe chronic pain referred to multidisciplinary pain treatment have higher cause-specific mortality rates than the general population.

Methods

In this register-linkage cohort study, data from 6,142 chronic pain patients (female: n=3,941, male: n=2,201, mean age: 48.2±14.2; range: 16–97 years) attending an interdisciplinary Pain Center in Odense, Denmark from 2005 to 2014 were linked to the Danish Register of Causes of Death. Age and gender standardized mortality ratios (SMRs) with their 95% confidence intervals (CI) were calculated and compared with those of the general population. Data from the general population was extracted from the Danish Register of Causes of Death, and Causes of death were classified according to national Classification of Disease (ICD-10).

Results

In all, 276 deaths (women: n=152, men: n=124) were observed among the chronic pain patients, and a six-fold higher overall mortality rate was found [SMR: 6.2 (95% CI: 5.5–7.0)] compared with the general population. Elevated cause-specific mortality rates were noted for chronic patients with respect to cancer and neoplasms [4.7 (95% CI: 3.7–5.9)], diseases of the circulatory system [5.7 (95% CI: 4.3–7.3)], diseases of the respiratory system [8.7 (95% CI: 6.2–11.9)], and suicide [7.3 (95% CI: 2.7–15.9)].

Conclusions

The overall mortality rate of patients with severe chronic pain in this study was six-fold higher than the rate of the general population in this region. This was reflected in select specific causes of death (cancer and neoplasms, diseases of the circulatory system, diseases of the respiratory system, and suicide). The results are in agreement with previous studies and emphasize the need to understand which factors causally affect this increased mortality allowing for targeted interventions in similar chronic pain populations.

Implications

Potential reasons for the excess mortality should be adequately addressed by future studies in order to better target this in the management of these patients. The chronic pain population included in this study may have several comorbidities contributing to the increased mortality. To better address these aspects, complete medical profiles are needed in future studies. In addition, implementation of management strategies towards potential risk factors such as poor diet, low levels of physical activity, smoking, and high BMI as well as sleep deprivation and morphine use previously shown associated with having pain may reduce the excess mortality ratio.

Identifying characteristics of the most severely impaired chronic pain patients treated at a specialized inpatient pain clinic

BACKGROUND AND AIMS

Patients suffering from chronic nonmalignant pain constitute a heterogeneous population in terms of clinical presentation and treatment results. Few data are available about what distinguishes different groups in this huge population of patients with chronic persistent pain (CPP). A subgroup that is poorly studied, consists of the most severely impaired chronic pain patients. At the Uppsala University Hospital Pain Clinic, there is a specialized department accepting the most complex patients for rehabilitation. In the endeavour to improve and evaluate treatment for this subgroup, a better understanding of the complex nature of the illness is essential. This prospective study aimed to describe the characteristics of this subgroup of patients with CPP.

METHODS

Seventy-two consecutive patients enrolled in the Uppsala programme were evaluated. We collected data on demographics, type of pain and experienced symptoms other than pain using a checklist of 41 possible symptoms. Psychiatric comorbidity was assessed by a psychiatrist using a structured clinical interview. Quality of life (QoL), pain rating and medication/drug/alcohol usage were measured by validated questionnaires: SF-36, NRS, DUDIT and AUDIT. Concerning physical functioning and sick leave, a comparison was made with data from the Swedish Quality Register Registry for pain rehabilitation (SQRP).

RESULTS

The cohort consisted of 61% women and the average age was 45 (range 20-70) years. For this cohort, 74% reported being on sick leave or disability-pension. In the SQRP 59% were on sick leave at the time they entered the rehabilitation programmes [1]. On average, the study-population reported 22 symptoms other than pain, to be at a high rate of severity. Patients treated in conventional pain-rehabilitation programmes reported a mean of 10 symptoms in average. Symptoms reported with the highest frequency (>80%), were lethargy, tiredness, headache and difficulties concentrating. Seventy-six percent were diagnosed with a psychiatric disorder. Sixty-nine fulfilled the criteria for depression or depression/anxiety disorder despite that most (65%) were treated with psychotropic medication. Alcohol/drug abuse was minimal. Seventy-one percent were on opioids but the doses were moderate (<100mg) MEq. The pain rating was ≥7 (out of a maximum of 10) for 60% of the patients.

CONCLUSION

This study describes what makes the subgroup of pain patients most affected by their pain special according to associated factors and comorbidity We found that they were distinguished by a high degree of psychiatric comorbidity, low physical functioning and extreme levels of symptom preoccupation/hypervigilance. Many severe symptoms additional to pain (e.g. depression/anxiety, tiredness, disturbed sleep, lack of concentration, constipation) were reported. The group seems hypervigilant, overwhelmed with a multitude of different symptoms on a high severity level.

IMPLICATIONS

When treating this complex group, the expressions of the illness can act as obstacles to achieve successful treatment outcomes. The study provides evidence based information, for a better understanding of the needs concerning these pain patients. Our result indicates that parallel assessment and treatment of psychiatric comorbidities and sleep disorders combined with traditional rehabilitation, i.e. physical activation and cognitive reorganization are imperative for improved outcomes.

Persons with chronic widespread pain experience excess mortality: longitudinal results from UK Biobank and meta-analysis

Objective

It is uncertain whether persons with chronic widespread pain (CWP) experience premature mortality. Using the largest study conducted, we determine whether such a relationship exists, estimate its magnitude and establish what factors mediate any relationship.

Methods

UK Biobank, a cohort study of 0.5 million people aged 40–69 years, recruited throughout Great Britain in 2006–2010. Participants reporting ‘pain all over the body’ for >3 months were compared with persons without chronic pain. Information on death (with cause) was available until mid-2015. We incorporated these results in a meta-analysis with other published reports to calculate a pooled estimate of excess risk.

Results

7130 participants reported CWP and they experienced excess mortality (mortality risk ratio 2.43, 95%CI 2.17 to 2.72). Specific causes of death in excess were cancer (1.73adjusted age and sex, 95% CI 1.46 to 2.05), cardiovascular (3.24adjusted age and sex, 95% CI 2.55 to 4.11), respiratory (5.66adjusted age and sex, 95% CI 4.00 to 8.03) and other disease-related causes (4.04adjusted age and sex, 95% CI 3.05 to 5.34). Excess risk was substantially reduced after adjustment for low levels of physical activity, high body mass index, poor quality diet and smoking. In meta-analysis, all studies showed significant excess all-cause (combined estimate 1.59 (95% CI 1.05 to 2.42)), cardiovascular and cancer mortality.

Conclusions

Evidence is now clear that persons with CWP experience excess mortality. UK Biobank results considerably reduce uncertainty around the magnitude of excess risk and are consistent with the excess being explained by adverse lifestyle factors, which could be targeted in the management of such patients.

The Mortality Associated With Chronic Widespread Musculoskeletal Complaints: A Systematic Review of the Literature

BACKGROUND

Chronic widespread musculoskeletal complaints (CWMSC) are a prevalent condition with a large impact on quality of life and with a large burden on society. Studies investigating the relationship between CWMSC and mortality have yielded inconsistent results. The present study aimed to clarify this relationship through a systematic review of the existing literature, including meta-analyses, to estimate pooled results and heterogeneity.

METHODS

The MEDLINE, EMBASE and Science Citation Index Expanded databases were searched in February 2016. Broad search terms were used to identify as many observational studies as possible that investigated the association between CWMSC and mortality. The identified studies were evaluated according to predetermined inclusion criteria.

RESULTS

Six studies fulfilled the inclusion criteria. In pooled unadjusted analyses of three studies evaluating CWMSC, a non-significant tendency of increased overall mortality was found [mortality risk ratio (MRR) 1.69, 95% confidence interval (CI) 0.91-3.14]. However, in pooled analyses of all six studies reporting adjusted results, the non-significant tendency for higher mortality rates in those with CWMSC was nearly eliminated (MRR 1.13, 95% CI 0.95-1.34). Heterogeneity between studies was moderate to high, particularly regarding the use of confounding factors.

CONCLUSIONS

In this systematic review, based on a limited number of studies, pooled data gave no evidence of a higher mortality rate among individuals with CWMSC. The non-significant tendency for a higher mortality rate in unadjusted pooled analyses was nearly eliminated in the adjusted pooled analyses, considering lifestyle factors such as physical activity smoking. In population-based studies evaluating the relationship between CWMSC and mortality rates, we recommend that both unadjusted and adjusted analyses should be presented. Copyright © 2016 John Wiley & Sons, Ltd.

Knee Pain and Structural Damage as Risk Factors for Incident Widespread Pain: Data From the Multicenter Osteoarthritis Study

OBJECTIVE

To examine the longitudinal relationship of knee pain, radiographic osteoarthritis (OA), symptomatic knee OA, and knee pain severity to incident widespread pain.

METHODS

The Multicenter Osteoarthritis Study is a longitudinal cohort of persons with or at risk of knee OA. Participants were characterized as having consistent frequent knee pain, radiographic OA (Kellgren/Lawrence scale grade ≥2), symptomatic OA, and knee pain severity at the 60-month visit (baseline). Widespread pain was categorized as pain above and below the waist, on both sides of the body and axially, using a standard homunculus, excluding knee pain. Incident widespread pain was defined as the presence of widespread pain at 84 months in those who were free of widespread pain at baseline. We assessed the relationship of baseline radiographic OA, symptomatic OA, consistent frequent knee pain, and knee pain severity, respectively, with incident widespread pain using logistic regression, adjusting for potential confounders, including models with and without pain severity.

RESULTS

At baseline, 1,129 subjects were eligible for analysis (mean ± SD age 66.7 ± 7.8 years; mean ± SD body mass index 30.1 ± 5.8 kg/m² ; 52% women). Radiographic OA in either knee (adjusted odds ratio [OR_adj ] 0.90 [95% confidence interval (95% CI) 0.63-1.30]; P = 0.587) was not associated with incident widespread pain. Baseline bilateral consistent frequent knee pain (OR_adj 2.35 [95% CI 1.37-4.03]), bilateral symptomatic OA (OR_adj 2.11 [95% CI 1.04-4.24]), and knee pain severity (worst knee) (OR_adj 1.11 [95% CI 1.05-1.17]; P < 0.001) were significantly associated with incident widespread pain.

CONCLUSION

Consistent frequent knee pain, symptomatic OA, and knee pain severity increased the risk of developing widespread pain, independently of structural pathology. These results suggest that knee pain, and not structural pathology, contributes to the onset of widespread pain.

The Effect of Widespread Pain on Knee Pain Worsening, Incident Knee Osteoarthritis (OA), and Incident Knee Pain: The Multicenter OA (MOST) Study

OBJECTIVE

Whether widespread pain (WSP) affects the risk of developing knee pain or knee osteoarthritis (OA) is unknown and could enhance understanding of pain mechanisms in OA.

METHODS

Subjects from the Multicenter OA (MOST) study, a US National Institutes of Health-funded prospective cohort of older adults with or at risk of knee OA, were characterized regarding WSP, defined as pain above and below the waist on both sides of the body and axially using a standard homunculus, excluding knee pain at 60 months (baseline). Followup occurred 2 years later. We assessed the relation of WSP to odds of knee pain worsening (≥ 2-point increase in the Western Ontario and McMaster Universities Arthritis Index pain subscale) using logistic regression, and to odds of incident radiographic knee OA (ROA; Kellgren-Lawrence arthritis scale ≥ grade 2 of either knee among those free of ROA at baseline) and incident consistent frequent knee pain (CFKP; knee pain on most days during the past month among participants free of knee pain at baseline) in 1 or both knees using multinomial regression adjusting for potential confounders.

RESULTS

There were 1752 participants available for analysis [mean age (SD) 67.0 yrs (7.7), body mass index 30.5 kg/m2 (5.9), 59% women]. Baseline presence of WSP was not associated with worsened knee pain (adjusted OR 1.15, 95% CI 0.89-1.48, p = 0.30), ROA (adjusted OR 0.86, 95% CI 0.46-1.63, p = 0.65), or incident CFKP (adjusted OR 1.69, 95% CI 0.96-2.96, p = 0.07).

CONCLUSION

WSP was not significantly associated with worsening knee pain, incident ROA, or CFKP. Development of knee pain and ROA does not appear to be influenced by underlying WSP.

Musculoskeletal Complaints (Pain and/or Stiffness) and Their Impact on Mortality in the General Population. The Tromsø Study

Background

The long-term consequences of chronic pain and/or stiffness from the musculoskeletal system (musculoskeletal complaints: MSCs) have not been well explored. The aims of this study were to investigate whether MSCs reported at baseline influence all-cause and cause-specific mortality during 21 years follow-up of a general Northern Norwegian adult population.

Methods

A total of 26,977 men and women aged 25–97 years who participated in the 1994–1995 survey of the Tromsø study (response rate 77%) were included in the present prospective cohort study. Baseline data were collected from the 1994–1995 survey and information on death and emigration was taken from the National Register of Norway. Cox regression analyses were performed to examine if MSCs predicted risk of mortality.

Results

5693 (21.1%) participants died during follow-up. Mean time between entry into the survey and death or emigration was 18.6 years (standard deviation 4.87) for all-cause mortality. There was an increased risk of death among those with MSCs at baseline in the crude Cox regression model. However, the multivariable model revealed no significant association between MSCs at baseline and all-cause mortality by sex (women: hazard ratio [HR] = 0.93, 95% confidence interval [CI]: 0.85–1.01; men: HR = 0.93, 95%CI: 0.85–1.01). Furthermore, no significant associations were found between widespread MSCs at baseline and all-cause mortality in multivariable models (women: HR = 0.90, 95%CI: 0.80–1.01; men HR = 0.87, 95%CI: 0.76–1.00). Analyses on cause-specific mortality did not reveal any significant results.

Conclusion

MSCs are not independently associated with increased risk of death from cardiovascular disease, cancer, or death from all causes.

The risk of suicide mortality in chronic pain patients

Chronic pain has long been considered an important risk factor for suicidal behavior. Less well understood are the factors associated with the increased risk for suicide death within chronic pain populations. The purpose of this review is to examine recent research with regard to rates of and risk factors for suicide mortality in patients with chronic musculoskeletal pain. We conclude that patients with a number of chronic pain states are at increased risk for suicide death, and that this risk appears to be due, at least in part, to other well-known correlates of pain such as depression and substance use disorders. However, in all likelihood, there are aspects of chronic pain itself that add uniquely to an individual's suicide risk profile. Lastly, we address a theoretical perspective and offer recommendations for clinical practice.

TRPV1 pain receptors regulate longevity and metabolism by neuropeptide signaling

The sensation of pain is associated with increased mortality, but it is unknown whether pain perception can directly affect aging. We find that mice lacking TRPV1 pain receptors are long-lived, displaying a youthful metabolic profile at old age. Loss of TRPV1 inactivates a calcium-signaling cascade that ends in the nuclear exclusion of the CREB-regulated transcriptional coactivator CRTC1 within pain sensory neurons originating from the spinal cord. In long-lived TRPV1 knockout mice, CRTC1 nuclear exclusion decreases production of the neuropeptide CGRP from sensory endings innervating the pancreatic islets, subsequently promoting insulin secretion and metabolic health. In contrast, CGRP homeostasis is disrupted with age in wild-type mice, resulting in metabolic decline. We show that pharmacologic inactivation of CGRP receptors in old wild-type animals can restore metabolic health. These data suggest that ablation of select pain sensory receptors or the inhibition of CGRP are associated with increased metabolic health and control longevity.