Association between musculoskeletal pain at multiple sites and objectively measured physical activity and work capacity: Results from UK Biobank study

Association between leisure-time physical activity and musculoskeletal pain before and during the COVID-19 pandemic in working adults

BACKGROUND

The COVID-19 pandemic had major impacts on the physical lives of individuals, especially on home office workers. In this way, the practice of physical activity has been identified as an ally in the reduction and prevention of musculoskeletal pain.

OBJECTIVE

To investigate the association between leisure-time physical activity and musculoskeletal pain in adult workers before and during the COVID-19 pandemic.

METHODS

A cross-sectional study was conducted with 374 workers of both sexes (age = 46.5±10.5 years). Leisure-time physical activity, number of pain sites, and musculoskeletal pain status were investigated using a questionnaire designed for the study. Statistical analysis was performed using Multinomial Logistic Regression. The significance level adopted was 5%.

RESULTS

A significant association was found between physical activity status and the number of pain sites (p = 0.002). In addition, an inverse association was found between physical activity before and during the quarantine and the number of pain sites (two pain sites - OR = 0.40; 95% CI = 0.2-0.7; three or more pain sites - OR = 0.24; 95% CI = 0.1-0.5). Physical activity interruption during quarantine increased pain perception by 2.86 times (OR = 2.86; 95% CI = 1.0-7.5).

CONCLUSIONS

The findings showed that physical activity before and during the pandemic was a protective factor for body pain during the COVID-19 pandemic.

Deciphering nociplastic pain: clinical features, risk factors and potential mechanisms

Nociplastic pain is a mechanistic term used to describe pain that arises or is sustained by altered nociception, despite the absence of tissue damage. Although nociplastic pain has distinct pathophysiology from nociceptive and neuropathic pain, these pain mechanisms often coincide within individuals, which contributes to the intractability of chronic pain. Key symptoms of nociplastic pain include pain in multiple body regions, fatigue, sleep disturbances, cognitive dysfunction, depression and anxiety. Individuals with nociplastic pain are often diffusely tender - indicative of hyperalgesia and/or allodynia - and are often more sensitive than others to non-painful sensory stimuli such as lights, odours and noises. This Review summarizes the risk factors, clinical presentation and treatment of nociplastic pain, and describes how alterations in brain function and structure, immune processing and peripheral factors might contribute to the nociplastic pain phenotype. This article concludes with a discussion of two proposed subtypes of nociplastic pain that reflect distinct neurobiological features and treatment responsivity.

The Relationships Among Chronic Pain Subtypes, Motor Function, and Physical Activity in Community-Dwelling Japanese Older Adults: A Cross-Sectional Study

PURPOSE

We investigated the relationships among motor function, physical activity, and the characteristics of chronic pain (the number of pain sites, pain intensity, and pain-type).

DESIGN

Cross-sectional study.

SETTING

An ongoing community-based prospective study conducted in Itoshima, Japan.

SUBJECTS

Community-dwelling Japanese aged 65-75 years (n = 805; 401 men, 404 women).

MEASURES

Chronic pain subtypes were examined in terms of the number of pain sites, pain intensity, and pain type. Motor function was evaluated by handgrip strength, walking speed, and the 5 Times Stand-up and Sit Test (FTSST). Locomotive activity, non-locomotive activity, and sedentary time were evaluated by a tri-axial accelerometer as physical-activity parameters.

ANALYSIS

Multiple regression model adjusting for age, sex, education level, employment status, subjective economic status, body mass index, cognitive function, comorbidity, current tobacco use, current alcohol consumption, and regular exercise.

RESULTS

In a multivariate analysis, the subjects' walking speed was negatively associated with multisite, moderate-to-severe, and neuropathic-like pain. The FTSST was positively associated with single-site, moderate-to-severe, and neuropathic-like pain. There was no significant association between handgrip strength and any chronic pain subtypes. Locomotive activity was negatively related to multisite, moderate-to-severe, and neuropathic-like pain, but there was no clear association between the amount of non-locomotive activity, sedentary time, and chronic pain subtypes.

CONCLUSION

Severe chronic pain was associated with decreased locomotion-related motor function and physical activity.

Associations between back pain incidence, and physical activity and sedentary behaviours: A prospective cohort study with data from over 365,000 participants

OBJECTIVE: To examine the associations between (i) various types of physical activity and the risk of back pain incidence, and (ii) the influence of substituting sedentary behaviours with physical activities on back pain incidence. DESIGN: A prospective cohort study. METHODS: We analyzed UK Biobank data collected from 365,307 participants who were free of back pain at baseline. The exposures were total, light, moderate and vigorous physical activity, and sedentary behaviours. The outcome was back pain incidence. The main statistical models were the Cox proportional hazard model and the isotemporal substitution model. RESULTS: In the follow-up time (median, 12.97 years; inter-quartile range, 12.10-13.71), 25,189 individuals developed back pain. The associations between all types of physical activity and incident back pain were significantly non-linear (p < 0.001) among the general population and other subgroups. High physical activity was associated with a decreased risk of back pain compared with no physical activity. The lowest risk occurred in the 1801-2400 MET-min/week subgroup of total physical activity (HR 0.64, 95% CI 0.59-0.69), approximately consisting of 1200, 600, and 600 MET-min/week of light, moderate and vigorous physical activity, respectively. Extremely high vigorous physical activity was related to high risk, specifically in males (HR 1.13, 95% CI 1.02-1.25). Replacing 1 hour/day of sedentary behaviours with an equal time of physical activity reduced the risk of incident back pain by 2%-8% (p < 0.05). CONCLUSION: Physical activity was related to a reduced risk of back pain incidence (except over-high vigorous physical activity). Substituting sedentary behaviours with physical activities reduced the risk of future back pain.

Examining the Association Between Objective Physical Activity and Momentary Pain: A Systematic Review of Studies Using Ambulatory Assessment

Chronic pain (CP) is a debilitating and increasingly common health condition that adversely impacts function, including physical activity (PA). Research using ambulatory assessment (AA) methods (eg, ecological momentary assessment, actigraphy) offers promise for elucidating the relationship between momentary pain and objective PA in CP populations. This study aimed to systematically review articles assessing the association between momentary pain and PA in adults with CP as measured using AA and to make recommendations for the measurement and study of this relationship. Five databases were systematically searched, and 13 unique records (N = 768) met the inclusion criteria. CP conditions included mixed/nonspecific CP (k = 3), low back pain (k = 2), fibromyalgia (k = 1), unspecified arthritis (k = 1), and hip/knee osteoarthritis (k = 6). The average age of participants across studies was 55.29 years, and the majority identified as women (60.68%) and White (83.16%). All studies measured objective PA via actigraphy, and momentary pain with either a diary/log or ratings on an actigraph. Studies varied in the quantification of PA (ie, activity counts, step count, moderate-vigorous PA), statistical method (ie, correlation, regression, multilevel modeling), and inclusion of moderators (eg, pain acceptance). Studies reported mixed results for the pain-PA relationship. This heterogeneity suggests that no summarizing conclusions can be drawn about the pain-PA relationship without further investigation into its complex nuances. More within-person and exploratory examinations that maximize the richness of AA data are needed. A greater understanding of this relationship can inform psychotherapeutic and behavioral recommendations to improve CP outcomes. PERSPECTIVE: This article presents a systematic review of the literature on the association between momentary pain and PA in adults with CP as measured using AA methods. A better understanding of this nuanced relationship could help elucidate areas for timely intervention and may inform clinical recommendations to improve CP outcomes. PROSPERO REGISTRATION NUMBER: CRD42023389913.

Objectively evaluated physical activity among individuals following anterior cruciate ligament reconstruction: a systematic review and meta-analysis

Objective

To compare time spent in moderate-to-vigorous physical activity (MVPA) per week, MVPA per day, and steps per day between individuals that were subjected to the anterior cruciate ligament reconstruction (ACLR) and healthy control group.

Design

Systematic review and meta-analysis of observational studies.

Data sources

Web of Science, Scopus, and PubMed have been comprehensively searched to identify relevant investigations.

Eligibility criteria for selecting studies

An observational research that objectively evaluated physical activity among respondents with a history of ACLR.

Results

Of 302 records, a total of 12 studies fulfilled the eligibility criteria. Four hundred and forty-three participants underwent the ACLR, 153 men and 290 women. The mean time between anterior cruciate ligament (ACL) surgery and evaluation of analysed outcomes was 34.8 months. The main findings demonstrated that the ACLR group spent less time in weekly MVPA (standardised mean differences (SMD)=-0.43 (95% CI -0.66 to -0.20); mean = -55.86 min (95% CI -86.45 to -25.27); p=0.0003; τ2=0.00), in daily MVPA (SMD=-0.51 95% CI -0.76 to -0.26]; mean = -15.59 min (95% CI -22.93 to -8.25); p<0.0001; τ2=0.00), and they had fewer daily steps (SMD=-0.60 95% CI -0.90 to -0.30); mean = -1724.39 steps (95% CI -2552.27 to -896.50); p<0.0001; τ2=0.00) relative to their non-injured counterparts. Additionally, available investigations indicated that individuals with a history of ACLR participated in 316.8 min of MVPA per week, 67 min in MVPA per day, and 8337 steps per day.

Conclusion

Long-term after ACLR, participants undergoing ACL surgery were less physically active compared with their non-injured peers, and they did not satisfy recommendations regarding steps per day.

PROSPERO registration number

CRD42023431991.

Multidimensional characteristics of musculoskeletal pain and risk of hip fractures among elderly adults: the first longitudinal evidence from CHARLS

BACKGROUND

Hip fractures are a major public health concern among middle-aged and older adults. It is important to understand the associated risk factors to inform health policies and develop better prevention strategies. Musculoskeletal pain is a possible implicating factor, being associated with physical inactivity and risk of falls. However, the association between musculoskeletal pain and hip fractures has not been clearly investigated.

METHODS

A nationally representative sample of the Chinese population was obtained from the China Health and Retirement Longitudinal Study (CHARLS). The study collected patient information on their demographic characteristics, socioeconomic status, other health-related behavior, and history of musculoskeletal pain and hip fractures. Univariate and multivariate analyses were conducted to investigate the factors influencing the risk of hip fracture, including factors related to the individual and to musculoskeletal pain. P for trend test was performed to assess the trend of each continuous variable. The robustness and bias were assessed using the bootstrap method. Restricted cubic spline regression was utilized to identify linear or non-linear relationships.

RESULTS

Among the 18,813 respondents, a total of 215 individuals reported that they have experienced a hip fracture. An increased risk of hip fracture was associated with the presence of waist pain and leg pain (P < 0.05), as well as with an increased number of musculoskeletal pain sites (P < 0.05). For individuals aged 65 and above, a significant association was found between age and the risk of hip fracture (P < 0.05). Furthermore, respondents with lower education level had a higher risk of hip fracture compared to those with higher education levels (P < 0.05).

CONCLUSION

In the Chinese population, the risk of hip fracture was found to be associated with both the location and extent of musculoskeletal pain, as well as with other factors such as age and demographic characteristics. The findings of this study may be useful for informing policy development and treatment strategies, and provide evidence for comparison with data from other demographic populations.

Changes in Desk-Based Workers' Sitting, Standing, and Stepping Time: Short- and Longer-Term Effects on Musculoskeletal Pain

PURPOSE

Sitting at work can be associated with musculoskeletal pain, but the effect of reductions in sitting is not well understood. We examined relationships with musculoskeletal pain of changes in sitting, standing, stepping, and short and long bouts of these behaviors.

METHODS

Analyses pooled data from 224 desk workers (68.4% women; mean ± SD age = 45.5 ± 9.4 yr; body mass index = 28.1 ± 6.1 kg⋅m -2 ) in intervention trial. Device-assessed (activPAL3) sitting, standing, and stepping time and multisite musculoskeletal pain (Nordic Questionnaire; 12 body areas) were assessed at baseline, 3 months, and 12 months. Compositional data analyses in linear mixed-effects regressions examined relationships within 16 waking hours of the behaviors and their short and long bouts, with changes from baseline in acute and chronic multisite musculoskeletal pain at 3 and 12 months. Analyses were adjusted for initial group randomization and relevant covariates.

RESULTS

At 3 months, increased standing relative to changes in other compositions was significantly associated with increased multisite musculoskeletal pain (acute: β = 1.54, 95% confidence interval [CI] = 0.10 to 2.98; chronic: β = 1.49, 95% CI = 0.12 to 2.83). By contrast, increased stepping relative to changes in other compositions was significantly associated with reduced multisite musculoskeletal pain (acute: β = -1.49, 95% CI = -2.97 to -0.02; chronic: β = -1.87, 95% CI = -3.75 to -0.01). Neither sitting reduction relative to changes in other compositions nor changes in short bouts relative to long bouts of the behaviors were significantly associated with multisite musculoskeletal pain changes. At 12 months, there were no significant associations for any of the compositional changes.

CONCLUSIONS

In the short term, while increasing standing with reduced sitting time can be unfavorable, concurrently increasing stepping could potentially reduce musculoskeletal pain. In the longer term, musculoskeletal pain may not be increased by moderate reductions in sitting time through spending more time standing or stepping.

Objectively and subjectively measured physical activity levels in individuals with whiplash associated disorder and aged-matched healthy controls

BACKGROUND

Whiplash associated disorders (WAD) are the most common non-hospitalised injuries resulting from a motor vehicle crash. Half of individuals with WAD experience ongoing pain and disability. Furthermore, individuals with persistent WAD have lower levels of aerobic capacity and isometric strength compared with age-matched controls. It is not known whether these differences are associated with increased levels of pain and disability, or with reduced physical activity (PA) participation.

OBJECTIVE

Our primary aim was to compare PA levels in individuals with persistent WAD with healthy controls. Secondary aims were to: compare objective and subjective measurements of PA; explore factors that may influence PA; and describe proportions of these populations meeting World Health Organisation PA guidelines.

METHODS

Objective (ActiGraph accelerometer; seven days) and subjective (International Physical Activity Questionnaire (IPAQ)) PA data were collected for n = 53 age-matched participants (WAD n = 28; controls n = 25).

RESULTS

Independent sample t-tests showed no significant difference in objectively measured PA (p>0.05) between WAD and controls. For the subjective measure (IPAQ), controls reported more overall weekly PA (t = 0.219, p<0.05), while WAD participants reported more weekly walking minutes (t = -0.712, p<0.05). Linear regression showed mental health quality-of-life predicted objectively measured moderate intensity PA (R2 = 0.225, F (2, 44) = 6.379, p<0.004) and subjectively reported overall PA (R2 = 0.132, F (1, 41) = 6.226, p<0.017). Bland-Altman analyses indicated that subjects over-reported MVPA and under-reported sedentary time using the IPAQ.

CONCLUSIONS

Individuals with WAD had levels of physical and mental health quality-of-life significantly lower than controls and below population norms yet participated in similar levels of PA. Given that increased perceptions of mental health quality-of-life were positively associated with objectively measured MVPA and subjectively reported overall PA, strategies to help people with WAD achieve adequate doses of MVPA may be beneficial. ActiGraph-measured and IPAQ-reported PA were discordant. Hence, IPAQ may not be a reliable measure of habitual PA in WAD.

Big data, big consortia, and pain: UK Biobank, PAINSTORM, and DOLORisk

Chronic pain (CP) is a common and often debilitating disorder that has major social and economic impacts. A subset of patients develop CP that significantly interferes with their activities of daily living and requires a high level of healthcare support. The challenge for treating physicians is in preventing the onset of refractory CP or effectively managing existing pain. To be able to do this, it is necessary to understand the risk factors, both genetic and environmental, for the onset of CP and response to treatment, as well as the pathogenesis of the disorder, which is highly heterogenous. However, studies of CP, particularly pain with neuropathic characteristics, have been hindered by a lack of consensus on phenotyping and data collection, making comparisons difficult. Furthermore, existing cohorts have suffered from small sample sizes meaning that analyses, especially genome-wide association studies, are insufficiently powered. The key to overcoming these issues is through the creation of large consortia such as DOLORisk and PAINSTORM and biorepositories, such as UK Biobank, where a common approach can be taken to CP phenotyping, which allows harmonisation across different cohorts and in turn increased study power. This review describes the approach that was used for studying neuropathic pain in DOLORisk and how this has informed current projects such as PAINSTORM, the rephenotyping of UK Biobank, and other endeavours. Moreover, an overview is provided of the outputs from these studies and the lessons learnt for future projects.

Genetic liability to multi-site chronic pain increases the risk of cardiovascular disease

BACKGROUND

Observational studies have shown associations between multi-site chronic pain (MCP) and cardiovascular disease. However, it remains unclear whether these associations are causal. Therefore, this study aimed to assess the causal associations between MCP and cardiovascular disease and identify possible mediators between them.

METHODS

A two-sample Mendelian randomisation analysis was applied in this study. The summary data for MCP were obtained from a genome-wide association study that included 387 649 individuals from the UK Biobank, whereas summary-level data for cardiovascular disease and its subtypes were obtained from relevant genome-wide association studies. Finally, summary-level data for common cardiovascular risk factors and inflammatory biomarkers were leveraged to identify possible mediators.

RESULTS

Genetic liability to multi-site chronic pain is associated with higher risks for coronary artery disease (CAD), myocardial infarction (MI), heart failure (HF), and stroke, with a combined odds ratio (OR) of 1.537 (per site increment in MCP; 95% confidence interval [CI]: 1.271-1.858; P=0.0001) for CAD, 1.604 (95% CI: 1.277-2.014; P=0.0005) for MI, 1.722 (95% CI: 1.423-2.083; P<0.00001) for HF, and 1.332 (95% CI: 1.093-1.623; P=0.00001) for stroke. Genetic liability to MCP was found to be associated with mental disorders, smoking initiation, physical activity, BMI, and lipid metabolites. Multivariable Mendelian randomisation suggested a mediating role for mental disorders, smoking initiation, physical activity, and BMI in the relationship between multi-site chronic pain and cardiovascular disease.

CONCLUSIONS

Our findings provide new insights into the role of multi-site chronic pain in cardiovascular disease. Additionally, we identified several modifiable risk factors for reducing cardiovascular disease.

Association between chronic pain and risk of incident dementia: findings from a prospective cohort

BACKGROUND

Chronic musculoskeletal pain has been linked to dementia; however, chronic pain typically occurs in multiple sites; therefore, this study was to investigate whether greater number of chronic pain sites is associated with a higher risk of dementia and its subtypes.

METHODS

Participants (N = 356,383) in the UK Biobank who were dementia-free at baseline were included. Pain in the hip, knee, back, and neck/shoulder or 'all over the body' and its duration were assessed. Participants were categorised into six groups: no chronic pain; chronic pain in 1, 2, 3, and 4 sites, and 'all over the body'. All-cause dementia and its subtypes were ascertained using hospital inpatient and death registry records. Cox regression was used to investigate the associations between the number of chronic pain sites and the incidence of all-cause dementia and its subtypes.

RESULTS

Over a median follow-up of 13 years, 4959 participants developed dementia. After adjustment for sociodemographic, lifestyle, comorbidities, pain medications, psychological problems, and sleep factors, greater number of chronic pain sites was associated with an increased risk of incident all-cause dementia (hazard ratio [HR] = 1.08 per 1 site increase, 95% CI 1.05-1.11) and Alzheimer's disease (AD) (HR = 1.09 per 1-site increase, 95% CI 1.04-1.13) in a dose-response manner but not vascular and frontotemporal dementia. No significant association was found between the number of chronic pain sites and the risk of incident all-cause dementia among a subsample that underwent a fluid intelligence test.

CONCLUSIONS

Greater number of chronic pain sites was associated with an increased risk of incident all-cause dementia and AD, suggesting that chronic pain in multiple sites may contribute to individuals' dementia risk and is an underestimated risk factor for dementia.

The association between physical activity and musculoskeletal disorders-a cross-sectional study of teachers

Purpose

Combined with insufficient physical activity (PA) prolonged and improperly performed sedentary work can lead to musculoskeletal disorders (MSDs). The aim of this study was (I) to evaluate the self-reported level of PA and the prevalence of MSDs in male and female teachers, and (II) to investigate the association between PA and MSDs in teachers in Polish primary and secondary schools.

Methods

The study included 254 teachers from primary and secondary schools from Upper Silesia, Poland, excluding physical education teachers. The level of PA was assessed using the Seven-Day Physical Activity Recall (SDPAR). A standardized Nordic Musculoskeletal Questionnaire (NMQ) was used to assess the prevalence of MSDs.

Results

A similar percentage of female (80%) and male (90%) teachers met the WHO recommendations on moderate-intensity PA. The recommendations on performing vigorous-intensity PA were met by significantly (p = 0.002) less female than male teachers (50% and 75% respectively). Lower back disorders during the last 12 months and the last 7 days (57% and 45%, respectively) were the most commonly reported MSDs by teachers, followed by neck (53%, 40%), upper back (39%, 28%), and knee disorders (37%, 26%). The highest pain intensity was experienced by the teachers in the lower back and neck. Teachers with a greater number of MSDs were less likely to engage in vigorous-intensity PA and total PA than those with fewer painful areas of the body. Pain intensity in the neck, knees, upper- and lower back, and wrists/hands was negatively related to moderate and total PA. BMI negatively correlated with total PA, moderate-intensity PA vigorous-intensity PA, and high vigorous-intensity PA.

Conclusions

The study revealed the association between PA and MSDs in studied teachers. The most of the studied teachers met the WHO recommendation, and women were less likely to perform vigorous and high-vigorous PA than men. The lower back and neck disorders were the most common among the teachers.

Association between chronic pain and physical activity in a Swiss population-based cohort: a cross-sectional study

OBJECTIVE

To assess the bidirectional association between chronic pain and both subjectively and objectively measured physical activity (PA).

DESIGN

Cross-sectional study.

SETTING

Population-based sample in Lausanne, Switzerland, May 2014 to April 2017.

PARTICIPANTS

Non-stratified, representative sample of the population of Lausanne (Switzerland) aged 35-75 years. Participants were excluded if they had missing data for the pain or the PA questionnaires, for accelerometry (defined as >20% of non-wear time or duration <7 days) or for covariates.

PRIMARY OUTCOMES

Primary outcomes were association between chronic pain and previous, subjectively assessed PA (questionnaire), and subsequent, objectively assessed PA (accelerometry). Daily pain, pain duration, number of painful sites and pain intensity were assessed by questionnaire. PA was assessed by questionnaire 2 weeks prior and by accelerometry 2 weeks after completion of the pain questionnaire. PA was further categorised as sedentary (SED), light and moderate-to-vigorous PA.

RESULTS

2598 participants (52.9% women, mean age 60.5 years) had subjectively assessed PA. Multivariable analysis showed time spent in SED to be negatively associated with the number of painful sites: adjusted mean±SE 528±5, 522±7 and 502±7 min/day for 0, 1-2 and 3+ painful sites, respectively, p for trend <0.005. No other association was found between chronic pain and subjectively assessed PA categories. 2205 participants (52.8% women, mean age 61.7 years) had accelerometry-derived PA. No significant association between chronic pain and subsequent objectively assessed PA was found after multivariable analyses.

CONCLUSION

In this Swiss population-based cohort, no consistent association was found between chronic pain and PA. Hence, in the general population, chronic pain does not significantly impact time spent in PA.

Hippocampal volume, FKBP5 genetic risk alleles, and childhood trauma interact to increase vulnerability to chronic multisite musculoskeletal pain

Chronic multisite musculoskeletal pain (CMP) is common and highly morbid. However, vulnerability factors for CMP are poorly understood. Previous studies have independently shown that both small hippocampal brain volume and genetic risk alleles in a key stress system gene, FKBP5, increase vulnerability for chronic pain. However, little is known regarding the relationship between these factors and CMP. Here we tested the hypothesis that both small hippocampal brain volume and FKBP5 genetic risk, assessed using the tagging risk variant, FKBP5rs3800373, increase vulnerability for CMP. We used participant data from 36,822 individuals with available genetic, neuroimaging, and chronic pain data in the UK Biobank study. Although no main effects were observed, the interaction between FKBP5 genetic risk and right hippocampal volume was associated with CMP severity (β = -0.020, p_raw = 0.002, p_adj = 0.01). In secondary analyses, severity of childhood trauma further moderated the relationship between FKBP5 genetic risk, right hippocampal brain volume, and CMP (β = -0.081, p = 0.016). This study provides novel evidence that both FKBP5 genetic risk and childhood trauma moderate the relationship between right hippocampal brain volume and CMP. The data increases our understanding of vulnerability factors for CMP and builds a foundation for further work assessing causal relationships that might drive CMP development.

Lipidomic Profiling Identifies Serum Lipids Associated with Persistent Multisite Musculoskeletal Pain

Lipid mediators have been suggested to have a role in pain sensitivity and response; however, longitudinal data on lipid metabolites and persistent multisite musculoskeletal pain (MSMP) are lacking. This study was to identify lipid metabolic markers for persistent MSMP. Lipidomic profiling of 807 lipid species was performed on serum samples of 536 participants from a cohort study. MSMP was measured by a questionnaire and defined as painful sites ≥4. Persistent MSMP was defined as having MSMP at every visit. Logistic regression was used with adjustment for potential confounders. The Benjamini–Hochberg method was used to control for multiple testing. A total of 530 samples with 807 lipid metabolites passed quality control. Mean age at baseline was 61.54 ± 6.57 years and 50% were females. In total, 112 (21%) of the participants had persistent MSMP. Persistent MSMP was significantly associated with lower levels of monohexosylceramide (HexCer)(d18:1/22:0 and d18:1/24:0), acylcarnitine (AC)(26:0) and lysophosphatidylcholine (LPC)(18:1 [sn1], 18:2 [sn1], 18:2 [sn2], and 15-MHDA[sn1] [104_sn1]) after controlling for multiple testing. After adjustment for age, sex, body mass index, comorbidities, and physical activity, HexCer(d18:1/22:0 and d18:1/24:0) and LPC(15-MHDA [sn1] [104_sn1]) were significantly associated with persistent MSMP [Odds Ratio (OR) ranging from 0.25–0.36]. Two lipid classes—HexCer and LPC—were negatively associated with persistent MSMP after adjustment for covariates (OR = 0.22 and 0.27, respectively). This study identified three novel lipid signatures of persistent MSMP, suggesting that lipid metabolism is involved in the pathogenesis of persistent pain.

Clustering Accelerometer Activity Patterns from the UK Biobank Cohort

Many researchers are beginning to adopt the use of wrist-worn accelerometers to objectively measure personal activity levels. Data from these devices are often used to summarise such activity in terms of averages, variances, exceedances, and patterns within a profile. In this study, we report the development of a clustering utilising the whole activity profile. This was achieved using the robust clustering technique of k-medoids applied to an extensive data set of over 90,000 activity profiles, collected as part of the UK Biobank study. We identified nine distinct activity profiles in these data, which captured both the pattern of activity throughout a week and the intensity of the activity: "Active 9 to 5", "Active", "Morning Movers", "Get up and Active", "Live for the Weekend", "Moderates", "Leisurely 9 to 5", "Sedate" and "Inactive". These patterns are differentiated by sociodemographic, socioeconomic, and health and circadian rhythm data collected by UK Biobank. The utility of these findings are that they sit alongside existing summary measures of physical activity to provide a way to typify distinct activity patterns that may help to explain other health and morbidity outcomes, e.g., BMI or COVID-19. This research will be returned to the UK Biobank for other researchers to use.

Cardiorespiratory fitness assessment using risk-stratified exercise testing and dose-response relationships with disease outcomes

Cardiorespiratory fitness (CRF) is associated with mortality and cardiovascular disease, but assessing CRF in the population is challenging. Here we develop and validate a novel framework to estimate CRF (as maximal oxygen consumption, VO2max) from heart rate response to low-risk personalised exercise tests. We apply the method to examine associations between CRF and health outcomes in the UK Biobank study, one of the world's largest and most inclusive studies of CRF, showing that risk of all-cause mortality is 8% lower (95%CI 5-11%, 2670 deaths among 79,981 participants) and cardiovascular mortality is 9% lower (95%CI 4-14%, 854 deaths) per 1-metabolic equivalent difference in CRF. Associations obtained with the novel validated CRF estimation method are stronger than those obtained using previous methodology, suggesting previous methods may have underestimated the importance of fitness for human health.

Smoking Is Associated with Pain in All Body Regions, with Greatest Influence on Spinal Pain

OBJECTIVE

Examine the interrelationship between smoking and pain in the US population.

DESIGN

A cross-sectional population-based study.

SETTING

Nationwide survey.

METHODS

Comprehensive pain reports categorically defined as head, spine, trunk, and limb pain; smoking history; demographics; medical history from a total of 2,307 subjects from the 2003-2004 National Health and Nutrition Examination Survey obtained from the Centers for Disease Control were analyzed. Unpaired t tests were used to analyze independent continuous variables, and chi-square tests were used to analyze categorical variables between smoker and nonsmoker groups. Weighted multivariate logistic regression analyses determined the association of current smoking with the presence of pain in various body regions.

RESULTS

Smoking is most strongly associated with spine pain (odds ratio [OR] = 2.89, 95% confidence interval [CI] = 2.21-3.77), followed by headache (OR = 2.47, 95% CI = 1.73-3.53), trunk pain (OR = 2.17, 95% CI = 1.45-2.74), and limb pain (OR = 1.99, 95% CI = 1.45-2.73).

CONCLUSIONS

Current smoking is associated with pain in every region of the body. This association is strongest for spine and head pain. Given that pain is a strong motivator and that current smoking was associated with pain in all body regions, we recommend that these results be used to further raise public awareness about the potential harms of smoking.

An Exploratory Analysis of Accelerometer-Measured Physical Activity and Emotional Functioning in Patients With Chronic Pain

BACKGROUND

Physical activity (PA) can benefit pain and emotional functioning for patients with chronic pain. However, associations between different intensities of PA (moderate-to-vigorous PA, light PA, and sedentary behavior), pain, and emotional functioning are not well understood in patients with chronic pain.

OBJECTIVE

The goals of this study were to (1) describe PA patterns of adult patients with chronic pain using accelerometers and (2) explore preliminary associations between PA intensities, pain, and emotional functioning.

METHODS

Thirteen patients with chronic pain completed self-report measures of pain, cognitive and emotional reactions to pain, depression and anxiety, and wore ActiGraph accelerometers for 1 week before participating in a pilot mind-body PA intervention.

RESULTS

Sedentary behavior and light activity were strongly inversely correlated (r = -0.93, P < 0.01). Greater sedentary behavior was associated with lower pain during activity (r = -0.55, P = 0.05), and greater light activity was correlated with higher pain during activity (r = 0.63, P = 0.02) and pain at rest (r = 0.54, P = 0.06). However, greater moderate-to-vigorous PA was correlated with lower pain at rest (r = -0.66, P = 0.01), pain catastrophizing (r = -0.53, P = 0.06), depression (r = -0.44, P = 0.14), and anxiety (r = -0.57, P = 0.04).

CONCLUSIONS

Objective accelerometer-measured PA has the potential to reveal differential associations between PA intensities, pain, and emotional functioning. Findings here suggest preliminary recommendations to focus on interconnections between moderate-to-vigorous PA, pain at rest, pain catastrophizing, anxiety, and depression for patients with chronic pain.

What factors are associated with health-related quality of life among patients with chronic musculoskeletal pain? A cross-sectional study in primary health care

BACKGROUND

Chronic musculoskeletal pain (CMP) affects daily life function and is the most prevalent disorder in primary health care. The primary objective was to examine demographic factors and pain characteristics associated with reduced health-related quality of life (HRQoL) among patients in primary care reporting CMP. Our secondary objective was to compare HRQoL in patients with and without CMP.

METHOD

This cross-sectional study was conducted in Trondheim, Norway. Twenty randomly selected GPs, and their listed patients aged 21-58 were invited to participate. Self-reported CMP data was collected using online questionnaires. HRQoL was measured by the 15D questionnaire, total score of 0.9 was used as cut-off for clinical reduced HRQoL.

RESULTS

A total of 969 patients (650 females) were recruited from six GPs' patient lists, mean age 45.6 (SD 10.1). CMP was reported by 517 (53%). Factors significantly associated with reduced HRQoL were gender (OR 2.0, 95% CI 1.2, 3.4), disability pension (OR 26.6, 95% CI 3.1, 228.0), mood (OR 1.3, 95% CI 1.1, 1.6), relations with other people (OR 0.8, 95% CI 0.6, 0.9), sleep (OR 1.2, 95% CI 1.0, 1.3) and enjoyment (OR 1.2, 95% CI 1.0). CMP patients had significantly lower total HRQoL score compared to patients without CMP (Between group difference 0.08, 95% CI 0.07-0.09). Half of the CMP patients reported a HRQoL score < 0.9 compared to 14% in the no CMP group.

CONCLUSIONS

Being female, receiving disability pension, and several psychosocial factors were found highly associated with reduced HRQoL in CMP patients, whereas pain characteristics were not. Patients with CMP reported statistically and clinically significant lower HRQoL than patients without CMP. Due to low response rate the conclusions must be handled with caution.

TRIAL REGISTRATION

Clinicaltrials.gov (NCT02020772).

Sleep Disturbance and Its Association with Pain Severity and Multisite Pain: A Prospective 10.7-Year Study

INTRODUCTION

Sleep disturbance is often comorbid with chronic pain disorders, with emerging evidence suggesting a stronger effect of sleep disturbance on pain than vice versa; however, few studies have evaluated the long-term associations between sleep disturbance and pain. This study was to examine the associations of sleep disturbance with knee pain severity, number of painful sites (NPS) and persistent pain in a 10.7-year cohort study.

METHODS

A total of 1099 community-dwelling older adults (age mean ± SD, 63 ± 7.5 years; 51% female) were recruited and followed up at 2.6, 5.1 and 10.7 years later. Data on demographics, body mass index, physical activity and comorbidities were collected. At each time point, sleep disturbance, knee pain severity and NPS were assessed by using questionnaires. Multisite pain (MSP) was defined as NPS ≥ 2. Persistent knee pain or MSP was defined as having knee pain or MSP at all time points, respectively. Multivariable mixed-effects models and log-binomial regression were applied.

RESULTS

In multivariable analyses, sleep disturbance was associated with greater knee pain severity (β 0.91/unit, 95% CI 0.70-1.11) and more NPS [(relative risk (RR) 1.10/unit, 95% CI 1.07-1.14] in a dose-response manner. Persistent sleep disturbance was associated with persistent knee pain (RR 1.90, 1.26-2.87) and MSP (RR 1.29, 1.07-1.56). Persistent knee pain and MSP were also associated with persistent sleep disturbance (knee pain: RR = 1.99; MSP: RR = 2.71, both P < 0.05).

CONCLUSIONS

Sleep disturbance was independently associated with greater pain severity and NPS in a dose-response manner. A reciprocal relationship between persistent sleep disturbance and persistent pain suggests treating either problem could help the other.

Association of Pain, Severe Pain, and Multisite Pain with the Level of Physical Activity and Sedentary Behavior in Severely Obese Adults: Baseline Data from the DieTBra Trial

The study aimed to assess the prevalence of pain, severe pain, and pain in four or more regions associated with physical activity and sedentary behavior, as well as other associated factors in severely obese adults (Body Mass Index ≥ 35 kg/m2). Baseline data from the DieTBra Trial were analyzed. The outcome variables were pain (yes/no) and pain in four or more sites (yes/no), as identified by the Brazilian version of the Nordic Musculoskeletal Questionnaire, along with the presence of severe pain (yes/no), identified based on the Numerical Pain Rating Scale (≥8). The main independent variables were moderate to vigorous physical activity (MVPA), light physical activity, and sedentary behavior, assessed by triaxial accelerometry. The variables were analyzed using multiple hierarchical Poisson regression. In 150 individuals (men, 14.67%; and women, 85.33%), with a mean age of 39.6 ± 0.7 years, there was a high prevalence of pain (89.33%), severe pain (69.33%), and pain in four or more regions (53.33%). The associated factors were shorter MVPA time with pain (p = 0.010); arthritis/arthrosis (p = 0.007) and the use of muscle relaxants (p = 0.026) with severe pain; and economic class C (p = 0.033), and economic class D (p = 0.003), along with arthritis and arthrosis (p = 0.025) with pain in four or more sites. There were no significant associations between sedentary behavior and any of the three outcomes analyzed. These findings indicate that, in severely obese individuals, shorter MVPA time is associated with a higher prevalence of pain. Future studies on physical activity intervention may contribute to the reduction in the prevalence and severity of pain in adults with severe obesity.

l-Serine and EPA Relieve Chronic Low-Back and Knee Pain in Adults: A Randomized, Double-Blind, Placebo-Controlled Trial

BACKGROUND

Multisite pain, including low-back and knee pain, is a major health issue that greatly decreases quality of life.

OBJECTIVES

This study analyzed the effects of l-serine, which provides necessary components for nerve function, and EPA, which exerts anti-inflammatory properties, on pain scores of adults with pain in at least the low back and knee for ≥3 mo.

METHODS

This was a randomized, double-blind, placebo-controlled, parallel-group study. The Japan Low Back Pain Evaluation Questionnaire (JLEQ) and Japanese Knee Osteoarthritis Measure (JKOM) were applied as primary outcomes. The Brief Pain Inventory (BPI) and safety evaluation were secondary outcomes. We enrolled 120 participants aged ≥20 y (36 men and 84 women: mean ± SD age = 40.8 ± 10.9 y). The participants were randomly allocated to either the active group (daily ingestion of 594 mg l-serine and 149 mg EPA) or placebo group. The study period consisted of 8-wk dosing and 4-wk posttreatment observation. ANCOVA between groups for each time point was conducted using the baseline scores as covariates.

RESULTS

The JLEQ scores (active compared with placebo: 14.2 ± 11.2 compared with 19.0 ± 10.2) at week 8 were lower in the active group (P < 0.001). The JKOM scores at week 4 (11.7 ± 9.0 compared with 13.9 ± 7.9), week 8 (10.4 ± 7.9 compared with 13.1 ± 7.1), and week 12 (10.3 ± 7.4 compared with 13.8 ± 7.5) were lower in the active group (P ≤ 0.04). Additionally, the active group had 11-27% better scores compared with the placebo group for BPI1 (worst pain), BPI3 (average pain), and BPI5D (pain during moving) at week 4 (P ≤ 0.028) and week 8 (P ≤ 0.019), respectively, and BPI5D was 23% better in the active group at week 12 (P = 0.007). No adverse events were observed.

CONCLUSIONS

l-Serine and EPA were effective for pain relief in adults with low-back and knee pain after multiplicity adjustment.This trial was registered at the University Hospital Medical Information Network Clinical Trials Registry as UMIN000035056.

Objectively measured versus self-reported occupational physical activity and multisite musculoskeletal pain: a prospective follow-up study at 20 nursing homes in Denmark

Purpose

To explore the prospective association of objectively measured and self-reported occupational physical activity (OPA) with multisite musculoskeletal pain (MSP) among Danish eldercare workers.

Methods

The study population consisted of eldercare workers in 20 Danish nursing homes (N = 553, response rate 59%, 525 female). Baseline data were collected in 2013–2014 and the 1-year follow-up was completed in 2016. At baseline, we measured objective OPA by a thigh-worn ActiGraph GT3X + accelerometer during work and self-reported OPA by a questionnaire survey. Information on musculoskeletal pain during the past four weeks in seven different body sites was reported by a structured questionnaire at baseline (n = 389) and by SMS and telephone interview during follow-up (n = 284). MSP was defined as having pain in two or more body sites. Using log-binomial models we calculated risk ratios (RRs) with their 95% confidence intervals (CIs) to estimate the association between objectively measured and self-reported OPA and MSP.

Results

We found statistically significant positive associations between self-reported OPA (RR for high OPA 1.24, 95% CI 1.05–1.46) and MSP while there was no significant association found between objective OPA and MSP.

Conclusion

Our study indicates that self-reported, but not objectively measured OPA is positively associated with MSP. This finding highlights the need for better understanding, use, and interpretation of self-reported and objectively measured OPA in the study of MSP.

Association Between Objectively Measured Physical Activity And Musculoskeletal Disorders, And Perceived Work Ability Among Adult, Middle-Aged And Older Women

Purpose

The purpose of this study was to assess the relationship between objectively measured physical activity and perceived work ability and musculoskeletal disorders among adult, middle-aged, and older women.

Patients and methods

This study used a cross-sectional design with a convenience sample of 348 women divided into 3 age groups: 30–49 years (n=111), 50–65 years (n=120), 66–75 years (n=117). Weekly physical activity was monitored using tri-axial accelerometer ActiGraph Gt3X. Perceived work ability was assessed using the standardized Work Ability Index (WAI) questionnaire. Information about the occurrence and intensity of musculoskeletal disorders was collected using standardized Nordic Musculoskeletal Questionnaire (NMQ) expanded by visual analog pain intensity scale (VAS).

Results

Regardless of age, women who met physical activity recommendations achieved higher scores in each part of the WAI, and also in the total WAI scores. However, the most significant differences were found in women aged 50–64 years, and included the following items: subjective work ability, work ability in relation to demands, work impairments, sick leave in the past year. Total WAI scores were also significantly higher in women aged 30–49 and 50–64 years who met PA recommendations in comparison to women who did not meet recommendations. Also, significant relations between the frequency of occurrence of musculoskeletal problems and meeting physical activity recommendations were found in women aged 50–64 years. Those who were more physically active reported less musculoskeletal problems in shoulders (p=0.006) and ankles/feet (p=0.018) regions.

Conclusion

Adherence to Global Recommendations on Physical Activity for Health disseminated by WHO is related to better-perceived work ability among adult (30–49 years) and middle-aged (50–64 years) women. There is also a relationship between adherence to recommendations of physical activity and frequency and intensity of musculoskeletal pain among middle-aged women.

Pain at Multiple Sites Is Associated With Prevalent and Incident Fractures in Older Adults

Musculoskeletal pain is common and typically occurs at multiple sites. Pain has been shown to be associated with falls risk; however, whether an increased risk for falls associated with multisite pain (MSP) translates into an increased risk of fractures has not been investigated. This study aimed to examine the association of number of painful sites with prevalent and incident fractures. Data from a longitudinal population-based study of older adults (mean age 63 years) were utilized. Follow-up was performed at 2.6, 5.1, and 10.7 years later, respectively. Presence/absence of pain at the neck, back, hands, shoulders, hips, knees, and feet was assessed by questionnaire at baseline. Participants were classified into three groups according to the total number of painful sites: zero to two, three to four, and five to seven. Fractures were self-reported at each time point. BMD was measured by DXA. Falls risk was calculated based on the Short-Form Physiological Profile Assessment. Log-binomial regression was used for the analyses. There were 450 fractures at baseline and 154 new fractures reported during a mean follow-up period of 10.7 years (range 9.2 to 12.5 years). In multivariable analyses, number of painful sites was associated with prevalent fractures at any and nonvertebral site. Furthermore, participants with five to seven painful sites had an increased risk of incident fractures at any site (RR 1.69; 95% CI, 1.13 to 2.53); major site, including the femur, radius, ulnar, vertebral, rib, and humerus (RR 2.17; 95% CI 1.12 to 4.22); and vertebral site (RR 6.44, 95% CI, 1.64 to 25.33) compared with those with pain at zero to two sites. These associations remained statistically significant after further adjustment for falls risk and BMD. Pain at multiple sites was associated with incident fracture risk in a dose-response manner, suggesting that widespread pain is an independent contributor to fracture risk. The potential for pain management in fracture prevention warrants further exploration. © 2019 American Society for Bone and Mineral Research.