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Aleksej Logacjov,1 Eivind Schjelderup Skarpsno,2,3 Atle Kongsvold,2 Kerstin Bach,1 Paul Jarle Mork2 1Department of Computer Science, Norwegian University of Science and Technology, Trondheim, Norway; 2Department of Public Health and Nursing, Norwegian University of Science and Technology, Trondheim, Norway; 3Department of Neurology and Clinical Neurophysiology, St. Olavs Hospital, Trondheim, NorwayCorrespondence: Aleksej Logacjov, Department of Computer Science, Faculty of Information Technology and Electrical Engineering, Norwegian University of Science and Technology, Trondheim, 7034, Norway, Email aleksej.logacjov@ntnu.noPurpose: Body-worn accelerometers are commonly used to estimate sleep duration in population-based studies. However, since accelerometry-based sleep/wake-scoring relies on detecting body movements, the prediction of sleep duration remains a challenge. The aim was to develop and evaluate the performance of a machine learning (ML) model to predict accelerometry-based sleep duration and to explore if this prediction can be improved by adding skin temperature data, circadian rhythm based on the estimated midpoint of sleep, and cyclic time features to the model.Patients and Methods: Twenty-nine adults (17 females), mean (SD) age 40.2 (15.0) years (range 17– 70) participated in the study. Overnight polysomnography (PSG) was recorded in a sleep laboratory or at home along with body movement by two accelerometers with an embedded skin temperature sensor (AX3, Axivity, UK) positioned at the low back and thigh. The PSG scoring of sleep/wake was used as ground truth for training the ML model.Results: Based on pure accelerometer data input to the ML model, the specificity and sensitivity for predicting sleep/wake was 0.52 (SD 0.24) and 0.95 (SD 0.03), respectively. Adding skin temperature data and contextual information to the ML model improved the specificity to 0.72 (SD 0.20), while sensitivity remained unchanged at 0.95 (SD 0.05). Correspondingly, sleep overestimation was reduced from 54 min (228 min, limits of agreement range [LoAR]) to 19 min (154 min LoAR).Conclusion: An ML model can predict sleep/wake periods with excellent sensitivity and moderate specificity based on a dual-accelerometer set-up when adding skin temperature data and contextual information to the model.Keywords: actigraphy, epidemiology, sedentary behaviors, sleep quality, supervised machine learning, support vector machines

Eivind Schjelderup Skarpsno,1,2 Melanie Rae Simpson,1 Arnfinn Seim,1,3 Maria Hrozanova,1 Marthe Alida Bakøy,3 Nina Elisabeth Klevanger,1 Lene Aasdahl1,3 1Department of Public Health and Nursing, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway; 2Department of Neurology and Clinical Neurophysiology, St. Olavs Hospital, Trondheim, Norway; 3Unicare Helsefort Rehabilitation Centre, Rissa, NorwayCorrespondence: Eivind Schjelderup Skarpsno, Department of Public Health and Nursing, NTNU, Trondheim, Norway, Tel +47 97521297, Email eivind.s.skarpsno@ntnu.noBackground: Insomnia is prevalent among patients receiving treatment for long-term musculoskeletal complaints in inpatient rehabilitation settings. Cognitive-behavioral therapy for insomnia (CBT-I) is effective for improving sleep quality in patients with pain, but a lack of therapists often limits the capacity to use this therapy in rehabilitation programs. The aim of this randomized clinical trial (RCT) is to evaluate the effectiveness of app-delivered CBT-I adjunct to inpatient multimodal rehabilitation for individuals with comorbid musculoskeletal complaints and insomnia, compared with rehabilitation (usual care) only.Methods: This RCT has two parallel arms: 1) inpatient multimodal rehabilitation and 2) app-delivered CBT-I adjunct to inpatient multimodal rehabilitation. Patients referred to Unicare Helsefort (Norway) with long-term chronic musculoskeletal complaints are invited to the study. Eligible and consenting participants will be randomized to the intervention and usual care at a ratio of 2:1. Assessments will be carried out at baseline (prior to randomization), 6 weeks (at the end of rehabilitation), 3 months (primary outcome), as well as 6 and 12 months after the rehabilitation. The primary outcome is insomnia severity measured at 3 months. Secondary outcomes include pain intensity, health-related quality of life, fatigue, physical function, work ability, expectations about sick leave length, sick leave, and prescribed medication. Exploratory analyses are planned to identify moderators and mediators of the effect of the app-delivered intervention.Discussion: This RCT will provide novel knowledge about the effectiveness of app-delivered CBT-I as an adjunct to usual care among patients participating in inpatient multimodal pain rehabilitation. Regardless of the results from this trial, the results will improve our understanding of the utility of dCBT-I in the field of rehabilitation and the importance of adding sleep therapy to this patient group.Trial Registration: This trial was prospectively registered in ClinicalTrials.gov October 10, 2022 (ClinicalTrials.gov identifier: NCT05572697).Keywords: sleep, sleeplessness, chronic pain, digital therapy

Eivind Schjelderup Skarpsno,1,2 Sigmund Østgård Gismervik,1,3 Marius Steiro Fimland,4,5 Lene Aasdahl1,5 1Department of Public Health and Nursing, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; 2Department of Neurology and Clinical Neurophysiology, St. Olavs Hospital, Trondheim, Norway; 3Department of Physical Medicine and Rehabilitation, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway; 4Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, NTNU, Norwegian University of Science and Technology, Trondheim, Norway; 5Unicare Helsefort Rehabilitation Centre, Rissa, NorwayCorrespondence: Eivind Schjelderup SkarpsnoDepartment of Public Health and Nursing, Norwegian University of Science and Technology (NTNU), Trondheim, 7491, NorwayTel +47 97521297Email eivind.s.skarpsno@ntnu.noStudy Objectives: Insomnia is common among people with musculoskeletal and/or mental health disorders. This study aimed to assess whether insomnia is associated with the favorable effect from inpatient multimodal occupational rehabilitation on future work participation among individuals with these conditions.Methods: Insomnia was measured at baseline through a randomized clinical trial that compared the effect of inpatient multimodal occupational rehabilitation with a less-comprehensive program of outpatient acceptance and commitment therapy on future work participation. The inpatient multimodal program lasted 3.5 weeks at the rehabilitation center, comprising psychoeducational sessions (including sleep education), fixed schedules, acceptance and commitment therapy, physical exercise and work-related problem-solving, whereas the outpatient program comprised mainly six weekly acceptance and commitment therapy sessions. Both programs were group-based. The study tracked cumulative sick leave during the 12 months of follow-up using national registry data.Results: Among the 163 adults included in this subgroup analysis, 56% (n=91) reported insomnia. Overall, we found statistical evidence of interaction between the occupational program and insomnia concerning cumulative sick leave (p=0.03). Compared with people without insomnia in the comprehensive inpatient multimodal program, people with insomnia had 12 (95% CI: − 48 to 24) fewer days with sick leave if they participated in the inpatient program and 46 (95% CI: 8 to 83) more days if they participated in the outpatient program.Conclusion: These findings suggest that insomnia should be addressed specifically before individuals on sick leave are considered for participation in occupational rehabilitation and that individuals with insomnia may benefit in particular from inpatient rehabilitation.Keywords: sleep problems, occupational therapy, work, chronic pain, mental health, sick leave

Eivind Schjelderup Skarpsno,1,2 Paul Jarle Mork,1 Knut Hagen,3,4 Tom Ivar Lund Nilsen,1,5 Anna Marcuzzi1 1Department of Public Health and Nursing, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; 2Department of Neurology and Clinical Neurophysiology, St. Olavs Hospital, Trondheim, Norway; 3Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; 4Clinical Research Unit Central Norway, St. Olavs Hospital, Trondheim, Norway; 5Clinic of Anaesthesia and Intensive Care, St. Olavs Hospital, Trondheim University Hospital, Trondheim, NorwayCorrespondence: Eivind Schjelderup SkarpsnoDepartment of Public Health and Nursing, Norwegian University of Science and Technology (NTNU), Håkon Jarls Gate 11, Samfunnsmedisinbygget, Trondheim 7030, NorwayTel +47 97521297Email eivind.s.skarpsno@ntnu.noStudy Objectives: To examine the association between the number of chronic nighttime insomnia symptoms and the risk of chronic widespread pain (CWP) and pain-related disability.Methods: A prospective study of 10,847 participants in the Norwegian HUNT Study without chronic musculoskeletal pain at baseline in 2006– 2008. We used a modified Poisson regression model to estimate adjusted risk ratios (RRs) with a 95% confidence interval (CI) for CWP and pain-related disability at follow-up in 2017– 2019 associated with insomnia and number of nighttime insomnia symptoms at baseline. Chronic insomnia was defined according to the current classification system and grouped into three categories based on the number of reported nighttime symptoms (ie, difficulty initiating sleep, trouble maintaining sleep and early morning awakenings).Results: Compared to the reference group of people without insomnia, people with insomnia had RRs for CWP and pain-related disability of 1.64 (1.26– 2.14) and 1.63 (1.37– 1.94), respectively. When people with insomnia were categorized based on the number of nighttime symptoms, people who reported one, two, or three nighttime symptoms had RRs of CWP of 1.19 (95% CI 0.80– 1.78), 1.78 (95 CI 1.13– 2.80) and 3.08 (95% CI 1.93– 4.92), respectively, compared to people without insomnia. The corresponding RRs for pain-related disability were 1.49 (95% CI 1.17– 1.89), 1.46 (95% CI 2.04– 2.05), and 2.46 (95% CI 1.76– 3.42).Conclusion: These findings indicate that people with insomnia characterized by symptoms in all phases of the sleep period have a substantially increased risk of CWP and pain-related disability.Keywords: sleeplessness, insomnia disorder, chronic insomnia, musculoskeletal, pain, chronic, widespread chronic pain, relative risk, epidemiology

Eivind Schjelderup Skarpsno,1,2 Paul Jarle Mork,1 Tom Ivar Lund Nilsen,1 Andreas Holtermann3,4 1Department of Public Health and Nursing, Norwegian University of Science and Technology (NTNU), 2Liaison Committee between Central Norway Regional Health Authority and NTNU, Trondheim, Norway; 3National Research Centre for the Working Environment, Copenhagen, 4Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark Background: In order to establish normative values for body positions and movements during sleep, the objective of this study was to explore the distribution of sleep positions and extent of nocturnal body moments and the association with sex, age, body-mass index (BMI), smoking, alcohol consumption, and insomnia symptoms. Materials and methods: This cross-sectional study comprised data on a working population (363 men and 301 women) who participated in the Danish Physical Activity Cohort with Objective Measurements (DPHACTO). Measures of body position and movements were obtained from actigraph accelerometers on the thigh, upper back, and upper arm. Linear regression was used to estimate adjusted mean differences in movements among categories of demographic and lifestyle characteristics. Results: During their time in bed, participants spent 54.1% (SD 18.1%) in the side position, 37.5% (SD 18.2%) in the back position, and 7.3% (SD 12.3%) in the front position. Increasing age and BMI were associated with increased time in the side position and a proportional reduction in time in the back position. There were on average 1.6 (SD 0.7) position shifts per hour. Compared to males, females had fewer position shifts (–0.37, 95% CI –0.48 to –0.24) and fewer arm, thigh, and upper-back movements. Participants aged 20–34 years had more arm, thigh, and upper-back movements compared to participants ≥35 years. Obese participants had fewer shifts in body position (–0.15, 95% CI –0.27 to 0), but more arm, thigh, and upper-back movements compared to normal-weight participants. Smokers had fewer shifts in body position than nonsmokers (–0.27, 95% CI –0.4 to –0.13). Conclusion: The predominant sleep position in adults is on the side. This preference increases with age and BMI. The extent of nocturnal body movements is associated with sex, age, BMI, and smoking. Keywords: sleep, sleep positions, body movements, accelerometers, lifestyle

Objectives: The objectives of this study are to examine the association of physical activity in parents with physical activity in their adult offspring and explore if the offspring's genetic liability (ie, polygenic risk score) to physical activity influences this association., Methods: The Trøndelag Health Study cohort is a population-based longitudinal study with data collected in 1984-1986, 1995-1997, 2006-2008 and 2017-2019. We calculated the odds ratio for being physically active and mean difference in physical activity levels according to parental physical activity (device-measured and self-reported) and own polygenic risk score., Results: Compared with offspring with mothers in the lowest third of metabolic equivalent of task (MET)-min/day accumulated by vigorous physical activities, offspring with mothers in the upper third had an OR of 1.93 (95% CI 1.65 to 2.27) for accumulating ≥900 MET-min/week of vigorous physical activity. The OR for the corresponding father-offspring association was 1.78 (95% CI 1.48 to 2.14). Compared with offspring of parents not accumulating ≥900 MET-min/week, we found an OR of 1.89 (95% CI 1.45 to 2.44) for offspring to meet the same threshold if both parents accumulated ≥900 MET-min/week. Offspring with higher polygenic risk score to bephysically active and having physically active parents did more weekly physical activity, but we found no strong evidence of multiplicative synergistic effects between these two factors (all p values ≥0.01)., Conclusion: Both parental physical activity and offspring's polygenic risk score were positively associated with physical activity levels in the adult offspring, but there was no evidence of effect modification between these factors. A family-based approach to promote physical activity may be effective from a public health perspective., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Family factors, sleep, and physical activity have previously been associated with risk of sick leave and disability benefits due to musculoskeletal disorders. However, how these factors act during adolescence and young adulthood is unclear. The aim of this study was to (i) examine if chronic pain, disability benefits and education in parents influence the risk of long-term sick leave due to musculoskeletal disorders in young adulthood, and (ii) to explore if offspring sleep problems and physical activity modify these effects., Methods: A population-based prospective study of 18,552 adolescents and young adults (≤ 30 years) in the Norwegian HUNT Study. Survey data was linked to national registry data on sick leave, disability benefits, family relations and educational attainment. We used Cox regression to estimate hazard ratio (HR) with 95% confidence interval (CI) for long-term (≥ 31 days) sick leave due to a musculoskeletal disorder in offspring associated with parental factors and the joint effect of parental factors and offspring lifestyle factors., Results: Parental chronic pain (HR 1.36, 95% CI 1.27-1.45), disability benefits (HR 1.41, 95% CI 1.33-1.48) and low educational attainment (HR 1.78, 95% CI 1.67-1.90) increased the risk of long-term sick leave due to musculoskeletal disorders among offspring. There was no strong evidence that sleep and physical activity modified these effects., Conclusion: Chronic pain, disability benefit and low education in parents increased the risk of long-term sick leave due to musculoskeletal disorders among offspring, but these effects were not modified by offspring sleep problems or physical activity level. The findings suggest that efforts beyond individual lifestyle factors might be important as preventive measures., (© 2024. The Author(s).)

Introduction: Insomnia is prevalent among patients visiting physiotherapists due to musculoskeletal complaints and associated with poorer pain prognosis. Cognitive-Behavioural Therapy for Insomnia (CBT-I) may be effective for improving sleep quality and pain-related outcomes in these patients, but its availability and utility are limited in daily physiotherapy practice. The aim of this randomised controlled trial (RCT) is to evaluate the effectiveness of digital CBT-I in addition to usual treatment in patients with chronic musculoskeletal complaints and insomnia, compared with usual treatment only., Methods and Analysis: In this RCT, eligible and consenting participants will be randomised (1:1 ratio) to one of two interventions: (1) digital CBT-I adjunct to physiotherapy treatment or (2) usual physiotherapy treatment. Patients with musculoskeletal complaints and insomnia visiting a physiotherapist in Norway will be invited to participate in the study. We aim to include 188 participants to detect a difference in the primary outcome. Outcome variables will be assessed at baseline (prior to randomisation) and at 6-week, 3-month, 6-month and 12-month follow-up. The primary outcome is between-group difference in insomnia severity, assessed with the Insomnia Severity Index (0-28 points) at 3 months. Secondary outcomes include between-group differences in pain intensity, physical function, work ability, health-related quality of life, mental distress, and self-reported use of sleep and pain medication. Exploratory analyses will identify patient characteristics influencing the effect of the digital intervention., Ethics and Dissemination: This trial is approved by the Regional Committee for Medical and Health Research Ethics in Central Norway (Ref. 2023/533381). The results of the trial will be published in peer-review journals and disseminated at national and international conferences., Trial Registration Number: ISRCTN91221906., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: To investigate whether the combination of multiple healthy lifestyle factors modify the well-established association between insomnia disorder and risk of activity-limiting spinal pain., Methods: We conducted a prospective study of 10,228 individuals who participated in two surveys over ∼11 years and were free of chronic pain in the neck, upper back, and lower back at baseline. Adjusted risk ratios (RRs) were calculated for the risk of activity-limiting chronic spinal pain (i.e., pain that impairs daily activities at work or leisure time) at follow-up associated with the joint association of insomnia disorder and the combination of five lifestyle factors (body mass index, leisure time physical activity, alcohol consumption, diet, and smoking) at baseline., Results: Our data indicate an additive interaction between insomnia disorder and lifestyle on risk of activity-limiting spinal pain, i.e., compared with participants without insomnia disorder and the best lifestyle score, participants with insomnia disorder and the worst lifestyle score had a RR of activity-limiting spinal pain of 3.57 (95 % CI: 2.65-4.80); participants with insomnia disorder and the best lifestyle score had a RR of 1.56 (95 % CI: 0.97-2.50); and those without insomnia disorder and the worst lifestyle score had a RR of 1.32 (95 % CI: 1.12-1.55)., Conclusions: Poor lifestyle behaviour amplifies the adverse effect of insomnia disorder on the risk of activity-limiting chronic spinal pain., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Objective: Studies suggest that symptom reduction is not necessary for improved return-to-work after occupational rehabilitation programmes. This secondary analysis of a randomized controlled trial examined whether pain intensity and mental distress mediate the effect of an inpatient programme on sustainable return-to-work., Methods: The randomized controlled trial compared inpatient multimodal occupational rehabilitation (n = 82) with outpatient acceptance and commitment therapy (n = 79) in patients sick-listed due to musculoskeletal and mental health complaints. Pain and mental distress were measured at the end of each programme, and patients were followed up on sick-leave for 12 months. Cox regression with an inverse odds weighted approach was used to assess causal mediation., Results: The total effect on return-to-work was in favour of the inpatient programme compared with the control (hazard ratio (HR) 1.96; 95% confidence interval (95% CI) 1.15-3.35). There was no evidence of mediation by pain intensity (indirect effect HR, 0.98; 95% CI, 0.61-1.57, direct effect HR, 2.00; 95% CI, 1.02-3.90), but mental distress had a weak suppression effect (indirect effect HR, 0.89; 95% CI, 0.59-1.36, direct effect HR, 2.19; 95% CI, 1.13-4.26)., Conclusion: These data suggest that symptom reduction is not necessary for sustainable return-to-work after an inpatient multimodal occupational rehabilitation intervention.

Background: Insomnia symptoms that influence daytime functioning are common among adults with type 2 diabetes. However, no previous study has examined if levels of physical activity differ among adults with diabetes with and without insomnia symptoms. Thus, the aim of this study was to assess the difference in total physical activity (TPA) and moderate-to-vigorous physical activity (MVPA) levels in individuals with diabetes with and without insomnia symptoms., Methods: This cross-sectional study included 1,354 participants with any type of diabetes who participated in the Norwegian HUNT4 Study, 2017-19. Participants were defined to have 'insomnia symptoms' if they reported difficulty initiating and/or maintaining sleep ≥ 3 nights/week during the last 3 months. MVPA (defined as moderate/brisk walking [> 4.0 km/h], running, and cycling), and TPA (MVPA including slow walking [≤ 4.0 km/h]) were determined from two accelerometers worn on the thigh and lower back. Analyses were stratified by age and sex., Results: The median age was 67 years and 491 (36%) had insomnia symptoms and 37 (3%) had insomnia disorder. Among women, 28% with one or more insomnia symptoms fulfilled the recommended minimum level of physical activity, as compared to 34% in women without insomnia symptoms. The corresponding proportions in men were 48% and 45%. Women above 65 years with insomnia symptoms performed less TPA (-73 min/week, 95% CI -122 to -24) and MVPA (-33 min/week, 95% CI -50 to -15), compared to women without insomnia symptoms in the same age group. There was no clear difference in physical activity levels according to insomnia symptoms in men or women below 65 years. Women and men with insomnia disorder had substantially lower TPA (women: -192 min/week, 95% CI -278 to -106; men: -276 min/week, 95% CI -369 to -193) and MVPA (women: -37 min/week, 95% CI -63 to -11; men: -67 min/week, 95% CI -83 to -50) than those without insomnia symptoms., Conclusions: This study showed that women above 65 years with insomnia symptoms and individuals with insomnia disorder performed less physical activity, suggesting that these subgroups may suffer from additional challenges that prevent them from engaging in regular physical activity., Supplementary Information: The online version contains supplementary material available at 10.1186/s44167-024-00066-4., Competing Interests: Competing interestsThe authors declare no competing interests., (© The Author(s) 2024.)

Background: Despite apparent shortcomings such as measurement error and low precision, self-reported sedentary time is still widely used in surveillance and research. The aim of this study was threefold; (i) to examine the agreement between self-reported and device-measured sitting time in a general adult population; (ii), to examine to what extent demographics, lifestyle factors, long-term health conditions, physical work demands, and educational level is associated with measurement bias; and (iii), to explore whether correcting for factors associated with bias improves the prediction of device-measured sitting time based on self-reported sitting time., Methods: A statistical validation model study based on data from 23 993 adults in the Trøndelag Health Study (HUNT4), Norway. Participants reported usual sitting time on weekdays using a single-item questionnaire and wore two AX3 tri-axial accelerometers on the thigh and low back for an average of 3.8 (standard deviation [SD] 0.7, range 1-5) weekdays to determine their sitting time. Statistical validation was performed by iteratively adding all possible combinations of factors associated with bias between self-reported and device-measured sitting time in a multivariate linear regression. We randomly selected 2/3 of the data (n = 15 995) for model development and used the remaining 1/3 (n = 7 998) to evaluate the model., Results: Mean (SD) self-reported and device-measured sitting time were 6.8 (2.9) h/day and 8.6 (2.2) h/day, respectively, corresponding to a mean difference of 1.8 (3.1) h/day. Limits of agreement ranged from - 8.0 h/day to 4.4 h/day. The discrepancy between the measurements was characterized by a proportional bias with participants device-measured to sit less overestimating their sitting time and participants device-measured to sit more underestimating their sitting time. The crude explained variance of device-measured sitting time based on self-reported sitting time was 10%. This improved to 24% when adding age, body mass index and physical work demands to the model. Adding sex, lifestyle factors, educational level, and long-term health conditions to the model did not improve the explained variance., Conclusions: Self-reported sitting time had low validity and including a range of factors associated with bias in self-reported sitting time only marginally improved the prediction of device-measured sitting time., (© 2023. The Author(s).)

Background: Few studies have investigated the joint effects of sleep traits on the risk of acute myocardial infarction (AMI). No previous study has used factorial Mendelian randomization (MR) which may reduce confounding, reverse causation, and measurement error. Thus, it is prudent to study joint effects using robust methods to propose sleep-targeted interventions which lower the risk of AMI., Methods: The causal interplay between combinations of two sleep traits (including insomnia symptoms, sleep duration, or chronotype) on the risk of AMI was investigated using factorial MR. Genetic risk scores for each sleep trait were dichotomized at their median in UK Biobank (UKBB) and the second survey of the Trøndelag Health Study (HUNT2). A combination of two sleep traits constituting 4 groups were analyzed to estimate the risk of AMI in each group using a 2×2 factorial MR design., Results: In UKBB, participants with high genetic risk for both insomnia symptoms and short sleep had the highest risk of AMI (hazard ratio (HR) 1.10; 95% confidence interval (CI) 1.03, 1.18), although there was no evidence of interaction (relative excess risk due to interaction (RERI) 0.03; 95% CI -0.07, 0.12). These estimates were less precise in HUNT2 (HR 1.02; 95% CI 0.93, 1.13), possibly due to weak instruments and/or small sample size. Participants with high genetic risk for both a morning chronotype and insomnia symptoms (HR 1.09; 95% CI 1.03, 1.17) and a morning chronotype and short sleep (HR 1.11; 95% CI 1.04, 1.19) had the highest risk of AMI in UKBB, although there was no evidence of interaction (RERI 0.03; 95% CI -0.06, 0.12; and RERI 0.05; 95% CI -0.05, 0.14, respectively). Chronotype was not available in HUNT2., Conclusions: This study reveals no interaction effects between sleep traits on the risk of AMI, but all combinations of sleep traits increased the risk of AMI except those with long sleep. This indicates that the main effects of sleep traits on AMI are likely to be independent of each other., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Insomnia and short/long sleep duration increase the risk of AMI, but their interaction with each other or with chronotype is not well known. We investigated the prospective joint associations of any two of these sleep traits on risk of AMI. We included 302 456 and 31 091 participants without past AMI episodes from UK Biobank (UKBB; 2006-10) and the Trøndelag Health Study (HUNT2; 1995-97), respectively. A total of 6 833 and 2 540 incident AMIs were identified during an average 11.7 and 21.0 years follow-up, in UKBB and HUNT2, respectively. Compared to those who reported normal sleep duration (7-8 h) without insomnia symptoms, the Cox proportional hazard ratios (HRs) for incident AMI in UKBB among participants who reported normal, short and long sleep duration with insomnia symptoms were 1.07 (95% CI 0.99, 1.15), 1.16 (95% CI 1.07, 1.25) and 1.40 (95% CI 1.21, 1.63), respectively. The corresponding HRs in HUNT2 were 1.09 (95% CI 0.95, 1.25), 1.17 (95% CI 0.87, 1.58) and 1.02 (95% CI 0.85, 1.23). The HRs for incident AMI in UKBB among evening chronotypes were 1.19 (95% CI 1.10, 1.29) for those who had insomnia symptoms, 1.18 (95% CI 1.08, 1.29) for those with short sleep duration, and 1.21 (95% CI 1.07, 1.37) for those with long sleep duration, compared to morning chronotypes without another sleep symptom. The relative excess risk for incident AMI in UKBB due to interaction between insomnia symptoms and long sleep duration was 0.25 (95% CI 0.01, 0.48). Insomnia symptoms with long sleep duration may contribute more than just an additive effect of these sleep traits on the risk of AMI., (© 2023. The Author(s).)

Background: Insomnia is common in the general population and is a risk factor for ill-health, which highlights the importance of treating insomnia effectively and cost-efficiently. Cognitive-behavioural therapy for insomnia (CBT-I) is recommended as first-line treatment due to its long-term effectiveness and few side-effects, but its availability is limited. The aim of this pragmatic, multicentre randomized controlled trial is to investigate the effectiveness of group-delivered CBT-I in primary care compared to a waiting-list control group., Methods: A pragmatic multicentre randomized controlled trial will be conducted with about 300 participants recruited across 26 Healthy Life Centres in Norway. Participants will complete online screening and provide consent before enrolment. Those who meet the eligibility criteria will be randomized to a group-delivered CBT-I or to a waiting list according to a 2:1 ratio. The intervention consists of four two-hour sessions. Assessments will be performed at baseline, 4 weeks, 3- and 6 months post-intervention, respectively. The primary outcome is self-reported insomnia severity at 3 months post-intervention. Secondary outcomes include health-related quality of life, fatigue, mental distress, dysfunctional beliefs and attitudes about sleep, sleep reactivity, 7-day sleep diaries, and data obtained from national health registries (sick leave, use of relevant prescribed medications, healthcare utilization). Exploratory analyses will identify factors influencing treatment effectiveness, and we will conduct a mixed-method process evaluation to identify facilitators and barriers of participants' treatment adherence. The study protocol was approved by the Regional Committee for Medical and Health Research ethics in Mid-Norway (ID 465241)., Discussion: This large-scale pragmatic trial will investigate the effectiveness of group-delivered cognitive behavioural therapy versus waiting list in the treatment of insomnia, generating findings that are generalizable to day-to-day treatment of insomnia in interdisciplinary primary care services. The trial will identify those who would benefit from the group-delivered therapy, and will investigate the rates of sick leave, medication use, and healthcare utilization among adults who undergo the group-delivered therapy., Trial Registration: The trial was retrospectively registered in the ISRCTN registry (ISRCTN16185698)., (© 2023. The Author(s).)

Although sleep quantity and quality appear to be interrelated, most previous studies have considered sleep duration and insomnia symptoms as distinct entities. We therefore examined whether there is a joint effect of sleep duration and long-term changes in insomnia symptoms on the risk of recurrent chronic spinal pain. We performed a prospective study of 8,788 participants who participated in three surveys over ∼22 years and reported chronic spinal pain at the first, second, or both surveys. Adjusted risk ratios (RRs) were calculated for the risk of recurrent spinal pain at the last survey associated with self-reported sleep duration at the first survey and changes in insomnia symptoms between the two first surveys. Compared to participants with normal sleep duration (7-9 h) and no insomnia symptoms at the two first surveys, participants with insomnia symptoms over the same period had RRs of spinal pain of 1.33 (95% CI 1.26-1.41) in the last survey if they reported normal sleep duration and 1.50 (95% CI 1.34-1.67) if they reported short sleep (≤6 h). The corresponding RRs for spinal pain for participants who improved their sleep symptoms were 1.09 (95% CI 1.00-1.19) for those with normal sleep and 1.13 (95% CI 0.88-1.45) for those with short sleep. In conclusion, people who reported insomnia symptoms over ∼10 years in combination with short sleep had a particularly increased risk of recurrent spinal pain. Improvement in insomnia symptoms was associated with a favorable prognosis., Competing Interests: Declaration of competing interest None., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Objectives: To examine the possible bidirectional association between insomnia and comorbid chronic low back pain (LBP) and lower limb pain and to explore whether high-sensitivity C-reactive protein (hsCRP) amplifies these associations., Methods: We calculated adjusted risk ratios (RR) with 95% confidence intervals (CI) for the development of insomnia and mild-to-severe chronic LBP and lower limb pain at 11 years follow-up in participants aged ≥32 years and with hsCRP ≤10 mg/L at baseline in 2007-2008: 3,714 without chronic LBP or lower limb pain (sample 1) and 7,892 without insomnia (sample 2)., Results: Compared to participants without chronic pain, participants with comorbid chronic LBP and lower limb pain had a RR of insomnia of 1.37 (95% CI 1.12-1.66). Compared with participants without insomnia, participants with insomnia did not have an increased risk of comorbid chronic LBP and lower limb pain (RR: 1.06, 95% CI 0.76-1.46); however, participants with insomnia had a RR of chronic LBP of 1.20 (95% CI 1.02-1.42). There was no strong amplifying effect of elevated hsCRP (3.00-10.0 mg/L) on these associations., Conclusions: These findings suggest that elevated hsCRP does not amplify the associations between insomnia and mild-to-severe chronic LBP and lower limb pain. Further research using data on the temporal relation between insomnia, chronic pain, and inflammatory responses are required to fully understand the causal pathways., (© 2022 Walter de Gruyter GmbH, Berlin/Boston.)

Background: Chronic musculoskeletal pain and insomnia frequently co-occur and are known independent risk factors for anxiety and depression. However, the interplay between these two conditions on the risk of anxiety and depression has not been explored., Methods: A population-based prospective study of 18,301 adults in the Norwegian HUNT Study without anxiety or depression at baseline (2006-2008). We calculated adjusted risk ratios (RRs) with 95% confidence intervals (CIs) for anxiety and/or depression at follow-up (2017-2019), associated with i) number of chronic pain sites, and ii) chronic pain and insomnia symptoms jointly., Results: At follow-up, 2155 (11.8%) participants reported anxiety and/or depression. The number of pain sites was positively associated with risk of anxiety and/or depression (P trend , < 0.001). Compared to people without chronic pain and insomnia symptoms, people with ≥5 pain sites and no insomnia symptoms had a RR of 1.52 (95% CI: 1.28 to 1.81) for anxiety and/or depression, those with no chronic pain but with insomnia had a RR of 1.78 (95% CI: 1.33 to 2.38), whereas the RR among people with both ≥5 pain sites and insomnia was 2.42 (95% CI: 1.85 to 3.16). We observed no synergistic effect above additivity for the combination of ≥5 pain sites and insomnia on risk of anxiety and/or depression., Conclusions: This study shows that people with multisite chronic pain who also suffer from insomnia are at a particularly high risk for anxiety and/or depression, suggesting that insomnia symptoms are important contributors to the association between multisite pain and common mental health problems., (© 2022. The Author(s).)

We examined the association between long-term (~10 years) changes in self-reported sleep quality and risk of any chronic musculoskeletal pain and chronic widespread pain. The study comprised data on 6,033 people who participated in three consecutive surveys in the Norwegian HUNT Study (1995-1997, 2006-2008 and 2017-2019) and who were without chronic musculoskeletal pain at the first two surveys. We used a modified Poisson regression model to calculate adjusted risk ratios for chronic pain at follow-up (2017-2019) associated with categories of poor and good sleep quality reported in 1995-1997 and 2006-2008. Compared with people who reported good sleep at both surveys (crude absolute risk: 32.4%), the risk ratios of any chronic pain were 1.20 (95% confidence interval: 1.02-1.41) for those who changed from poor to good sleep; 1.25 (95% confidence interval: 1.12-1.39) for those who changed from good to poor sleep; and 1.41 (95% confidence interval: 1.21-1.63) for those who reported long-term poor sleep. The corresponding risk ratios for chronic widespread pain were 1.35 (95% confidence interval: 0.82-2.23), 1.55 (95% confidence interval: 1.14-2.12) and 2.09 (95% confidence interval: 1.38-3.17), respectively. In conclusion, these findings indicate that people with long-term poor sleep quality have a markedly higher risk of chronic musculoskeletal pain and chronic widespread pain, compared with people who remain good sleep quality., (© 2021 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.)

Objective: To examine the association between subtypes of insomnia and the risk of chronic spinal pain., Methods: The study comprised 16,401 participants without chronic spinal pain at baseline who were followed for ∼11 years. People were categorized into 'no insomnia symptoms', 'subthreshold insomnia', and 'insomnia'. Insomnia was defined according to the diagnostic classification system requiring both daytime and nighttime symptoms, and further categorized into subtypes based on nighttime symptoms (ie, sleep onset latency [SOL-insomnia], wake after sleep onset [WASO-insomnia], early morning awakening [EMA-insomnia], or combinations of these). Subthreshold insomnia comprised those with only daytime impairment or one or more nighttime symptoms. Chronic spinal pain was defined as pain in either 'neck', 'low back', or 'upper back', or a combination of these., Results: In multivariable regression analysis using people without insomnia as reference, people with subthreshold insomnia or insomnia had relative risks (RRs) of chronic spinal pain of 1.29 (95% confidence interval [CI] 1.21-1.38) and 1.50 (95% CI 1.34-1.68), respectively. The RRs for people with one nighttime symptom were 1.30 (95% CI 0.83-2.05) for WASO-insomnia, 1.32 (95% CI 1.06-1.65) for EMA-insomnia, and 1.70 (95% CI 1.32-2.18) for SOL-insomnia, respectively. Combinations of nighttime insomnia symptoms gave RRs from 1.45 (95% CI 1.08-1.94) for WASO + EMA-insomnia to 1.72 (95% CI 1.36-2.19) for all nighttime symptoms (SOL + WASO + EMA-insomnia)., Conclusions: These findings suggest that the risk of chronic spinal pain is highest among persons with insomnia subtypes characterized by sleep onset latency or among those having insomnia symptoms in all parts of the sleep period., (Copyright © 2021 The Author(s). Published by Elsevier B.V. All rights reserved.)

Sleep problems and regular leisure time physical activity (LTPA) are interrelated and have contrasting effects on risk of back pain. However, no studies have investigated the influence of long-term poor sleep quality on risk of back-related disability, or if LTPA modifies this association. The study comprised data on 8601 people who participated in three consecutive surveys over ~ 22 years, and who reported no chronic back pain at the two first surveys. Adjusted risk ratios (RRs) for back-related disability were calculated at the last survey, associated with the joint effect of changes in sleep quality between the two first surveys and meeting physical activity guidelines at the second survey. Compared to people with long-term good sleep, people with long-term poor sleep had nearly twice the risk of back-related disability (RR 1.92, 95% CI 1.48-2.49). There was no statistical interaction between sleep and LTPA but people who reported long-term poor sleep and meeting the physical activity guidelines had 35% lower risk of back-related disability compared to people with same level of sleep problems, but who not met the guidelines. These findings suggest that long-term poor sleep quality contributes to a substantially increased risk of chronic and disabling back pain irrespective of LTPA., (© 2021. The Author(s).)

Background: Research shows that part of the variation in physical activity and sedentary behaviour may be explained by genetic factors. Identifying genetic variants associated with physical activity and sedentary behaviour can improve causal inference in physical activity research. The aim of this systematic review was to provide an updated overview of the evidence of genetic variants associated with physical activity or sedentary behaviour., Methods: We performed systematic literature searches in PubMed and Embase for studies published from 1990 to April 2020 using keywords relating to "physical activity", "exercise", "sedentariness" and "genetics". Physical activity phenotypes were either based on self-report (e.g., questionnaires, diaries) or objective measures (e.g., accelerometry, pedometer). We considered original studies aiming to i) identify new genetic variants associated with physical activity or sedentary behaviour (i.e., genome wide association studies [GWAS]), or ii) assess the association between known genetic variants and physical activity or sedentary behaviour (i.e., candidate gene studies). Study selection, data extraction, and critical appraisal were carried out by independent researchers, and risk of bias and methodological quality was assessed for all included studies., Results: Fifty-four out of 5420 identified records met the inclusion criteria. Six of the included studies were GWAS, whereas 48 used a candidate gene approach. Only one GWAS and three candidate gene studies were considered high-quality. The six GWAS discovered up to 10 single nucleotide polymorphisms (SNPs) associated with physical activity or sedentariness that reached genome-wide significance. In total, the candidate gene studies reported 30 different genes that were associated (p < 0.05) with physical activity or sedentary behaviour. SNPs in or close to nine candidate genes were associated with physical activity or sedentary behaviour in more than one study., Conclusion: GWAS have reported up to 10 loci associated with physical activity or sedentary behaviour. Candidate gene studies have pointed to some interesting genetic variants, but few have been replicated. Our review highlights the need for high-quality GWAS in large population-based samples, and with objectively assessed phenotypes, in order to establish robust genetic instruments for physical activity and sedentary behaviour. Furthermore, consistent replications in GWAS are needed to improve credibility of genetic variants., Trial Registration: Prospero CRD42019119456 .

Objectives: To examine associations between long-term (11-22 years) adherence to physical activity recommendations and mortality from all causes and from cardiovascular disease., Design: Prospective population-based study with repeated assessments of self-reported physical activity (1984-86, 1995-97 and 2006-08) and follow-up until the end of 2013., Setting: County of Nord-Trøndelag, Norway., Participants: Men and women aged ≥20 years; 32 811 who participated in 1984-86 and 1995-97; 22 058 in 1984-86 and 2006-08; 31 948 in 1995-97 and 2006-09 and 19 349 in all three examinations (1984-1986, 1995-95 and 2006-08)., Main Outcome Measures: All-cause mortality and cardiovascular disease mortality from the national Cause of Death Registry., Results: Compared with the reference category comprising individuals who adhered to the physical activity recommendations (≥150 min of moderate intensity or ≥60 min of vigorous intensity physical activity per week) over time, individuals who remained inactive (reporting no or very little physical activity) from 1984-86 to 1995-97 had HRs (95% CI) of 1.56 (1.40 to 1.73) for all-cause mortality and 1.94 (1.62 to 2.32) for cardiovascular disease mortality. Individuals who were inactive in 1984-86 and then adhered to recommendations in 2006-08 had HRs of 1.07 (0.85 to 1.35) for all-cause mortality and 1.31 (0.87 to 1.98) for cardiovascular disease mortality. In a subsample of individuals who participated at all three time points, those who were inactive or physically active below the recommended level across three decades (1984-86, 1995-97 and 2006-2008) had an HR of 1.57 (1.22 to 2.03) for all-cause mortality and 1.72 (1.08 to 2.73) for cardiovascular disease mortality., Conclusion: Individuals who remained, or became, physically inactive had substantially greater risk of all-cause and cardiovascular disease mortality compared with those who met the physical activity recommendations throughout the lifespan., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective/background: To examine the prospective association between work-related mental fatigue and risk of insomnia symptoms, and if leisure time physical activity modifies this association., Participants: A total of 8,464 women and 7,480 men who participated in two consecutive surveys of the Norwegian HUNT study., Methods: The study comprises longitudinal data on persons who were vocationally active and without insomnia symptoms at baseline in 1995-1997. We used a modified Poisson regression model to calculate adjusted risk ratios (RRs) with a 95% confidence interval (CI) for insomnia symptoms at follow-up in 2006-2008 associated with work-related mental fatigue and leisure time physical activity at baseline., Results: Women and men who always experienced mental fatigue after a workday had RRs of insomnia symptoms of 2.55 (95% CI 1.91-3.40) and 2.61 (95% CI 1.80-3.78), respectively, compared to workers who never or seldom had this experience. There was no strong modifying effect of leisure time physical activity on this association, but workers who always experienced mental fatigue had a RR of insomnia symptoms of 3.17 (95% CI 2.28-4.40) if they reported low physical activity and a RR of 2.52 (95% 1.89-3.39) if they reported high physical activity., Conclusion: This study shows that work-related mental fatigue, caused by high cognitive workload, is a strong risk factor for insomnia symptoms. There was no clear modifying effect of leisure time physical activity but workers who experienced excessive work-related fatigue accompanied by low physical activity had the highest risk of insomnia symptoms.

Background: The multidimensional array of clinical features and prognostic factors makes it difficult to optimize management within the heterogeneity of patients with common musculoskeletal pain. This study aimed to identify phenotypes across prognostic factors and musculoskeletal complaints. Concurrent and external validity were assessed against an established instrument and a new sample, respectively, and treatment outcome was described., Methods: We conducted a longitudinal observational study of 435 patients (aged 18-67 years) seeking treatment for nonspecific complaints in the neck, shoulder, low back or multisite/complex pain in primary health care physiotherapy in Norway. Latent class analysis was used to identify phenotypes based on 11 common prognostic factors within four biopsychosocial domains; pain, beliefs and thoughts, psychological and activity and lifestyle., Results: Five distinct phenotypes were identified. Phenotype 1 (n = 77, 17.7%) and 2 (n = 142, 32.6%) were characterized by the lowest scores across all biopsychosocial domains. Phenotype 2 showed somewhat higher levels of symptoms across the biopsychosocial domains. Phenotype 3 (n = 89, 20.5%) and 4 (n = 78, 17.9%) were more affected across all domains, but phenotype 3 and 4 had opposite patterns in the psychological and pain domains. Phenotype 5 (n = 49, 11.3%) were characterized by worse symptoms across all domains, indicating a complex phenotype. The identified phenotypes had good external and concurrent validity, also differentiating for the phenotypes in function and health-related quality of life outcome at 3-month follow-up., Conclusion: The phenotypes may inform the development of targeted interventions aimed at improving the treatment efficiency in patients with common musculoskeletal disorders., Significance: This observational prospective study identified five distinct and clinically meaningful phenotypes based on biopsychosocial prognostic factors across common musculoskeletal pain. These phenotypes were independent of primary pain location, showed good external validity, and clear variation in treatment outcome. The findings are particularly valuable as they describe the heterogeneity of patients with musculoskeletal pain and points to a need for more targeted interventions in common musculoskeletal disorders to improve treatment outcome., (© 2020 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation - EFIC ®.)

Background: We investigated the influence of sleeplessness and number of insomnia symptoms on the probability of recovery from chronic low back pain (LBP), and the possible interplay between sleeplessness and co-occurring musculoskeletal pain on this association., Methods: The study comprised data on 3712 women and 2488 men in the Norwegian HUNT study who reported chronic LBP at baseline in 1995-1997. A modified Poisson regression model was used to calculate adjusted risk ratios (RRs) for the probability of recovery from chronic LBP at follow-up in 2006-2008, associated with sleep problems and co-occurring musculoskeletal pain at baseline., Results: Compared with persons without sleeplessness, persons who often/always experienced sleeplessness had a lower probability of recovery from chronic LBP (RR 0.65, 95% CI 0.57 to 0.74 in women and RR 0.81, 95% CI 0.69 to 0.95 in men). Although there was no clear evidence of statistical interaction between sleeplessness and co-occurring musculoskeletal pain, women and men who often/always experienced sleeplessness and had ≥5 additional chronic pain sites had RRs of recovery of 0.40 (95% CI 0.33 to 0.48) and 0.59 (95% CI 0.45 to 0.78), respectively, compared with persons without sleeplessness and 1-2 chronic pain sites., Conclusion: These findings suggest that preventing or reducing sleep problems among people with chronic LBP may have the potential of improving the long-term prognosis of this condition, also among those with several additional pain sites., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Study Objectives: To examine independent associations of sleeplessness and high-sensitivity C-reactive protein (hsCRP) with risk of chronic musculoskeletal pain, and to explore the joint effect of sleeplessness and hsCRP on risk of chronic musculoskeletal pain., Methods: A population-based prospective study of 3214 women and 3142 men (mean age: 55.4, range: 32-87) without severe chronic musculoskeletal pain and with hsCRP ≤ 10 mg/L at baseline in 2007-2008. Modified Poisson regression was used to calculate adjusted risk ratios (RRs) with 95% confidence intervals (CIs) for any chronic musculoskeletal pain and chronic widespread pain (CWP) at follow-up in 2015-2016 associated with self-reported sleeplessness and hsCRP at baseline., Results: Compared with persons without sleeplessness, women and men reporting often/or always sleeplessness had RRs of CWP of 2.53 (95% CI: 1.94-3.29) and 2.48 (95% CI: 1.63-3.77), respectively. There was no clear association between hsCRP and risk of any chronic musculoskeletal pain or CWP. Joint effect analyses using persons without sleeplessness and with a hsCRP < 1.00 mg/L as the reference gave RRs for chronic musculoskeletal pain of 1.73 (95% CI: 1.26-2.37) for those with often/always sleeplessness and hsCRP < 1.00 mg/L; 1.01 (95% CI: 0.78-1.32) for those without sleeplessness and hsCRP ≥3.00 mg/L; and 2.47 (95% CI: 1.79-3.40) if they had both often/always sleeplessness and hsCRP ≥ 3.00 mg/L. The corresponding RRs for CWP were 1.89 (95% CI: 1.27-2.83), 0.96 (95% CI: 0.68-1.37), and 2.83 (95% CI: 1.91-4.20), respectively., Conclusions: These results suggest that there is an interplay between sleeplessness and hsCRP on risk of any chronic musculoskeletal pain and CWP., (© Sleep Research Society 2019. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.)

Objectives: To investigate the association between insomnia symptoms and risk of self-reported fibromyalgia in women, and to explore whether leisure time physical activity and body mass index (BMI) modify this association., Design: Prospective cohort study., Setting: We used longitudinal data from the Norwegian Nord-Trøndelag Health Study collected in 1995-1997 (baseline) and 2006-2008 (follow-up)., Participants: A total of 14 172 women who reported to be free from fibromyalgia at baseline., Primary Outcome Measures: We estimated adjusted risk ratios (RRs) with 95% CI for self-reported fibromyalgia at follow-up associated with baseline insomnia symptoms, leisure time physical activity and BMI., Results: Overall, 466 incident cases of fibromyalgia were reported during the follow-up period of approximately 11 years, corresponding to a crude absolute risk (AR) of 3.3%. Compared with women without insomnia symptoms (crude AR=2.8%), women who reported one, two or three symptoms had RRs of fibromyalgia of 1.39 (95% CI: 1.08 to 1.80), 1.86 (95% CI: 1.33 to 2.59) and 2.66 (95% CI: 1.75 to 4.06), respectively. Compared with highly physically active women without insomnia symptoms (crude AR=2.7%), women with one or more insomnia symptoms had a RR of fibromyalgia of 1.90 (95% CI: 1.30 to 2.79) if they reported low physical activity and a RR of 1.55 (95% CI: 1.12 to 2.13) if they reported high physical activity. We found no synergistic effect between insomnia symptoms and BMI on risk of fibromyalgia; however, overweight and obese women with one or more insomnia symptoms had RRs of 2.35 (95% CI: 1.73 to 3.21) and 2.18 (95% CI: 1.42 to 3.35) compared with the reference group of normal weight women without insomnia symptoms (crude AR=2.3%)., Conclusions: Insomnia symptoms are strongly and positively associated with risk of fibromyalgia in adult women. Leisure time physical activity may compensate for some of the adverse effect of insomnia symptoms on risk of fibromyalgia., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Most previous studies have relied on single measurements of body weight and physical activity and have not considered the interplay between long-term changes in body weight and physical activity in relation to mortality. The aim of the current study was therefore to examine the joint effect of changes in body weight and leisure-time physical activity over a period of ~ 10 years on all-cause and cardiovascular mortality., Methods: The study population comprised 34,257 individuals who participated in the first (1984-86) and second (1995-97) waves of the HUNT Study, and were followed up through the Norwegian Cause of Death Registry until December 31st, 2013. We used Cox regression to estimate hazard ratios (HR) with 95% confidence intervals (CI) of death associated with changes in body weight and leisure-time physical activity., Results: Compared to the reference group with stable weight who were long-term physically active, people who gained ≥5% of their weight had a HR for all-cause mortality of 1.54 (95% CI: 1.28-1.85) if they were long-term physically inactive; a HR of 1.23 (1.09-1.40) if they became physically active, and a HR of 1.00 (95% CI 0.94-1.06) if they were long-term physically active. The corresponding HRs for cardiovascular mortality were 1.57 (95% CI 1.17-2.12), 1.28 (95% CI 1.04-1.58) and 1.06 (95% CI 0.96-1.16), respectively. Long-term physical inactivity was associated with increased all-cause (HR 1.29; 95% CI 1.08-1.53) and cardiovascular (HR 1.37; 95% CI 1.05-1.79) mortality among those who were weight stable., Conclusions: The risk of all-cause and cardiovascular mortality is particularly evident among people who gain weight while remaining inactive during a ~ 10 year period. However, participants who remained physically active had the lowest risk of premature mortality, regardless of maintenance or increase in weight. These findings suggest that there is an interplay between long-term changes in body weight and physical activity that should receive particular attention in the prevention of premature mortality.

Purpose: To investigate if occupational physical activity (OPA) and leisure-time physical activity (LTPA) influence the association between musculoskeletal pain and sleep problems., Methods: Cross-sectional study includes 678 workers in the Danish PHysical ACTivity cohort with Objective measurements (DPhacto). Musculoskeletal pain was assessed by questionnaires, while OPA and LTPA were measured with accelerometers for up to 6 consecutive days. We used logistic regression to calculate odds ratios (ORs) with 95% confidence intervals (CIs) for self-reported insomnia symptoms and non-restorative sleep., Results: Analyses of the joint association of musculoskeletal pain and OPA showed that workers with high pain and high OPA had ORs of 5.80 (95% CI 2.64-12.67) for insomnia symptoms and 2.50 (95% CI 1.37-4.57) for non-restorative sleep, compared to those with low pain and low OPA, whereas workers with high pain and low OPA had ORs of 4.67 (95% CI 2.17-10.07) for insomnia symptoms, and 2.67 (95% CI 1.46-4.89) for non-restorative sleep, respectively. Furthermore, workers with high pain and high LTPA had ORs of 4.23 (95% CI 2.16-8.32) for insomnia symptoms and 1.95 (95% CI 1.09-3.48) for non-restorative sleep, compared to those with low pain and low LTPA, whereas workers with high pain and low LTPA had ORs of 3.34 (95% CI 1.66-6.70) for insomnia symptoms and 2.14 (95% CI 1.21-3.80) for non-restorative sleep, respectively., Conclusions: Workers with high musculoskeletal pain who also conducted high levels of OPA or LTPA reported higher prevalence of insomnia symptoms.

Objectives: To prospectively investigate (i) the association of physical work demands and work-related physical fatigue with risk of insomnia symptoms and (ii) if these associations are influenced by chronic musculoskeletal pain., Methods: Prospective study on a working population of 8563 women and 7598 men participating in the Nord-Trøndelag Health Study (Norway) who reported no insomnia at baseline in 1995-1997. Occurrence of insomnia symptoms was assessed at follow-up in 2006-2008. A Poisson regression model was used to calculate adjusted risk ratios (RRs) for insomnia symptoms with 95% CI., Results: Compared with workers without work-related physical fatigue, women and men who reported that they were always fatigued had RRs of insomnia of 2.34 (95% CI 1.72 to 3.18) and 2.47 (95% CI 1.59 to 3.83), respectively. Overall, physical work demands was not associated with risk of insomnia, although men who reported heavy physical work had an RR of 0.67 (95% CI 0.47 to 0.97) compared with men with mostly sedentary work. Compared with the reference group of workers without work-related physical fatigue and no chronic pain, analyses of joint effects showed that women with excessive work-related fatigue had an RR of 4.20 (95% CI 2.95 to 5.98) if they reported chronic pain and an RR of 1.67 (95% CI 0.87 to 3.18) if they did not. Corresponding RRs in men were 3.55 (95% CI 2.11 to 5.98) and 2.13 (95% CI 1.07 to 4.25)., Conclusion: These findings suggest that there is an interplay between work-related physical fatigue and musculoskeletal pain that should receive particular attention in the prevention of insomnia in working populations., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Objectives This study aimed to investigate (i) the associations between occupational physical activity (OPA) and leisure-time physical activity (LTPA) with insomnia symptoms and non-restorative sleep and (ii) the joint associations between OPA and LTPA with insomnia symptoms and non-restorative sleep, respectively. Methods Data were drawn from a cross-sectional study including 650 workers in the Danish PHysical ACTivity cohort with Objective measurements (DPhacto). OPA and LTPA were measured with accelerometers on the thigh and upper back for up to six consecutive days and subsequently divided into quartiles of "very low", "low", "medium" and "high" activity. We used logistic regression to calculate odds ratios (OR) with 95% confidence intervals (CI) for insomnia symptoms and non-restorative sleep associated with OPA and LTPA. Results A 10% increase in OPA was associated with a higher prevalence of insomnia symptoms (OR 1.39, 95% CI 1.03-1.89) but not with the prevalence of non-restorative sleep (OR 0.93, 95% CI 0.71-1.21). On the other hand, a 10% increase in LTPA was associated with a lower prevalence of non-restorative sleep (OR 0.51, 95% CI 0.28-0.92). Although no significant additive interaction was found, analyses of the joint association of OPA and LTPA showed that people with high OPA and low LTPA had an OR of 2.07 (95% CI 1.01-4.24) for insomnia symptoms, compared to those with low OPA and high LTPA, whereas people with high levels of both OPA and LTPA had an OR of 1.47 (95% CI 0.73-2.96). Conclusions While LTPA was associated with lower prevalence of sleep problems, OPA was associated with higher prevalence of insomnia symptoms. A combination of high OPA and low LTPA were more strongly associated with insomnia symptoms compared to a combination of low OPA and high LTPA.

We investigated the prospective association between chronic musculoskeletal pain and risk of insomnia, and if leisure-time physical activity and body mass index modify this association. The study comprised historical data on 11 909 women and 9938 men in the Norwegian HUNT study without sleep problems at baseline in 1995-97 and followed-up for insomnia in 2006-08. Poisson regression was used to estimate adjusted risk ratios (RRs) with 95% confidence intervals (CIs). Compared to pain-free participants, any chronic pain was associated with a RR of insomnia of 2.27 (95% CI: 1.93, 2.66) in women and 1.58 (95% CI: 1.28, 1.95) in men, whereas reporting ≥5 chronic pain sites gave RRs of 3.20 (95% CI: 2.60, 3.95) and 2.40 (95% CI: 1.76, 3.27), respectively. Analysis of joint effects showed that: (i) compared to pain-free physically active people, RRs in people with ≥5 chronic pain sites were 3.77 (95% CI: 2.42-5.85) if they were inactive and 2.76 (95% CI: 2.29, 3.31) if they were active; and (ii) compared to pain-free people with normal weight, RRs in people with ≥5 chronic pain sites were 3.52 (95% CI: 2.81, 4.40) if they were obese and 2.93 (95% CI: 2.24, 3.84) if they had normal weight. In conclusion, chronic musculoskeletal pain increases the risk of insomnia, particularly among those who report several pain sites. Although there was no clear evidence of modifying effects, our results suggest that a healthy active lifestyle reduces the risk of insomnia in people with chronic musculoskeletal pain., (© 2017 European Sleep Research Society.)