Germ aversion is a risk factor for chronic low back pain and shoulder pain under the COVID-19 pandemic: an internet-based panel study

The COVID-19 pandemic has increased germ aversion, an aversive affective response to a high likelihood of pathogen transmission. While psychological factors are associated with chronic pain, the relationship between germ aversion and chronic pain remains unexplored. This study aimed to examine the relationship between germ aversion and new-onset and prognosis of chronic pain using longitudinal data collected during the COVID-19 pandemic. We conducted web-based surveys of full-time workers at baseline and after three months. Data were collected on demographic characteristics, psychological factors, and chronic pain. Germ aversion was assessed using a modified Perceived Vulnerability to Disease scale. We analyzed responses from 1265 panelists who completed the survey twice. The prevalence of chronic low back pain (CLBP) and chronic neck and shoulder pain (CNSP) was associated with sex, short sleep duration, psychological distress, loneliness, and germ aversion. Stratified analyses showed that germ aversion was a risk factor for CLBP at three months in both individuals with and without CLBP at baseline, and for CNSP at three months in those with CNSP at baseline, even after adjustment for confounders. In conclusion, this preliminary study suggests that high germ aversion is a risk factor for CLBP and CNSP in young and middle-aged workers.

App-Delivered Cognitive-Behavioral Therapy for Insomnia Among Patients with Comorbid Musculoskeletal Complaints and Insomnia Referred to 4-Week Inpatient Multimodal Rehabilitation: Protocol for a Randomized Clinical Trial

Background

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).

The bidirectional association between chronic musculoskeletal pain and sleep-related problems: a systematic review and meta-analysis

OBJECTIVES

This systematic review and meta-analysis synthesizes the evidence on prospective bidirectional associations between sleep-related problems (SRP) and chronic musculoskeletal pain (CMP).

METHODS

A literature search for cohort studies available in the PubMed, Scopus, Web of Science, PsycINFO and Cochrane Library databases as of 19 July 2022 was performed. Pooled odds ratios and effect sizes were calculated through random effects meta-analysis. Subgroup and meta-regression analyses were performed to explore differences by follow-up time, proportion of each sex and mean age. The Meta-analysis Of Observational Studies in Epidemiology guidelines were strictly followed.

RESULTS

Twenty studies with a total of 208 190 adults (aged 34.4-71.7 years) were included, with 17 of them being used in the meta-analysis. Individuals with SRP at baseline had a 1.79-fold higher incidence (odds ratio [OR] = 1.79; 95% CI: 1.55, 2.08; I2 = 84.7%; P < 0.001) and a 2.04-fold higher persistence (OR = 2.04; 95% CI: 1.42, 2.94; I2 = 88.5%; P < 0.005) of CMP than those without SRP. In the subgroup analysis of the association between SRP and CMP, the longer the follow-up time of the studies, the higher the heterogeneity between them. In the corresponding meta-regression, no significant effect was observed for follow-up time, sex proportion or age. Individuals with CMP at baseline had a 2.02-fold higher incidence of SRP (OR = 2.02; 95% CI: 1.62, 2.53; I2 = 90.0%; P < 0.001) than those without CMP.

CONCLUSION

This study provides robust evidence concerning the longitudinal association between SRP and incidence-persistence of CMP in adults. In addition, the available prospective studies support the existence of a bidirectional relationship between CMP and SRP.

PROSPERO REGISTRATION NUMBER

CRD42020212360.

Perioperative Sleep Disturbance Following Mastectomy: A Longitudinal Investigation of the Relationship to Pain, Opioid Use, Treatment, and Psychosocial Symptoms

OBJECTIVES

Sleep disturbance negatively impacts the quality of life and recovery. Our objective was to evaluate the relationship between the individual patient and surgical factors with greater sleep disturbance following breast surgery.

METHODS

In this prospective longitudinal study, patients completed validated measures regarding sleep disturbance, pain, opioid use, and psychological symptoms preoperatively and then 2 weeks, 6 and 12 months postoperatively. Univariable and multivariable generalized estimating equations evaluated demographic, surgical, pain, and psychological predictors of sleep disturbance during the first year after breast surgery.

RESULTS

Female patients (n=259) reported varying degrees of sleep disturbance, which were longitudinally associated with pain and psychosocial factors (eg, anxiety, depression, and affect). Independent preoperative predictors of worse sleep disturbance included younger age (B=-0.09, P =0.006), opioid use (B=3.09, P =0.02), and higher pain (B=0.19, P =<0.001) and anxiety (B=0.45, P =<0.001) at baseline. In addition, higher baseline positive affect (B=-0.14, P =<0.012) and the surgical category total mastectomy without reconstruction (B=-2.81, P =<0.006) were independently associated with lower sleep disturbance. Those with worse baseline sleep required more opioid analgesics during surgical recovery, and continued use of opioids at 2 weeks postsurgery was associated with disturbed sleep.

DISCUSSION

Certain patient characteristics, including younger age and baseline anxiety, positive affect, pain, and opioid use, were associated with greater sleep disturbance in the first year after breast surgery. Sleep disturbance was also associated with the greater perioperative and postoperative opioid requirements. Preoperative interventions (eg, anxiety management, cultivating positive affect, and multimodal pain management) in high-risk individuals may enhance sleep and recovery postoperatively, and allow more moderate and less prolonged opioid use.

A bidirectional study of the association between insomnia, high-sensitivity C-reactive protein, and comorbid low back pain and lower limb pain

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.

Relationship between fatty acid intake and chronic neck/shoulder/upper limb pain without elevated CRP in a Japanese population: a cross-sectional analysis of the Shika study

Although chronic pain (CP) is classified as inflammatory or non-inflammatory, the involvement of fatty acid intake in this process has not yet been examined in detail. Therefore, the present study investigated whether the relationship between CP and fatty acid intake differs between high and low C-reactive protein (CRP) levels in middle-aged and elderly individuals in the Shika study. One-thousand and seven males and 1216 females with mean ages of 68⋅78 and 69⋅65 years, respectively, participated in the present study. CRP was quantified by blood sampling from participants who responded to a CP questionnaire. The brief-type self-administered diet history questionnaire (BDHQ) was used to assess fatty acid intake. Interactions were observed between CP and CRP on monounsaturated fatty acids (MUFA) and eicosadienoic acid in a two-way analysis of covariance adjusted for sex, age, lack of exercise, lack of sleep, current smoking and drinking status, and BMI. MUFA (OR 1⋅359) and eicosadienoic acid (OR 1⋅072) were identified as significant independent variables for CP in a multiple logistic regression analysis, but only in the low CRP group. Only a high intake of MUFA and eicosadienoic acid was associated with chronic neck/shoulder/upper limb pain without elevated CRP. In psychogenic and neuropathic pain without elevated CRP, an increased intake of MUFA and eicosadienoic acid, a family member of n -6 fatty acids, appears to affect CP. Further longitudinal studies are needed to elucidate this relationship.

Shift work, inflammation and musculoskeletal pain-The HUNT Study

BACKGROUND

Studies have indicated that shift work, in particular night work, is associated with chronic musculoskeletal pain but the mechanisms are unclear. It has been suggested that sleep disturbance, a common complaint among shift and night workers, may induce low-grade inflammation as well as heightened pain sensitivity.

AIMS

Firstly, this study was aimed to examine the cross-sectional associations between shift work, C-reactive protein (CRP) level and chronic musculoskeletal pain, and secondly, to analyse CRP as a mediator between shift work and chronic musculoskeletal pain.

METHODS

The study included 23 223 vocationally active women and men who participated in the HUNT4 Survey of the Trøndelag Health Study (HUNT). Information was collected by questionnaires, interviews, biological samples and clinical examination.

RESULTS

Regression analyses adjusted for sex, age and education revealed significant associations between shift work and odds of any chronic musculoskeletal pain (odd ratio [OR] 1.11, 95% confidence interval [CI] 1.04-1.19), between shift work and CRP level (OR 1.09, 95% CI 1.03-1.16) and between CRP level 3.00-10 mg/L and any chronic musculoskeletal pain (OR 1.38, 95% CI 1.27-1.51). Shift work and CRP were also associated with number of chronic pain sites. Mediation analysis indicated that shift work was indirectly associated with any chronic musculoskeletal pain through CRP (OR 1.03, 95% CI 1.01-1.06).

CONCLUSIONS

The results support the hypothesis that shift work is associated with chronic musculoskeletal pain, and that systemic inflammation may be a biological mechanism linking shift work to chronic pain.

Postoperative Pain Mediates the Association Between Peripheral Nerve Blocks and Postoperative Sleep Following Lower Extremity Arthroplasty

OBJECTIVES

Despite substantial research showing the bidrectional relationship between sleep and pain, there remains a dearth of research examining the role of perioperative pain management interventions in mitigating postoperative sleep disturbances. This secondary analysis of a prospective observational multisite study examined the association between peripheral nerve block (PNB) use during total knee or total hip arthroplasty (TKA/THA) procedures and postoperative pain and sleep outcomes.

MATERIALS AND METHODS

Adult patients undergoing TKA or THA procedures were recruited from 2 tertiary care facilities. Average pain and sleep disturbance scores were collected preoperatively and at 1- and 2-week postoperatively. Participants were not randomized to receive PNB. Postoperative outcomes were compared based on receipt of PNB during surgery. Structural equation modeling path analysis was utilized to model multiple co-occurring relationships, including mediation pathways between perioperative pain management approaches, pain, and postoperative sleep outcomes.

RESULTS

Of the 197 participants, 53% received PNB. Mediation analyses indicated that PNB was indirectly associated with 1-week sleep disturbance via its effects on 1-week pain intensity (β=-0.02, 95% confidence interval [CI] -0.04, -0.001, P=0.04). In addition, PNB was indirectly associated with 2-week sleep disturbance, via its effects on 1-week pain intensity and 1-week sleep disturbance (β=-0.04, 95% CI -0.07, -0.02, P=0.04). Lastly, PNB was indirectly associated with 2-week pain intensity via its effects on 1-week pain intensity (β=-0.10, 95% CI -0.19, -0.02, P=0.02).

CONCLUSIONS

Receipt of PNB during TKA or THA was found to be associated with improved 1-week postoperative pain intensity, which in turn was found to be associated with lower sleep disturbances at both 1- and 2-week postoperative time points. Multimodal opioid sparing pain management interventions, capable of improving postoperative sleep, are vital to improving recovery and rehabilitation following arthroplasty.

Subtypes of insomnia and the risk of chronic spinal pain: the HUNT study

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.

Long-term changes in self-reported sleep quality and risk of chronic musculoskeletal pain: The HUNT Study

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.

Shift work, low-grade inflammation, and chronic pain: a 7-year prospective study

Objectives

We investigated prospective associations of shift work with chronic pain and C‐reactive protein (CRP), an indicator of inflammation. Furthermore, we elucidated CRP as a possible mediator and/or moderator of effects of shift work on pain.

Methods

Data from a 7 years follow‐up study were analyzed (N = 2323). Shift work and chronic pain of “neck/shoulder”, “arm/hand”, “upper back”, “low back”, “hip/leg/feet”, and “other regions” were measured by questionnaires. “Chronic widespread pain”, “number of chronic pain sites”, and “any chronic pain” were computed. CRP was measured in serum samples. Logistic and Poisson regressions were conducted. Mediation was assessed by casual mediation analyses and moderation by the Relative Excess Risk due to Interaction (RERI).

Results

Shift work was not associated with any chronic pain variable and no mediation was detected. CRP was associated with low back pain, hip/leg pain, and “number of pain sites”, and also with the combination of shift work and CRP of 1–2.99 mg/L (compared to: no shiftwork and CRP < 1). Additionally, shiftwork and CRP 1–2.99 mg/L was associated with risk of “any chronic pain” (OR: 1.76, 95% CI: 1.12, 2.85), which was not associated with CRP alone. Moderation analyses suggested the risks for “any chronic pain” and “number of pain regions” increased when individuals with elevated CRP worked shifts—beyond what the separate effects of CRP and shift would suggest.

Conclusions

We found no evidence of shift work in general affecting CRP or chronic pain. However, shift work and elevated CRP combined may influence chronic pain.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00420-020-01626-2.

Insomnia is Associated with the Effect of Inpatient Multimodal Occupational Rehabilitation on Work Participation in Workers with Musculoskeletal or Mental Health Disorders: Secondary Analyses of a Randomized Clinical Trial

STUDY 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.

Number of Chronic Nighttime Insomnia Symptoms and Risk of Chronic Widespread Pain and Pain-Related Disability: The HUNT Study

STUDY 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.

Influence of sleep problems and co-occurring musculoskeletal pain on long-term prognosis of chronic low back pain: the HUNT Study

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.