The association of sleep and pain: an update and a path forward

Association between Lower Urinary Tract Symptoms and Sleep Quality of Patients with Depression

Background and Objectives: In the general population, sleep disorders are associated with lower urinary tract symptoms (LUTS) including urinary incontinence (UI). This connection has not been explored fully in specific patient groups. Thus, we investigated the association between sleep quality and LUTS for patients with depression. Materials and Methods: This study was prospective and cross-sectional. We analyzed questionnaire data on depression, sleep quality, LUTS, and UI from depressed patients treated in our department of adult psychiatry. We used the Hamilton Rating Scale for Depression, the Holland Sleep Disorders Questionnaire, the International Prostate Symptom Score, and the International Consultation on Incontinence Questionnaire-Short Form. Results: In total, 102 patients treated for depression were enrolled. We found a statistically significant correlation between depression severity and sleep quality. A significant correlation was also investigated for sleep quality and LUTS severity. The group of depressed patients with moderate or severe LUTS had greater sleep problems compared with patients who had mild urinary tract symptoms or no symptoms. With regression analysis, we further demonstrated that the relationships between LUTS and sleep quality as well as UI and sleep quality in depressed patients are independent from age and sex. Conclusions: In the cohort of patients treated for depression, sleep quality correlated with LUTS including UI. We suggest that the negative effect of LUTS and UI on sleep quality that we observed should lead to the re-evaluation of current recommendations for diagnosis and treatment of sleep problems among patients with depression.

Pain reduction induced by tapentadol in patients with musculoskeletal chronic pain fosters better sleep quality

Background

Poor sleep may predict the increase and intensification of pain over time with increased insomnia symptoms being both a predictor and an indicator of worse pain outcomes and physical functioning status over time. However, the impact of different analgesic therapies on quality of life, functional recovery and sleep has been poorly assessed to date, whereas these evaluations may greatly help clinicians in the selection of treatment when dealing with patients with chronic pain (CP).

Methods

To explore whether tapentadol-induced pain relief may drive improved sleep quality, we carried out a pooled analysis of real-world data collected from 487 patients with CP (mean age, 68.3 years; 57.7% women) suffering from a wide range of chronic musculoskeletal pain conditions and treated with tapentadol.

Results

Following tapentadol treatment, patients experienced an 80% reduction in the frequency of very disturbed sleep as well as a 50% reduction in the predominant sleep complaint reported by patients with CP - that is, nocturnal awakenings. A significantly greater proportion of patients reported good/restful sleep at the end of the study period compared to baseline (72.4% versus 25.3%; p<0.01). This benefit was observed regardless of the clinical setting, treatment duration, posology or patient age and was associated with a higher proportion of patients reporting an improved global health status and good tolerability.

Conclusion

The reduction in pain intensity provided by tapentadol fosters sleep quality and favours a better quality of life. Therefore, our findings provide the rationale for addressing sleep quality as a relevant outcome, complementary to pain relief in CP management.

Relationship between unhealthy sleep status and dry eye symptoms in a Japanese population: The JPHC-NEXT study

PURPOSE

To investigate whether and how unhealthy sleep habits (i.e., the frequency of difficulty falling or staying asleep, and the frequency of waking up tired) and the duration of sleep are related to the prevalence of dry eye disease (DED) in a general population.

METHODS

This study included a total of 106,282 subjects aged 40-74 years who participated in a baseline survey of the Japan Public Health Center-based Prospective Study for the Next Generation. DED was defined as the presence of clinically diagnosed DED or severe symptoms. Multivariable-adjusted logistic regression models were used to assess the relationships of various components of sleep status with DED.

RESULTS

Higher frequencies of having difficulty falling or staying asleep, and waking up tired were significantly related to increased DED in both sexes (P_trend<0.001). Compared with those with 8 h/day of sleep, shorter sleepers had an increased prevalence of DED in both sexes, although DED was increased among men who slept ≥10 h/day. By comparing participants with the greatest vs. the least difficulty of falling asleep, the multivariable-adjusted odds ratios (95% confidence interval [CI]) were 2.23 (95% CI, 1.99-2.49) for men and 1.91 (95% CI, 1.76-2.07) for women. When analyzed separately, the magnitude of each relationship was stronger with severe DED symptoms than with clinically diagnosed DED.

CONCLUSIONS

Sleep deprivation and poor sleep quality were significantly related to DED in a Japanese population.

Associations between migraine attacks and nightly sleep characteristics among adults with episodic migraine: a prospective cohort study

STUDY OBJECTIVES

Given the unknown immediate impact of migraine on nighttime sleep, we prospectively examined whether migraine headaches were associated with subsequent shorter sleep duration, higher fragmentation, and poorer quality in a cohort of 98 adults with episodic migraine.

METHODS

Participants completed twice-daily electronic diaries and wore actigraphs continuously for 6 weeks. We examined whether days with headaches were associated with changes in that night's sleep characteristics compared with headache-free days, using adjusted multivariable linear mixed models with subject-specific intercepts.

RESULTS

Participants were 35 ± 12 years old, 88% women, with an average of five migraine headaches per month. Over 4,406 days, we observed 1,077 headache days, representing 823 discrete headaches. Average nightly objective sleep duration was 7.3 ± 1.2 hr, efficiency 89.5 ± 3.3%, and wake after sleep onset (WASO) 44.8 ± 17.0 min. Objective sleep duration was 7.3 min (95% CI: 1.5, 13.0) longer on nights following a headache day compared with nights on a headache-free day. Objective sleep efficiency, WASO, and reported sleep quality were not significantly different on headache days compared with headache-free days (sleep efficiency: -0.06 min, 95% CI: -0.3, 0.2; WASO 1.5 min, 95% CI: 0.0, 3.0; sleep quality: 1.0, 95% CI: 0.8, 1.3).

CONCLUSIONS

Sleep periods immediately following migraine headaches are not associated with shorter duration, higher disruption, or poorer sleep quality in patients with episodic migraine. These results suggest that clinical evaluation of sleep disturbance in patients with episodic migraine should be approached independently of their migraine status.

Sleep disturbance in patients attending specialized chronic pain clinics in Denmark: a longitudinal study examining the relationship between sleep and pain outcomes

OBJECTIVES

Sleep disturbances are highly prevalent in patients with chronic pain. However, the majority of studies to date examining sleep disturbances in patients with chronic pain have been population-based cross-sectional studies. The aims of this study were to 1) examine the frequency of sleep disturbances in patients referred to two interdisciplinary chronic pain clinics in Denmark, 2) explore associations between sleep disturbances and pain intensity, disability and quality of life at baseline and follow-up, and 3) explore whether changes in sleep quality mediated the relationships between pain outcomes at baseline and pain outcomes at follow-up.

METHODS

We carried out a longitudinal observational study, examining patients enrolled in two chronic pain clinics assessed at baseline (n=2,531) and post-treatment follow-up (n=657). Patients reported on their sleep disturbances using the sleep quality subscale of the Karolinska Sleep Questionnaire (KSQ), their pain intensity using 0-10 numerical rating scales, their pain-related disability using the Pain Disability Index (PDI), and quality of life using the EuroQol-VAS scale. The average time between baseline and follow-up was 207 days (SD=154).

RESULTS

At baseline, the majority of patients reported frequent sleep disturbances. We found a significant association at baseline between self-reported sleep disturbances and pain intensity, pain-related disability, and quality of life, where greater sleep disturbance was associated with poorer outcomes. At follow-up, patients reported significant improvements across all pain and sleep outcomes. In two mediation models, we showed that changes in sleep disturbances from baseline to follow-up were significantly associated with (i) pain intensity at follow-up, and (ii) pain disability at follow-up. However, baseline pain intensity and disability scores were not associated with changes in sleep disturbances and, we did not find evidence for significant mediation of either pain outcome by changes in sleep disturbances.

CONCLUSIONS

Self-reported sleep disturbances were associated with pain outcomes at baseline and follow-up, with greater sleep disturbances associated with poorer pain outcomes. Changes in sleep quality did not mediate the relationships between baseline and follow-up scores for pain intensity and disability. These findings contribute to a growing body of evidence confirming an association between sleep and chronic pain experience, particularly suggestive of a sleep to pain link. Our data following patients after interdisciplinary treatment suggests that improved sleep is a marker for a better outcome after treatment.

Fibromyalgia: Pathogenesis, Mechanisms, Diagnosis and Treatment Options Update

Fibromyalgia is a syndrome characterized by chronic and widespread musculoskeletal pain, often accompanied by other symptoms, such as fatigue, intestinal disorders and alterations in sleep and mood. It is estimated that two to eight percent of the world population is affected by fibromyalgia. From a medical point of view, this pathology still presents inexplicable aspects. It is known that fibromyalgia is caused by a central sensitization phenomenon characterized by the dysfunction of neuro-circuits, which involves the perception, transmission and processing of afferent nociceptive stimuli, with the prevalent manifestation of pain at the level of the locomotor system. In recent years, the pathogenesis of fibromyalgia has also been linked to other factors, such as inflammatory, immune, endocrine, genetic and psychosocial factors. A rheumatologist typically makes a diagnosis of fibromyalgia when the patient describes a history of pain spreading in all quadrants of the body for at least three months and when pain is caused by digital pressure in at least 11 out of 18 allogenic points, called tender points. Fibromyalgia does not involve organic damage, and several diagnostic approaches have been developed in recent years, including the analysis of genetic, epigenetic and serological biomarkers. Symptoms often begin after physical or emotional trauma, but in many cases, there appears to be no obvious trigger. Women are more prone to developing the disease than men. Unfortunately, the conventional medical therapies that target this pathology produce limited benefits. They remain largely pharmacological in nature and tend to treat the symptomatic aspects of various disorders reported by the patient. The statistics, however, highlight the fact that 90% of people with fibromyalgia also turn to complementary medicine to manage their symptoms.

Open-loop Audio-Visual Stimulation for sleep promotion in older adults with comorbid insomnia and osteoarthritis pain: results of a pilot randomized controlled trial

Osteoarthritis is commonly comorbid with insomnia in older adults. While cognitivebehavioral therapy for insomnia is the recommended first-line treatment for insomnia, alternative efficacious non-pharmacological options are needed. This study examined sleep and pain in 30 community-dwelling older adults with comorbid insomnia and osteoarthritis pain randomized to two weeks of 30 min of bedtime active (n = 15, mean age 66.7 ± 5.2) or placebo control (n = 15, mean age 68.9 ± 5.0) Audiovisual Stimulation (AVS). After AVS use, improvements in sleep, pain, and depression were reported for both groups but between-group comparisons were non-significant. A posthoc analysis examined the effects of AVS in the 11 subjects who reported sleep latency complaints (≥30 min). No significant group differences were found for this small sleep latency subsample; however, the pre-post effect sizes (ES) of active AVS versus placebo were greatly increased for the subsample relative to the total sample for sleep (ES = 0.41 versus 0.18 for the Insomnia Severity Index, and 0.60 versus 0.03 for the Pittsburgh Sleep Quality Index, respectively). A similar enhanced effect pattern was found for pain (ES = 0.41 versus 0.15 for the Brief Pain Inventory). Study findings suggest that the 30-min AVS program may have potential to improve sleep in older adults with sleep onset but not sleep maintenance difficulty. Despite study limitations of a small sample size and lack of follow-up, results offer valuable insights into the functionality of AVS treatment. Future research should focus on subjects with sleep onset complaints, who are most likely to receive benefit from this treatment modality.

Disturbed Sleep Connects Symptoms of Posttraumatic Stress Disorder and Somatization: A Network Analysis Approach

Posttraumatic stress disorder (PTSD) and physical health problems, particularly somatic symptom disorder, are highly comorbid. Studies have only examined this co-occurrence at the disorder level rather than assessing the associations between specific symptoms. Using network analysis to identify symptoms that act as bridges between these disorders may allow for the development of interventions to specifically target this comorbidity. We examined the association between somatization and PTSD symptoms via network analysis. This included 349 trauma-exposed individuals recruited through the National Centre for Mental Health PTSD cohort who completed the Clinician-Administered PTSD Scale for DSM-5 and the Patient Health Questionnaire-15. A total of 215 (61.6%) individuals met the DSM-5 diagnostic criteria for PTSD. An exploratory graph analysis identified four clusters of densely connected symptoms within the overall network: PTSD, chronic pain, gastrointestinal issues, and more general somatic complaints. Sleep difficulties played a key role in bridging PTSD and somatic symptoms. Our network analysis demonstrates the distinct nature of PTSD and somatization symptoms, with this association connected by disturbed sleep.

Effect of Telephone Cognitive Behavioral Therapy for Insomnia in Older Adults With Osteoarthritis Pain: A Randomized Clinical Trial

IMPORTANCE

Scalable delivery models of cognitive behavioral therapy for insomnia (CBT-I), an effective treatment, are needed for widespread implementation, particularly in rural and underserved populations lacking ready access to insomnia treatment.

OBJECTIVE

To evaluate the effectiveness of telephone CBT-I vs education-only control (EOC) in older adults with moderate to severe osteoarthritis pain.

DESIGN, SETTING, AND PARTICIPANTS

This is a randomized clinical trial of 327 participants 60 years and older who were recruited statewide through Kaiser Permanente Washington from September 2016 to December 2018. Participants were double screened 3 weeks apart for moderate to severe insomnia and osteoarthritis (OA) pain symptoms. Blinded assessments were conducted at baseline, after 2 months posttreatment, and at 12-month follow-up.

INTERVENTIONS

Six 20- to 30-minute telephone sessions provided over 8 weeks. Participants submitted daily diaries and received group-specific educational materials. The CBT-I instruction included sleep restriction, stimulus control, sleep hygiene, cognitive restructuring, and homework. The EOC group received information about sleep and OA.

MAIN OUTCOMES AND MEASURES

The primary outcome was score on the Insomnia Severity Index (ISI) at 2 months posttreatment and 12-month follow-up. Secondary outcomes included pain (score on the Brief Pain Inventory-short form), depression (score on the 8-item Patient Health Questionnaire), and fatigue (score on the Flinders Fatigue Scale).

RESULTS

Of the 327 participants, the mean (SD) age was 70.2 (6.8) years, and 244 (74.6%) were women. In the 282 participants with follow-up ISI data, the total 2-month posttreatment ISI scores decreased 8.1 points in the CBT-I group and 4.8 points in the EOC group, an adjusted mean between-group difference of -3.5 points (95% CI, -4.4 to -2.6 points; P < .001). Results were sustained at 12-month follow-up (adjusted mean difference, -3.0 points; 95% CI, -4.1 to -2.0 points; P < .001). At 12-month follow-up, 67 of 119 (56.3%) participants receiving CBT-I remained in remission (ISI score, ≤7) compared with 33 of 128 (25.8%) participants receiving EOC. Fatigue was also significantly reduced in the CBT-I group compared with the EOC group at 2 months posttreatment (mean between-group difference, -2.0 points; 95% CI, -3.1 to -0.9 points; P = <.001) and 12-month follow-up (mean between-group difference, -1.8 points; 95% CI, -3.1 to -0.6 points; P = .003). Posttreatment significant differences were observed for pain, but these differences were not sustained at 12-month follow-up.

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial, telephone CBT-I was effective in improving sleep, fatigue, and, to a lesser degree, pain among older adults with comorbid insomnia and OA pain in a large statewide health plan. Results support provision of telephone CBT-I as an accessible, individualized, effective, and scalable insomnia treatment.

TRIAL REGISTRATION

Clinical Trials.gov Identifier: NCT02946957.

Daily associations between sleep and opioid use among adults with comorbid symptoms of insomnia and fibromyalgia

STUDY OBJECTIVES

Disturbed sleep and use of opioid pain medication are common among individuals with chronic pain. Anecdotally, opioids are thought to promote sleep by relieving pain. This study aimed to determine whether opioid use is associated with daily sleep parameters (and vice versa) in adults with comorbid symptoms of insomnia and fibromyalgia.

METHODS

Individuals reporting symptoms of insomnia and opioid use for fibromyalgia (n = 65, 93% women, 79% White) wore wrist actigraphy and completed daily diaries for 14 days (910 observations). Analyses examined daily associations between opioid dose (measured in lowest recommended dosage units) and three sleep parameters (actigraphy/self-reported total wake time and self-reported sleep quality). Multilevel models were used to account for the clustering of daily sleep and opioid assessments (level 1) within individuals (level 2).

RESULTS

Opioid use did not have a significant daily effect on total wake time or sleep quality, and sleep parameters did not significantly impact opioid use the next day; however, participants reported worse sleep quality and greater doses of opioids on evenings that they experienced greater pain.

CONCLUSIONS

Among adults reporting symptoms of insomnia and opioid use for fibromyalgia pain, opioid use is not reliably associated with wake time or sleep quality that night, and these sleep parameters are not significantly associated with opioid use the next day; however, evening pain has an adverse daily impact on both sleep quality and opioid use. Studies identifying strategies to prevent and manage fibromyalgia pain are needed, especially for individuals reporting comorbid insomnia and opioid use.

The influence of sleep disturbances and sleep disorders on pain outcomes among veterans: A systematic scoping review

Chronic nonmalignant pain, sleep disturbances and sleep disorders are highly prevalent conditions among U.S. military veterans. Evidence summaries highlight the influence of sleep on pain outcomes in the general adult population but not for the military veteran population. This is a significant gap as U.S. military veterans are an exceedingly high-risk population for both chronic pain and sleep disturbances and/or disorders. We aimed to review the influence of sleep disturbances and sleep disorders on pain outcomes among veterans with chronic nonmalignant pain. A systematic scoping review was conducted using PubMed/Medline, EMBASE, Scopus, CINAHL, and PsycINFO. Twenty-six out of 1450 studies from initial search were included in this review resulting in a combined sample size of N = 923,434 participants. Sleep disturbances and sleep disorders were associated with worse pain outcomes among veterans with chronic pain. Treatment-induced sleep improvements ameliorated pain outcomes in veterans with sleep disorders and sleep disturbances. Research is indicated to address an overlooked pain treatment opportunity - that of sleep disturbance and sleep disorder management.

Longitudinal sleep characteristics and hypertension status: results from the Wisconsin Sleep Cohort Study

AIMS

Sleep characteristics such as short sleep duration or sleep-disordered breathing are established predictors of hypertension. However, few studies have used in-lab polysomnography with a longitudinal design to measure how hypertension is associated with different sleep stages over time. The purpose of this study is to examine whether hypertension is associated with the longitudinal course of sleep quality over time.

METHODS

The current study evaluated data from the Wisconsin Sleep Cohort Study, which consists of 1525 adults in a community-based population of middle-aged to older adults followed for approximately 12-25 years. Sleep characteristics were objectively measured using polysomnography and subjectively assessed using a self-report questionnaire on insomnia complaints. We used linear mixed-effects regression models and cumulative logit models to assess whether the interaction of hypertension and time is associated with objective and subjective sleep.

RESULTS

We found people with hypertension exhibited a greater decline in total sleep time in rapid eye movement sleep (%) over time than those without hypertension (P < 0.05). Individuals with hypertension had less decline in % N3 sleep over time than those without hypertension (P < 0.05). Among the subjective insomnia complaints, our findings indicate hypertensive individuals have a higher probability of having higher levels of 'difficulties in falling asleep' compared with people without hypertension.

CONCLUSION

These findings suggest that hypertension is associated with modified longitudinal changes of objective and subjective sleep characteristics.

Validation of the Leiden Visual Sensitivity Scale and Visual Discomfort Scale in Chronic Pain Conditions

Discomfort provoked by normally innocuous visual stimuli has been reported by people with chronic pain. Visual discomfort may be higher in pain conditions in which central sensitization is implicated, such as Complex Regional Pain Syndrome (CRPS) and fibromyalgia. In an online study, we validated the Leiden Visual Sensitivity Scale (L-VISS) and Visual Discomfort Scale (VDS) in people with CRPS (n = 57), fibromyalgia (n = 75), and general chronic pain (n = 53); investigated whether these groups and pain-free controls (n = 125) differed in visual discomfort; and evaluated the effect of age. The L-VISS and VDS had good internal consistency. Both scales were positively related with experimentally induced visual distortions for mid-spatial frequency striped patterns, suggesting good construct validity. The scales were positively related with each other, and dissociated between the pain and pain-free groups in similar ways, suggesting good construct validity. There was no relationship between age and L-VISS scores and a small negative relationship between age and VDS scores. Visual discomfort was highest in the fibromyalgia group, followed by the CRPS group. This research confirms the utility of the L-VISS and VDS for measuring visual sensitivity in chronic pain and adds to evidence that central sensitization is an important mechanism of visual discomfort.

Prescribing Patterns of Pain Medications in Unspecific Low Back Pain in Primary Care: A Retrospective Analysis

Acute low back pain (LBP) is one of the most prevalent diseases worldwide. Since there is evidence of excessive prescriptions of analgesics, i.e., opioids, the aim of this study was to describe the use of pain medications in patients with LBP in the Swiss primary care setting. A retrospective, observational study was performed using medical prescriptions of 180 general practitioners (GP) during years 2009–2020. Patterns of pain medications (nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol, and opioids) as well as co-medications were analyzed in patients with a LBP diagnosis. Univariable and multivariable regression analyses assessed GP and patient characteristics associated with the prescription of pain medication. Patients included were 10,331 (mean age 51.7 years, 51.2% female); 6449 (62.4%) received at least one pain medication and of these 86% receive NSAIDs and 22% opioids. GP characteristics (i.e., self-employment status) and patient characteristics (male gender and number of consultations) were associated with significantly higher odds of receiving any pain medication in multivariable analysis. 3719 patients (36%) received co-medications. Proton-pump-inhibitors and muscle relaxants were the most commonly used co-medications. In conclusion, two-thirds of LBP patients were treated with pain medications. Prescribing patterns were conservative, with little use of strong opioids and co-medications.

Preoperative sleep quality and adverse pain outcomes after total hip arthroplasty

BACKGROUND

Sleep disturbance is thought to aggravate acute postoperative pain. The influence of preoperative sleep problems on pain control in the long-term and development of chronic postsurgical pain is largely unknown.

METHODS

This prospective, observational study aimed to examine the links between preoperative sleep disturbance (Pittsburgh Sleep Quality Index, PSQI) and pain severity (Brief Pain Inventory, BPI) 6 months postoperative (primary outcome), objective measures of pain and postoperative pain control variables (secondary outcomes). Patients (n = 52) with disabling osteoarthritis (OA) pain undergoing total hip arthroplasty (THA) were included. Quantitative sensory testing (QST) was performed preoperatively on the day of surgery to evaluate pain objectively. Clinical data, as well as measures of sleep quality and pain, were obtained preoperatively and longitudinally over a 6-month period.

RESULTS

Preoperatively, sleep disturbance (i.e., PSQI score >5) occurred in 73.1% (n = 38) of THA patients, and pain severity was high (BPI pain severity 5.4 ± 1.3). Regression models, adjusting for relevant covariates, showed that preoperative PSQI score predicted pain severity 6 months postoperative (β = 0.091 (95% CI 0.001-0.181), p = .048, R²  = 0.35). Poor sleep quality was associated with increased pressure pain sensitivity and impaired endogenous pain inhibitory capacity (R² range 0.14-0.33, all p's < 0.04). Moreover, preoperative sleep disturbance predicted increased opioid treatment during the first 24 hr after surgery (unadjusted β = 0.009 (95% CI 0.002-0.015) mg/kg, p = .007, R²  = 0.15).

CONCLUSIONS

Preoperative sleep disturbance is prevalent in THA patients, is associated with objective measures of pain severity, and independently predicts immediate postoperative opioid treatment and poorer long-term pain control in patients who have undergone THA.

SIGNIFICANCE

Poor sleep quality and impaired sleep continuity are associated with heightened pain sensitivity, but previous work has not evaluated whether preoperative sleep problems impact long-term postoperative pain outcomes. Here, we show that sleep difficulties prior to total hip arthroplasty adversely predict postoperative pain control 6 months after surgery. Given sleep difficulties robustly predict pain outcomes, targeting and improving sleep may have salutary effects on postoperative pain reports and management.

The Role of Sleep in the Transition from Acute to Chronic Musculoskeletal Pain in Youth-A Narrative Review

Musculoskeletal pain is common in the general pediatric population and is a challenge to youth, their parents, and society. The majority of children experiencing musculoskeletal pain will recover; however, a small subgroup of youth develops chronic pain. There is limited understanding of the factors that affect the transition from acute to chronic pain in youth. This review introduces sleep deficiency in the acute to chronic pain transition, exploring the potential mediational or mechanistic role and pathways of sleep in this process, including the interaction with sensory, psychological, and social components of pain and highlighting new avenues for treatment. Biological mechanisms include the increased production of inflammatory mediators and the effect on the hypothalamus-pituitary-adrenal (HPA) axis and on the dopaminergic signaling. Psychological and social components include the effect of sleep on the emotional-affective and behavioral components of pain, the negative impact on daily and social activities and coping strategies and on the reward system, increased pain catastrophizing, fear of pain, pain-related anxiety, hypervigilance, and social isolation. Future longitudinal studies are needed to elucidate these mechanistic pathways of the effect of sleep on the transition from acute to chronic pain, which may lead to the development of new treatment targets to prevent this transition.

Pediatric recurring pain in the community: the role of children's sleep and internalizing symptoms

Associations between poor sleep and pain may be amplified for children who also have depressive or anxious symptoms. This study examined associations between child sleep at eight years and recurrent pain at nine years along with the moderating role of internalizing symptoms. Families were from a community-based, ongoing longitudinal study (N = 632 children). At eight and nine years, twins (49.2% female, 56.7% non-Latinx European American, 28.8% Latinx) and caregivers participated in assessments focused on child sleep and pain, respectively. Approximately 53% of children had pain in at least one location at least monthly. Internalizing symptoms at age eight were positively associated with number of pain sites at age nine. Lower sleep efficiencies were associated with more pain sites for children with higher levels of internalizing symptoms. Later midpoint times were associated with more pain sites for children with lower levels of internalizing symptoms. Interventions focused on improving children's pain outcomes may consider targeting sleep behaviors and mental health.

Associations between adolescent sleep deficiency and prescription opioid misuse in adulthood

STUDY OBJECTIVES

The main aim of this study was to estimate the association between sleep deficiency in adolescence and subsequent prescription opioid misuse in adulthood using United States nationally representative longitudinal data.

METHODS

Self-reported data captured in the National Longitudinal Study of Adolescent to Adult Health at baseline (Wave 1; mean age = 16 years) and 12 year follow-up (Wave 4; mean age = 29 years). Participants (n = 12,213) reported on four measures of sleep during adolescence (Wave 1) and on lifetime prescription opioid misuse during adulthood (Wave 4). Associations between adolescent sleep and adult opioid misuse were estimated using multivariate logistic regression analysis controlling for sociodemographics, chronic pain, mental health, childhood adverse events, and a history of substance use.

RESULTS

During adolescence, 59.2% of participants reported sleep deficiency. Prospectively, adolescents reporting not getting enough sleep, chronic unrestful sleep, and insomnia were associated with an increased risk for prescription opioid misuse (adjusted odds ratios [OR] = 1.2, p < 0.005 for all three variables). Short sleep duration was not associated with opioid misuse.

CONCLUSION

This is the first study to longitudinally link sleep deficiency as an independent risk factor for the development of prescription opioid misuse. Sleep deficiency could be a driver of the opioid crisis affecting young people in the United States. Future studies should determine whether early and targeted sleep interventions may decrease risk for opioid misuse in high-risk patients prescribed opioids for pain.

Experimental sleep restriction increases latency jitter in pain elicited cortical responses

Objective

Previous studies have shown increased pain scores to painful stimulation after experimental sleep restriction, but reduced or unchanged magnitude of the event related potentials (ERPs) when averaged in the time-domain. However, some studies found increased response magnitude when averaging in the time-frequency domain. The aim of this study was to determine whether ERP-latency jitter may contribute to this discrepancy.

Methods

Ninety painful electrical stimuli were given to 21 volunteers after two nights of 50% sleep restriction and after two nights of habitual sleep. ERPs were analyzed in the time-domain (N2-and P2-peaks) and time-frequency domain (power spectral density). We quantified latency jitter by the mean consecutive difference (MCD) between single-trial peak latencies and by phase locking value (PLV) across trials.

Results

P2-MCD increased from 20.4 ± 2.1 ms after habitual sleep to 24.3 ± 2.2 ms after sleep restriction (19%, p = 0.038) and PLV decreased from 0.582 ± 0.015 after habitual sleep to 0.536 ± 0.015 after sleep restriction (7.9%, p = 0.009). We found no difference for N2-MCD.

Conclusions

Our results indicate that partial sleep restriction increase latency jitter in cortical responses to experimental pain.

Significance

Latency jitter may contribute to the discrepancies between ERP-responses in the time-frequency domain and time-domain. Latency jitter should be considered when ERPs are analyzed.

Examination of the clinical factors associated with attendance at emergency departments for chronic pain management and the cost of treatment relative to that of other significant medical conditions

ABSTRACT

Little is known about risk factors for emergency department (ED) attendance for chronic pain (CP) management and the relative service burden. We examined ED utilisation in patients with CP, identified risk factors associated with attendance for chronic musculoskeletal pain (CMP), and estimated the comparative cost of treatment. The study cohort comprised a random sample of 3700 adults from the general population in Tayside, Scotland. Linked regional extracts, spanning a 12-month period, were obtained from national registers, providing information on ED attendances, community-dispensed prescribing, and outpatient clinic attendances. The National Health Service Scotland Cost Book was used to ascertain the current average cost of an ED attendance (£130; ∼$167). All-cause ED attendance was higher in those with CP (68.5%; n = 252) than without (29.3%; n = 967). In the entire cohort, more patients attended the ED for the treatment of CMP than for any other medical condition (n = 119; 32.3% of those with CP). Risk factors for ED attendance for CMP were: recent analgesic dose decreases (OR = 4.55); and transitioning from opioid to nonopioid analgesics (OR = 5.08). Characteristics protective of ED attendance for CMP were: being in receipt of strong opioids (OR = 0.21); transitioning from nonopioid to opioid analgesics (OR = 0.25); recent analgesic dose increases (OR = 0.24); and being prescribed tricyclic antidepressants (OR = 0.10), benzodiazepines (OR = 0.46), or hypnotics (OR = 0.45). Chronic musculoskeletal pain was one of the most expensive conditions to treat (£17,680 [∼$22,668] per annum), conferring a substantial burden on ED services. Improved understanding of the risk/protective factors could inform healthcare redesign to reduce avoidable ED attendances for CMP management.

Sleep Disruption Due to Stress in Women Veterans: A Comparison between Caregivers and Noncaregivers

Objective/Background: Sleep problems are common in women and caregiving for an adult is a common role among women. However, the effects of caregiving on sleep and related daytime impairment are poorly understood among women veterans. This study compared stress-related sleep disturbances, insomnia symptoms, and sleep-related daytime impairment between women veterans who were caregivers and those who did not have a caregiving role. Participants: Of 12,225 women veterans who received care in one Veterans Administration Healthcare System, 1,457 completed data on a postal survey (mean age = 51.7 ± 15.9 years). Two hundred forty three (17%) respondents (mean age 53.8 ± 12.7 years) were caregivers for an adult, predominantly for a parent, providing transportation. Methods: The survey included items that addressed insomnia symptoms, total sleep time, sleep-related daytime impairments, caregiving characteristics, self-rated health, pain, stress, body mass index, and demographic information. Results: In adjusted analyses, caregiver status did not directly predict sleep complaints alone. However, in multiple regression analyses, being a caregiver (odds ratio 1.7, p = .001) significantly predicted stress-related sleep disturbance, even after adjusting for age, pain, self-rated health, and other characteristics. Furthermore, being a caregiver (β = 3.9, p = .031) significantly predicted more symptoms of sleep-related daytime impairment after adjusting for age, pain, self-rated health, and other factors. Conclusions: Compared to noncaregivers, women veterans who were caregivers for an adult were more likely to report stress causing poor sleep, and more daytime impairment due to poor sleep. These findings suggest the need to target stress and other factors when addressing sleep disturbance among women veterans who are caregivers.

Efficacy and Safety of Pregabalin for Fibromyalgia in a Population of Chinese Subjects

PURPOSE

Fibromyalgia (FM) may go underdiagnosed and untreated in China in part due to a lack of awareness and understanding of the condition, and limited available treatments.

PATIENTS AND METHODS

This randomized, double-blind, Phase III local registration trial compared the efficacy and safety of pregabalin (flexibly dosed 300-450 mg/day) versus placebo for the management of pain in Chinese adults diagnosed with FM according to American College of Rheumatology 1990 criteria, across 22 centers within China. Patients reported pain score of ≥40 mm on 100-mm scale (from 0 "no pain" to 100 "worst possible pain"). The primary efficacy endpoint was change from baseline to Week 14 in mean pain score (MPS). Secondary endpoints included measures of sleep and sleep interference. Safety and tolerability were monitored throughout.

RESULTS

Median pregabalin dose was 335 mg/day. A significant reduction from baseline to Week 14 in weekly MPS was seen for patients treated with pregabalin (n=170) versus placebo (n=164) (least-squares mean difference [95% confidence interval]: -0.73 [-1.10 to -0.36]; P=0.0001). Significantly greater proportions of patients experienced ≥30% and ≥50% reductions in MPS at Week 14 with pregabalin versus placebo. Pregabalin-treated subjects demonstrated improvements in measures of sleep and sleep interference. Pregabalin was generally well tolerated. The most common adverse events were dizziness and somnolence; no serious adverse events (SAEs) occurred in pregabalin-treated subjects. Nine placebo-treated subjects experienced SAEs.

CONCLUSION

Pregabalin (300-450 mg/day) is a safe and effective treatment for reducing pain and improving sleep in native Chinese subjects with FM.

CLINICALTRIALSGOV IDENTIFIER

NCT01387607.

Beyond single sleep measures: A composite measure of sleep health and its associations with psychological and physical well-being in adulthood

RATIONALE

Sleep is important for many functions including body and mind restoration. Studies report the association of sleep with stress and physical deterioration, often focusing only on sleep duration; yet, sleep health needs to be understood by multiple dimensions to comprehensively capture its impact on well-being.

OBJECTIVE

This study examined cross-sectional and longitudinal associations of multidimensional sleep health with perceived stress and chronic physical conditions.

METHODS

We used a sample of 441 adults (M age = 57 years) who participated in the biomarker project of the Midlife in the United States Study. Participants provided self-report and actigraphy sleep data in 2004-2009 (T1). We created a composite score of sleep health (Range = 0-6; higher indicating more sleep problems) encompassing: actigraphy-measured regularity, timing, efficiency, duration, and self-reported satisfaction and alertness. Participants responded to the perceived stress scale and chronic physical conditions checklist at T1; chronic physical conditions were reassessed in 2013-2015 (T2).

RESULTS

Cross-sectionally, a composite score of sleep health problems was uniquely associated with higher perceived stress and more chronic conditions, explaining additional variance that each individual sleep variable did not explain. Sleep duration - one of the most commonly researched dimensions of sleep - was not associated with either perceived stress or chronic conditions. Longitudinally, for individuals who had fewer chronic conditions at T1, having more sleep health problems was associated with an increase in chronic conditions at T2. Among the multiple dimensions, sleep satisfaction was most consistently and strongly associated with the outcomes.

CONCLUSION

Findings suggest the importance of considering multiple sleep dimensions concerning psychological and physical well-being in adulthood.

Insomnia severity and depressive symptoms in people living with HIV and chronic pain: associations with opioid use

Chronic pain commonly occurs in people living with HIV (PLWH). Many PLWH in the United States obtain opioids for chronic pain management. Whether insomnia severity and depressive symptoms are exacerbated by chronic pain and opioid use in PLWH remains to be determined. This study examined insomnia severity and depressive symptoms in 85 PLWH with chronic pain and 35 PLWH without chronic pain. Among PLWH with chronic pain, reported opioid use was examined in relation to insomnia severity and depressive symptoms. PLWH with chronic pain reported significantly greater insomnia severity (p = .033) and depressive symptoms (p = .025) than PLWH without chronic pain. Among PLWH with chronic pain who reported opioid use (n = 36), insomnia severity was greater compared to those who denied opioid use (n = 49), even after controlling for pain severity and number of comorbidities (p = .026). Greater pain severity was significantly associated with greater insomnia severity (p < .001) and depressive symptoms (p = .048) among PLWH with chronic pain who reported opioid use. These associations were not significant among those PLWH with chronic pain who denied opioid use. Findings suggest that PLWH with chronic pain are likely to experience poor sleep and depressed mood. Furthermore, poor sleep was associated with opioid use among PLWH with chronic pain.

Challenges and opportunities in translational pain research - An opinion paper of the working group on translational pain research of the European pain federation (EFIC)

For decades, basic research on the underlying mechanisms of nociception has held promise to translate into efficacious treatments for patients with pain. Despite great improvement in the understanding of pain physiology and pathophysiology, translation to novel, effective treatments for acute and chronic pain has however been limited, and they remain an unmet medical need. In this opinion paper bringing together pain researchers from very different disciplines, the opportunities and challenges of translational pain research are discussed. The many factors that may prevent the successful translation of bench observations into useful and effective clinical applications are reviewed, including interspecies differences, limited validity of currently available preclinical disease models of pain, and limitations of currently used methods to assess nociception and pain in non-human and human models of pain. Many paths are explored to address these issues, including the backward translation of observations made in patients and human volunteers into new disease models that are more clinically relevant, improved generalization by taking into account age and sex differences, and the integration of psychobiology into translational pain research. Finally, it is argued that preclinical and clinical stages of developing new treatments for pain can be improved by better preclinical models of pathological pain conditions alongside revised methods to assess treatment-induced effects on nociception in human and non-human animals. Significance: For decades, basic research of the underlying mechanisms of nociception has held promise to translate into efficacious treatments for patients with pain. Despite great improvement in the understanding of pain physiology and pathophysiology, translation to novel, effective treatments for acute and chronic pain has however been limited, and they remain an unmet medical need.

The Early Impact of COVID-19 on Chronic Pain: A Cross-Sectional Investigation of a Large Online Sample of Individuals with Chronic Pain in the United States, April to May, 2020

OBJECTIVE

Individuals with chronic pain are uniquely challenged by the COVID-19 pandemic, as increased stress may exacerbate chronic pain, and there are new barriers to receiving chronic pain treatment. In light of this, using a large online sample in the United States, we examined 1) the early impact of COVID-19 on pain severity, pain interference, and chronic pain management; and 2) variables associated with perceived changes in pain severity and pain interference.

DESIGN

A cross-sectional study.

METHODS

Online survey data for 1,453 adults with chronic pain were collected via Amazon's Mechanical Turk platform.

RESULTS

Although a large proportion of participants reported no perceived changes in their pain severity and pain interference since the outbreak, approximately 25-30% of individuals reported exacerbation in these domains. Individuals identifying as Black and of non-Hispanic origin, who experienced greater disruptions in their mood and sleep quality, were more likely to report worsened pain interference. The majority of participants reported engaging in self-management strategies as usual. However, most appointments for chronic pain treatment were either postponed or canceled, with no future session scheduled. Furthermore, a notable proportion of participants had concerns about or difficulty accessing prescription opioids due to COVID-19.

CONCLUSIONS

We may expect to see a long-term exacerbation of chronic pain and related interference in functioning and chronic pain management among individuals most impacted by the pandemic. These individuals may benefit from remotely delivered intervention to effectively mitigate COVID-19-related exacerbations in chronic pain and interruptions in face-to-face treatment.

Factors associated with seeking medical care for low back pain in a twin adult sample

BACKGROUND

Previous studies have only investigated how symptom presentation and socio-demographic factors influence care-seeking for low back pain (LBP). However, the influence of health and lifestyle factors remains unclear, and the potential confounding effects of aggregated familial factors (including genetics and the early shared environment) has not been considered extensively.

METHODS

A cross-sectional analysis was performed on 1605 twins enrolled in the Murcia Twin Registry (Spain). The outcome was seeking medical care for LBP and various self-reported demographic, health and lifestyle factors were considered predictors. All variables except sleep quality and diabetes were collected in 2013, which were cross-referenced from 2009 to 2010. A multivariate logistic regression model was performed on the total sample, followed by a co-twin case-control analysis.

RESULTS

The only significant factor found to increase the odds of seeking medical care for LBP without being affected by familial factors was poor sleep quality (total sample OR = 1.58, 95%CI 1.24-2.01; case-control OR = 1.75, 95%CI 1.14-2.69). The factors that were associated with reduced odds of seeking medical care for LBP and not confounded by familial factors were male sex (case-control OR = 0.55, 95%CI 0.33-0.93), alcohol intake (case-control OR = 0.90, 95%CI 0.82-0.99) and a history of diabetes (case-control OR = 0.50, 95%CI 0.25-0.97). No other factors significantly influenced medical care-seeking for LBP.

CONCLUSIONS

People reporting poor sleep quality are more likely to seek medical care for LBP in the long term, with this relationship being independent from aggregated familial factors. Conversely, males, people reporting higher alcohol intake, and people with a history of diabetes are less likely to seek medical care for LBP.

SIGNIFICANCE

This is the first study investigating the factors that influence seeking medical care for LBP, while adjusting for the influence of familial factors using a co-twin control design. Poor sleep quality is associated with seeking medical care for LBP in the long term and does not appear to be confounded by familial factors. Early screening for indicators of poor sleep quality and appropriate referral to interventions for improving sleep quality or reducing pain in sleep may improve LBP management.

Dysmenorrhea Symptom-Based Phenotypes: A Replication and Extension Study

BACKGROUND

Dysmenorrhea is a prevalent pain condition among women and a risk factor for other chronic pain conditions. Individuals vary in dysmenorrhea pain severity, the number of painful sites, and co-occurring gastrointestinal symptoms. Three dysmenorrhea symptom-based phenotypes were previously identified using latent class analysis; however, there is a need to validate these in an independent sample, so they can be used in mechanistic and interventional research. There is also a need to further characterize dysmenorrhea symptom-based phenotypes in terms of demographic, clinical, and psychobehavioral characteristics so they can be used to inform precision dysmenorrhea treatment.

OBJECTIVES

The study objectives were to (a) determine whether the same dysmenorrhea symptom-based phenotypes would be found in a new sample; (b) determine whether including demographic, clinical, and psychobehavioral covariates in latent class analyses would change individuals' phenotype memberships; and (c) investigate relationships between dysmenorrhea symptom-based phenotypes and demographic, clinical, and psychobehavioral characteristics.

METHODS

This cross-sectional survey study included 678 women (aged 14-42 years) with dysmenorrhea. Participants reported dysmenorrhea symptom severity, demographic, clinical (comorbid chronic pain and gynecological conditions), and psychobehavioral characteristics (perceived stress, anxiety, depression, sleep disturbance, and pain catastrophizing). We used latent class analysis to identify symptom-based phenotypes. We compared analyses with and without covariates (i.e., demographic, clinical, and psychobehavioral characteristics) to determine if individuals' phenotype memberships changed. We then examined associations between phenotypes and demographic, clinical, and psychobehavioral characteristics.

RESULTS

We reproduced three dysmenorrhea symptom-based phenotypes: the "mild localized pain" phenotype (characterized by mild abdominal cramps), the "severe localized pain" phenotype (characterized by severe abdominal cramps), and the "multiple severe symptoms" phenotype (characterized by severe pain at multiple locations and gastrointestinal symptoms). Analyses with and without covariates had little effect on individuals' phenotype membership. Race, comorbid chronic pain condition, endometriosis, and pain catastrophizing were significantly associated with the dysmenorrhea phenotypes.

DISCUSSION

Findings provide a foundation to further study mechanisms of dysmenorrhea symptom heterogeneity and develop dysmenorrhea precision treatments. The three dysmenorrhea symptom-based phenotypes were validated in a second sample. Demographic, clinical, and psychobehavioral factors were associated with dysmenorrhea symptom-based phenotypes.

Co-occurrence of chronic pain, depressive symptoms, and poor sleep quality in a health check-up population in China:A multicenter survey

OBJECTIVES

This study aimed to investigate the cooccurrence of chronic pain (CP), depressive symptoms, and poor sleep quality in terms of prevalence and associated factors in a nationwide health check-up population in China.

METHODS

This multicenter cross-sectional survey was performed in 2017. All the participants aged ≥18 years from eight health check-up institutions in 6 provinces and cities were invited to complete a self-report health questionnaire through online resources.

RESULTS

132,444 participants completed the online survey and the overall prevalence of CP and that of the three symptoms were 11.0% (95% confidence interval [95% CI]: 10.8-11.1) and 2.7% (95% CI: 2.6-2.8), respectively. The cooccurrence of all three symptoms increased with age, being higher in the female, widowed, unemployed, and lower education level groups. The respondents with multiple symptoms reported poorer self-rated health. Binary logistic regression analyses identified female sex (adjusted odds ratio [aOR]: 1.51; 95% CI: 1.42-1.62), a widowed status (aOR: 1.39; 95% CI: 1.04-1.84), a lower education level (aORs ranging from 1.46 to 2.47), and having one or more chronic diseases (aORs ranging from 1.43 to 2.02) to be significantly associated with reporting all three symptoms (all P ˂0.05). While long-term medication and regular exercise were the protective factors.

CONCLUSION

This study suggests that the cooccurrence of the three symptoms accounts for a certain proportion of the Chinese health check-up population. Integrated interventions that address CP and mental health cooccurrence may be an essential target for heath management in this population to tackle this considerable burden.

Supplementation with Vitamins C and E and Exercise-Induced Delayed-Onset Muscle Soreness: A Systematic Review

Muscle damage induced by exercise may have several consequences such as delayed-onset muscle soreness, a side-effect of the release of free radicals during oxidative stress. To mitigate the oxidative stress cascade, the oral intake of antioxidants has been assessed by several research groups. This review examines whether supplementation with vitamin C and/or vitamin E is able to prevent or attenuate delayed-onset muscle soreness after eccentric exercise. The PubMed, Web of Science, Medline, and Embase databases were searched to identify studies meeting the inclusion criteria: primary randomized control trials, healthy male and female participants aged 16–80 years, and an intervention consisting of the intake of vitamin C and/or vitamin E without other supplements plus a controlled eccentric exercise regimen. Further requirements were the measurement of muscle soreness or markers of delayed-onset muscle soreness. All original full-text articles in English or translated into English published from January 2000 to June 2020 were considered for this review. Fourteen studies were finally identified, including 280 participants, 230 men, and 50 women aged 16–30 years. All participants were healthy individuals with different starting levels of physical activity. Supplementation was acute in two studies and chronic in 12, and its consisted of vitamin C in eight studies, vitamin E in two studies, and both in four studies. Only in 3 of the 14 studies was muscle soreness found to be significantly reduced in response to vitamin C and/or vitamin E supplementation at all time points when compared to the placebo group. Despite some studies showing the beneficial effects of chronic supplementation with these vitamins on muscle soreness manifesting 24–72 h after eccentric exercise, the evidence is so far insufficient to confirm that the intake of antioxidant vitamins is able to minimize delayed-onset muscle soreness in this context.

Insomnia - A Heterogenic Disorder Often Comorbid With Psychological and Somatic Disorders and Diseases: A Narrative Review With Focus on Diagnostic and Treatment Challenges

Patients with insomnia complain of problems with sleep onset or sleep maintenance or early morning awakenings, or a combination of these, despite adequate opportunity and circumstances for sleep. In addition, to fulfill the diagnostic criteria for insomnia the complaints need to be associated with negative daytime consequences. For chronic insomnia, the symptoms are required to be present at least 3 days per week for a duration of at least 3 months. Lastly, for insomnia to be defined as a disorder, the sleep complaints and daytime symptoms should not be better explained by another sleep disorder. This criterion represents a diagnostic challenge, since patients suffering from other sleep disorders often complain of insomnia symptoms. For instance, insomnia symptoms are common in e.g., obstructive sleep apnea and circadian rhythm sleep-wake disorders. It may sometimes be difficult to disentangle whether the patient suffers from insomnia disorder or whether the insomnia symptoms are purely due to another sleep disorder. Furthermore, insomnia disorder may be comorbid with other sleep disorders in some patients, e.g., comorbid insomnia and sleep apnea (COMISA). In addition, insomnia disorder is often comorbid with psychological or somatic disorders and diseases. Thus, a thorough assessment is necessary for correct diagnostics. For chronic insomnia disorder, treatment-of-choice is cognitive behavioral therapy, and such treatment is also effective when the insomnia disorder appears comorbid with other diagnoses. Furthermore, studies suggest that insomnia is a heterogenic disorder with many different phenotypes or subtypes. Different insomnia subtypes may respond differently to treatment, but more research on this issue is warranted. Also, the role of comorbidity on treatment outcome is understudied. This review is part of a Research Topic on insomnia launched by Frontiers and focuses on diagnostic and treatment challenges of the disorder. The review aims to stimulate to more research into the bidirectional associations and interactions between insomnia disorder and other sleep, psychological, and somatic disorders/diseases.

COVID-19 psychological factors associated with pain status, pain intensity, and pain-related interference

The 2019 novel SARS-CoV2 disease causing COVID-19 has had a devastating impact on the world, and those with pain conditions may be at heightened risk for these negative consequences. Given COVID-19 limitations, including social distancing and stay-at-home orders, pain is likely largely going untreated, leading to greater pain and associated consequences. Mental health symptoms, which have been found to be elevated due to COVID-19, may contribute to elevated pain experience, but little work has examined how COVID-19-specific mental health factors may be associated with pain. Therefore, the current study examined (1) how COVID-19-specific psychological factors and general mental health symptoms differ between those with pain and without, and (2) among those with pain, which psychological factors were most strongly associated with pain experience. Results from a national (U.S. based) online sample of 174 adults (42.5% female, M_age = 37.80 years, SD = 11.30, 88 with pain) collected between April and May 2020 indicated that, compared to those individuals reporting no pain, those with pain reported significantly higher values on all variables. Additionally, COVID-19 fear and sleep problems were associated with pain intensity, and for pain-related interference, fear, sleep problems, and depression were significantly associated. These results highlight the potential importance of COVID-19-specific psychological factors in pain experience.

Sleep Disorders in dogs: A Pathophysiological and Clinical Review

Sleep is a fundamental process in mammals, including domestic dogs. Disturbances in sleep affect physiological functions like cognitive and physical performance, immune response, pain sensation and increase the risk of diseases. In dogs, sleep can be affected by several conditions, with narcolepsy, REM sleep behavior disorder and sleep breathing disorders being the most frequent causes. Furthermore, sleep disturbances can be a symptom of other primary diseases where they can contribute to the worsening of clinical signs. This review describes reciprocally interacting sleep and wakefulness promoting systems and how their dysfunction can explain the pathophysiological mechanisms of sleep disorders. Additionally, this work discusses the clinical characteristics, diagnostic tools and available treatments for these disorders while highlighting areas in where further studies are needed so as to improve their treatment and prevention.

Preliminary investigation of interactive associations of sleep and pain with cognition in sedentary middle-aged and older adults

STUDY OBJECTIVES

The objective of this study was to examine independent and interactive associations between self-reported sleep (sleep efficiency and total sleep time [TST]) and pain with cognition in sedentary middle-aged and older adults.

METHODS

Seventy-five sedentary adults at least 50 years of age (Mage = 63.24, standard deviation = 8.87) completed 14 daily diaries measuring sleep and pain. Weekly average sleep efficiency, TST, and pain were computed. Participants also completed computerized cognitive tasks: Letter Series (reasoning), N-back (working memory), Symbol Digit Modalities Test (processing speed, attention), and Number Copy (processing speed). Multiple regression analyses were conducted to determine independent and interactive (with pain) associations of sleep efficiency and TST with cognition, controlling for age, education, and sex.

RESULTS

Sleep efficiency and pain interacted in their associations with Letter Series performance and N-back difference scores (2-back minus 1-back). Specifically, higher sleep efficiency was associated with better reasoning and working memory in those with highest pain but not average or lowest pain. TST and pain also interacted in their associations with Letter Series performance. Specifically, longer TST associated with worse reasoning in those with lowest (not average or highest) pain.

CONCLUSIONS

Preliminary results show that in sedentary middle-aged and older adults, pain and sleep interact in their associations with executive function tasks. Higher sleep efficiency may be associated with better reasoning and working memory in those with highest pain. Lower TST may be associated with better reasoning in those with lowest pain. Studies evaluating temporal associations between sleep, pain, and cognition are needed.

Masterclass: A pragmatic approach to pain sensitivity in people with musculoskeletal disorders and implications for clinical management for musculoskeletal clinicians

INTRODUCTION

Research on musculoskeletal disorders indicates that pain sensitivity can be an important consideration for musculoskeletal clinicians in the holistic view of a patient presentation. However, diversity in research findings in this field can make this a difficult concept for clinicians to navigate. Limited integration of the concept of pain sensitivity into clinical practice for musculoskeletal clinicians has been noted.

PURPOSE

The purpose of this masterclass is to provide a framework for the consideration of pain sensitivity as a contributing factor in the presentation of people with musculoskeletal pain. It provides pragmatic synthesis of the literature related to pain sensitivity through a lens of how this information can inform clinical practice for musculoskeletal clinicians. Guidance is provided in a 'how to' format for integration of this knowledge into the clinical encounter to facilitate personalised care.

IMPLICATIONS

The relationship of pain sensitivity with pain and disability is not clear or linear. The real importance of pain sensitivity in a clinical presentation may be: (1) the potential for pain sensitivity to modify the effect of common treatments utilised by musculoskeletal clinicians, or (2) the effect of pain sensitivity on the prognosis/course of a disorder. Screening tools and subjective features have been highlighted to indicate when physical assessment of pain sensitivity should be prioritised in the physical examination. A pragmatic blueprint for specific assessment related to pain sensitivity has been outlined. A framework for integrating assessment findings into clinical reasoning to formulate management plans for the pain sensitive patient is provided.

Association Between Pretreatment Sleep Disturbance and Radiation Therapy-Induced Pain in 573 Women With Breast Cancer

CONTEXT

Pain can be a debilitating side effect of radiation therapy (RT). Data from the general population have shown that sleep disturbance can influence pain incidence and severity; however, less is known about this relationship in patients with breast cancer receiving RT.

OBJECTIVES

This secondary analysis examined the association of pretreatment moderate/severe levels of sleep disturbance with subsequent RT-induced pain after adjusting for pre-RT pain.

METHODS

We report on 573 female patients with breast cancer undergoing RT from a previously completed Phase II clinical trial for radiation dermatitis. Sleep disturbance, total pain, and pain subdomains-sensory pain, affective pain, and perceived pain intensity were assessed at pre-RT and post-RT. At pre-RT, patients were dichotomized into two groups: those with moderate/severe sleep disturbance (N = 85) vs. those with no/mild sleep disturbance (control; N = 488).

RESULTS

At pre-RT, women with moderate/severe sleep disturbance were younger, less likely to be married, more likely to have had mastectomy and chemotherapy, and more likely to have depression/anxiety disorder and fatigue than the control group (all Ps < 0.05). Generalized estimating equations model, after controlling for pre-RT pain and other covariates (e.g., trial treatment condition and covariates that were significantly correlated with post-RT pain), showed that women with moderate/severe sleep disturbance at pre-RT vs. control group had significantly higher mean post-RT total pain as well as sensory, affective, and perceived pain (effect size = 0.62, 0.60, 0.69, and 0.52, respectively; all Ps < 0.05).

CONCLUSION

These findings suggest that moderate/severe disturbed sleep before RT is associated with increased pain from pre-to-post-RT in patients with breast cancer.

Pain Catastrophizing and Arthritis Self-Efficacy as Mediators of Sleep Disturbance and Osteoarthritis Symptom Severity

OBJECTIVE

Sleep and pain-related experiences are consistently associated, but the pathways linking these experiences are not well understood. We evaluated whether pain catastrophizing and arthritis self-efficacy mediate the association between sleep disturbance and osteoarthritis (OA) symptom severity in patients with knee OA.

METHODS

We analyzed cross-sectional baseline data collected from Veterans Affairs (VA) patients enrolled in a clinical trial examining the effectiveness of a positive psychology intervention in managing pain from knee OA. Participants indicated how often in the past two weeks they were bothered by trouble falling asleep, staying asleep, or sleeping too much. We used validated scales to assess the primary outcome (OA symptom severity) and potential mediators (arthritis self-efficacy and pain catastrophizing). To test the proposed mediation model, we used parallel multiple mediation analyses with bootstrapping, controlling for sociodemographic and clinical characteristics with bivariate associations with OA symptom severity.

RESULTS

The sample included 517 patients (Mage = 64 years, 72.9% male, 52.2% African American). On average, participants reported experiencing sleep disturbance at least several days in the past two weeks (M = 1.41, SD = 1.18) and reported moderate OA symptom severity (M = 48.22, SD = 16.36). More frequent sleep disturbance was associated with higher OA symptom severity directly (b = 3.08, P <0.001) and indirectly, through higher pain catastrophizing (b = 0.60, 95% confidence interval [CI] = 0.20 to 1.11) and lower arthritis self-efficacy (b = 0.84, 95% CI = 0.42 to 1.42).

CONCLUSIONS

Pain catastrophizing and arthritis self-efficacy partially mediated the association between sleep disturbance and OA symptom severity. Behavioral interventions that address pain catastrophizing and/or self-efficacy may buffer the association between sleep disturbance and OA symptom severity.

Pregabalin for neuropathic pain in primary care settings: recommendations for dosing and titration

Pregabalin is one of the first-line treatments approved for the management of neuropathic pain (NeP). While many patients benefit from treatment with pregabalin, they are often treated with suboptimal doses, possibly due to unfamiliarity around prescribing the drug and/or side effects that can occur with up-titration. This narrative review discusses key aspects of initiating, titrating, and managing patients prescribed pregabalin therapy, and addresses concerns around driving and the potential for abuse, as well as when to seek specialist opinion. To ensure that patients derive maximum therapeutic benefit from the drug, we suggest a 'low and slow' dosing approach to limit common side effects and optimize tolerability alongside patients' expectations. When requiring titration to higher doses, we recommend initiating 'asymmetric dosing,' with the larger dose in the evening. Fully engaging patients in order for them to understand the expected timeline for efficacy and side effects (including their resolution), can also help determine the optimal titration tempo for each individual patient. The 'low and slow' approach also recognizes that patients with NeP are heterogeneous in terms of their optimal therapeutic dose of pregabalin. Hence, it is recommended that general practitioners closely monitor patients and up-titrate according to pain relief and side effects to limit suboptimal dosing or premature discontinuation.

Chronic musculoskeletal pain prospectively predicts insomnia in older people, not moderated by age, gender or co-morbid illnesses

The study evaluated if chronic musculoskeletal (MSK) pain predicts the severity of insomnia, and whether the effect is moderated by age, gender, and number of comorbid diseases in older people. An 18-month prospective study was performed within the framework of a community health program in Hong Kong. A total of 498 older people aged ≥ 60 with multimorbidity were recruited. The predictors included the presence of chronic MSK pain, pain measured by the Brief Pain Inventory (BPI), insomnia measured by baseline Insomnia Severity Index (ISI), and number of co-morbid diseases, age, and gender. The outcome was ISI repeated at 18 months. The moderators included age, gender, and number of comorbid diseases. Multivariate linear regression and moderation analysis were conducted. We found that the presence of chronic MSK pain (β = 1.725; 95% CI, 0.607-2.842; P < 0.01) predicted the severity of ISI, after controlling for age, gender, BMI, and the number of comorbid diseases. Participants with chronic MSK pain throughout the period had worse trend of improvement in ISI compared to those who were "pain-free" (β = 2.597; 95% CI, 1.311-3.882; P < 0.001). Age, gender, and number of comorbid diseases did not moderate the longitudinal relationship. We propose that pain management should prioritized in the prevention of insomnia.

MicroRNA-19b predicts widespread pain and posttraumatic stress symptom risk in a sex-dependent manner following trauma exposure

Posttraumatic widespread pain (PTWP) and posttraumatic stress symptoms (PTSS) are frequent comorbid sequelae of trauma that occur at different rates in women and men. We sought to identify microRNA (miRNA) that may contribute to sex-dependent differences in vulnerability to these outcomes. Monte Carlo simulations (x10,000) identified miRNA in which predicted targeting of PTWP or PTSS genes was most enriched. Expression of the leading candidate miRNA to target PTWP/PTSS-related genes, miR-19b, has been shown to be influenced by estrogen and stress exposure. We evaluated whether peritraumatic miR-19b blood expression levels predicted PTWP and PTSS development in women and men experiencing trauma of motor vehicle collision (n = 179) and in women experiencing sexual assault trauma (n = 74). A sex-dependent relationship was observed between miR-19b expression levels and both PTWP (β = -2.41, P = 0.034) and PTSS (β = -3.01, P = 0.008) development 6 months after motor vehicle collision. The relationship between miR-19b and PTSS (but not PTWP) was validated in sexual assault survivors (β = -0.91, P = 0.013). Sex-dependent expression of miR-19b was also observed in blood and nervous tissue from 2 relevant animal models. Furthermore, in support of increasing evidence indicating a role for the circadian rhythm (CR) in PTWP and PTSS pathogenesis, miR-19b targets were enriched in CR gene transcripts. Human cohort and in vitro analyses assessing miR-19b regulation of key CR transcripts, CLOCK and RORA, supported the potential importance of miR-19b to regulating the CR pathway. Together, these results highlight the potential role that sex-dependent expression of miR-19b might play in PTWP and PTSS development after trauma/stress exposure.

The relationship between dry eye and sleep quality

PURPOSE

Sleep is an important determinant of health and quality of life. This study aimed to clarify the association between dry eye and sleep quality using a large population-based cohort.

METHODS

71,761 participants (19-94 yrs, 59.4% female) from the Lifelines cohort in the Netherlands were assessed for dry eye using the Women's Health Study Dry Eye Questionnaire. Sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI). Logistic regression was used to examine the relationship between poor sleep quality (PSQI score >5) and dry eye, while correcting for age, sex, BMI, education, income, and 51 possible confounding comorbidities, including autoimmune diseases and psychiatric disorders.

RESULTS

Overall, 8.9% of participants had dry eye. Of these, 36.4% had poor sleep quality compared to 24.8% of controls (OR 1.52 (95%CI 1.44-1.60), P < 0.0001, corrected for age and sex). After correcting for all comorbidities, dry eye was still associated with poor sleep (OR 1.20 (95%CI 1.11-1.28), P < 0.0001). This relationship was seen across all ages and sexes. Patients with dry eye scored worse on all subcomponents of the PSQI. Almost one-in-two (44.9%) persons with dry eye symptoms "often" or "constantly" had poor sleep quality. This proportion was similar to participants with sleep apnea and osteoarthritis. Additionally, increasing symptom frequency was tied to increased prevalence of poor sleep quality.

CONCLUSIONS

All components of sleep quality were significantly reduced in participants with dry eye, even after correcting for comorbidities. These results indicate the substantial impact of dry eye on patients' lives, especially for those with frequent symptoms.

Positive Encounters as a Buffer: Pain and Sleep Disturbances in Older Adults' Everyday Lives

Objectives: To test whether older adults' pain was bidirectionally associated with nighttime sleep disturbances and whether daily positive encounters attenuated these associations. Methods: Participants (N = 292, mean = 73.71 years old) from the Daily Experiences and Well-being Study indicated pain and positive encounters with close partners (e.g., family and friends) and nonclose partners (e.g., acquaintances and service providers) every 3 hours throughout each day across 4-6 days. They also reported nighttime sleep disturbances the following morning. Results: Multilevel models revealed that participants with more prior nighttime sleep disturbances reported more severe pain the next day. This link was attenuated on days when participants had a greater proportion of positive encounters or viewed encounters as more pleasant, especially when these encounters occurred with close partners. Discussion: This study identifies benefits of positive encounters to older adults and sheds light on ways that may alleviate their pain from a social perspective.

Machine learning suggests sleep as a core factor in chronic pain

Patients with chronic pain have complex pain profiles and associated problems. Subgroup analysis can help identify key problems. We used a data-based approach to define pain phenotypes and their most relevant associated problems in 320 patients undergoing tertiary pain management. Unsupervised machine learning analysis of parameters "pain intensity," "number of pain areas," "pain duration," "activity pain interference," and "affective pain interference," implemented as emergent self-organizing maps, identified 3 patient phenotype clusters. Supervised analyses, implemented as different types of decision rules, identified "affective pain interference" and the "number of pain areas" as most relevant for cluster assignment. These appeared 698 and 637 times, respectively, in 1000 cross-validation runs among the most relevant characteristics in an item categorization approach in a computed ABC analysis. Cluster assignment was achieved with a median balanced accuracy of 79.9%, a sensitivity of 74.1%, and a specificity of 87.7%. In addition, among 59 demographic, pain etiology, comorbidity, lifestyle, psychological, and treatment-related variables, sleep problems appeared 638 and 439 times among the most important characteristics in 1000 cross-validation runs where patients were assigned to the 2 extreme pain phenotype clusters. Also important were the parameters "fear of pain," "self-rated poor health," and "systolic blood pressure." Decision trees trained with this information assigned patients to the extreme pain phenotype with an accuracy of 67%. Machine learning suggested sleep problems as key factors in the most difficult pain presentations, therefore deserving priority in the treatment of chronic pain.

A Novel Application of Ketamine for Improving Perioperative Sleep Disturbances

Perioperative sleep disturbances are commonly observed before, during, and after surgery and can be caused by several factors, such as preoperative negative moods, general anesthetics, surgery trauma, and pain. Over the past decade, the fast-acting antidepressant effects of the N-methyl-D-aspartate (NMDA) receptor antagonist ketamine represent one of the most attractive discoveries in the field of psychiatry, such as antidepressant and anxiolytic effects. It is also widely used as a short-acting anesthetic and analgesic. Recent research has revealed new possible applications for ketamine, such as for perioperative sleep disorders and circadian rhythm disorders. Here, we summarize the risk factors for perioperative sleep disturbances, outcomes of perioperative sleep disturbances, and mechanism of action of ketamine in improving perioperative sleep quality.

Increased Pain Symptomatology Among Females vs. Males With Fragile X-Associated Tremor/Ataxia Syndrome

Individuals with the fragile X premutation report symptoms of chronic pain from multiple systems, have increased incidence of comorbid conditions where pain is a prominent feature, and pathophysiology that supports disrupted pain regulation, inflammation, and energy imbalance. Less is known about how pain manifests for the subpopulation of carriers that develop the motor and cognitive changes of fragile X-associated tremor and ataxia syndrome (FXTAS), and how pain may differ between men and women. We gathered data collected from 104 males and females with FXTAS related to chronic pain, comorbid conditions related to pain, and medications used for pain control to further explore the types of pain experienced and to better characterize how individuals with the fragile X premutation experience pain sensation across genders. We found that women experience significantly more pain symptoms than men, particularly allodynia (20 vs. 2.0%, p = 0.008), peripheral neuropathy pain (43.9 vs. 25.4%, p = 0.0488), migraine (43.9 vs. 14.5%, p = 0.0008), fibromyalgia (26.8 vs. 0%, p = 0.0071) and back pain (48.5 vs. 23.4%, p = 0.008). We found onset of peripheral neuropathy predicts the onset of ataxia (β = 0.63 ± 0.25, p = 0.019) and tremor (β = 0.56 ± 0.17, p = 0.004) across gender. Women also report significantly more anxiety (82.9 vs. 39.7%, p < 0.001), which has implications for ideal pain treatment. These pain symptoms need to be recognized in the medical history and treated appropriately, with consideration for overlapping comorbidities.

Patient phenotyping in clinical trials of chronic pain treatments: IMMPACT recommendations

There is tremendous interpatient variability in the response to analgesic therapy (even for efficacious treatments), which can be the source of great frustration in clinical practice. This has led to calls for “precision medicine” or personalized pain therapeutics (ie, empirically based algorithms that determine the optimal treatments, or treatment combinations, for individual patients) that would presumably improve both the clinical care of patients with pain and the success rates for putative analgesic drugs in phase 2 and 3 clinical trials. However, before implementing this approach, the characteristics of individual patients or subgroups of patients that increase or decrease the response to a specific treatment need to be identified. The challenge is to identify the measurable phenotypic characteristics of patients that are most predictive of individual variation in analgesic treatment outcomes, and the measurement tools that are best suited to evaluate these characteristics. In this article, we present evidence on the most promising of these phenotypic characteristics for use in future research, including psychosocial factors, symptom characteristics, sleep patterns, responses to noxious stimulation, endogenous pain-modulatory processes, and response to pharmacologic challenge. We provide evidence-based recommendations for core phenotyping domains and recommend measures of each domain.