Sleep, chronic pain, and opioid risk for apnea

Comparison of actigraphy with a sleep protocol maintained by professional caregivers and questionnaire-based parental judgment in children and adolescents with life-limiting conditions

BACKGROUND

Actigraphy offers a promising way to objectively assess pediatric sleep. Aim of the study was investigating the extent to which actigraphy used in children and adolescents with life-limiting conditions is consistent with two other measures of sleep diagnostics.

METHODS

In this monocentric prospective study N = 26 children and adolescents with life-limiting conditions treated on a pediatric palliative care unit were assessed. For three consecutive nights they wore an actigraph; the 24-hours sleep protocol documented by nurses and the Sleep Screening for Children and Adolescents with Complex Chronic Conditions (SCAC) answered by parents were analyzed. Patient characteristics and the parameters sleep onset, sleep offset, wake after sleep onset (WASO), number of wake phases, total sleep time (TST) and sleep efficiency (SE) were descriptively examined. Percentage bend correlations evaluated the three measures' concordance.

RESULTS

Descriptively, and except for the number of waking episodes, the different measures' estimations were comparable. Significant correlations existed between actigraphy and the sleep protocol for sleep onset (r = 0.83, p = < 0.001) and sleep offset (r = 0.89, p = < 0.001), between actigraphy and SCAC for SE (r = 0.59, p = 0.02).

CONCLUSION

Agreement of actigraphy with the focused sleep measures seems to be basically given but to varying degrees depending on the considered parameters.

Benefit in physical function and quality of life to nonsurgical treatment of varicose veins: Pilot study

BACKGROUND

Studies on varicose veins have focused its effects on physical function; however, whether nonsurgical treatments alter muscle oxygenation or physical function remains unclear. Moreover, the differences in such functions between individuals with varicose veins and healthy individuals remain unclear.

AIM

To investigate changes in physical function and the quality of life (QOL) following nonsurgical treatment of patients with varicose veins and determine the changes in their muscle oxygenation during activity.

METHODS

We enrolled 37 participants (those with varicose veins, n = 17; healthy individuals, n = 20). We performed the following measurements pre- and post-nonsurgical treatment in the varicose vein patients and healthy individuals: Calf muscle oxygenation during the two-minute step test, open eyes one-leg stance, 30 s sit-to-stand test, visual analog scale (VAS) for pain, Pittsburgh sleep quality index, physical activity assessment, and QOL assessment.

RESULTS

Varicose veins patients and healthy individuals differ in most variables (physical function, sleep quality, and QOL). Varicose veins patients showed significant differences between pre- and post-nonsurgical treatment- results in the 30 sit-to-stand test [14.41 (2.45) to 16.35 (4.11), P = 0.018), two-minute step test [162.29 (25.98) to 170.65 (23.80), P = 0.037], VAS for pain [5.35 (1.90) to 3.88 (1.73), P = 0.004], and QOL [39.34 (19.98) to 26.69 (17.02), P = 0.005]; however, no significant difference was observed for muscle oxygenation.

CONCLUSION

Nonsurgical treatment improved lower extremity function and QOL in varicose veins patients, bringing their condition close to that of healthy individuals. Future studies should include patients with severe varicose veins requiring surgery to confirm our findings.

Everyday Pain in Middle and Later Life: Associations with Daily and Momentary Present-Moment Awareness as One Key Facet of Mindfulness

This study investigated everyday associations between one key facet of mindfulness (allocating attention to the present moment) and pain. In Study 1, 89 community-dwelling adults (33-88 years; Mage = 68.6) who had experienced a stroke provided 14 daily end-of-day present-moment awareness and pain ratings. In Study 2, 100 adults (50-85 years; Mage = 67.0 years) provided momentary present-moment awareness and pain ratings three times daily for 10 days. Multi-level models showed that higher trait present-moment awareness was linked with lower overall pain (both studies). In Study 1, participants reported less pain on days on which they indicated higher present-moment awareness. In Study 2, only individuals with no post-secondary education reported less pain in moments when they indicated higher present-moment awareness. Findings add to previous research using global retrospective pain measures by showing that present-moment awareness might correlate with reduced pain experiences, assessed close in time to when they occur.

Association Between Pharmacotherapy and Sleep Quality in Patients with Chronic Orofacial and Chronic Body Pain: A Cross-Sectional Study

Purpose

Sleep impairment is associated with many chronic pain disorders. While there is an association between chronic pain and sleep disturbances, little is known about the influence of pharmacotherapy for chronic pain conditions, particularly chronic opioid therapy, on sleep. This study aimed to 1) compare the sleep quality (SQ) in patients with two different pain conditions-chronic body pain and chronic orofacial pain; 2) assess the correlation of SQ and pain intensity; and 3) evaluate the association between pharmacotherapy and SQ.

Patients and Methods

The Pittsburgh Sleep Quality Index (PSQI) was used to measure the SQ in subjects with 1) chronic body pain (n = 100) and 2) chronic orofacial pain (n = 100). The visual analogue scale was applied for pain intensity rating. All subjects were adults recruited at Massachusetts General Hospital, United States. The subjects' demographic data, pain intensity, diagnosis and concurrent use of medications were extracted from their electronic medical records (EMR). Statistical analyses were performed using T-test and Pearson correlation coefficient.

Results

Among 200 subjects (mean age 51.01 ± 15.52 years), 141 (70.5%) were females. PSQI and pain intensity were statistically significantly different between the two groups (p < 0.05 and p < 0.0001, respectively) and higher in subjects with chronic body pain. There was a positive correlation between PSQI and pain intensity (chronic orofacial pain r = 0.3535, p = 0.0004; chronic body pain: r = 0.2247, p < 0.026). PSQI was higher in chronic orofacial pain subjects utilizing opioids and benzodiazepines (PSQI = 15.25).

Conclusion

Chronic pain impairs SQ, which is noticeably worse in subjects with body pain conditions. In addition, pain intensity was correlated with poorer SQ, which in turn was linked to the concomitant use of opioid and benzodiazepine therapy in chronic orofacial pain.

Evaluation of the relationship between pain inflammation due to dental caries and growth parameters in preschool children

OBJECTIVES

To evaluate the relationship between pain inflammation due to dental caries and growth parameters, sleep disturbances, and oral health-related quality of life (OHRQoL) in preschool children before/after dental treatment and compare the results with the control group.

MATERIALS AND METHODS

Study (pain inflammation due to caries) and control groups were included in this prospective clinical trial. The Child Sleep Habits Questionnaire (CSHQ) assessing sleep disturbances and the Early Childhood Oral Health Impact Scale (ECOHIS) assessing OHRQoL were applied in the corresponding time intervals to the study and control groups, respectively: baseline (T0_study), 7 days after treatment (T1_study), and following 6 months (T2_study); baseline (T0_control), and the following 6 months (T2_control). Biochemical growth parameters (insulin-like growth factor-1 and insulin-like growth factor binding protein-3) and anthropometric measurements (standard deviation score of height, weight, and body mass index) were obtained at T0_study, T2_study, and T0_control. Mann-Whitney U and the Student t-tests were used for statistical analyses. The significance level was set at p < 0.05.

RESULTS

Data on 45 children (mean age: 55.6 ± 10.37 months) were analyzed. T2_study was statistically higher than T0_study for the anthropometric measurements and biochemical growth parameters (p < 0.05). T0_study was statistically higher than T0_control for biochemical growth parameters (p < 0.05). CSHQ and ECOHIS scores were found statistically significant at T0_study than T0_control (p < 0.05). Statistical scores of CSHQ and ECOHIS in T2_study were significantly reduced compared to T0_study (p < 0.05).

CONCLUSION

Children's growth parameters, sleep disturbances, and OHRQoL improved after the elimination of pain and inflammation.

CLINICAL RELEVANCE

This study's novelty is the observation of drastically increased growth parameters and reduced sleep disturbances following dental treatment.

P2X7 receptor-activated microglia in cortex is critical for sleep disorder under neuropathic pain

Neuropathic pain (NP) is associated with sleep disturbances, which may substantially influence the quality of life. Clinical and animal studies demonstrated that neurotransmitter is one of the main contributors to cause sleep disturbances induced by NP. Recently, it was reported that P2X7 receptors (P2X7R) are widely expressed in microglia, which serves crucial role in neuronal activity in the pain and sleep-awake cycle. In this study, we adopted the chronic constriction injury (CCI) model to establish the progress of chronic pain and investigated whether P2X7R of microglia in cortex played a critical role in sleep disturbance induced by NP. At electroencephalogram (EEG) level, sleep disturbance was observed in mice treated with CCI as they exhibited mechanical and thermal hypersensitivity, and inhibition of P2X7R ameliorated these changes. We showed a dramatic high level of P2X7R and Iba-1 co-expression in the cortical region, and the inhibition of P2X7R also adversely affected it. Furthermore, the power of LFPs in ventral posterior nucleus (VP) and primary somatosensory cortex (S1) which changed in the CCI group was adverse after the inhibition of P2X7R. Furthermore, inhibition of P2X7R also decreased the VP-S1 coherence which increased in CCI group. Nuclear magnetic resonance demonstrated inhibition of P2X7R decreased glutamate (Glu) levels in thalamic and cortical regions which were significantly increased in the CCI mice. Our findings provide evidence that NP has a critical effect on neuronal activity linked to sleep and may built up a new target for the development of sleep disturbances under chronic pain conditions.

Assessment of Neurotoxic Effects of Oxycodone and Naloxone in SH-SY5Y Cell Line

Opioid drugs have analgesic properties used to treat chronic and post-surgical pain due to descending pain modulation. The use of opioids is often associated with adverse effects or clinical issues. This study aimed to evaluate the toxicity of opioids by exposing the neuroblastoma cell line (SH-SY5Y) to 0, 1, 10, and 100 µM oxycodone and naloxone for 24 h. Analyses were carried out to evaluate cell cytotoxicity, identification of cell death, DNA damage, superoxide dismutase (SOD), glutathione S-transferase (GST), and acetylcholinesterase (AChE) activities, in addition to molecular docking. Oxycodone and naloxone exposure did not alter the SH-SY5Y cell viability. The exposure to 100 µM oxycodone and naloxone significantly increased the cells' DNA damage score compared to the control group. Naloxone exposure significantly inhibited AChE, GST, and SOD activities, while oxycodone did not alter these enzymes' activities. Molecular docking showed that naloxone and oxycodone interact with different amino acids in the studied enzymes, which may explain the differences in enzymatic inhibition. Naloxone altered the antioxidant defenses of SH-SY5Y cells, which may have caused DNA damage 24 h after the exposure. On the other hand, more studies are necessary to explain how oxycodone causes DNA damage.

Can noninvasive Brain Stimulation Improve Pain and Depressive Symptoms in Patients With Neuropathic Pain? A Systematic Review and Meta-Analysis

CONTEXT

Noninvasive brain stimulations (NIBS) have been increasingly applied to the patients with neuropathic pain (NP), while the effectiveness of NIBS in the management of NP is still conflicting.

OBJECTIVES

To examine the effectiveness of NIBS on pain and depression symptoms of patients with NP.

METHODS

A comprehensive literature retrieval was performed on MEDLINE, Embase, PsycINFO, PEDro, and CENTRAL from the establishment of the databases to June 2021. Randomized controlled trials comparing NIBS with sham stimulation were included.

RESULTS

A total of thirteen trials comprising 498 participants met the inclusion criteria. The pooled analysis found a significant effect on the improvement of pain scores at post-treatment, favoring NIBS over sham stimulation (SMD = -0.60; 95% CI: -1.00 to -0.20; P = 0.004). Subgroup analysis showed that only transcranial direct current stimulation (tDCS) (SMD = -0.38; 95% CI: -0.71 to -0.04; P = 0.030) and high-frequency repetitive transcranial magnetic stimulation (H-rTMS) (SMD = -0.95; 95% CI: -1.85 to -0.04; P = 0.040) had positive effects on pain reduction among all types of NIBS. The favorable effects of NIBS remained significant at follow-up visit (SMD = -0.51; 95% CI: -0.79 to -0.23; P = 0.000), while only H-rTMS was found in subgroup analyses to significantly improve pain scales of the patients (SMD = -0.54; 95% CI: -0.85 to -0.24; P = 0.000). Additionally, overall NIBS showed no beneficial effect over sham stimulation in reducing depression symptoms of NP patients either at post-treatment (SMD = -0.19; 95% CI: -0.39 to 0.01; P = 0.061) or at follow-up visit (SMD = -0.18; 95% CI: -0.45 to 0.10; P = 0.202).

CONCLUSION

This meta-analysis revealed the analgesic effect of NIBS on patients with NP, while no beneficial effect was observed on reducing concomitant depression symptoms. The findings recommended the clinical application of NIBS in patients with NP.

Down syndrome: orofacial pain, masticatory muscle hypotonia, and sleep disorders

The aim of the present study was to investigate orofacial pain in individuals with Down syndrome (DS) and determine possible associations with masticatory muscle hypotonia (MMH), maximum mouth opening (MMO), and sleep disorders. Twenty-three individuals with DS underwent a standardized clinical examination using Axis I of the Diagnostic Criteria for Temporomandibular Disorders, for the diagnosis of pain in the masseter and temporal muscles and temporomandibular joint (TMJ). MMH was investigated using electromyography of the temporal and masseter muscles and the measurement of maximum bite force (MBF). MMO was measured using an analog caliper. Sleep disorders (obstructive sleep apnea [OSA], snoring index [SI], and sleep bruxism index [SBI]) were investigated using type II polysomnography. Statistical analysis was performed. Nonsignificant differences were found in muscle and TMJ pain between the sexes. However, myalgia and referred myofascial pain in the left masseter muscle were more frequent in males (69%) than females (40%). Electrical activity of the temporal (left: p = .002; right: p = .004) and masseter (left: p = .008) muscles was significantly lower in males than in females. MBF range was lower in males than females, indicating the highest MMH among males. OSA, SI, and SBI were identified in both sexes, but with no statistically significant differences. We concluded that myalgia and referred myofascial pain were found in some individuals with DS, especially in males. Arthralgia was found mainly in females. Temporal and masseter myalgia may have exerted an influence on the severity of MMH in males, particularly on the left side.

Past-year use or misuse of an opioid is associated with use of a sedative-hypnotic medication: a US National Survey on Drug Use and Health (NSDUH) study

STUDY OBJECTIVES

Prescription use and misuse of opioids are linked to greater sleep disturbance. However, there are limited data on the prevalence of sedative-hypnotic medication use among persons who use opioids. Therefore, this study examined whether past-year sedative-hypnotic use among persons who used/misused opioids was higher than among individuals who did not use opioids.

METHODS

Data were acquired from the US National Survey on Drug Use and Health for 2015-2018. Use of a sedative benzodiazepine (temazepam, flurazepam, triazolam) or a Z-drug (eszopiclone, zaleplon, zolpidem) was examined in relation to use/misuse of an opioid within the past year. Logistic regression models estimated the associations between opioids and sedative-hypnotics using inverse probability of treatment weighting. A secondary machine learning analysis tested 6 binary classifiers to predict sedative-hypnotic use based on opioid use/misuse and other covariates.

RESULTS

Of 171,766 respondents, 24% used a prescription opioid whereas 3.6% misused an opioid in the past year. Among those who used a prescription opioid, 1.9% received a sedative benzodiazepine and 9% received a Z-drug during the same time frame. Use of an opioid was associated with greater odds of sedative benzodiazepine use (odds ratio, 4.4; 95% confidence interval, 3.61-5.4) and Z-drug use (odds ratio, 3.8; 95% confidence interval, 3.51-4.09), and stronger associations were noted for misuse of an opioid. Machine learning models accurately classified sedative-hypnotic medication use for > 70% of respondents based on opioid use/misuse.

CONCLUSIONS

Sedative-hypnotic use is common among persons who use opioids, which is of concern given the elevated mortality risk with concurrent use of these substances.

CITATION

Tubbs AS, Ghani SB, Naps M, Grandner MA, Stein MD, Chakravorty S. Past-year use or misuse of an opiod is associated with use of a sedative-hypnotic medication: a US National Survey on Drug Use and Health (NSDUH) study. J Clin Sleep Med. 2022;18(3):809-816.

Systemic Administration of Tempol, a Superoxide Dismutase Mimetic, Augments Upper Airway Muscle Activity in Obese Zucker Rats

Obstructive sleep apnea (OSA) is characterized by repetitive partial/complete collapse of the pharynx during sleep, which results in apnea/hypopnea leading to arterial oxygen desaturations and arousals. Repetitive apnea/hypopnea-arousal episodes cause hypoxia/reoxygenation cycles, which increase free radical generation and oxidative stress that cause motor/sensory nerve impairments and muscle damage. We hypothesize that antioxidants may protect and/or reverse from oxidative stress-induced damage in OSA patients. To understand the acute protective effects of antioxidants on respiratory muscles, we studied the systemic effects of a membrane permeable superoxide dismutase mimetic, Tempol, on genioglossus (EMG_GG) and diaphragmatic (EMG_DIA) electro-myographic activities, hypoglossal motoneuron (HMN) nerve activity and cardiorespiratory parameters (mean arterial blood pressure, heart rate) in adult isoflurane-anesthetized obese Zucker rats (OZR) and age-matched lean Zucker rats (LZR). Tempol dose-dependently (1-100 mg/kg) increased EMG_GG without changing EMG_DIA in OZR and LZR. Tempol increased respiratory rate and tidal volume in OZR and LZR. Tempol (1-25 mg/kg) dose-dependently increased HMN nerve activity in healthy Sprague Dawley rats. Tempol (100 mg/kg) increased EMG_GG output by 189% in OZR and 163% in LZR. With respect to mechanisms of effect, Tempol (100 mg/kg) did not augment EMG_GG after bilateral HMN transection in Sprague Dawley rats. Although future studies are warranted, available data suggest that in addition to its antioxidant and antihypertensive properties, Tempol can selectively augment EMG_GG through modulating HMN and this effect may prevent collapsibility and/or improve stability of the upper airway pharyngeal dilator muscles during episodes of partial and/or complete collapse of the upper airway in OSA human subjects.

The Association of Self-Reported Iron and Vitamin D Levels on Sleep Quality and Pain Perception in a Subset of Saudi Population

Background and Aims

There has been a rising concern regarding the relationship of iron levels, vitamin D, and consumption of multivitamins on pain perception and sleep quality. The purpose of this study is to shed light on these connections in hopes of enhancing quality of sleep.

Methods

A cross-sectional analysis was used, and data collection was based on close-ended online questionnaire created on Survey Monkey. The survey included an operator designed questionnaire, questions from both the Brief Pain Inventory and Sleep Quality questionnaires. The targeted population was participants who were medically fit, non-pregnant Saudi citizens aged between 25 and 55 years.

Results

Prior to the COVID-19 crisis, data were collected during the months of February and March 2020, with a grand total of 3127 participants, out of which 2774 responses were included. The outcome of the research revealed that diminished levels of vitamin D, and iron had a negative impact on sleep quality. In turn, poor sleep quality had a significant pain response.

Conclusion

This study reveals the detrimental role of vitamins on sleep, and their concurrent domino effect on pain.

The influence of opioids and nonopioid central nervous system active medications on central sleep apnea: a case-control study

STUDY OBJECTIVES

Opioids are known to contribute to central sleep apnea (CSA), but the influence of nonopioid central nervous system active medications (CNSAMs) on CSA remains unclear. In light of the hypothesized impact of nonopioid CNSAMs on respiration, we examined the relationships between the use of opioids only, nonopioid CNSAMs alone, and their combination with CSA.

METHODS

Among all adults who underwent polysomnography testing at the University of Michigan's sleep laboratory between 2013 and 2018 (n = 10,606), we identified 212 CSA cases and randomly selected 300 controls. Participants were classified into four groups based on their medication use: opioids alone, nonopioid CNSAMs only, their combination, and a reference group, including those who did not use any of these medications. We defined CSA as a binary outcome and as a continuous variable using central apnea index data. Logistic and linear regression were used to examine associations between medication use, CSA diagnosis, and central apnea index.

RESULTS

Study participants included 58% men, and mean age was 50 (± 14 standard deviation years. Nearly half of the study participants did not use opioids or nonopioid CNSAMs, 6% used opioids alone, 27% nonopioid CNSAMs alone, and 16% used a combination of these medications. In adjusted analyses, opioids-only users had a nearly twofold increase in CSA odds, whereas those who used a combination of opioids and nonopioid CNSAMs had fivefold higher odds of CSA relative to the reference group. In contrast, the use of nonopioid CNSAMs alone had protective associations with CSA.

CONCLUSIONS

This report showed increased odds of CSA, particularly among patients with sleep complaints who were prescribed opioids in combination with nonopioid CNSAMs compared with those who did not use any of these medications.

Predictive Performance of Oximetry to Detect Sleep Apnea in Patients Taking Opioids

BACKGROUND

Long-term use of opioids for treatment of chronic pain is associated with significant risks including worsening unrecognized or untreated sleep apnea that may increase morbidity and mortality. Overnight oximetry has been validated for predicting sleep apnea in surgical and sleep clinic patients. The objective of the study was to assess the predictive accuracy of oxygen desaturation index (ODI 4%) from home overnight oximetry when compared to apnea hypopnea index (AHI) from polysomnography for predicting sleep apnea in patients taking opioids for chronic pain.

METHODS

This was a planned post hoc analysis of a prospective cohort study conducted at 5 pain clinics. Patient characteristics and daily morphine milligram equivalent (MME) dose were recorded. All consented patients underwent home overnight oximetry (PULSOX-300i, Konica Minolta Sensing, Inc, Osaka, Japan) and in-laboratory polysomnography. The predictive performance of ODI 4% from oximetry was assessed against AHI from polysomnography.

RESULTS

Among 332 consented patients, 181 with polysomnography and overnight oximetry data were analyzed. The mean age and body mass index of 181 patients were 52 ± 13 years and 29 ± 6 kg/m2, respectively, with 40% men. The area under the receiver operating curve for ODI to predict moderate-to-severe sleep apnea (AHI ≥15 events/h) and severe sleep apnea (AHI ≥30 events/h) was 0.82 (95% confidence interval [CI], 0.75-0.88) and 0.87 (95% CI, 0.80-0.94). ODI ≥5 events/h had a sensitivity of 85% (95% CI, 74-92) and specificity of 57% (95% CI, 52-61) to predict moderate-to-severe sleep apnea. ODI ≥15 events/h had a sensitivity of 71% (95% CI, 55-83) and specificity of 88% (95% CI, 84-91) to predict severe sleep apnea.

CONCLUSIONS

Overnight home oximetry has a high predictive performance in predicting moderate-to-severe and severe sleep apnea in patients on opioids for chronic pain. It is a useful additional tool for health care providers for the screening of sleep apnea in this high-risk group.

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.

Multitargeting the sleep-pain interaction with pharmacological approaches: A narrative review with suggestions on new avenues of investigation

The multimorbidity formed by sleep disturbances and pain conditions is highly prevalent and has a significant impact in global health and in the socioeconomic system. Although different approaches have been directed toward its management, evidence regarding an optimal treatment is lacking, and pharmacological options are often preferred. Health professionals (e.g., pain and sleep clinicians) tend to focus on their respective expertise, targeting a single symptom with a single drug. This may increase polypharmacy and the risk of drug interactions, adverse events, and mortality. Hence, the use of medications that can directly or indirectly improve sleep, pain, and other possible accompanying conditions without exacerbating them becomes especially relevant. The objectives of this comprehensive review are to: a) describe the beneficial or deleterious effects that some commonly used medications to manage pain have on sleep and sleep disorders; and b) describe the beneficial or deleterious effects that frequently prescribed medications for sleep may have on pain. Moreover, medications targeting some specific sleep-pain interactions will be suggested and future directions for improving sleep and alleviating pain of these patients will be provided with clinical and research perspectives.

The relationship between opioid use and obstructive sleep apnea: A systematic review and meta-analysis

We conducted a systematic review to address limited evidence suggesting that opioids may induce or aggravate obstructive sleep apnea (OSA). All clinical trials or observational studies on adults from 1946 to 2018 found through MEDLINE, EMBASE, CINAHL, PsycINFO, Cochrane Databases were eligible. We assessed the quality of the studies using published guidelines. Fifteen studies (six clinical trials and nine observational) with only two of good quality were included. Fourteen studies investigated the impact of opioids on the presence or severity of OSA, four addressed the effects of treatment for OSA  in opioid users, and none explored the consequences of opioid use in individuals with OSA. Eight of 14 studies found no significant relationship between opioid use or dose and apnea-hypopnea index (AHI) or degree of nocturnal desaturation. A random-effects meta-analysis (n = 10) determined the pooled mean change in AHI associated with opioid use of 1.47/h (-2.63-5.57; I² = 65%). Three of the four studies found that continuous positive airway pressure (CPAP) therapy reduced AHI by 17-30/h in opioid users with OSA. Bilevel therapy with a back-up rate and adaptive servo-ventilation (ASV) without mandatory pressure support successfully normalized AHI (≤5) in opioid users. Limited by a paucity of good-quality studies, our review did not show a significant relationship between opioid use and the severity of OSA. There was some evidence that CPAP, Bilevel therapy, and ASV alleviate OSA for opioid users, with higher failure rates observed in patients on CPAP in opioid users.

Exploring the Connection Between Sleep and Cluster Headache: A Narrative Review

Cluster headache is a rare form of headache associated with sleep and even speculated to be a manifestation of a sleep disorder rather than a primary headache. Cluster headache exhibits both circadian and circannual rhythmicity. While attacks often occur during sleep, the implication that cluster headaches might be involved with rapid eye movement (REM) sleep phases has neither been fully established nor refuted. The regulatory mechanisms governing sleep including hypothalamic activity and the autonomic nervous system response may play a role. Hypothalamic activation has been observed in cluster headache patients during positron emission tomography testing, but only during attacks. While sleep apnea is associated with morning headaches in general, the link between sleep-disordered respiration and cluster headache remains elusive. Hypoarousal during sleep and periods of hypoxia are associated with cluster headache, the latter likely involving inflammatory processes rather than apnea. Further study is needed, as cluster headaches represent a serious primary cephalgia that is incompletely understood.

Chronic non-cancer pain and its association with healthcare use and costs among individuals with obstructive sleep apnea

Aim: To evaluate the impact of chronic non-cancer pain (CNCP) on healthcare use and costs among individuals diagnosed with obstructive sleep apnea (OSA). Materials & methods: Using the IQVIA PharMetrics^® Plus database, we identified individuals (18-64 years old) during 2007-2014, divided into two groups: OSA + CNCP versus OSA-only. Generalized linear models were used to analyze binary and count outcomes. Results: Relative to OSA-only controls, OSA + CNCP cases had increased odds for inpatient and emergency department visits and higher rates for physician office visits, non-physician outpatient visits, and prescription drug fills. Relative to controls, direct healthcare costs for cases were higher, primarily driven by inpatient and non-physician outpatient visit costs. Conclusion: Relative to OSA-only controls, OSA + CNCP cases displayed increased healthcare use and costs across all points of service.

Sleep-disordered breathing in patients on opioids for chronic pain

The past two decades has seen a substantial rise in the use of opioids for chronic pain, along with opioid-related mortality and adverse effects. A contributor to opioid-associated mortality is the high prevalence of moderate/severe sleep-disordered breathing, including central sleep apnea and obstructive sleep apnea, in patients with chronic pain. Although evidence-based treatments are available for sleep-disordered breathing, patients are not frequently assessed for sleep-disordered breathing in pain clinics. To aid healthcare providers in this area of clinical uncertainty, we present evidence on the interaction between opioids and sleep-disordered breathing, and the prevalence and predictive factors for sleep-disordered breathing in patients on opioids for chronic pain. We provide recommendations on how to evaluate patients on opioids for risk of moderate/severe sleep-disordered breathing in clinical care, which could lead to earlier use of therapeutic interventions for opioid-associated sleep-disordered breathing, such as opioid cessation or positive airway pressure therapy. This would improve quality of life and well-being of patients with chronic pain.

The face of Dental Sleep Medicine in the 21st century

It becomes increasingly clear that some sleep disorders have important diagnostic and/or management links to the dental domain, hence the emergence of the discipline ‘Dental Sleep Medicine’. In this review, the following topics are discussed: 1. the reciprocal associations between oro‐facial pain and sleep; 2. the associations between sleep bruxism and other sleep‐related disorders; 3. the role of the dentist in the assessment and management of sleep bruxism; and 4. the dental management of obstructive sleep apnoea. From these topics' descriptions, it becomes clear that the role of the dentist in the recognition and management of sleep‐related oro‐facial pain, sleep bruxism and obstructive sleep apnoea is large and important. Since many dental sleep disorders can have severe consequences for the individual's general health and well‐being, it is imperative that dentists are not only willing to take on that role, but are also able to do so. This requires more attention for Dental Sleep Medicine in the dental curricula worldwide, as well as better postgraduate training of dentists who are interested in specialising in this intriguing domain. This review contributes to increasing the dental researcher's, teacher's and care professional's insight into the discipline ‘Dental Sleep Medicine’ as it has taken shape in the 21st century, to the benefit of all patients suffering from dental sleep disorders.

Dental sleep medicine: Time to incorporate sleep apnoea education in the dental curriculum

Dental sleep medicine is a discipline that includes conditions such as sleep breathing disorders (eg snoring and sleep apnoea), sleep bruxism, orofacial pain and sleep-related complaints, and to some extent gastro-oesophageal reflux disorder and/or insomnia. Obstructive sleep apnoea (OSA) is a life-threatening condition that dentists need to identify and manage when indicated in order to increase patient well-being and to be taken in consideration in the dental curriculum. The main objective of this paper is to highlight the relevance of dental sleep medicine in the context of dental education, and to discuss potential educational content for integration in the dental curriculum with a focus on OSA, a condition that is not yet integrated in many dental training curricula around the world.

Opioid use, pain intensity, age, and sleep architecture in patients with fibromyalgia and insomnia

Opioid use and sleep disruption are prevalent in fibromyalgia. Yet, the effects of opioids on physiological sleep in fibromyalgia are unclear. This study assessed associations between opioid use/dosage and polysomnographically assessed sleep in patients with fibromyalgia and insomnia (FMI) and examined moderating effects of age and pain. Participants (N = 193, Mage = 51.7, SD = 11.8, range = 18-77) with FMI completed ambulatory polysomnography and 14 daily diaries. Multiple regression determined whether commonly prescribed oral opioid use or dosage (among users) independently predicted or interacted with age/pain intensity to predict sleep, controlling for sleep medication use and apnea hypopnea index. Opioid use predicted greater %stage 2 and lower %slow-wave sleep (%SWS). Opioid use interacted with age to predict greater sleep onset latency (SOL) in middle-aged/older adults. Among opioid users (n = 65, ∼3 years usage), opioid dose (measured in lowest recommended dosage) interacted with age to predict SOL and sleep efficiency; specifically, higher dosage predicted longer SOL and lower sleep efficiency for older, but not middle-aged/younger adults. Opioid dose interacted with pain to predict %SWS and arousal index. Specifically, higher dosage predicted reduced %SWS and higher arousal index for individuals with lower pain, increased %SWS for individuals with higher pain, and did not predict %SWS for patients with average pain. Opioid use/dosage did not predict wake after sleep onset, total sleep time, %stage 1 or %rapid eye movement sleep. Opioid use prompts changes in sleep architecture among individuals with FMI, increasing lighter sleep and reducing SWS. Sleep disruption is exacerbated at higher opioid doses in older adults and patients with low pain.

Experience and sleep-dependent synaptic plasticity: from structure to activity

Synaptic plasticity is important for learning and memory. With increasing evidence linking sleep states to changes in synaptic strength, an emerging view is that sleep promotes learning and memory by facilitating experience-induced synaptic plasticity. In this review, we summarize the recent progress on the function of sleep in regulating cortical synaptic plasticity. Specifically, we outline the electroencephalogram signatures of sleep states (e.g. slow-wave sleep, rapid eye movement sleep, spindles), sleep state-dependent changes in gene and synaptic protein expression, synaptic morphology, and neuronal and network activity. We highlight studies showing that post-experience sleep potentiates experience-induced synaptic changes and discuss the potential mechanisms that may link sleep-related brain activity to synaptic structural remodelling. We conclude that both synapse formation or strengthening and elimination or weakening occur across sleep. This sleep-dependent synaptic plasticity plays an important role in neuronal circuit refinement during development and after learning, while sleep disorders may contribute to or exacerbate the development of common neurological diseases. This article is part of the Theo Murphy meeting issue 'Memory reactivation: replaying events past, present and future'.

Pharmacologic Approach to Insomnia

Sleep management is essential to effective treatment of pain symptoms. Identification of the precise nature of sleep complaint, awareness of patient's age and co-morbid conditions and choice of the hypnotic medication class can help guide treatment approach. In addition to benzodiazepine and non-benzodiazepine medications acting at the GABA receptor, novel approaches, including orexin receptor agonists, may be safer and more promising pharmacologic approaches. Pharmacologic interventions, when used cautiously for a limited period of time and in complement with behavioral and cognitive approaches, can serve to improve sleep quality and significantly help in management of pain.

Critical Issues in Dental and Medical Management of Obstructive Sleep Apnea

This critical review focuses on obstructive sleep apnea (OSA) and its management from a dental medicine perspective. OSA is characterized by ≥10-s cessation of breathing (apnea) or reduction in airflow (hypopnea) ≥5 times per hour with a drop in oxygen and/or rise in carbon dioxide. It can be associated with sleepiness and fatigue, impaired mood and cognition, cardiometabolic complications, and risk for transportation and work accidents. Although sleep apnea is diagnosed by a sleep physician, its management is interdisciplinary. The dentist’s role includes 1) screening patients for OSA risk factors (e.g., retrognathia, high arched palate, enlarged tonsils or tongue, enlarged tori, high Mallampati score, poor sleep, supine sleep position, obesity, hypertension, morning headache or orofacial pain, bruxism); 2) referring to an appropriate health professional as indicated; and 3) providing oral appliance therapy followed by regular dental and sleep medical follow-up. In addition to the device features and provider expertise, anatomic, behavioral, demographic, and neurophysiologic characteristics can influence oral appliance effectiveness in managing OSA. Therefore, OSA treatment should be tailored to each patient individually. This review highlights some of the putative action mechanisms related to oral appliance effectiveness and proposes future research directions.

Exploring the Relationship Between Social Support and Sleep

Background. Getting a sufficient amount of sleep is an important component of living a healthy lifestyle. Consequently, it is important for researchers to identify the factors that influence sleep duration. Aims. The current study has a twofold objective. The first is to see if two types of social support are associated with sleep duration. The second objective is to see if meaning in life and depressive symptoms serve as indirect pathways in the relationship between social support and sleep. Method. The data come from an internet survey of a random probability sample of adults who reside in the United States (N = 2,287). Questions were administered on received support, satisfaction with support, meaning in life, depressive symptoms, and sleep. Results. The findings indicate that the amount of support that is received is associated with satisfaction with support, greater satisfaction with support is associated with a stronger sense of meaning in life, a stronger sense of meaning is related to fewer depressive symptoms, and fewer depressive symptoms is significantly associated with the likelihood of getting the recommended number of hours of sleep. Discussion and Conclusions. Instead of merely showing that social support is associated with sleep, our findings take a modest step toward explaining how this relationship arises (i.e., through an increased sense of meaning in life and, in turn, reduced depressive symptoms). This theoretical specificity is helpful for devising interventions to improve sleep habits.

Fractures as a suicidal behavior risk factor: A nationwide population-based cohort study

This study aimed to evaluate the association between fracture history and sequential risk of suicidal behavior.A total of 82,804 patients with fractures and 82,804 control subjects without fractures were matched. The influence of fractures on the risk of suicidal behavior-related hospital visit was analyzed using a Cox proportional hazards model.The overall adjusted hazard ratio (aHR) of suicidal behavior-related hospital visit was 2.21 in fracture cohort. The aHR declined from 2.90 at the 1-year follow-up to 2.00 after 5 years or more. In fracture patients, the risk of suicidal behavior-related hospital visit was higher at age <35 years, with comorbidities of stroke and sleep disorder. Patients with multiple fractures had a 1.69-fold risk.Fractures are an independent risk factor for suicidal behavior. Individuals aged younger than 35 years, with comorbidities of stroke and sleep disorder, and those who have suffered multiple fractures have elevated risk of suicidal behavior among subjects in the fracture group. Furthermore, this increased risk remained even after 5 years had passed since the fracture incident.

Both melatonin and meloxicam improved sleep and pain in females with primary dysmenorrhea-results from a double-blind cross-over intervention pilot study

Up to 25% of ovulating women suffer from primary dysmenorrhea, a condition associated with pain and transient-reduced quality of life, along with greater irritability and impaired sleep. In the present study, we asked whether and if so to what extent melatonin and meloxicam can improve subjective and objective sleep and reduce pain among women with primary dysmenorrhea (PD). To this end, we conducted a double-blind cross-over clinical trial lasting for three menstrual cycles. A total of 14 women (mean age M = 27.5 years) with primary dysmenorrhea took part in the study. At baseline, that is, during the first menstruation, they completed a visual analogue scale to rate pain; sleep continuity was assessed via actigraphs, and overall sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI). Next, participants were randomly assigned to one of two conditions, either melatonin during the second, and meloxicam during the third menstruation, or meloxicam during the second, and melatonin during the third menstruation. Neither participants nor investigators were aware of participants' study assignment. During the second and third menstruations, the assessments described above were repeated. At baseline, sleep assessed both objectively and subjectively was impaired, and pain was high. Subjective sleep improved and pain decreased during the second and third menstruations irrespective of whether melatonin or meloxicam was administered first or second. Likewise, objective sleep efficiency increased and objective sleep latency shortened. The efficacy of melatonin was superior to that of meloxicam. The present pattern of results suggests that both melatonin and meloxicam are suitable to treat pain and PD-related sleep complaints among women with primary dysmenorrhea.

Pain intensity as a moderator of the association between opioid use and insomnia symptoms among adults with chronic pain

OBJECTIVE

Research documenting the impact of opioid use on sleep among individuals with chronic pain has been mixed. This study aimed to determine if pain intensity moderates the association between opioid use and insomnia symptoms among adults with comorbid symptoms of insomnia and chronic widespread pain.

METHODS

Participants (N = 144; 95% female; mean age = 51.6, SD = 11.4) completed assessments of insomnia symptoms, pain and use of sleep/pain medication. Multiple regression was used to determine if pain intensity moderates the association between opioid use (yes/no) sleep onset latency (SOL), wake after sleep onset (WASO), sleep quality, or time in bed. Analyses controlled for gender, symptoms of sleep apnea, symptoms of depression, use of sleep medication (yes/no), and use of non-opioid pain medication (yes/no).

RESULTS

Stronger pain intensity was associated with longer self-reported WASO and worse sleep quality, independent of opioid use. Conversely, opioid use was associated with longer time in bed, independent of pain intensity. Opioid use and pain intensity interacted in the prediction of SOL, such that opioid use (vs. non-use) was associated with longer SOL in the context of mild but not moderate to severe pain intensity.

CONCLUSIONS

Opioid use was associated with more difficulty falling asleep among adults with chronic pain; however, this cross-sectional effect was only significant among those reporting lower pain intensity. Authors speculate that this effect is masked among those with severe pain because the pain-related sleep debt they acquire throughout the night then facilitates sleep onset the next day.

In Search of a Good Night's Sleep: Hormones, Mind, Movement, and Breath

Sleep disturbances are common in postmenopausal women and contribute to increased morbidity and mortality. Sleep apnea may be underdiagnosed in women, and other conditions such as insomnia and restless legs may coexist with sleep apnea. This case illustrates the complex interplay of anatomical, hormonal, metabolic and psychological factors that can interfere with restorative sleep, and the importance of both diagnostic testing and clinical history in identifying which combination of therapies will be most beneficial in improving sleep quality and quantity.