The prevalence and awareness of sleep apnea in patients suffering chronic pain: an assessment using the STOP-Bang sleep apnea questionnaire

Insight and Recommendations for Fragile X-Premutation-Associated Conditions from the Fifth International Conference on FMR1 Premutation

The premutation of the fragile X messenger ribonucleoprotein 1 (FMR1) gene is characterized by an expansion of the CGG trinucleotide repeats (55 to 200 CGGs) in the 5' untranslated region and increased levels of FMR1 mRNA. Molecular mechanisms leading to fragile X-premutation-associated conditions (FXPAC) include cotranscriptional R-loop formations, FMR1 mRNA toxicity through both RNA gelation into nuclear foci and sequestration of various CGG-repeat-binding proteins, and the repeat-associated non-AUG (RAN)-initiated translation of potentially toxic proteins. Such molecular mechanisms contribute to subsequent consequences, including mitochondrial dysfunction and neuronal death. Clinically, premutation carriers may exhibit a wide range of symptoms and phenotypes. Any of the problems associated with the premutation can appropriately be called FXPAC. Fragile X-associated tremor/ataxia syndrome (FXTAS), fragile X-associated primary ovarian insufficiency (FXPOI), and fragile X-associated neuropsychiatric disorders (FXAND) can fall under FXPAC. Understanding the molecular and clinical aspects of the premutation of the FMR1 gene is crucial for the accurate diagnosis, genetic counseling, and appropriate management of affected individuals and families. This paper summarizes all the known problems associated with the premutation and documents the presentations and discussions that occurred at the International Premutation Conference, which took place in New Zealand in 2023.

Obstructive sleep apnea is common in patients with high-impact chronic pain - an exploratory study from an interdisciplinary pain center

OBJECTIVES

Sleep disturbances are increasingly recognized as a major part of chronic pain pathology. Obstructive sleep apnea (OSA) is a common occurrence in patients with chronic pain attending specialized pain clinics, yet its prevalence remains unclear. Using screening tools such as the Berlin and STOP-BANG questionnaires may aid in early identification of OSA and improve clinical care. This study i) examined the frequency of OSA based on objective sleep monitoring in patients with high-impact chronic pain, ii) explored potential differences in self-reported pain and sleep characteristics between patients with and without OSA, and iii) tested the agreement between OSA classification based on objective assessment and two OSA screening questionnaires.

METHODS

A consecutive cohort of 90 patients (71 women and 19 men; mean age: 47.1 ± 11.0 years) referred for interdisciplinary pain treatment, underwent one night of sleep monitoring using portable respiratory polygraphy (RP), and suspected OSA was confirmed with polysomnography (PSG). Self-reported data on clinical pain (severity, pain drawings and health-related quality of life), sleep characteristics (sleep quality insomnia, sleepiness), and risk of OSA (Berlin and STOP-BANG questionnaires) were collected the day before RP assessment.

RESULTS

Forty-six (51.1%) patients were classified with OSA according to RP and verified with PSG. Twenty-eight patients (31.1%) had moderate or severe OSA (apnea-hypopnea index [AHI] >15). Patients with OSA reported lower sleep quality compared with patients without OSA. Scores on pain severity, disability, quality of life, insomnia and sleepiness were comparable between patients with and without OSA. Sensitivity and specificity were 78.6 and 45.2% respectively for the Berlin questionnaire, and 71.4 and 58.1% respectively for the STOP-BANG questionnaire. The agreement for both questionnaires with objective assessment was poor-to-fair. Both questionnaires had acceptable negative predictive values but low positive predictive values reducing the clinical utility to identify patients with low OSA-risk in this sample.

CONCLUSIONS

The current study demonstrates a high prevalence of OSA in patients with high-impact chronic pain referred to specialized pain treatment, however the clinical pain profiles were similar in patients with and without OSA. The Berlin and STOP-BANG questionnaires have poor specificity and low-to-fair agreement with RP/PSG questioning their clinical utility in identifying OSA in this sample.

Pain Experiences in Individuals with Reported and Suspected Sleep Disorders

The purpose of the present study was to examine whether individuals with varying reported and/or suspected insomnia and sleep apnea presentations differed with respect to pain.Data included 3,161 adults who participated in an online study investigating sleep and health. Participants reported a lifetime history of prior sleep disorder diagnoses while the presence of suspected sleep disorders was determined using the Insomnia Severity Index and the STOP-Bang. Average pain intensity was assessed using a visual analogue scale and pain interference was determined using two items from the PHQ-15. Participants who reported diagnoses of insomnia and/or sleep apnea reported greater pain intensity and interference compared to those with no sleep disorder; however, no differences in pain were observed between the various reported sleep disorders. Of participants who did not report either insomnia or sleep apnea diagnoses, 24% were suspected of having either insomnia, sleep apnea, or both disorders based on responses to questionnaires. Participants with one or more suspected sleep disorders reported higher pain intensity and interference than those without a suspected disorder. Additionally, having either suspected insomnia or suspected comorbid insomnia and sleep apnea was associated with greater pain intensity compared to only having suspected sleep apnea. Sleep disorders go commonly undiagnosed and are associated with adverse pain experiences. While results do not support a synergistic effect of suspected insomnia and sleep apnea on pain, findings indicate that screening for sleep disorders is warranted and may have important implications for pain treatment.

Orofacial Pain and Snoring/Obstructive Sleep Apnea in Individuals with Head and Neck Cancer: A Critical Review

AIMS

(1) To summarize current knowledge on the prevalence, intensity, and descriptors of orofacial pain and snoring/obstructive sleep apnea (OSA) before and after head and neck cancer (HNC) treatment; and (2) to propose future directions for research.

METHODS

The median prevalence for each condition was estimated from the most recent systematic reviews (SRs) and updated with new findings retrieved from the PubMed, Web of Science, Embase, and Cochrane databases up to December 2021.

RESULTS

The prevalence of HNC pain seems relatively stable over time, with a median of 31% before treatment in three studies to a median of 39% at 1 month to 16 years after treatment in six studies. HNC pain intensity remains mild to moderate. There was a threefold increase in temporomandibular pain prevalence after surgery (median 7.25% before to 21.3% after). The data for snoring prevalence are unreliable. The OSA/HNC prevalence seems relatively stable over time, with a median of 72% before treatment in three studies to 77% after treatment in 14 studies.

CONCLUSION

With the exception of temporomandibular pain, the prevalence of HNC pain and OSA seems to be stable over time. Future studies should: (1) compare the trajectory of change over time according to each treatment; (2) compare individuals with HNC to healthy subjects; (3) use a standardized and comparable method of data collection; and (4) assess tolerance to oral or breathing devices, since HNC individuals may have mucosal sensitivity or pain.

Simple screening model for identifying the risk of sleep apnea in patients on opioids for chronic pain

BACKGROUND

There is an increased risk of sleep apnea in patients using opioids for chronic pain. We hypothesized that a simple model comprizing of: (1) STOP-Bang questionnaire and resting daytime oxyhemoglobin saturation (SpO₂); and (2) overnight oximetry will identify those at risk of moderate-to-severe sleep apnea in patients with chronic pain.

METHOD

Adults on opioids for chronic pain were recruited from pain clinics. Participants completed the STOP-Bang questionnaire, resting daytime SpO₂, and in-laboratory polysomnography. Overnight oximetry was performed at home to derive the Oxygen Desaturation Index. A STOP-Bang score ≥3 or resting daytime SpO₂ ≤95% were used as thresholds for the first step, and for those identified at risk, overnight oximetry was used for further screening. The Oxygen Desaturation Index from overnight oximetry was validated against the Apnea-Hypopnea Index (≥15 events/hour) from polysomnography.

RESULTS

Of 199 participants (52.5±12.8 years, 58% women), 159 (79.9%) had a STOP-Bang score ≥3 or resting SpO₂ ≤95% and entered the second step (overnight oximetry). Using an Oxygen Desaturation Index ≥5 events/hour, the model had a sensitivity of 86.4% and specificity of 52% for identifying moderate-to-severe sleep apnea. The number of participants who would require diagnostic sleep studies was decreased by 38% from Step 1 to Step 2 of the model.

CONCLUSION

A simple model using STOP-Bang questionnaire and resting daytime SpO₂, followed by overnight oximetry, can identify those at high risk of moderate-to-severe sleep apnea in patients using opioids for chronic pain.

TRIAL REGISTRATION NUMBER

NCT02513836.

The effect of long-term poor sleep quality on risk of back-related disability and the modifying role of physical activity

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

Treatment for patients with sleep apnea on opioids for chronic pain: results of the OpSafe trial

STUDY OBJECTIVES

Approximately 20% of North Americans are afflicted with chronic pain with 3% being opioid users. The objective was to determine whether patients on opioids for chronic pain with newly diagnosed sleep apnea attended sleep clinic review and followed treatment recommendations.

METHODS

The study was a post hoc analysis from a multicenter perspective cohort study. Inclusion criteria included adults taking opioid medications for chronic pain for >3 months. Demographic data and daily opioid dose were collected. Sleep apnea was diagnosed via level 1 polysomnography. Patients who attended sleep clinic review were grouped based on the types of treatment they received.

RESULTS

A total of 204 patients completed polysomnography and 58.8% were diagnosed to have sleep apnea (apnea-hypopnea index ≥5 events/h). Of those with sleep apnea, 58% were recommended to have an evaluation by a sleep physician. Body mass index and age were 29.5 ± 6 kg/m² and 56 ± 12 years, respectively. Of those with newly diagnosed sleep apnea, 25% received treatment, with the majority being treated with positive airway pressure therapy, whereas the rest received positional therapy and opioids/sedative reduction. The adherence rate of positive airway pressure therapy was 55% at 1 year. Over 50% of participants on opioids for chronic pain with newly diagnosed sleep apnea declined attendance for sleep clinic review or treatment.

CONCLUSIONS

There was a high refusal rate to attend clinic for treatment. Adherence to positive airway pressure therapy was low at 55%. This sheds light on the high rate of treatment nonadherence and the need for further research.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Name: Opioid Safety Program in Pain Clinics (Op-Safe); URL: https://www.clinicaltrials.gov/ct2/show/NCT02513836; Identifier: NCT02513836.

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

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

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.

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

STUDY OBJECTIVES

To examine the association between the number of chronic nighttime insomnia symptoms and the risk of chronic widespread pain (CWP) and pain-related disability.

METHODS

A prospective study of 10,847 participants in the Norwegian HUNT Study without chronic musculoskeletal pain at baseline in 2006-2008. We used a modified Poisson regression model to estimate adjusted risk ratios (RRs) with a 95% confidence interval (CI) for CWP and pain-related disability at follow-up in 2017-2019 associated with insomnia and number of nighttime insomnia symptoms at baseline. Chronic insomnia was defined according to the current classification system and grouped into three categories based on the number of reported nighttime symptoms (ie, difficulty initiating sleep, trouble maintaining sleep and early morning awakenings).

RESULTS

Compared to the reference group of people without insomnia, people with insomnia had RRs for CWP and pain-related disability of 1.64 (1.26-2.14) and 1.63 (1.37-1.94), respectively. When people with insomnia were categorized based on the number of nighttime symptoms, people who reported one, two, or three nighttime symptoms had RRs of CWP of 1.19 (95% CI 0.80-1.78), 1.78 (95 CI 1.13-2.80) and 3.08 (95% CI 1.93-4.92), respectively, compared to people without insomnia. The corresponding RRs for pain-related disability were 1.49 (95% CI 1.17-1.89), 1.46 (95% CI 2.04-2.05), and 2.46 (95% CI 1.76-3.42).

CONCLUSION

These findings indicate that people with insomnia characterized by symptoms in all phases of the sleep period have a substantially increased risk of CWP and pain-related disability.

Chronic pain: a review of its epidemiology and associated factors in population-based studies

Chronic pain is a common, complex, and distressing problem that has a profound impact on individuals and society. It frequently presents as a result of a disease or an injury; however, it is not merely an accompanying symptom, but rather a separate condition in its own right, with its own medical definition and taxonomy. Studying the distribution and determinants of chronic pain allows us to understand and manage the problem at the individual and population levels. Targeted and appropriate prevention and management strategies need to take into account the biological, psychological, socio-demographic, and lifestyle determinants and outcomes of pain. We present a narrative review of the current understanding of these factors.

Fragile X-Associated Neuropsychiatric Disorders (FXAND)

Fragile X syndrome (FXS) is caused by the full mutation (>200 CGG repeats) in the Fragile X Mental Retardation 1 (FMR1) gene. It is the most common inherited cause of intellectual disability (ID) and autism. This review focuses on neuropsychiatric disorders frequently experienced by premutation carriers with 55 to 200 CGG repeats and the pathophysiology involves elevated FMR1 mRNA levels, which is different from the absence or deficiency of fragile X mental retardation protein (FMRP) seen in FXS. Neuropsychiatric disorders are the most common problems associated with the premutation, and they affect approximately 50% of individuals with 55 to 200 CGG repeats in the FMR1 gene. Neuropsychiatric disorders in children with the premutation include anxiety, ADHD, social deficits, or autism spectrum disorders (ASD). In adults with the premutation, anxiety and depression are the most common problems, although obsessive compulsive disorder, ADHD, and substance abuse are also common. These problems are often exacerbated by chronic fatigue, chronic pain, fibromyalgia, autoimmune disorders and sleep problems, which are also associated with the premutation. Here we review the clinical studies, neuropathology and molecular underpinnings of RNA toxicity associated with the premutation. We also propose the name Fragile X-associated Neuropsychiatric Disorders (FXAND) in an effort to promote research and the use of fragile X DNA testing to enhance recognition and treatment for these disorders.