Management of insomnia in sleep disordered breathing

Obstructive sleep apnea syndrome, orexin, and sleep-wake cycle: The link with the neurodegeneration

Obstructive sleep apnea syndrome (OSAS) significantly affects the sleep-wake circadian rhythm through intermittent hypoxia and chronic sleep fragmentation. OSAS patients often experience excessive daytime sleepiness, frequent awakenings, and sleep fragmentation, leading to a disrupted circadian rhythm and altered sleep-wake cycle. These disruptions may exacerbate OSAS symptoms and contribute to neurodegenerative processes, particularly through the modulation of clock gene expression such as CLOCK, BMAL1, and PER. Emerging evidence connects OSAS to cognitive impairment and suggests that these changes may contribute to the development of neurodegenerative disorders such as Alzheimer disease, suggesting that OSAS could be a reversible risk factor for these conditions. Biomarkers, including melatonin and orexin, play crucial roles in understanding these mechanisms. In OSAS patients, melatonin, a marker of circadian rhythmicity, often shows altered secretion patterns that are not fully corrected by continuous positive airway pressure therapy. Orexin, which regulates the sleep-wake cycle, exhibits increased cerebrospinal fluid levels in OSAS patients, possibly due to compensatory mechanisms against sleep impairment and daytime sleepiness. These biomarkers highlight the intricate relationship between circadian rhythm disruptions and neurodegenerative risks in OSAS, emphasizing the need for further research and potential therapeutic strategies to mitigate these effects and improve patient outcomes.

Protocol of a randomized controlled trial into guided internet-delivered cognitive behavioral therapy for insomnia in autistic adults (i-Sleep Autism)

BACKGROUND

Sleep problems, especially insomnia, are prevalent among autistic adults, affecting about 60 %, and significantly impact their quality of life. Internet-based cognitive behavioral therapy for insomnia (iCBT-I) could provide accessible and scalable treatment. Given the unique sensory- and information processing, and social challenges at play in autism, a tailored treatment approach may be essential to tackle sleep problems. Yet, interventions developed and tested specifically for autistic adults were scarce. Addressing this gap is crucial to meet the urgent need for effective insomnia treatments in this population.

METHODS

With this two-arm, parallel, superiority randomized controlled trial, we will assess the effectiveness of a guided iCBT-I intervention for adults (N = 160) with autism and insomnia (i-Sleep Autism). In co-creation, i-Sleep Autism has been adjusted from an existing intervention (i-Sleep). Inclusion criteria are: age ≥ 18, an ASD diagnosis, and at least sub-threshold insomnia (Insomnia Severity Index ≥10). Participants are randomly assigned to either i-Sleep Autism or an information only waitlist control condition (online psychoeducation and sleep hygiene). After 6 weeks, the control group receives the intervention. Insomnia severity is the primary outcome. Secondary outcomes include pre-sleep arousal, general mental health, depression, anxiety, daily functioning, and quality of life. Assessments will occur at baseline, mid-intervention (3 weeks), post-intervention (6 weeks), and at 6-month follow-up (the intervention group). Linear mixed-effect regression models are employed to evaluate the effectiveness of i-Sleep Autism, alongside exploration of potential moderators and mediators.

CONCLUSION

This trial can reveal whether autistic adults with insomnia benefit from a guided e-health intervention.

TRIAL REGISTRATION

NL-OMON56692.

Effects of combined morbid insomnia and sleep apnea on long-term cardiovascular risk and all-cause mortality in elderly patients: a prospective cohort study

PURPOSE

It is reported that insomnia and obstructive sleep apnea (OSA) increase the incidence of adverse cardiovascular events. The aim of this study was to analyze the risk of cardiovascular disease and mortality in elderly patients with comorbid insomnia and obstructive sleep apnea (COMISA).

METHODS

We included 868 elderly patients with OSA who underwent sleep monitoring at a multicenter sleep room from January 2015 to October 2017. We collected demographic data, clinical features, medical history, sleep parameters, and laboratory findings. Cox proportional hazards analysis was used to identify the relationship between COMISA and adverse cardiovascular events and all-cause mortality.

RESULTS

There were 181 elderly patients with COMISA. The median follow-up was 43 months, during which we observed major adverse cardiac events (MACE) in 90 patients. The Kaplan-Meier survival curve indicated a significant relationship between COMISA and MACE (Plog Rank < 0.001). Multivariate Cox regression analysis showed that COMISA increased the incidence of MACE (HR = 2.328, 95% CI: 1.349-4.018, P = 0.002), hospitalization for unstable angina (HR = 2.915, 95% CI: 1.397-6.081, P = 0.004), and the combination of all events (HR = 2.301, 95% CI: 1.393-3.803, P = 0.001). However, there were no significant differences in cardiovascular death, all-cause mortality, myocardial infarction, or hospitalized heart failure in patients with COMISA (P > 0.05). Subgroup analyses showed that among COMISA patients, male sex (HR = 2.800, 95% CI: 1.458-5.377, P = 0.002), age < 70 years (HR = 4.050, 95% CI: 2.022-8.115, P < 0.001), and overweight and obesity (HR = 2.482, 95% CI: 1.383-4.453, P = 0.002) were associated with a higher risk of MACE.

CONCLUSIONS

Our results showed that COMISA increased the risk of MACE, unstable angina, and the compound occurrence of all events. Male, overweight or obese COMISA patients under 70 years of age have an increased risk of MACE.

Comorbid Insomnia and Sleep Apnea: COMISA

The term "comorbid insomnia and sleep apnea" (COMISA) has been used to categorize the co-occurrence of the most prevalent and impacting sleep disorders. Meanwhile, both insomnia and sleep apnea have been shown to be associated with increased stress levels and cardiometabolic risk, a major cause of mortality. The better knowledge about such convergence would be critical for better understanding pathophysiological pathways and mechanisms. This article provides an overview of epidemiologic aspects, clinical findings, and mechanisms subsiding COMISA. Odontostomatological approach with mandibular advancement devices are discussed as an effective therapeutic approach in these patients.

Comorbid Insomnia and Sleep Apnea: Challenges and Treatments

Insomnia and obstructive sleep apnea (OSA) are 2 of the most prevalent sleep disorders and frequently co-occur. Therapy can be challenging as treatment of 1 disease may worsen the other. Cognitive behavioral therapy for insomnia is the first-line treatment for insomnia and has been shown to improve compliance with positive airway pressure therapy. Other alternatives to OSA treatment may have higher acceptance in those with comorbid insomnia and sleep apnea (COMISA), such as mandibular advancement devices or emerging pharmacotherapies. Surgery, particularly hypoglossal nerve stimulation, appears to be well tolerated and may improve insomnia in those with COMISA. Otolaryngologists must be cognizant of the common presentation of COMISA in patients seeking surgical treatment and utilize a multidisciplinary approach to the treatment of these complex patients.

Effect of melatonin on insomnia and daytime sleepiness, in patients with obstructive sleep apnea and insomnia (COMISA): A randomized double-blinded placebo-controlled trial

BACKGROUND

COMISA is a common disorder that results in nighttime awakenings ,daytime sleepiness and PAP intolerance. Cognitive behavioral therapy for insomnia is used to improve PAP adherence and no medication has been evaluated in such population yet. Melatonin with its chronobiotic and antioxidant effects may have potential benefits on COMISA consequences at the appropriate dose and time. This study aimed to evaluate the effect of melatonin on sleep quality, daytime sleepiness and PAP Compliance in patients with COMISA.

METHODS

This double-blind placebo trial randomly assigned eligible OSA patients who suffered from insomnia despite using PAP for over a month to receive either melatonin 10 mg or placebo. The primary outcomes were measured by changes in the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), Epworth Sleepiness Scale (ESS), and Functional Outcomes of Sleep Questionnaire (FOSQ-10) over one month. Adherence to PAP was measured by the results of the PAP device reports on the average length of time and number of nights that the device was used.

RESULTS

Thirty patients were enrolled in the study after randomization. The melatonin arm showed significant improvement in all four primary outcomes compared to the placebo arm. The PSQI score was 3.836±1.839 in the melatonin arm versus 10.522±3.626 in the placebo arm (Pvalue<0.001). The ISI score was 8.476±3.568 in the melatonin arm versus 14.47±4.50 in the placebo arm (Pvalue<0.001). The ESS score was 6.854±4.334 in the melatonin arm versus 13.298±5.119 in the placebo arm (Pvalue<0.001). The FOSQ-10 score was 24.93±5.02 in the melatonin arm versus 19.87±4.24 in the placebo arm (Pvalue= 0.006). Additionally, nighttime consequences such as sleep latency and awakenings showed significant improvement in the melatonin arm. PAP devices results revealed improvement in duration of PAP use overnight.  CONCLUSIONS: Administering melatonin has been shown to improve self-reported sleep quality and PAP adherence in patients with COMISA.

TRIAL REGISTRATION

Registration number IRCT20220105053635N1 was issued by the Iranian Registry of Clinical Trials (IRCT).

Clinical and Polysomnographic Characteristics of Adult Patients with Suspected Obstructive Sleep Apnea from Different Sleep Clinics at a Single Tertiary Center

INTRODUCTION

The characteristics of patients across different sleep clinics may vary because they selectively visit specific specialists on the basis of their primary symptoms. This study aimed to compare the clinical and polysomnography (PSG) features of patients with suspected obstructive sleep apnea (OSA) at three sleep specialty clinics (otolaryngology [ENT], neurology [NR], and psychiatry [PSY]).

METHODS

We retrospectively analyzed the medical records and PSG reports of adult patients who underwent full-night PSG between January 2022 and June 2023 at a tertiary medical center. The demographic, questionnaire, and PSG variables were compared.

RESULTS

Of the 407 patients, 83.0% exhibited sleep-disordered breathing (apnea-hypopnea index ≥ 5) with varying severity among the specialty pathways. Patients in the ENT group (n = 231) were the youngest and had the shortest sleep latency and most severe OSA markers with the highest positive airway pressure (PAP) acceptance, while those in the NR group (n = 79) had similar OSA-related PSG parameters to those in the ENT group but were older and had more OSA-related comorbidities, although their PAP acceptance was relatively low. The PSY group (n = 97) included a significant proportion of patients with normal or mild OSA, a female majority, high levels of depression, and subjective sleep distress.

CONCLUSION

Our results highlight the multidisciplinary aspects of sleep medicine and diverse patients, and specialist needs for diagnosing sleep disorders and PAP acceptance. Exploring the potential differences in prognosis and treatment responses across various sleep specialty clinics would facilitate the development of personalized strategies.

Comorbid Insomnia and Sleep Apnea: Challenges and Treatments

Insomnia and obstructive sleep apnea (OSA) are 2 of the most prevalent sleep disorders and frequently co-occur. Cognitive behavioral therapy for insomnia is the first line treatment for insomnia and has been shown to improve compliance with positive airway pressure therapy. Other alternatives to OSA treatment may have higher acceptance in those with comorbid insomnia and sleep apnea (COMISA). Surgery, particularly hypoglossal nerve stimulation, appears to be well tolerated and may improve insomnia in those with COMISA. Otolaryngologists must be cognizant of the common presentation of COMISA in patients seeking surgical treatment and utilize a multidisciplinary approach.

Clinical usefulness of dual orexin receptor antagonism beyond insomnia: Neurological and psychiatric comorbidities

Orexin is a neurotransmitter produced by a small group of hypothalamic neurons. Besides its well-known role in the regulation of the sleep-wake cycle, the orexin system was shown to be relevant in several physiological functions including cognition, mood and emotion modulation, and energy homeostasis. Indeed, the implication of orexin neurotransmission in neurological and psychiatric diseases has been hypothesized via a direct effect exerted by the projections of orexin neurons to several brain areas, and via an indirect effect through orexin-mediated modulation of sleep and wake. Along with the growing evidence concerning the use of dual orexin receptor antagonists (DORAs) in the treatment of insomnia, studies assessing their efficacy in insomnia comorbid with psychiatric and neurological diseases have been set in order to investigate the potential impact of DORAs on both sleep-related symptoms and disease-specific manifestations. This narrative review aimed at summarizing the current evidence on the use of DORAs in neurological and psychiatric conditions comorbid with insomnia, also discussing the possible implication of modulating the orexin system for improving the burden of symptoms and the pathological mechanisms of these disorders. Target searches were performed on PubMed/MEDLINE and Scopus databases and ongoing studies registered on Clinicaltrials.gov were reviewed. Despite some contradictory findings, preclinical studies seemingly support the possible beneficial role of orexin antagonism in the management of the most common neurological and psychiatric diseases with sleep-related comorbidities. However, clinical research is still limited and further studies are needed for corroborating these promising preliminary results.

The DS-14 questionnaire: psychometric characteristics and utility in patients with obstructive sleep apnea

Little is known about type D personality in patients with obstructive sleep apnea (OSA). The DS-14 questionnaire is the standard tool to assess this personality type, but it has not been properly validated in patients with OSA, nor has it been correlated with clinical features in these patients.

PURPOSE

To determine the internal consistency and test-retest reliability of the DS-14 questionnaire, as well as the prevalence of type D personality in the overall OSA sample and subgroups. We assessed the influence of type D on perceived symptoms and its congruence with self-reported measures of personality, depression, fatigue, anxiety, quality of life, and quality of sleep.

METHODS

Patients with OSA completed the DS-14 questionnaire, Big Five Inventory-2 questionnaire, Hospital Anxiety and Depression Scale, SF-36 Health Survey Questionnaire, Epworth Sleepiness Scale and Stanford Sleepiness Scale, Pittsburgh Sleep Quality Index and Insomnia Severity Index, Fatigue Assessment Scale, and Checklist Individual Strength. After 1 month, the DS-14 questionnaire was repeated.

RESULTS

The overall prevalence of type D personality was 32%. Internal consistency (negative affectivity: α = 0.880, social inhibition: α = 0.851) and diagnostic test-retest reliability (kappa value = 0.664) of the DS-14 questionnaire were high. Significantly more symptoms of anxiety, depression, poor sleep quality, fatigue, and a worse health perception were found in OSA with type D. Neither OSA severity nor REM predominance altered these observations.

CONCLUSION

The DS-14 questionnaire showed excellent psychometric properties in patients with OSA. The prevalence of type D personality in patients with OSA was higher than in the general population. The presence of type D personality was associated with higher symptom burden.

Comorbidities in COPD: Current and Future Treatment Challenges

Chronic obstructive pulmonary disease (COPD) is a heterogeneous lung condition, primarily characterized by the presence of a limited airflow, due to abnormalities of the airways and/or alveoli, that often coexists with other chronic diseases such as lung cancer, cardiovascular diseases, and metabolic disorders. Comorbidities are known to pose a challenge in the assessment and effective management of COPD and are also acknowledged to have an important health and economic burden. Local and systemic inflammation have been proposed as having a potential role in explaining the association between COPD and these comorbidities. Considering that the number of patients with COPD is expected to rise, understanding the mechanisms linking COPD with its comorbidities may help to identify new targets for therapeutic purposes based on multi-dimensional assessments.

Urinary metabolite signatures reflect the altered host metabolism in severe obstructive sleep apnea

Obstructive sleep apnea (OSA) is a common sleep-related breathing disorder. The onset and progression of OSA are often linked with severe cardiovascular and metabolic comorbidities. At the same time, given the increasing prevalence of OSA, novel methods to screen OSA and its follow-up are needed. Untargeted metabolic profiling of OSA patients and healthy controls was planned to capture a snapshot of urinary metabolites and potential biomarkers using the gas chromatography-mass spectrometry (GC-MS) method.Polysomnography (PSG) confirmed severe OSA patients with AHI index ≥ 30 were considered for urine sample collection. The sample size was constituted of OSA (n = 36) and healthy controls (n = 36). Metabolite extraction and derivatization were performed and metabolomic analysis was performed by using GC-MS.The obtained data set was statistically analyzed using univariate and multivariate analysis. The Orthogonal partial least-squares discriminant analysis (OPLS-DA) was performed to screen differential metabolites between OSA patients and healthy controls.The metabolomic analysis revealed a total of 142 significantly altered metabolites of interest.Biomarker analysis allows for the creation of a list of putative urinary biomarkers including GABA, malic acid, glutamic acid, epichoric acid etc., with an accuracy of 99.8 % to 100 % for OSA screening. Subsequently, pathway analysis revealed that related biochemical pathways like the tricarboxylic acid cycle (TCA), glutamate/glutamine, amino acid and fatty acid metabolism, that are significantly interlinked with these metabolic biomarkers can play a crucial role in the pathogenesis of OSA. This study paves the way to undertake mass screening in a larger population to identify specific and reliable biomarkers.

Links between Sleep Apnoea and Insomnia in a British Cohort

Poor sleep is a major public health problem with implications for a wide range of critical health outcomes. Insomnia and sleep apnoea are the two most common causes of poor sleep, and recent studies have shown that these disorders frequently co-occur. Comorbid insomnia and sleep apnoea can substantially impair quality of life and increase the overall risk of mortality. However, the causal and physiological links between sleep apnoea and insomnia are unclear. It is also unknown whether having a higher risk for one condition can increase the risk of developing the other. Here, we investigated links between sleep apnoea and insomnia in a British population using a combination of self-reported questionnaires and causal inference. We found that 54.3% of the cohort had moderate insomnia, 9.4% had moderate sleep apnoea, and that 6.2% scored high for both conditions. Importantly, having a higher risk of sleep apnoea was associated with a higher risk of insomnia and vice versa. To determine the causal directionality between sleep apnoea and insomnia, we used Mendelian randomisation and found evidence that sleep apnoea could cause insomnia, but not the reverse. To elucidate how both sleep apnoea and insomnia were linked to each other, we looked at the behavioural markers of poor sleep. We found that feeling fatigued after sleeping and having noticeable sleep problems were linked to a higher burden of both sleep apnoea and insomnia. In conclusion, our results show that sleep apnoea increases the risk of developing insomnia, and both conditions can result in fatigue. We highlight the importance of considering and treating the symptoms of both conditions.

Sleep structure in patients with COMISA compared to OSA and insomnia

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) and insomnia frequently co-occur, making diagnosis and treatment challenging. We investigated differences in sleep structure between patients with OSA, insomnia, and comorbid insomnia and sleep apnea (COMISA) to identify characteristics that can be used to improve the diagnosis of COMISA.

METHODS

We obtained polysomnography data of 326 patients from the Sleep and OSA Monitoring with Non-Invasive Applications database. The group included patients with OSA (n = 199), insomnia (n = 47), and COMISA (n = 80). We compared statistics related to sleep structure between the 3 patient groups.

RESULTS

Wake after sleep onset was significantly shorter for the OSA group (median: 60.0 minutes) compared to the COMISA (median: 83.3 minutes, P < .01) and the insomnia (median: 83.5 minutes, P = .01) groups. No significant differences were found in the total number of awakenings and the number of short (up to and including 2 minutes) and medium-length awakenings (2.5 up to and including 4.5 minutes). However, the number of long awakenings (5 minutes or longer) and wake after sleep onset containing only long awakenings was significantly lower for patients with OSA (median: 2 awakenings and 25.5 minutes) compared to patients with COMISA (median: 3 awakenings, P < .01 and 43.3 minutes, P < .001) or with insomnia (median: 3 awakenings, P < .01 and 56.0 minutes, P < .001). Total sleep time was significantly longer and sleep efficiency was significantly higher for the OSA group (median: 418.5 minutes and 84.4%) compared to both the COMISA (median: 391.5 minutes, P < .001 and 77.3%, P < .001) and the insomnia (median: 381.5 minutes, P < .001 and 78.2%, P < .001) groups. The number of sleep-stage transitions during the night for patients with COMISA (median: 194.0) was lower compared to that for patients with OSA (median: 218.0, P < .01) and higher compared to that for patients with insomnia (median: 156.0, P < .001). Other sleep architectural parameters were not discriminative between the groups.

CONCLUSIONS

Patients with COMISA show specific characteristics of insomnia, including prolonged awakenings. This variable is distinctive in comparison to patients with OSA. The combination of prolonged awakenings and the presence of sleep-disordered breathing leads to increased sleep disturbance compared to patients having only 1 of the sleep disorders.

CITATION

Wulterkens BM, Hermans LWA, Fonseca P, et al. Sleep structure in patients with COMISA compared to OSA and insomnia. J Clin Sleep Med. 2023;19(6):1051-1059.

Exercise as an Adjunct Treatment to Cognitive Behavior Therapy for Insomnia

The question that guided this review is whether exercise can add to the improvements in insomnia in patients treated with cognitive behavioral therapy for insomnia (CBT-I). CBT-I has long been recommended as the first-line treatment of chronic insomnia. However, CBT-I is not effective for as many as 30% to 40% of patients with insomnia. There is accumulating evidence for positive effects on insomnia following acute and chronic exercise. However, to the best of our knowledge, the effects of CBT-I combined with exercise have not been explored in clinical trials. In this article, we develop a rationale for combining CBT-I with exercise.

Comorbid insomnia and sleep apnea in children: a preliminary explorative study

Insomnia and sleep-disordered breathing (SDB) are prevalent sleep disorders. These disorders can therefore be concurrently present - comorbid insomnia and sleep apnea (COMISA). The prevalence of COMISA in the paediatric age range is unclear. As such, phenotypic constructs should help better define this comorbid condition if it exists in children and improve both diagnostic sensitivity and ultimately clinical care outcomes. We aimed to evaluate the frequency of insomnia in children and adolescents referred for evaluation of sleep symptoms suggestive of SDB in one initial (Cohort#1) and verify such findings in an independent cohort (Cohort#2) using a retrospective cross-sectional approach in patients aged 9-19 years presenting at a sleep centre to be evaluated for symptoms of SDB. Cohort #1 comprised 50 consecutive children (58% males; mean [SD] age 13.6 [3.3] years; median [interquartile range, IQR] Epworth Sleepiness Scale score 10 [6-12]) who were evaluated using validated SDB and insomnia questionnaires. Cohort#2 was extracted from electronic medical records and included 384 polysomnographically evaluated children (mean [SD] age 12.9 [3.6] years; mean [SD] body mass index z score 1.27 [0.28]; median Epworth Sleepiness Scale score 9.7 [4-17]). In Cohort #1, 56% were at high risk of SDB, 36% had insomnia alone, and 18% were at high risk of COMISA. The prevalence of COMISA in Cohort #2 was 16%, 72% had SDB alone, and 12% had insomnia alone. In both cohorts, COMISA manifested as increased propensity for sleepiness and fatigue during both waking and daytime. Thus, the presence of COMISA is frequent in the paediatric age range and accompanied by a more prominent symptomatic phenotype.

Factors Associated With Residual Apnea-Hypopnea Index Variability During CPAP Treatment

BACKGROUND

CPAP is the first-line therapy for OSA. A high or variable residual apnea-hypopnea index (rAHI) reflects treatment failure and potentially is triggered by exacerbation of cardiovascular comorbidities. Previous studies showed that high rAHI and large rAHI variability are associated with underlying comorbidities, OSA characteristics at diagnosis, and CPAP equipment, including mask type and settings.

RESEARCH QUESTION

What factors are associated with predefined groups with low to high rAHI variability?

STUDY DESIGN AND METHODS

This registry-based study included patients with a diagnosis of OSA who were receiving CPAP treatment with at least 90 days of CPAP remote monitoring. We applied the hidden Markov model to analyze the day-to-day trajectories of rAHI variability using telemonitoring data. An ordinal logistic regression analysis identified factors associated with a risk of having a higher and more variable rAHI with CPAP treatment.

RESULTS

The 1,126 included patients were middle-aged (median age, 66 years; interquartile range [IQR], 57-73 years), predominantly male (n = 791 [70.3%]), and obese (median BMI, 30.6 kg/m² (IQR, 26.8-35.2 kg/m²). Three distinct groups of rAHI trajectories were identified using hidden Markov modeling: low rAHI variability (n = 393 [35%]), moderate rAHI variability group (n = 420 [37%]), and high rAHI variability group (n = 313 [28%]). In multivariate analysis, factors associated with high rAHI variability were age, OSA severity at diagnosis, heart failure, opioids and alcohol consumption, mental and behavioral disorders, transient ischemic attack and stroke, an oronasal mask, and level of leaks when using CPAP.

INTERPRETATION

Identifying phenotypic traits and factors associated with high rAHI variability will allow early intervention and the development of personalized follow-up pathways for CPAP treatment.

Functional roles of orexin in obstructive sleep apnea: From clinical observation to mechanistic insights

Obstructive sleep apnea is the most common sleep-related breathing disorder. Repetitive episodes of the obstructive respiratory events lead to arousal, sleep fragmentation, and excessive daytime sleepiness. Orexin, also known as hypocretin, is one of the most important neurotransmitters responsible for sleep and arousal regulation. Deficiency of orexin has been shown to be involved in the pathogenesis of narcolepsy, which shares cardinal symptoms of sleep apnea and excessive daytime sleep with obstructive sleep apnea. However, the relationship between orexin and obstructive sleep apnea is not well defined. In this review, we summarize the current evidence, from in vitro, in vivo, and clinical data, regarding the association between orexin and obstructive sleep apnea. The effects of orexin on sleep apnea, as well as how the consequences of obstructive sleep apnea affect the orexin system function are also discussed. Additionally, the contrary findings are also included and discussed.

Evaluation of HIF-1 Involvement in the BDNF and ProBDNF Signaling Pathways among Obstructive Sleep Apnea Patients

Obstructive Sleep Apnea (OSA) is a chronic condition characterized by intermittent hypoxia associated with multiple comorbidities, including psychiatric disorders, such as depression, insomnia, and cognitive impairment. The brain-derived neurotrophic factor (BDNF) and proBDNF singling pathways have been shown to be involved in this group of diseases. Furthermore, their expression might be affected by hypoxia-inducible factor 1 (HIF-1), which is an oxygen sensitive transcription factor due to its alpha subunit. Therefore, this study aimed to evaluate the association between HIF-1α, BDNF, and proBDNF protein levels among OSA patients. This study included 40 individuals who underwent polysomnography (PSG) and were divided into the OSA group (n = 20; AHI ≥ 30) and healthy control (n = 20; AHI < 5) based on the apnea−hypopnea index (AHI). All participants had their peripheral blood collected in the evening before and the morning after the PSG. BDNF, proBDNF, and HIF-1α protein concertation measurements were performed using ELISA. No differences were found in BDNF, proBDNF, and HIF-1α protein levels between OSA and the control group, both in the evening and in the morning. In the OSA group, i.e., the linear regression model, the morning BDNF protein level was predicted by age (ß = −0.389, p = 0.023) and the mean SpO2 of desaturations during sleep (ß = −0.577, p = 0.002). This model accounted for 63.3% of the variability in the morning BDNF protein level (F = 14.639, p < 0.001). The morning proBDNF protein level was predicted by age (ß = −0.395, p = 0.033) and HIF-1α morning protein level (ß = −3.192, p = 0.005). This model accounted for 52.4% of the variability in the morning BDNF protein level (F = 9.355, p = 0.002). The obtained results suggest that the HIF-1 transcription factor might be involved in the pathway activated by proBDNF, which may have protective properties from hypoxia in OSA patients.

Co-morbid insomnia and obstructive sleep apnoea is associated with all-cause mortality

STUDY OBJECTIVES

Increased mortality has been reported in people with insomnia and in those with obstructive sleep apnoea (OSA). However, these conditions commonly co-occur and the combined effect of co-morbid insomnia and sleep apnoea (COMISA) on mortality risk is unknown. This study used Sleep Heart Health Study (SHHS) data to assess associations between COMISA and all-cause mortality risk.

METHODS

Insomnia was defined as difficulties falling asleep, maintaining sleep, and/or early morning awakenings from sleep ≥16 times a month and daytime impairment. OSA was defined as an apnoea-hypopnoea index ≥15 events/h sleep. COMISA was defined if both conditions were present. Multivariable adjusted Cox proportional hazard models were used to determine the association between COMISA and all-cause mortality (n=1210) over 15 years of follow-up.

RESULTS

5236 participants were included. 2708 (52%) did not have insomnia/OSA (control), 170 (3%) had insomnia-alone, 2221 (42%) had OSA-alone, and 137 (3%) had COMISA. COMISA participants had a higher prevalence of hypertension (ORs [95%CI]; 2.00 [1.39, 2.90]) and cardiovascular disease compared to controls (1.70 [1.11, 2.61]). Insomnia-alone and OSA-alone were associated with higher risk of hypertension but not cardiovascular disease compared to controls. Compared to controls, COMISA was associated with a 47% (HR, 95% CI; 1.47 (1.06, 2.07)) increased risk of mortality. The association between COMISA and mortality was consistent across multiple definitions of OSA and insomnia.

CONCLUSIONS

Co-morbid insomnia and sleep apnoea was associated with higher rates of hypertension and cardiovascular disease at baseline, and an increased risk of all-cause mortality compared to no insomnia/OSA.

The negative health effects of having a combination of snoring and insomnia

STUDY OBJECTIVES

Insomnia and snoring are common sleep disorders. The aim was to investigate the association of having a combination of insomnia symptoms and snoring with comorbidity and daytime sleepiness.

METHODS

The study population comprised 25,901 participants (16-75 years, 54.4% women) from four Swedish cities, who answered a postal questionnaire that contained questions on snoring, insomnia symptoms (difficulties initiating and/or maintaining sleep and/or early morning awakening), smoking, educational level, and respiratory and non-respiratory disorders.

RESULTS

Snoring was reported by 4,221 (16.2%), while 9,872 (38.1%) reported ≥ 1 insomnia symptom. A total of 2,150 (8.3%) participants reported both insomnia symptoms and snoring. The association with hypertension (adj. OR 1.4, 95% CI: 1.2-1.6), chronic obstructive pulmonary disease (COPD) (adj. OR 1.8, 95% CI: 1.3-2.4), asthma (adj. OR 1.9; 95% CI: 1.6-2.3), daytime sleepiness (adj. OR 7.9, 95% CI 7.1-8.8) and the use of hypnotics (adj. OR 7.5, 95% CI: 6.1-9.1) was highest for the group with both insomnia symptoms and snoring.

CONCLUSIONS

Participants with both snoring and insomnia run an increased risk of hypertension, COPD, asthma, daytime sleepiness and the use of hypnotics. It is important to consider snoring in patients seeking medical assistance for insomnia and, vice versa, in patients with snoring inquiring about insomnia.

The Role of Patient-Reported Outcomes in Sleep Measurements

Several questionnaires aka patient-reported outcome measures (PROMs) have been developed for specific use in sleep medicine. Some PROMS are "disease-specific," that is, related to a specific sleep disorder, whereas others are generic. These PROMS constitute a valuable add-on to the conventional history taking. They can be used in the areas of research, clinical practice, and quality of health care appraisal. Still, these instruments have inherent limitations, requiring proficient application in the various areas of interest. Disease-specificity includes a risk for nosologic bias that may confound diagnostic and therapeutic results. Future research should provide solutions for shortcomings of presently available questionnaires.

Comorbid Insomnia and Obstructive Sleep Apnea (COMISA): Current Concepts of Patient Management

Obstructive sleep apnea (OSA) and insomnia are the two most common sleep disorders among the general population, and they may often coexist in patients with sleep-disordered breathing (SDB). The higher prevalence of insomnia symptoms in patients with OSA (40–60%) compared to that observed in the general population has thus led researchers to identify a new disorder named comorbid insomnia and OSA (COMISA), whose true burden has been so far largely underestimated. The combined treatment of COMISA patients with positive-airway pressure ventilation (PAP) with cognitive behavioral therapy for insomnia (CBTi) has shown a better patient outcome compared to that obtained with a single treatment. Furthermore, recent evidence has shown that an innovative patient-centered approach taking into consideration patient characteristics, treatment preferences and accessibility to treatment is recommended to optimize clinical management of COMISA patients. However, in this complex mosaic, many other sleep disorders may overlap with COMISA, so there is an urgent need for further research to fully understand the impact of these therapies on outcomes for OSA patients with comorbidity. In light of this need, this review focuses on the major sleep disorders comorbid with OSA and the recent advances in the management of these insomniac patients.

Effect of the new dual orexin receptor antagonist daridorexant on nighttime respiratory function and sleep in patients with mild and moderate obstructive sleep apnea

In this randomized, double-blind, placebo-controlled, two-period crossover study, the effect of the dual orexin receptor antagonist daridorexant was evaluated on nighttime respiratory function and sleep in 28 patients with mild and moderate obstructive sleep apnea (OSA). In each period, 50 mg daridorexant or placebo was administered every evening for 5 days. The primary endpoint was apnea/hypopnea index (AHI) during total sleep time (TST) after the last dosing. Other endpoints included peripheral oxygen saturation (SpO2), sleep duration, latency to persistent sleep (LPS), wake after sleep onset (WASO), and sleep efficiency index (SEI). Pharmacokinetics, safety, and tolerability were also assessed. The mean treatment difference for AHI during TST (i.e. daridorexant - placebo) after the last dosing was 0.74 events/hour (90% confidence interval [CI]: -1.43, 2.92). The corresponding treatment difference for SpO2 during TST was 0.16% [90% CI: -0.21, 0.53]. Overall, there was no clinically relevant effect of daridorexant on AHI or SpO2-related data after single and repeated dosing irrespective of sleep phase (i.e. rapid eye movement [REM] vs non-REM). Moreover, after single and repeated dosing, daridorexant prolonged TST by 39.6 minutes (90% CI: 16.9, 62.3) and 38.8 minutes (19.7, 57.9), respectively, compared with placebo and favorably modulated other sleep-related endpoints (i.e. increased SEI, decreased WASO, and shortened LPS). It attained expected plasma concentrations and was well tolerated in patients with mild and moderate OSA. These results indicate that single and repeated doses of 50 mg daridorexant do not impair nighttime respiratory function and improve sleep in patients with mild and moderate OSA. Clinical Trial Registration: ClinicalTrials.gov NCT03765294. A study to investigate the effects of ACT-541468 on nighttime respiratory function in patients with mild to moderate obstructive sleep apnea. https://clinicaltrials.gov/ct2/show/ NCT03765294.

Bi-directional relationships between co-morbid insomnia and sleep apnea (COMISA)

Insomnia and obstructive sleep apnea (OSA) commonly co-occur. Approximately 30-50% of patients with OSA report clinically significant insomnia symptoms, and 30-40% of patients with chronic insomnia fulfil diagnostic criteria for OSA. Compared to either insomnia or OSA alone, co-morbid insomnia and sleep apnea (COMISA) is associated with greater morbidity for patients, complex diagnostic decisions for clinicians, and reduced response to otherwise effective treatment approaches. Potential bi-directional causal relationships between the mechanisms and manifestations of insomnia and OSA could play an integral role in the development and management of COMISA. A greater understanding of these relationships is required to guide personalized diagnostic and treatment approaches for COMISA. This review summarizes the available evidence of bi-directional relationships between COMISA, including epidemiological research, case studies, single-arm treatment studies, randomized controlled treatment trials, and objective sleep study data. This evidence is integrated into a conceptual model of COMISA to help refine the understanding of potential bi-directional causal relationships between the two disorders. This theoretical framework is essential to help guide future research, improve diagnostic tools, determine novel therapeutic targets, and guide tailored sequenced and multi-faceted treatment approaches for this common, complex, and debilitating condition.

Sex differences within symptom subtypes of mild obstructive sleep apnea

OBJECTIVES

Prior studies have identified symptom subtypes of moderate to severe (AHI >15) obstructive sleep apnea (OSA). They have not yet been consistently examined in those with mild OSA (AHI 5-15 events/hour). This is important as women are more likely than men to present with mild OSA and may present with different OSA symptoms. The objectives of this study were to determine 1) symptom subtypes in mild OSA and 2) if there are sex differences in the distribution of subtypes.

METHODS

The sample included men (n = 921) and women (n = 797) with mild OSA, aged 39-90 years, evaluated with a single night of in-home polysomnography as part of the Sleep Heart Health Study. Latent class analysis determined symptom subtypes. Testing for sex differences relative to OSA severity and symptom subtype used chi-squared test for independence. Bonferroni corrected z-tests compared column proportions.

RESULTS

Symptom subtypes of mild OSA were not significantly different than those identified in prior studies of moderate-severe OSA (p > 0.05): minimally symptomatic (36.4%), disturbed sleep (11.6%), moderately sleepy (37%), and excessively sleepy (15%), p > 0.05. Sex differences within the symptom subtypes were significant [χ²(df = 3) = 30.04, p < 0.001, Cramer's V = 0.132]. Relative to men, women were more likely to be in the disturbed sleep subtype (p < 0.05), and the excessively sleepy subtype (p < 0.05) while less likely to be in the moderately sleep (<0.05) subtype. Women and men were equally represented in the minimal symptoms subtype (p > 0.05).

CONCLUSIONS

Results suggest symptom reporting among individuals with mild OSA differs as a function of sex. These data have important clinical implications for screening men and women for OSA.

Comorbid Insomnia and Sleep Apnea: mechanisms and implications of an underrecognized and misinterpreted sleep disorder

Sleep-disordered breathing (SDB) and insomnia have long been recognized as important sleep disrupters often associated with increased morbidity and mortality. Although they are often seen as divergent conditions, mainly because their cardinal symptoms (excessive daytime sleepiness, and sleep loss) differ, these two sleep disorders present with many common symptoms, which may hinder diagnosis and treatment. In addition to possible bidirectional pathways between SDB and insomnia, other factors such as circadian timing may play a role. In this paper, we review the mechanisms, differential clinical aspects, and implications of Comorbid Insomnia and Sleep Apnea, sometimes termed COMISA.

Insomnia disorder: clinical and research challenges for the 21st century

BACKGROUND AND PURPOSE

Insomnia is a common and debilitating disorder that is frequently associated with important consequences for physical health and well-being.

METHODS

An international expert group considered the current state of knowledge based on the most relevant publications in the previous 5 years, discussed the current challenges in the field of insomnia and identified future priorities.

RESULTS

The association of trajectories of insomnia with subsequent quality of life, health and mortality should be investigated in large populations. Prospective health economics studies by separating the costs driven specifically by insomnia and costs attributable to its long-term effects are needed. Ignoring the heterogeneity of insomnia patients leads to inadequate diagnosis and inefficient treatment. Individualized interventions should be promoted. More data are needed on both the impact of sleep on overnight effects, such as emotion regulation, and the potential compensatory effort to counteract diurnal impairments. Another gap is the definition of neurocognitive deficits in insomnia patients compared to normal subjects after chronic sleep loss. There are also a number of key gaps related to insomnia treatment. Expert guidelines indicate cognitive-behavioural therapy for insomnia as first-line treatment. They neglect, however, the reality of major healthcare providers. The role of combined therapy, cognitive-behavioural therapy for insomnia plus pharmacological treatment, should be evaluated more extensively.

CONCLUSION

Whilst insomnia disorder might affect large proportions of the population, there are a number of significant gaps in the epidemiological/clinical/research studies carried out to date. In particular, the identification of different insomnia phenotypes could allow more cost-effective and efficient therapies.

Impact of the COVID-19 pandemic on obstructive sleep apnea: recommendations for symptom management

STUDY OBJECTIVES

In the context of the current COVID-19 pandemic situation, we address the following important questions: (1) How can patients be identified for possible OSA while sleep clinic testing is temporarily unavailable or limited? and (2) What measures can be suggested to improve sleep health until proper diagnosis and treatment become safe and available again?

METHODS

As a proxy for home or in-laboratory testing, validation of a symptom-based measure of OSA risk is presented, based on an ongoing larger prospective study of 156 family medicine patients with OSA (88 women, 68 men; mean age, 57 years) and 60 control participants (36 women, 24 men; mean age, 54 years) recruited from the community. Participants completed the Sleep Symptom Checklist (SSC) and a range of other self-report measures; primary care patients also underwent a polysomnographic sleep study.

RESULTS

Results showed that (1) individuals with OSA reported more symptoms on the SSC related to insomnia, daytime symptoms, sleep disorders, and psychological maladjustment than did the control group (all P < .001), and (2) their sleep-related symptoms were significantly more severe than those of the control patients. In addition, several polysomnographic indices in recently diagnosed untreated individuals with OSA were significantly correlated with SSC measured sleep disorder symptoms, and SSC scores significantly distinguished participants with OSA from control participants.

CONCLUSIONS

Our findings suggest that family practitioners can effectively prescreen patients for possible OSA by inquiring about 5 items that form the SSC sleep disorders subscale. If OSA is suspected, then we can recommend a range of behavioral techniques to improve symptoms. The current pandemic causes us to reflect that the provisional targeting of symptoms and guidance regarding mitigation strategies while waiting for specialist care could serve patients well at any time.

Diagnostic and Therapeutic Approach to Sleep Disorders, High Blood Pressure and Cardiovascular Diseases: A Consensus Document by the Italian Society of Hypertension (SIIA)

Hypertension is a major contributor to fatal/nonfatal cardiovascular diseases, and timely identification and appropriate management of factors affecting hypertension and its control are mandatory public health issues. By inducing neurohormonal alterations and metabolic impairment, sleep disorders have an impact on a variety of cardiovascular risk factors, including hypertension, and ultimately increase the risk of cardiovascular events. There is evidence that qualitative and quantitative sleep disorders are associated with resistant hypertension and with impaired circadian blood pressure variations. However, sleep disturbances are often unrecognized, or heterogeneity exists in their management by non-specialists in the field. This document by the Italian Society of Hypertension summarizes the updated evidence linking sleep disorders to hypertension and cardiovascular diseases, the major underlying mechanisms, and the possible management strategies. A simplified, evidence-based diagnostic and therapeutic algorithm for comorbid hypertension and common sleep disorders, namely obstructive sleep apnoea and insomnia, is proposed.

The Impact of Sleep Disorders on Functional Recovery and Participation Following Stroke: A Systematic Review and Meta-Analysis

Background

Adequate sleep is vital for health and quality of life. People with stroke and a concomitant sleep disorder may have poorer outcomes than those without a sleep disorder.

Objective

To systematically evaluate the published literature to determine the impact of sleep disorders on physical, functional recovery at the activity and participation level after stroke.

Methods

A systematic review was conducted using PubMed, CINAHL, Scopus, and PsycINFO. Studies were selected that reported outcomes on physical, functional recovery at the activity and participation levels in participants with stroke and a diagnosed sleep disorder. A meta-analysis was performed on included studies that reported Barthel Index (BI) and modified Rankin Scale (mRS) scores. Results: A total of 33 studies were included in the systematic review with 9 of them in the meta-analysis. The mean mRS score was 0.51 points higher in participants with stroke and sleep disorders versus participants with stroke without sleep disorder [95% CI: 0.23-0.78]. The mean BI score was 10.2 points lower in participants with stroke and sleep disorders versus participants with stroke without sleep disorder [95% CI: −17.9 to −2.6].

Conclusions

People with stroke and a sleep disorder have greater functional limitations and disability than those without a sleep disorder. Rehabilitation professionals should screen their patients with stroke for potential sleep disorders and further research is needed to develop sleep and rehabilitation interventions that can be delivered in combination. PROSPERO registration number: CRD42019125562.

Cognitive behavioural therapy for insomnia reduces sleep apnoea severity: a randomised controlled trial

Insomnia and obstructive sleep apnoea (OSA) frequently co-occur and may be causally related through sleep fragmentation and/or hyperarousal mechanisms. Previous studies suggest that OSA treatment can improve insomnia severity. However, the effect of insomnia treatment on OSA severity has not been investigated. We performed a randomised controlled trial to investigate the effect of cognitive behavioural therapy for insomnia (CBTi) on OSA severity, controlling for potential sleep-stage and posture effects. 145 patients with comorbid insomnia (International Classification of Sleep Disorders, 3rd Edn) and untreated OSA (apnoea-hypopnoea index (AHI) ≥15 events·h-1 sleep) were randomised to a four-session CBTi programme or to a no-treatment control. Overnight sleep studies were completed pre- and post-treatment to measure AHI, arousal index and sleep architecture, to investigate the effect of intervention group, time, sleep stage (N1-3 or REM) and posture (supine or nonsupine) on OSA severity. The CBTi group showed a 7.5 event·h-1 greater AHI difference (mean (95% CI) decrease 5.5 (1.3-9.7) events·h-1, Cohen's d=0.2, from 36.4 events·h-1 pre-treatment) across sleep-stages and postures, compared to control (mean increase 2.0 (-2.0-6.1) events·h-1, d=0.01, from 37.5 events·h-1 at pre-treatment; interaction p=0.012). Compared to control, the CBTi group also had a greater reduction in total number (mean difference 5.6 (0.6-10.6) greater overall reduction; p=0.029) and duration of nocturnal awakenings (mean difference 21.1 (2.0-40.3) min greater reduction; p=0.031) but showed no difference in the arousal index, or sleep architecture. CBTi consolidates sleep periods and promotes a 15% decrease in OSA severity in patients with comorbid insomnia and OSA. This suggests that insomnia disorder may exacerbate OSA and provides further support for treating insomnia in the presence of comorbid OSA.

Co-Morbid Insomnia and Sleep Apnea (COMISA): Prevalence, Consequences, Methodological Considerations, and Recent Randomized Controlled Trials

Co-morbid insomnia and sleep apnea (COMISA) is a highly prevalent and debilitating disorder, which results in additive impairments to patients' sleep, daytime functioning, and quality of life, and complex diagnostic and treatment decisions for clinicians. Although the presence of COMISA was first recognized by Christian Guilleminault and colleagues in 1973, it received very little research attention for almost three decades, until the publication of two articles in 1999 and 2001 which collectively reported a 30%-50% co-morbid prevalence rate, and re-ignited research interest in the field. Since 1999, there has been an exponential increase in research documenting the high prevalence, common characteristics, treatment complexities, and bi-directional relationships of COMISA. Recent trials indicate that co-morbid insomnia symptoms may be treated with cognitive and behavioral therapy for insomnia, to increase acceptance and use of continuous positive airway pressure therapy. Hence, the treatment of COMISA appears to require nuanced diagnostic considerations, and multi-faceted treatment approaches provided by multi-disciplinary teams of psychologists and physicians. In this narrative review, we present a brief overview of the history of COMISA research, describe the importance of measuring and managing insomnia symptoms in the presence of sleep apnea, discuss important methodological and diagnostic considerations for COMISA, and review several recent randomized controlled trials investigating the combination of CBTi and CPAP therapy. We aim to provide clinicians with pragmatic suggestions and tools to identify, and manage this prevalent COMISA disorder in clinical settings, and discuss future avenues of research to progress the field.