Sleep Apnea, Sleepiness, and Driving Risk

Translation of obstructive sleep apnea pathophysiology and phenotypes to personalized treatment: a narrative review

Obstructive Sleep Apnea (OSA) arises due to periodic blockage of the upper airway (UA) during sleep, as negative pressure generated during inspiration overcomes the force exerted by the UA dilator muscles to maintain patency. This imbalance is primarily seen in individuals with a narrowed UA, attributable to factors such as inherent craniofacial anatomy, neck fat accumulation, and rostral fluid shifts in the supine posture. Sleep-induced attenuation of UA dilating muscle responsiveness, respiratory instability, and high loop gain further exacerbate UA obstruction. The widespread comorbidity profile of OSA, encompassing cardiovascular, metabolic, and neuropsychiatric domains, suggests complex bidirectional relationships with conditions like heart failure, stroke, and metabolic syndrome. Recent advances have delineated distinct OSA phenotypes beyond mere obstruction frequency, showing links with specific symptomatic manifestations. It is vital to bridge the gap between measurable patient characteristics, phenotypes, and underlying pathophysiological traits to enhance our understanding of OSA and its interplay with related outcomes. This knowledge could stimulate the development of tailored therapies targeting specific phenotypic and pathophysiological endotypes. This review aims to elucidate the multifaceted pathophysiology of OSA, focusing on the relationships between UA anatomy, functional traits, clinical manifestations, and comorbidities. The ultimate objective is to pave the way for a more personalized treatment paradigm in OSA, offering alternatives to continuous positive airway pressure therapy for selected patients and thereby optimizing treatment efficacy and adherence. There is an urgent need for personalized treatment strategies in the ever-evolving field of sleep medicine, as we progress from a 'one-size-fits-all' to a 'tailored-therapy' approach.

Obstructive sleep apnoea-hypopnoea syndrome: state of the art

Obstructive sleep apnoea-hypopnoea syndrome (OSAHS) is an extremely common sleep-related breathing disorder (SRBD) characterised by complete or partial collapse of the upper airways. These nocturnal phenomena cause high-frequency hypoxemic desaturations (or intermittent hypoxia, IH) during sleep and alterations in gas exchange. The result of IH is the development or worsening of cerebro-cardio-vascular, metabolic and other diseases, which cause a high risk of death. Hence, OSAHS is a multifactorial disease affecting several organs and systems and presenting with various clinical manifestations involving different medical branches. Although it has been estimated that about one billion individuals worldwide are affected by OSAHS, this SRBD remains underestimated also due to misinformation regarding both patients and physicians. Therefore, this review aims to provide information on the main symptoms and risk factors for the detection of individuals at risk of OSAHS, as well as to present the diagnostic investigations to be performed and the different therapeutic approaches. The scientific evidence reported suggest that OSAHS is an extremely common and complex disorder that has a large impact on the health and quality of life of individuals, as well as on healthcare expenditure. Moreover, given its multifactorial nature, the design and implementation of diagnostic and therapeutic programmes through a multidisciplinary approach are necessary for a tailor-made therapy for each patient.

To compare different non-surgical treatment modalities on treatment of obstructive sleep apnea: A systematic review and meta-analysis

The study aimed to assess the effect of mandibular advancement device (MAD) in patients with obstructive sleep apnea for reduction in 24-h mean blood pressure, sleep quality, Apnea Hypopnea Index (AHI), and patient compliance, compared to continuous positive airway pressure (CPAP), other interventions, or no treatment. Three different databases such as PubMed, EMBASE, and CENTRAL were searched using different search terms till July 2021 as per the inclusion and exclusion criteria. After inclusion of studies, data extraction including risk of bias assessment was done. For each study, we used odds ratio, mean difference, and 95% confidence interval to assess and synthesize the outcomes. The quality of evidence was evaluated as per the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE). Twenty-one randomized controlled trials were included: 497 patients in the MAD group, 239 patients in the CPAP group, and 274 patients in the sham group. In MAD-CPAP comparison, the results favored CPAP in the reduction of AHI of 3.48 (1.76-5.19). However, unclear results were found for sleep quality measured as Epworth Sleepiness Scale (ESS), patient compliance, and 24-h mean blood pressure. In MAD-sham comparison, the results favored MAD in the reduction of AHI of - 8.39 (-10.90--5.88] and ESS of - 0.91 (-1.70--0.12) and favored sham in terms of patient compliance while, unclear results for 24-h mean blood pressure. The GRADE score indicated that the quality of evidence is very low, low, and moderate for different outcomes. CPAP in comparison to MAD and MAD in comparison to sham showed a significant AHI reduction. However, patient compliance and 24-h mean blood pressure were not significantly different in MAD-CPAP or MAD-sham. Quality of evidence is very low and low when MAD was compared with CPAP and sham, respectively, for AHI.

Exploring the impact of excessive daytime sleepiness caused by obstructive sleep apnea on patient and partner quality of life: a time trade-off utility study in the UK general public

STUDY OBJECTIVES

This study aimed to quantify the impact of excessive daytime sleepiness (EDS) on patient and patient's partner health-related quality of life in the form of utility values typically used in health economic evaluations.

METHODS

A time trade-off study was conducted in a UK general population sample (representing a societal perspective) to elicit utility values, measured on a 0 to 1 scale, for health states with varying obstructive sleep apnea-associated EDS severity. In a time trade-off study, health states are described, and participants "trade off" time in a specific higher severity state for a shorter amount of time in full health.

RESULTS

Overall, the sample consisted of 104 participants, who were interviewed and took part in the time trade-off exercise to elicit utility values for patient and partner residual EDS health states. The average utility score declined with increasing obstructive sleep apnea-associated EDS severity for both patient (no EDS, 0.926; mild EDS, 0.794; moderate EDS, 0.614; severe EDS, 0.546) and partner (no EDS, 0.955; mild EDS, 0.882; moderate EDS, 0.751; severe EDS, 0.670) health states.

CONCLUSIONS

These results demonstrate the high impact that EDS in obstructive sleep apnea is estimated to have on patient and partner health-related quality of life.

CITATION

Tolley K, Noble-Longster J, Mettam S, et al. Exploring the impact of excessive daytime sleepiness caused by obstructive sleep apnea on patient and partner quality of life: a time trade-off utility study in the UK general public. J Clin Sleep Med. 2022;18(9):2237-2246.

Adverse driving behaviors are associated with sleep apnea severity and age in cognitively normal older adults at risk for Alzheimer's disease

Alzheimer's disease (AD) pathology accumulates for decades before the onset of cognitive decline. Cognitively normal individuals with biomarker evidence of AD brain pathology (i.e. biomarker + or preclinical AD) can be differentiated from individuals without AD brain pathology based on naturalistic driving data, such as hard acceleration or braking and speeding, measured using in-vehicle dataloggers. Older adults are at increased risk of injury and death from motor vehicle crashes and driving cessation is also linked to negative health outcomes. Identifying potentially modifiable risk factors that increase driving risk may prolong safe driving in old age. Sleep apnea is associated with adverse driving behaviors across the age span. In this study, we hypothesized that high-risk driving behaviors would be associated with increased sleep apnea severity and AD pathology. We found that higher sleep apnea severity measured by a home sleep apnea test was associated with a higher incidence of adverse driving behaviors even after controlling for multiple confounders (β = 0.24 ± 0.09, p < 0.01). This association was independent of AD biomarker positivity (i.e. increased t-tau/Aβ 42 ratio). Increasing age was associated with a higher likelihood of high-risk driving behaviors in individuals with AD brain pathology (β = 0.12 ± 0.04, p < 0.01), but a lower likelihood in individuals without AD brain pathology (β = -0.06 ± 0.03, p < 0.05). These findings suggest that adverse driving behaviors linked to a higher rate of traffic crashes in older adults are associated with sleep apnea severity and AD pathology even in cognitively unimpaired individuals. Further studies are needed to determine if treatment of sleep apnea decreases high-risk driving behaviors and therefore motor vehicle crashes.

Obstructive sleep apnea: transition from pathophysiology to an integrative disease model

Obstructive sleep apnea (OSA) is characterised by recurring episodes of upper airway obstruction during sleep and the fundamental abnormality reflects the inability of the upper airway dilating muscles to withstand the negative forces generated within the upper airway during inspiration. Factors that result in narrowing of the oropharynx such as abnormal craniofacial anatomy, soft tissue accumulation in the neck, and rostral fluid shift in the recumbent position increase the collapsing forces within the airway. The counteracting forces of upper airway dilating muscles, especially the genioglossus, are negatively influenced by sleep onset, inadequacy of the genioglossus responsiveness, ventilatory instability, especially post arousal, and loop gain. OSA is frequently associated with comorbidities that include metabolic, cardiovascular, renal, pulmonary, and neuropsychiatric, and there is growing evidence of bidirectional relationships between OSA and comorbidity, especially for heart failure, metabolic syndrome, and stroke. A detailed understanding of the complex pathophysiology of OSA encourages the development of therapies targeted at pathophysiological endotypes and facilitates a move towards precision medicine as a potential alternative to continuous positive airway pressure therapy in selected patients.

Louis EK. Cognition and driving ability in isolated and symptomatic REM sleep behavior disorder

STUDY OBJECTIVES

To analyze cognitive deficits leading to unsafe driving in patients with REM Sleep Behavior Disorder (RBD), strongly associated with cognitive impairment and synucleinopathy-related neurodegeneration.

METHODS

Twenty isolated RBD (iRBD), 10 symptomatic RBD (sRBD), and 20 age- and education-matched controls participated in a prospective case-control driving simulation study. Group mean differences were compared with correlations between cognitive and driving safety measures.

RESULTS

iRBD and sRBD patients were more cognitively impaired than controls in global neurocognitive functioning, processing speeds, visuospatial attention, and distractibility (p < .05). sRBD patients drove slower with more collisions than iRBD patients and controls (p < .05), required more warnings, and had greater difficulty following and matching speed of a lead car during simulated car-following tasks (p < .05). Driving safety measures were similar between iRBD patients and controls. Slower psychomotor speed correlated with more off-road accidents (r = 0.65) while processing speed (-0.88), executive function (-0.90), and visuospatial impairment (0.74) correlated with safety warnings in sRBD patients. Slower stimulus recognition was associated with more signal-light (0.64) and stop-sign (0.56) infractions in iRBD patients.

CONCLUSIONS

iRBD and sRBD patients have greater selective cognitive impairments than controls, particularly visuospatial abilities and processing speed. sRBD patients exhibited unsafe driving behaviors, associated with processing speed, visuospatial awareness, and attentional impairments. Our results suggest that iRBD patients have similar driving-simulator performance as healthy controls but that driving capabilities regress as RBD progresses to symptomatic RBD with overt signs of cognitive, autonomic, and motor impairment. Longitudinal studies with serial driving simulator evaluations and objective on-road driving performance are needed.

Upper airway stimulation vs other upper airway surgical procedures for OSA: a meta-analysis

PURPOSE

The aim was to compare the outcomes of upper airway stimulation (Stim) and other upper airway surgical procedures (Surg) in the treatment of obstructive sleep apnea (OSA).

METHODS

Data sources included PubMed, Ovid MEDLINE, Cochrane Library, Web of Science, Scopus, and reference lists. Relevant articles were identified from various databases according to the PRISMA guidelines.

RESULTS

Five articles with a total of 990 patients were included. The mean cure rates in the Stim group and the Surg group was 63% and 22%, and the mean success rates was 86% and 51% which were higher in the Stim group (p < 0.001). The apnea-hypopnea index reduction was -23.9 events/ hour (MD, 95% CI -25.53, -22.29) in the Stim group and -15.5 events/hour (MD, 95% CI -17.50, -13.45) in the Surg group which was greater in the Stim group (P < 0.001). Epworth Sleepiness Scale decreased -4.9 (MD, 95% CI -5.45, -4.32) in the Stim group and -5.1 (MD 95% CI -5.88, -4.37) in the Surg group without significant difference between the groups (P = 0.62). Oxygen saturation nadir improvement was 8.5% (MD 95% CI 7.05%, 9.92%) in the Stim group and 2.2% (MD 95% CI-0.22%, 4.58%) in the Surg group which was higher in the Stim group (P < 0.001). Hospital stay and readmission rate were lower in the Stim group. The timing of follow-up ranged from 2 to 13 months.

CONCLUSION

Upper airway stimulation provides improved objective and similar subjective outcomes compared to other upper airway surgical procedures for selected patients with moderate to severe OSA with difficulty adhering to CPAP treatment. However, further studies are essential to confirm outcomes in the long term.

Determinants of Sleepiness at Wheel and Missing Accidents in Patients With Obstructive Sleep Apnea

STUDY OBJECTIVES

Motor-vehicle crashes are frequent in untreated OSA patients but there is still uncertainty on prevalence as well as physiological or clinical determinants of sleepiness at the wheel (SW) in OSA patients. We assessed determinants of SW or sleepiness related near-miss car accident (NMA) in a group of non-professional drivers with OSA.

METHODS

A 237 consecutive, treatment-naïve PSG-diagnosed OSA patients (161 males, 53.1 ± 12.6 years) were enrolled. Self-reported SW was assessed by positive answer to the question, "Have you had episodes of falling asleep while driving or episodes of drowsiness at wheel that could interfere with your driving skill in the last year?" Occurrence of NMA in the last 3 years was also individually recorded. Habitual self-reported average sleep time was collected.

RESULTS

SW was found in 41.3% of patients but one-quarter of patients with SW did not report excessive daytime sleepiness. Predictors of SW were the following subjective factors: Epworth sleepiness scale score (ESS-OR 1.26; IC 1.1-1.4; p < 0.0001), depressive symptoms (BDI-OR 1.2; IC 1.06-1.18; p < 0.0001) and level of risk exposure (annual mileage-OR 1.9; IC 1.15-3.1; p = 0.007). NMAs were reported by 9.7% of patients, but more frequently by SW+ than SW- (22.4% vs. 0.7%; χ2 31, p < 0.0001). The occurrence of NMAs was significantly associated to ESS, BDI, habitual sleep duration and ODI (R 2 = 0.41).

CONCLUSION

SW is not predicted by severity of OSA. Evaluation of risk exposure, assessment of depressive symptoms, and reported NMA should be included in the clinical evaluation, particularly in patients with reduced habitual sleep time and severe nocturnal hypoxia.

Real-time assessment of daytime sleepiness in drivers with multiple sclerosis

BACKGROUND

Daytime sleepiness is a common symptom of multiple sclerosis (MS) that may jeopardize safe driving. Our aim was to compare daytime sleepiness, recorded in real-time through eyelid tracking, in a simulated drive between individuals with MS (iwMS) and healthy controls.

METHODS

Fifteen iwMS (age = median (Q1 - Q3), 55 (50 - 55); EDSS = 2.5 (2 - 3.5); 12 (80%) female) were matched for age, sex, education, and cognitive status with 15 controls. Participants completed self-reported fatigue and sleepiness scales including the Modified Fatigue Impact Scale (MFIS), Pittsburg Sleep Quality Inventory (PSQI), and Epworth Sleepiness Scale (ESS). Percentage of eyelid closure (PERCLOS) was extracted from a remote eye tracker while completing a simulated drive of 25 min.

RESULTS

Although iwMS reported more symptoms of fatigue (MFIS, p = 0.003) and poorer sleep quality (PSQI, p = 0.008), they did not report more daytime sleepiness (ESS, p = 0.45). Likewise, there were no differences between groups in real-time daytime sleepiness, indexed by PERCLOS (p = 0.82). Both groups exhibited more real-time daytime sleepiness as they progressed through the drive (time effect, p < 0.0001). The interaction effect of group*time (p = 0.05) demonstrated increased symptoms of daytime sleepiness towards the end of the drive in iwMS compared to controls. PERCLOS correlated strongly (Spearman ρ = 0.76, p = 0.001) with distance out of lane in iwMS.

CONCLUSION

IwMS show exacerbated symptoms of daytime sleepiness during a monotonous, simulate drive. Future studies should investigate the effect of MS on daytime sleepiness during real-world driving.

Efficacy and safety of solriamfetol for excessive daytime sleepiness in narcolepsy and obstructive sleep apnea: a systematic review and meta-analysis of clinical trials

INTRODUCTION

Excessive daytime sleepiness (EDS) is the inability to maintain wakefulness and alertness during the major waking episodes of the day, with sleep occurring unintentionally or at inappropriate times. Solriamfetol is a selective norepinephrine-dopamine reuptake inhibitor approved for EDS. This review was done to assess the efficacy and safety of solriamfetol in patients with EDS in narcolepsy or OSA.

METHODS

A systematic search of the electronic database was conducted for relevant studies. Any randomized controlled trial with outcome measures on the efficacy or safety of solriamfetol in EDS were eligible for inclusion. The primary outcomes were mean difference in the maintenance of wakefulness test (MWT), Epworth sleepiness scale (ESS) score, and risk ratio of adverse events. The random-effects model was used to calculate pooled effect estimates.

RESULTS

We identified 336 records from the database search. We analyzed eight articles reported from six clinical trials. We pooled outcome measures from five trials. The overall mean difference for MWT was 9.93 min (95% CI: 8.25-11.61), and the mean difference of ESS score was -4.44 (95% CI: -5.50 to -3.38), both in favor of solriamfetol over placebo. The overall risk ratio of adverse events with solriamfetol was 1.47 (95% CI: 1.28-1.69). The most common adverse events reported were headache, nausea, decreased appetite, anxiety, nasopharyngitis, and insomnia.

CONCLUSIONS

Solriamfetol is efficacious and has a favorable safety profile in the treatment of EDS in patients with narcolepsy and OSA. Solriamfetol is well tolerated and may be recommended for the treatment of EDS in these patients.

Long-Term Subjective Outcomes of Barbed Reposition Pharyngoplasty for Obstructive Sleep Apnea Syndrome Treatment

Background: The purpose of this study was to evaluate long-term subjective outcomes of barbed reposition pharyngoplasty for obstructive sleep apnea syndrome (OSAS) treatment using a specific questionnaire, the Palate Postoperative Problem Score (PPOPS). Methods: 140 patients who underwent barbed reposition pharyngoplasty (BRP) surgery in the Morgagni Pierantoni Hospital of Forlì, Italy were enrolled in the study. Postoperative outcomes were evaluated in a short- and long-term follow-up using the PPOPS questionnaire. The average period of follow-up was 26 months. All patients received the PPOPS questionnaire by telephone in a period between April and August 2019. Results: 51% of patients complained of swallowing problems after surgery. In 91% of cases, the problem cleared up spontaneously. At the time of the interview, only 9% of patients had a residual swallowing difficult. At the time of PPOPS evaluation, rhinolalia was observed in 8% of patients, whereas nose regurgitation was present in 2% of patients. In 20% of patients, the foreign body sensation was present during follow-up. The value of apnea–hypopnea index (AHI) reduced from the preoperative value of 31.5 to the postoperative value of 11.4. Conclusions: BRP surgery proved to be an effective technique, appreciated by the majority of patients. Use of the PPOPS questionnaire has demonstrated that the BRP technique seems to ensure efficacy and lower morbidity, with few complications after surgery.