Influence of nutrition and food on sleep-is there evidence?

BACKGROUND: The influence of sleep disorders on metabolism, especially concerning obesity and diabetes, as well as obesity and obstructive sleep apnea, has been widely investigated. However, the effect of nutrition and the intake of certain foods on sleep has only recently gained attention. In recent years, there have been publications on intake of certain foods and certain diets regarding their influence on sleep, as well as activity of adipocytes and their effect on production of sleep hormones. METHODS: Following PRISMA guidelines, we performed a PubMed search using the key words "sleep," "sleep disorders," "nutrition," "food," and "food intake" published from 2012 to 2022. We excluded by consensus all articles with diets and exercise programs or bariatric surgery for weight loss to treat sleep apnea, all articles on connections between sleep disorders and metabolic disorders, and articles concerning the influence of drugs on neuroactive substances. RESULTS: Of the 4155 publications revealed, 988 had nutrition, metabolism, and sleep as the primary topic of research. Of these 988 publications, only 26 fulfilled the content requirements concerning the influence of certain food and diets on sleep or sleep disorders, including the influence of the gastrointestinal system and adipocytes on sleep hormones. None of the investigations revealed clear evidence of an effect of a certain diet or food on sleep. Epidemiologic surveys suggest that shortened or fragmented sleep and chronotype in adults influence nutrition and fat metabolism. Additionally, there is evidence that adipocyte signaling influences neuronal mediators and hormones of the sleep-wake cycle. CONCLUSION: There is no evidence of a direct influence of certain nutrition or food intake on sleep. Obesity via adipocyte signaling may influence the sleep-wake cycle, though the molecular research on this topic is based on animal studies.

Exposure to Non-Steady-State Oxygen Is Reflected in Changes to Arterial Blood Gas Values, Prefrontal Cortical Activity, and Systemic Cytokine Levels.

Onboard oxygen-generating systems (OBOGSs) provide increased inspired oxygen (FiO2) to mitigate the risk of neurologic injury in high altitude aviators. OBOGSs can deliver highly variable oxygen concentrations oscillating around a predetermined FiO2 set point, even when the aircraft cabin altitude is relatively stable. Steady-state exposure to 100% FiO2 evokes neurovascular vasoconstriction, diminished cerebral perfusion, and altered electroencephalographic activity. Whether non-steady-state FiO2 exposure leads to similar outcomes is unknown. This study characterized the physiologic responses to steady-state and non-steady-state FiO2 during normobaric and hypobaric environmental pressures emulating cockpit pressures within tactical aircraft. The participants received an indwelling radial arterial catheter while exposed to steady-state or non-steady-state FiO2 levels oscillating ± 15% of prescribed set points in a hypobaric chamber. Steady-state exposure to 21% FiO2 during normobaria produced arterial blood gas values within the anticipated ranges. Exposure to non-steady-state FiO2 led to PaO2 levels higher upon cessation of non-steady-state FiO2 than when measured during steady-state exposure. This pattern was consistent across all FiO2 ranges, at each barometric condition. Prefrontal cortical activation during cognitive testing was lower following exposure to non-steady-state FiO2 >50% and <100% during both normobaria and hypobaria of 494 mmHg. The serum analyte levels (IL-6, IP-10, MCP-1, MDC, IL-15, and VEGF-D) increased 48 h following the exposures. We found non-steady-state FiO2 levels >50% reduced prefrontal cortical brain activation during the cognitive challenge, consistent with an evoked pattern of neurovascular constriction and dilation.

Diurnal changes in blood pressure and heart rate in children with narcolepsy with cataplexy.

The hypocretin neurons in the lateral hypothalamus are connected not only to brain alertness systems but also to brainstem nuclei that regulate blood pressure and heart rate. The premise is that regulation of blood pressure and heart rate is altered and affected by methylphenidate, a stimulant drug in children with narcolepsy with cataplexy. The changes in 24-hr ambulatory systolic and diastolic blood pressure and heart rate were compared among pre-treated narcolepsy with cataplexy patients (40 males, 10 females), with mean age 10.4 ± 3.5 years (M ±â€…SD, range 5-17 years) with values from 100 archival age-sex-body mass index matched controls. Patients had a lower diurnal systolic blood pressure (-6.5 mmHg; p = 0.000) but higher heart rate (+11.0 bpm; p = 0.000), particularly evident in the waketime, while diastolic blood pressure was comparable. With methylphenidate (18 mg sustained release at 08:00 hours), patients with narcolepsy with cataplexy had higher systolic blood pressure (+4.6 mmHg, p = 0.015), diastolic blood pressure (+3.3 mmHg, p = 0.005) and heart rate (+7.1 bpm, p = 0.028) during wake time, but nighttime cardiovascular values were unchanged from pre-treated values; amplitude variation in cardiovascular values was unchanged over 24 hr. In conclusion, children with narcolepsy with cataplexy had downregulation blood pressure profile but a higher heart rate, and lesser non-dipping profiles. Daytime methylphenidate treatment increases only waketime blood pressure and further elevated heart rate values.

Repeatability of adaptive traits among ethnic Tibetan highlanders.

OBJECTIVES: Connecting traits to biological pathways and genes relies on stable observations. Researchers typically determine traits once, expecting careful study protocols to yield measurements free of noise. This report examines that expectation with test-retest repeatability analyses for traits used regularly in research on adaptation to high-altitude hypoxia, often in settings without climate control. METHODS: Two hundred ninety-one ethnic Tibetan women residing from 3500 to 4200 m in Upper Mustang District, Nepal, provided three observations of hemoglobin concentration, percent of oxygen saturation of hemoglobin, and pulse by noninvasive pulse oximetry under conditions designed to minimize environmental noise. RESULTS: High-intraclass correlation coefficients and low within-subject coefficients of variation reflected consistent measurements. Percent of oxygen saturation had the highest intraclass correlation coefficient and the smallest within-subject coefficient of variability; measurement noise occurred mainly in the lower values. Hemoglobin concentration and pulse presented slightly higher within-subject coefficients of variation; measurement noise occurred across the range of values. The women had performed the same measurements 7 years earlier using the same devices and protocol. The sample means and SD observed across 7 years differed little. Hemoglobin concentration increased substantially after menopause. CONCLUSIONS: Analyzing repeatability features of traits may improve our interpretation of statistical analyses and detection of variation from measurement or biology. The high levels of measurement repeatability and biological stability support the continued use of these robust traits for investigating human adaptation in this altitude range.

Endotypic Mechanisms of Successful Hypoglossal Nerve Stimulation for Obstructive Sleep Apnea.

Rationale: Approximately one-third of patients with obstructive sleep apnea (OSA) treated with hypoglossal nerve stimulation (HGNS) therapy are incomplete responders, despite careful patient selection based on baseline characteristics and drug-induced sleep endoscopy.Objectives: Here we use polysomnographic endotyping to assess the pathophysiological mechanisms underlying favorable versus incomplete responses to HGNS therapy.Methods: Baseline polysomnography data of the STAR (Stimulation Therapy for Apnea Reduction) trial were included. Raw baseline polysomnographic data from 91/126 patients were available for analysis. Traits-loop gain, arousal threshold, collapsibility, and muscle compensation-were calculated from the baseline polysomnography data according to Sands and colleagues (AJRCCM 2018, SLEEP 2018). Logistic regression assessed apnea-hypopnea index (AHI)-adjusted associations between HGNS response (>50% reduction in AHI to <10/h at 1 yr) and OSA traits.Measurements and Main Results: Overall, HGNS treatment reduced AHI from 30.7 (24.9-39.9) to 8.5 (4.0-19.5) events/h (P < 0.0001; median [quartiles 1-3]); N = 53/91 were responders. In adjusted analysis, a favorable response to therapy was independently associated with higher arousal threshold (odds ratio [95% confidence interval]: 6.76 [2.44-23.3], P = 0.001), greater compensation (odds ratio: 4.22 [1.70-12.55] per SD, P = 0.004), and lower loop gain (in milder collapsibility, per significant interaction, P = 0.003). The higher arousal threshold was evident in responders before adjusted analysis. Predicted responders had an approximately fourfold lower treatment AHI versus predicted nonresponders (4.9 [2.7-8.5] vs. 20.7 [10.9-29.7], P < 0.0001; median [quartiles 1-3]); differences remained significant after cross-validation.Conclusions: Favorable responses to HGNS therapy are associated with the pathophysiological traits causing OSA, particularly a higher arousal threshold. Along with established criteria, individuals with favorable traits could potentially be prioritized for precision HGNS therapy.This analysis was a secondary analysis of the STAR trial registered with clinicaltrials.gov (NCT01161420).

Neurovascular and cortical responses to hyperoxia: enhanced cognition and electroencephalographic activity despite reduced perfusion.

KEY POINTS: Extreme aviation is accompanied by ever-present risks of hypobaric hypoxia and decompression sickness. Neuroprotection against those hazards is conferred through fractional inspired oxygen ( FI,O2 ) concentrations of 60-100% (hyperoxia). Hyperoxia reduces global cerebral perfusion (gCBF), increases reactive oxygen species within the brain and leads to cell death within the hippocampus. However, an understanding of hyperoxia's effect on cortical activity and concomitant levels of cognitive performance is lacking. This limits our understanding of whether hyperoxia could lower the brain's threshold of tolerance to physiological stressors inherent to extreme aviation, such as high gravitational forces. This study aimed to quantify the impact of hyperoxia upon global cerebral perfusion (gCBF), cognitive performance and cortical electroencephalography (EEG). Hyperoxia evoked a rapid reduction in gCBF, yet cognitive performance and vigilance were enhanced. EEG measurements revealed enhanced alpha power, suggesting less desynchrony, within the cortical temporal regions. Collectively, this work suggests hyperoxia-induced brain hypoperfusion is accompanied by enhanced cognitive processing and cortical arousal. ABSTRACT: Extreme aviators continually inspire hyperoxic gas to mitigate risk of hypoxia and decompression injury. This neuroprotection carries a physiological cost: reduced cerebral perfusion (CBF). As reduced CBF may increase vulnerability to ever-present physiological challenges during extreme aviation, we defined the magnitude and duration of hyperoxia-induced changes in CBF, cortical electrical activity and cognition in 30 healthy males and females. Magnetic resonance imaging with pulsed arterial spin labelling provided serial measurements of global CBF (gCBF), first during exposure to 21% inspired oxygen ( FI,O2 ) followed by a 30-min exposure to 100% FI,O2 . High-density EEG facilitated characterization of cortical activity during assessment of cognitive performance, also measured during exposure to 21% and 100% FI,O2 . Acid-base physiology was measured with arterial blood gases. We found that exposure to 100% FI,O2 reduced gCBF to 63% of baseline values across all participants. Cognitive performance testing at 21% FI,O2 was accompanied by increased theta and beta power with decreased alpha power across multiple cortical areas. During cognitive testing at 100% FI,O2 , alpha activity was less desynchronized within the temporal regions than at 21% FI,O2 . The collective hyperoxia-induced changes in gCBF, cognitive performance and EEG were similar across observed partial pressures of arterial oxygen ( PaO2 ), which ranged between 276-548 mmHg, and partial pressures of arterial carbon dioxide ( PaCO2 ), which ranged between 34-50 mmHg. Sex did not influence gCBF response to 100% FI,O2 . Our findings suggest hyperoxia-induced reductions in gCBF evoke enhanced levels of cortical arousal and cognitive processing, similar to those occurring during a perceived threat.

Solriamfetol for Excessive Sleepiness in Obstructive Sleep Apnea (TONES 3). A Randomized Controlled Trial.

Rationale: Primary treatment of obstructive sleep apnea can be accompanied by a persistence of excessive sleepiness despite adherence. Furthermore, effectiveness of sleep apnea treatment is limited by poor adherence. Currently available pharmacologic options for the treatment of sleepiness in this population are limited. Objectives: To evaluate the efficacy and safety of solriamfetol (JZP-110), a selective dopamine and norepinephrine reuptake inhibitor with robust wake-promoting effects, for the treatment of excessive sleepiness in participants with obstructive sleep apnea with current or prior sleep apnea treatment. Methods: This was a double-blind, randomized, placebo-controlled, parallel-group, 12-week trial comparing solriamfetol, 37.5, 75, 150, and 300 mg, with placebo. Measurements and Main Results: Of 476 randomized participants, 459 were included in the prespecified efficacy analyses. Coprimary endpoints (Maintenance of Wakefulness Test sleep latency and Epworth Sleepiness Scale score) were met at all solriamfetol doses (P < 0.05), with dose-dependent effects observed at Week 1 maintained over the study duration. All doses except 37.5 mg resulted in higher percentages of participants reporting improvement on Patient Global Impression of Change (key secondary endpoint; P < 0.05). Adverse events were reported in 47.9% of placebo- and 67.9% of solriamfetol-treated participants; five participants experienced serious adverse events (two [1.7%] placebo, three [0.8%] solriamfetol); none were deemed related to study drug. The most common adverse events with solriamfetol were headache (10.1%), nausea (7.9%), decreased appetite (7.6%), anxiety (7.0%), and nasopharyngitis (5.1%). Conclusions: Solriamfetol significantly increased wakefulness and reduced sleepiness in participants with obstructive sleep apnea and excessive sleepiness; most adverse events were mild or moderate in severity. Clinical trial registered with www.clinicaltrials.gov (NCT02348606) and www.eudract.ema.europa.eu (EudraCT 2014-005514-31).

Polysomnographic phenotypes and their cardiovascular implications in obstructive sleep apnoea.

BACKGROUND: Obstructive sleep apnoea (OSA) is a heterogeneous disorder, and improved understanding of physiologic phenotypes and their clinical implications is needed. We aimed to determine whether routine polysomnographic data can be used to identify OSA phenotypes (clusters) and to assess the associations between the phenotypes and cardiovascular outcomes. METHODS: Cross-sectional and longitudinal analyses of a multisite, observational US Veteran (n=1247) cohort were performed. Principal components-based clustering was used to identify polysomnographic features in OSA's four pathophysiological domains (sleep architecture disturbance, autonomic dysregulation, breathing disturbance and hypoxia). Using these features, OSA phenotypes were identified by cluster analysis (K-means). Cox survival analysis was used to evaluate longitudinal relationships between clusters and the combined outcome of incident transient ischaemic attack, stroke, acute coronary syndrome or death. RESULTS: Seven patient clusters were identified based on distinguishing polysomnographic features: 'mild', 'periodic limb movements of sleep (PLMS)', 'NREM and arousal', 'REM and hypoxia', 'hypopnoea and hypoxia', 'arousal and poor sleep' and 'combined severe'. In adjusted analyses, the risk (compared with 'mild') of the combined outcome (HR (95% CI)) was significantly increased for 'PLMS', (2.02 (1.32 to 3.08)), 'hypopnoea and hypoxia' (1.74 (1.02 to 2.99)) and 'combined severe' (1.69 (1.09 to 2.62)). Conventional apnoea-hypopnoea index (AHI) severity categories of moderate (15≤AHI<30) and severe (AHI ≥30), compared with mild/none category (AHI <15), were not associated with increased risk. CONCLUSIONS: Among patients referred for OSA evaluation, routine polysomnographic data can identify physiological phenotypes that capture risk of adverse cardiovascular outcomes otherwise missed by conventional OSA severity classification.

Proteomic profiling of the hypothalamus in two mouse models of narcolepsy.

Narcolepsy is a disabling neurological disorder of sleepiness linked to the loss of neurons producing orexin neuropeptides in the hypothalamus. Two well-characterized phenotypic mouse models of narcolepsy, loss-of-function (orexin-knockout), and progressive loss of orexin (orexin/ataxin-3) exist. The open question is whether the proteomics signatures of the hypothalamus would be different between the two models. To address this gap, we utilized a label-free proteomics approach and conducted a hypothalamic proteome analysis by comparing each disease model to that of wild type. Following data processing and statistical analysis, 14 484 peptides mapping to 2282 nonredundant proteins were identified, of which 39 proteins showed significant differences in protein expression across groups. Altered proteins in both models showed commonalties in pathways for mitochondrial dysfunction and neuronal degeneration, as well as altered proteins related to inflammatory demyelination, insulin resistance, metabolic responses, and the dopaminergic and monoaminergic systems. Model-specific alterations in insulin degraded enzyme (IDE) and synaptosomal-associated protein-25 were unique to orexin-KO and orexin/ataxin-3, respectively. For both models, proteomics not only identified clinically suspected consequences of orexin loss on energy homeostasis and neurotransmitter systems, but also identified commonalities in inflammation and degeneration despite the entirely different genetic basis of the two mouse models.

Upper-airway stimulation for obstructive sleep apnea.

BACKGROUND: Obstructive sleep apnea is associated with considerable health risks. Although continuous positive airway pressure (CPAP) can mitigate these risks, effectiveness can be reduced by inadequate adherence to treatment. We evaluated the clinical safety and effectiveness of upper-airway stimulation at 12 months for the treatment of moderate-to-severe obstructive sleep apnea. METHODS: Using a multicenter, prospective, single-group, cohort design, we surgically implanted an upper-airway stimulation device in patients with obstructive sleep apnea who had difficulty either accepting or adhering to CPAP therapy. The primary outcome measures were the apnea-hypopnea index (AHI; the number of apnea or hypopnea events per hour, with a score of ≥15 indicating moderate-to-severe apnea) and the oxygen desaturation index (ODI; the number of times per hour of sleep that the blood oxygen level drops by ≥4 percentage points from baseline). Secondary outcome measures were the Epworth Sleepiness Scale, the Functional Outcomes of Sleep Questionnaire (FOSQ), and the percentage of sleep time with the oxygen saturation less than 90%. Consecutive participants with a response were included in a randomized, controlled therapy-withdrawal trial. RESULTS: The study included 126 participants; 83% were men. The mean age was 54.5 years, and the mean body-mass index (the weight in kilograms divided by the square of the height in meters) was 28.4. The median AHI score at 12 months decreased 68%, from 29.3 events per hour to 9.0 events per hour (P<0.001); the ODI score decreased 70%, from 25.4 events per hour to 7.4 events per hour (P<0.001). Secondary outcome measures showed a reduction in the effects of sleep apnea and improved quality of life. In the randomized phase, the mean AHI score did not differ significantly from the 12-month score in the nonrandomized phase among the 23 participants in the therapy-maintenance group (8.9 and 7.2 events per hour, respectively); the AHI score was significantly higher (indicating more severe apnea) among the 23 participants in the therapy-withdrawal group (25.8 vs. 7.6 events per hour, P<0.001). The ODI results followed a similar pattern. The rate of procedure-related serious adverse events was less than 2%. CONCLUSIONS: In this uncontrolled cohort study, upper-airway stimulation led to significant improvements in objective and subjective measurements of the severity of obstructive sleep apnea. (Funded by Inspire Medical Systems; STAR ClinicalTrials.gov number, NCT01161420.).

Variability of breathing during wakefulness while using CPAP predicts adherence.

BACKGROUND AND OBJECTIVE: The standard therapy for obstructive sleep apnoea (OSA) is continuous positive airway pressure (CPAP) therapy. However, long-term adherence remains at ~50% despite improvements in behavioural and educational interventions. Based on prior work, we explored whether regularity of breathing during wakefulness might be a physiologic predictor of CPAP adherence. METHODS: Of the 117 consecutive patients who were diagnosed with OSA and prescribed CPAP, 79 CPAP naïve patients were enrolled in this prospective study. During CPAP initiation, respiratory signals were collected using respiratory inductance plethysmography while wearing CPAP during wakefulness in a seated position. Breathing regularity was assessed by the coefficient of variation (CV) for breath-by-breath estimated tidal volume (VT ) and total duration of respiratory cycle (Ttot). In a derivation group (n = 36), we determined the cut-off CV value which predicted poor CPAP adherence at the first month of therapy, and verified the validity of this predetermined cut-off value in the remaining participants (validation group; n = 43). RESULTS: In the derivation group, the CV for estimated VT was significantly higher in patients with poor adherence than with good adherence (median (interquartile range): 44.2 (33.4-57.4) vs 26.0 (20.4-33.2), P < 0.001). The CV cut-off value for estimated VT for poor CPAP adherence was 34.0, according to a receiver-operating characteristic (ROC) curve. In the validation group, the CV value for estimated VT >34.0 confirmed to be predicting poor CPAP adherence (sensitivity, 0.78; specificity, 0.83). CONCLUSION: At the initiation of therapy, breathing regularity during wakefulness while wearing CPAP is an objective predictor of short-term CPAP adherence.

An Official American Thoracic Society Statement: The Importance of Healthy Sleep. Recommendations and Future Priorities.

RATIONALE: Despite substantial public interest, few recommendations on the promotion of good sleep health exist to educate health care providers and the general public on the importance of sleep for overall health. OBJECTIVES: The aim of this American Thoracic Society (ATS) statement is to provide a review of the current scientific literature to assist health care providers, especially pulmonologists and sleep physicians, in making recommendations to patients and the general public about the importance of achieving good quality and adequate quantity of sleep. METHODS: ATS members were invited, based on their expertise in sleep medicine, and their conclusions were based on both empirical evidence identified after comprehensive literature review and clinical experience. MAIN RESULTS: We focus on sleep health in both children and adults, including the impact of occupation on sleep, the public health implications of drowsy driving, and the common sleep disorders of obstructive sleep apnea and insomnia. This ATS statement also delineates gaps in research and knowledge that should be addressed and lead to new focused research priorities to advance knowledge in sleep and sleep health. CONCLUSIONS: Good quality and quantity of sleep are essential for good health and overall quality of life; therefore a strong recommendation was made for the implementation of public education programs on the importance of sleep health.

The Determining Risk of Vascular Events by Apnea Monitoring (DREAM) study: design, rationale, and methods.

PURPOSE: The goal of the Determining Risk of Vascular Events by Apnea Monitoring (DREAM) study is to develop a prognostic model for cardiovascular outcomes, based on physiologic variables-related to breathing, sleep architecture, and oxygenation-measured during polysomnography in US veterans. METHODS: The DREAM study is a multi-site, retrospective observational cohort study conducted at three Veterans Affairs (VA) centers (West Haven, CT; Indianapolis, IN; Cleveland, OH). Veterans undergoing polysomnography between January 1, 2000 and December 31, 2004 were included based on referral for evaluation of sleep-disordered breathing, documented history and physical prior to sleep testing, and ≥2-h sleep monitoring. Demographic, anthropomorphic, medical, medication, and social history factors were recorded. Measures to determine sleep apnea, sleep architecture, and oxygenation were recorded from polysomnography. VA Patient Treatment File, VA-Medicare Data, Vista Computerized Patient Record System, and VA Vital Status File were reviewed on dates subsequent to polysomnography, ranging from 0.06 to 8.8 years (5.5 ± 1.3 years; mean ± SD). RESULTS: The study population includes 1840 predominantly male, middle-aged veterans. As designed, the main primary outcome is the composite endpoint of acute coronary syndrome, stroke, transient ischemic attack, or death. Secondary outcomes include incidents of neoplasm, congestive heart failure, cardiac arrhythmia, diabetes, depression, and post-traumatic stress disorder. Laboratory outcomes include measures of glycemic control, cholesterol, and kidney function. (Actual results are pending.) CONCLUSIONS: This manuscript provides the rationale for the inclusion of veterans in a study to determine the association between physiologic sleep measures and cardiovascular outcomes and specifically the development of a corresponding outcome-based prognostic model.

Genome wide analysis of narcolepsy in China implicates novel immune loci and reveals changes in association prior to versus after the 2009 H1N1 influenza pandemic.

Previous studies in narcolepsy, an autoimmune disorder affecting hypocretin (orexin) neurons and recently associated with H1N1 influenza, have demonstrated significant associations with five loci. Using a well-characterized Chinese cohort, we refined known associations in TRA@ and P2RY11-DNMT1 and identified new associations in the TCR beta (TRB@; rs9648789 max P = 3.7 × 10(-9) OR 0.77), ZNF365 (rs10995245 max P = 1.2 × 10(-11) OR 1.23), and IL10RB-IFNAR1 loci (rs2252931 max P = 2.2 × 10(-9) OR 0.75). Variants in the Human Leukocyte Antigen (HLA)- DQ region were associated with age of onset (rs7744020 P = 7.9×10(-9) beta -1.9 years) and varied significantly among cases with onset after the 2009 H1N1 influenza pandemic compared to previous years (rs9271117 P = 7.8 × 10(-10) OR 0.57). These reflected an association of DQB1*03:01 with earlier onset and decreased DQB1*06:02 homozygosity following 2009. Our results illustrate how genetic association can change in the presence of new environmental challenges and suggest that the monitoring of genetic architecture over time may help reveal the appearance of novel triggers for autoimmune diseases.

Effect of upper-airway stimulation for obstructive sleep apnoea on airway dimensions.

Upper-airway stimulation (UAS) using a unilateral implantable neurostimulator for the hypoglossal nerve is an effective therapy for obstructive sleep apnoea patients with continuous positive airway pressure intolerance. This study evaluated stimulation effects on retropalatal and retrolingual dimensions during drug-induced sedation compared with wakefulness to assess mechanistic relationships in response to UAS. Patients with an implanted stimulator underwent nasal video endoscopy while awake and/or during drug-induced sedation in the supine position. The cross-sectional area, anterior-posterior and lateral dimensions of the retropalatal and retrolingual regions were measured during baseline and stimulation. 15 patients underwent endoscopy while awake and 12 underwent drug-induced sedation endoscopy. Increased levels of stimulation were associated with increased area of both the retropalatal and retrolingual regions. During wakefulness, a therapeutic level of stimulation increased the retropalatal area by 56.4% (p=0.002) and retrolingual area by 184.1% (p=0.006). During stimulation, the retropalatal area enlarged in the anterior-posterior dimension while retrolingual area enlarged in both anterior-posterior and lateral dimensions. During drug-induced sedation endoscopy, the same stimulation increased the retropalatal area by 180.0% (p=0.002) and retrolingual area by 130.1% (p=0.008). Therapy responders had larger retropalatal enlargement with stimulation than nonresponders. UAS increases both the retropalatal and retrolingual areas. This multilevel enlargement may explain reductions of the apnoea-hypopnoea index in selected patients receiving this therapy.

An official American Thoracic Society Clinical Practice Guideline: sleep apnea, sleepiness, and driving risk in noncommercial drivers. An update of a 1994 Statement.

BACKGROUND: Sleepiness may account for up to 20% of crashes on monotonous roads, especially highways. Obstructive sleep apnea (OSA) is the most common medical disorder that causes excessive daytime sleepiness, increasing the risk for drowsy driving two to three times. The purpose of these guidelines is to update the 1994 American Thoracic Society Statement that described the relationships among sleepiness, sleep apnea, and driving risk. METHODS: A multidisciplinary panel was convened to develop evidence-based clinical practice guidelines for the management of sleepy driving due to OSA. Pragmatic systematic reviews were performed, and the Grading of Recommendations, Assessment, Development, and Evaluation approach was used to formulate and grade the recommendations. Critical outcomes included crash-related mortality and real crashes, whereas important outcomes included near-miss crashes and driving performance. RESULTS: A strong recommendation was made for treatment of confirmed OSA with continuous positive airway pressure to reduce driving risk, rather than no treatment, which was supported by moderate-quality evidence. Weak recommendations were made for expeditious diagnostic evaluation and initiation of treatment and against the use of stimulant medications or empiric continuous positive airway pressure to reduce driving risk. The weak recommendations were supported by very low-quality evidence. Additional suggestions included routinely determining the driving risk, inquiring about additional causes of sleepiness, educating patients about the risks of excessive sleepiness, and encouraging clinicians to become familiar with relevant laws. DISCUSSION: The recommendations presented in this guideline are based on the current evidence, and will require an update as new evidence and/or technologies becomes available.

An official American Thoracic Society statement: continuous positive airway pressure adherence tracking systems. The optimal monitoring strategies and outcome measures in adults.

BACKGROUND: Continuous positive airway pressure (CPAP) is considered the treatment of choice for obstructive sleep apnea (OSA), and studies have shown that there is a correlation between patient adherence and treatment outcomes. Newer CPAP machines can track adherence, hours of use, mask leak, and residual apnea-hypopnea index (AHI). Such data provide a strong platform to examine OSA outcomes in a chronic disease management model. However, there are no standards for capturing CPAP adherence data, scoring flow signals, or measuring mask leak, or for how clinicians should use these data. METHODS: American Thoracic Society (ATS) committee members were invited, based on their expertise in OSA and CPAP monitoring. Their conclusions were based on both empirical evidence identified by a comprehensive literature review and clinical experience. RESULTS: CPAP usage can be reliably determined from CPAP tracking systems, but the residual events (apnea/hypopnea) and leak data are not as easy to interpret as CPAP usage and the definitions of these parameters differ among CPAP manufacturers. Nonetheless, ends of the spectrum (very high or low values for residual events or mask leak) appear to be clinically meaningful. CONCLUSIONS: Providers need to understand how to interpret CPAP adherence tracking data. CPAP tracking systems are able to reliably track CPAP adherence. Nomenclature on the CPAP adherence tracking reports needs to be standardized between manufacturers and AHIFlow should be used to describe residual events. Studies should be performed examining the usefulness of the CPAP tracking systems and how these systems affect OSA outcomes.

Sleepiness in elderly veterans.

PURPOSE: This observational study seeks to describe the distribution of sleepiness among elderly male veterans and to explain the relationship between sleepiness and age, function, mobility, and depression in this population. METHODS: Veterans who were age 60 or older and had two or more functional limitations based on their activities of daily living or instrumental activities of daily living were recruited in outpatient clinics. They were recruited as part of a longitudinal study and completed questionnaires reported here at the 18-month data collection time point. RESULTS: Veterans report higher sleepiness than normal controls. Self-reported sleepiness scores are similar to those of patients who have been diagnosed with sleep disturbances. CONCLUSIONS: Interventions to identify and support aging veterans with perceived sleepiness should be developed and carefully evaluated.

Effects of environment light during sleep on autonomic functions of heart rate and breathing.

PURPOSE: Poor sleep hygiene including sleeping in the daytime or with the lights on at night is discovered during the assessment of many sleep disorders including sleep apnea. The aim of this study was to investigate whether environmental light affected autonomic control of heart rate, sleep-disordered breathing (SDB), and/or breathing patterning. METHODS: Seventeen non-obese healthy volunteers without witnessed snoring and apneas were recruited. Studies were performed at home using a type 3 portable monitor combined with actigraphy for sleep-wake timing, using a randomly assigned, crossover between dark, or 1,000 lx of fluorescent lighting environment. The outcomes were low-frequency power divided by high-frequency power (LF/HF ratio) in the analysis of heart rate variability, the apnea-hypopnea index (AHI), and ventilatory pattern variability before and after sleep onset between environments. RESULTS: The LF/HF ratio and AHI were both significantly higher in light as compared to dark. Before sleep onset, the coefficient of variation (CV) for breath-to-breath tidal volume representing breathing irregularity tended to be higher in light than in dark environment. The CV values for tidal volume after sleep onset were significantly decreased compared with before sleep onset in both sleep environments. Mutual information of the ventilatory pattern was significantly lower before sleep onset than after sleep onset, only in the light environment. CONCLUSIONS: Sleeping in the light has effects like that of a stressor as it is associated with neuroexcitation, SDB, and resting breathing irregularity in healthy volunteers. These findings may be relevant to many sleep disorders associated with poor sleep hygiene.