Association between sleep quality and dry eye disease: a literature review and meta-analysis.

OBJECTIVE: The purpose of this article is to systematically review the association between dry eye and sleep quality. METHODS: PubMed, EMBASE, Cochrane, Web of Science, and grey literature databases were searched for observational studies published before April 2023. Meta-analysis was performed using STAT15 software. RESULTS: A total of 21 studies with 419,218 participants were included. The results showed that the dry eye subjects had a worse sleep quality than the healthy population, with poorer subjective sleep quality, longer sleep latency, and a higher risk of unhealthy sleep duration such as insufficient sleep or excessive sleep. The Pittsburgh Sleep Quality Index (PSQI) scores of the dry eye subjects were significantly higher than those of the control subjects (WMD = 1.78, 95%CI: 1.06, 2.50, P < 0.001). The dry eye subjects scored higher than the control subjects in sleep quality, sleep latency, and sleep disturbance in PSQI; there was no difference between the dry eye individuals and control subjects in sleep duration, sleep efficiency, daytime dysfunction, and sleep medication scores. The risk of sleep disorders in the dry eye subjects was significantly higher than that in the non-dry eye subjects (RR = 2.20, 95%CI: 1.78, 2.72, P < 0.001); the risk of insufficient sleep in the dry eye subjects was higher than that in the control subjects (RR = 3.76, 95%CI: 3.15, 4.48, P < 0.001), and the prevalence of excessive sleepiness in dry eye subjects was higher than that in the control subjects (RR = 5.53, 95%CI: 3.83, 7.18, P < 0.001). The ESS scores of the dry eye subjects were significantly higher than those of the control subjects (WMD = 3.02, 95%CI: 2.43, 3.60, P < 0.01). CONCLUSION: Our meta-analysis suggests that individuals with dry eye have a worse sleep quality than the healthy population, with poorer subjective sleep quality, longer sleep latency, and higher risk of unhealthy sleep duration such as insufficient sleep or excessive sleepiness.

Sleep-related adverse events of smoking cessation drugs: A network meta-analysis of randomized controlled trials.

Smoking cessation medications have the potential to affect the functioning of the nervous system, leading to sleep disturbances. Our study aimed to compare the sleep-related side effects (such as insomnia, abnormal dreams, nightmares, and somnolence) induced by different smoking cessation medications in non-psychiatric smokers. We conducted a thorough search of five electronic databases (Cochrane, EMBASE, PubMed, PsycInfo, and Web of Science) for randomized controlled trials. This study was registered with the PROSPERO (registration number CRD42022347976). A total of 79 full-text articles, encompassing 36,731 participants, were included in our analysis. Individuals using bupropion, bupropion in combination with a nicotinic acetylcholine receptor agonist (NRA), and bupropion in conjunction with nicotine replacement therapy (NRT) exhibited a higher likelihood of experiencing insomnia compared to those using NRT alone. Bupropion plus NRA had the highest ranking on the surface under the cumulative ranking curve (SUCRA) for insomnia risk, while placebo had the lowest ranking. Additionally, NRA plus NRT ranked first for abnormal dream outcomes, NRA alone for nightmares, and nortriptyline for somnolence, based on the SUCRA results. Healthcare providers should exercise caution when prescribing smoking cessation drugs, particularly in consideration of their potential sleep-related side effects.

Sleep and subjective age: protect your sleep if you want to feel young.

The current studies examined the impact of insufficient sleep and sleepiness on the subjective experience of age. Study 1, a cross-sectional study of 429 participants (282 females (66%), 144 males, 3 other gender; age range 18-70), showed that for each additional day of insufficient sleep in the last 30 days, subjective age increased by 0.23 years. Study 2, an experimental crossover sleep restriction study (n = 186; 102 females (55%), 84 males; age range 18-46), showed that two nights of sleep restriction (4 h in bed per night) made people feel 4.44 years older compared to sleep saturation (9 h in bed per night). Additionally, moving from feeling extremely alert (Karolinska Sleepiness Scale (KSS) score of 1) to feeling extremely sleepy (KSS score of 9) was associated with feeling 10 years older in both studies. These findings provide compelling support for insufficient sleep and sleepiness to exert a substantial influence on how old we feel, and that safeguarding sleep is probably a key factor in feeling young.

A 90- followed by a 30-min nap reduces fatigue whereas a 30- followed by a 90-min nap maintains cognitive performance in night work: A randomized crossover-pilot study.

OBJECTIVE: To investigate the effects of combinations of brief naps (a 90- followed by a 30-min nap vs. a 30- followed by a 90-min nap) on sleep inertia, reducing sleepiness and fatigue, and maintaining performance during night hours. METHODS: This randomized, comparative, repeated-measure, cross-over study investigated subjective and cognitive performance in 12 healthy females, evaluated in three experimental nap conditions: 1) from 22:30 to 00:00 and 02:30 to 03:00 (Pre90-NAP group), 2) from 23:30 to 00:00 and 02:30 to 04:00 (Pre30-NAP) group, and 3) no naps (NO-NAP group). Participants' body temperature, psychomotor vigilance task (PVT) and Uchida-Kraepelin test (UKT) scores, and subjective feelings of drowsiness and fatigue were evaluated. Sleep state was determined by an actigraphy monitoring device worn by participants. RESULTS: Regardless of timing, both 90-min naps were associated with sleep inertia, and both 30-min naps with minimal sleep inertia. Reaction times were shorter and fewer errors were committed at 2 h post-nap in the Pre30-NAP and Pre90-NAP groups compared with those at the same time in the NO-NAP group. Adding a 90-min nap to a 30-min nap reduced subjective fatigue and shortened reaction times, and adding a 30-min nap to a 90-min nap was effective in maintaining performance, suggesting a synergistic effect. CONCLUSIONS: Taking two naps during a night work can mitigate sleepiness and fatigue, and maintain performance. A 90- followed by a 30-min nap reduced fatigue and reaction time, and a 30- followed by a 90-min nap maintained cognitive performance in the early morning.

Sleepiness and the transition from wakefulness to sleep.

The transition from wakefulness to sleep is a progressive process that is reflected in the gradual loss of responsiveness, an alteration of cognitive functions, and a drastic shift in brain dynamics. These changes do not occur all at once. The sleep onset period (SOP) refers here to this period of transition between wakefulness and sleep. For example, although transitions of brain activity at sleep onset can occur within seconds in a given brain region, these changes occur at different time points across the brain, resulting in a SOP that can last several minutes. Likewise, the transition to sleep impacts cognitive and behavioral levels in a graded and staged fashion. It is often accompanied and preceded by a sensation of drowsiness and the subjective feeling of a need for sleep, also associated with specific physiological and behavioral signatures. To better characterize fluctuations in vigilance and the SOP, a multidimensional approach is thus warranted. Such a multidimensional approach could mitigate important limitations in the current classification of sleep, leading ultimately to better diagnoses and treatments of individuals with sleep and/or vigilance disorders. These insights could also be translated in real-life settings to either facilitate sleep onset in individuals with sleep difficulties or, on the contrary, prevent or control inappropriate sleep onsets.

Making sense of narcolepsy: A qualitative exploration of how persons with narcolepsy perceive symptoms and their illness experience.

INTRODUCTION: Understanding how persons with narcolepsy conceptualize symptoms, daily impact and illness experience is key to facilitating dialogue between patients and healthcare professionals. These concepts are usually explored from the perspective of healthcare professionals/researchers and rarely from the perspective of those with narcolepsy. METHODS: 127 self-reported persons with narcolepsy were recruited from an Australian patient support group. A short demographic survey was completed. All agreed to participate in a subsequent 1:1 semi-structured interview. Saturation was reached after 24 interviews (mean age = 33 years (SD 11) with 44% reporting cataplexy). A multidisciplinary team of researchers/clinicians analyzed interview transcripts using thematic analysis. RESULTS: Participants perceived physical fatigue, sleepiness, and two separate experiences of 'falling asleep/sleep attacks' as distinct symptoms rather than a multidimensional construct (i.e. excessive daytime sleepiness). We also identified two experiences of cataplexy, one triggered by acute emotion and another by a stressor. Participants determined their narcolepsy to be 'well-managed' by the level of functional impairment rather than the frequency of any symptom. Almost all participants described experiencing anticipated stigma and internalized or 'self-' stigma, likely stemming from societal devaluation of sleep and the conflation of sleepiness with laziness. CONCLUSION: Descriptions of common symptoms often differed between participants and the existing literature. These differences likely impact patient-physician communication, with both parties utilizing the same terminology to communicate different concepts. The characterization of stigma in narcolepsy presents opportunities for future research exploring the impact and possible development of interventions to reduce the substantial psychological comorbidity in persons with narcolepsy.

Effects of chronotype on sleep, mood and cardiovascular circadian rhythms in rotating night shift medical workers.

PURPOSE: Whether chronotype affects the health outcomes of night shift work populations is unknown. This study aimed to assess the influence of different chronotypes in the rotating night shift population on sleep status, mood, blood pressure (BP), and heart rate variability (HRV), as well as the circadian rhythm of BP and HRV. METHODS: A total of 208 rotating night shift workers were included. All participants completed structured questionnaires to assess chronotype, mood and sleep status. During their daily lives outside of the night shift, they underwent 24-hour Holter electrocardiogram monitoring and 24-hour ambulatory blood pressure monitoring. Day-time and night-time BP and BP dipping were obtained. Day-time and night-time HRV values (SDNN, RMSSD, LF, HF, LF nu, SD1, SD2 and SD2/SD1) were calculated and fitted to the cosine period curve. Three circandian parameters (mesor, amplitude and acrophase) were extracted to quantify the circadian rhythm of the HRV indices. RESULTS: Among all three groups, E-type showed more fatigue and sleepiness. In addition, E-type showed blunted diastolic BP dipping. Notably, E-type showed association with higher RMSSD, LF, HF and SD1 in the night time, and higher mesors of RMSSD and LF and amplitude of SD2/SD1 in circadian analysis. CONCLUSION: Chronotype is a factor affecting fatigue, sleepiness and cardiovascular circadian rhythms of rotating night shift workers. Chronotype should be taken into consideration for managing night-shift rotation to promote occupational health.

The relationship between alpha power and heart rate variability commonly seen in various mental states.

The extensive exploration of the correlation between electroencephalogram (EEG) and heart rate variability (HRV) has yielded inconsistent outcomes, largely attributable to variations in the tasks employed in the studies. The direct relationship between EEG and HRV is further complicated by alpha power, which is susceptible to influences such as mental fatigue and sleepiness. This research endeavors to examine the brain-heart interplay typically observed during periods of music listening and rest. In an effort to mitigate the indirect effects of mental states on alpha power, subjective fatigue and sleepiness were measured during rest, while emotional valence and arousal were evaluated during music listening. Partial correlation analyses unveiled positive associations between occipital alpha2 power (10-12 Hz) and nHF, an indicator of parasympathetic activity, under both music and rest conditions. These findings underscore brain-heart interactions that persist even after the effects of other variables have been accounted for.

Sleep traits and associated factors among people living with HIV/AIDS in Iran: a two-step clustering analysis.

Sleep plays an essential role in improving the quality of life of people living with HIV (PLWH); however, sleep traits in this population are not well studied. This study aims to evaluate the sleep traits and related associated factors among PLWH in Iran. A nationwide cross-sectional study was conducted with 1185 PLWH who attended Voluntary Counseling and Testing centers in 15 provinces in Iran between April 2021 and March 2022. The Berlin Obstructive Sleep Apnea questionnaire, Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale and Insomnia Severity Index were used. A two-step clustering method was employed to identify the number of sleep clusters in PLWH. Prevalence of poor sleep quality, sleepiness and insomnia were 49.6%, 21.15% and 42.7% respectively. Three sleep trait clusters were identified: I. minor sleep problems (45.6%); II. Snoring & sleep apnea (27.8%), and III. poor sleep quality and insomnia (26.7%). Age (Odds Ratio (OR) 1.033, 95% Confidence Interval (CI) 1.017-1.050), academic education (OR 0.542, 95% CI 0.294-0.998) and HIV duration were associated with being in Snoring & sleep apnea cluster, while age (OR = 1.027, 95% CI 1.009-1.040) was associated with being in Poor sleep quality and insomnia cluster. PLWH with depression had higher odds of being in Poor sleep quality and insomnia cluster, and those with anxiety had higher odds of being in Snoring & sleep apnea cluster and Poor sleep quality and insomnia cluster. A significant proportion of PLWH have poor sleep quality, sleepiness, and insomnia. The identification of three distinct sleep trait clusters underscores the need for increased attention and tailored interventions to address the specific sleep issues experienced by PLWH.

Safety and Efficacy of Cenobamate for the Treatment of Focal Seizures in Older Patients: Post Hoc Analysis of a Phase III, Multicenter, Open-Label Study.

BACKGROUND: Cenobamate is an antiseizure medication (ASM) approved in the US and Europe for the treatment of uncontrolled focal seizures. OBJECTIVE: This post hoc analysis of a phase III, open-label safety study assessed the safety and efficacy of adjunctive cenobamate in older adults versus the overall study population. METHODS: Adults aged 18-70 years with uncontrolled focal seizures taking stable doses of one to three ASMs were enrolled in the phase III, open-label safety study; adults aged 65-70 years from that study were included in our safety analysis. Discontinuations due to adverse events and treatment-emergent adverse events (TEAEs) were assessed throughout the study in all patients who received one or more doses of cenobamate (safety study population). Efficacy was assessed post hoc in patients who had adequate seizure data available (post hoc efficacy population); we assessed patients aged 65-70 years from that population. Overall, 100% responder rates were assessed in the post hoc efficacy maintenance-phase population in 3-month intervals. Concomitant ASM drug load changes were also measured. For each ASM, drug load was defined as the ratio of actual drug dose/day to the World Health Organization defined daily dose (DDD). RESULTS: Of 1340 patients (mean age 39.7 years) in the safety study population, 42 were ≥ 65 years of age (mean age 67.0 years, 52.4% female). Median duration of exposure was 36.1 and 36.9 months for overall patients and older patients, respectively, and mean epilepsy duration was 22.9 and 38.5 years, respectively. At 1, 2, and 3 years, 80%, 72%, and 68% of patients overall, and 76%, 71%, and 69% of older patients, respectively, remained on cenobamate. Common TEAEs (≥ 20%) were somnolence and dizziness in overall patients, and somnolence, dizziness, fall, fatigue, balance disorder, and upper respiratory tract infection in older patients. Falls in older patients occurred after a mean 452.1 days of adjunctive cenobamate treatment (mean dose 262.5 mg/day; mean concomitant ASM drug load 2.46). Of 240 patients in the post hoc efficacy population, 18 were ≥ 65 years of age. Mean seizure frequency at baseline was 18.1 seizures/28 days for the efficacy population and 3.1 seizures/28 days for older patients. Rates of 100% seizure reduction within 3-month intervals during the maintenance phase increased over time for the overall population (n = 214) and older adults (n = 15), reaching 51.9% and 78.6%, respectively, by 24 months. Mean percentage change in concomitant ASM drug load, not including cenobamate, was reduced in the overall efficacy population (31.8%) and older patients (36.3%) after 24 months of treatment. CONCLUSIONS: Results from this post hoc analysis showed notable rates of efficacy in older patients taking adjunctive cenobamate. Rates of several individual TEAEs occurred more frequently in older patients. Further reductions in concomitant ASMs may be needed in older patients when starting cenobamate to avoid adverse effects such as somnolence, dizziness, and falls. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov NCT02535091.

Composite dietary antioxidant index and sleep health: a new insight from cross-sectional study.

BACKGROUND: Low-quality sleep and obstructive sleep apnea (OSA) can result in series of chronic diseases. Healthy diet has been considered as an effective and simple strategy to optimize sleep quality. However, current evidence on the correlation of dietary composite antioxidant intake with sleep health remained obscure. AIM OF THE STUDY: To determine the relationship of composite dietary antioxidant index (CDAI) and sleep health. METHODS: Cross-sectional analyses were based on National Health and Nutrition Examination Survey (NHANES) 2005-2008. Dietary consumption was assessed by trained staff using 24-h diet recall method and CDAI was calculated based on previous validated approach that included six antioxidants. Sleep-related outcomes were self-reported by a set of questionnaires and classified into OSA, day sleepiness, and insufficient sleep. Weighted logistic regression was conducted to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Restricted cubic spline (RCS) regressions were also used to evaluate the dose-response of CDAI and three sleep-related outcomes. RESULTS: A total of 7274 subjects included (mean age: 46.97 years) were enrolled in our study, including 3658 were females (52.54%) and 3616 were males (47.46%). Of them, 70.6%, 29.51%, and 35.57% of the subjects reported that they had OSA, day sleepiness and insufficient sleep, respectively. Logistic regression showed the highest quartile of CDAI was inversely associated with the risk of OSA (OR: 0.69, 95%CI: 0.49-0.97), day sleepiness (OR: 0.64, 95%CI: 0.44-0.94) and insufficient sleep (OR: 0.68, 95%CI: 0.50-0.92) compared with the lowest quartile. RCS showed linear relationship of CDAI and insufficient sleep but non-linear relationship of CDAI with OSA and day sleepiness. CONCLUSIONS: Our results show that CDAI was non-linearly associated with lower risk of OSA and day sleepiness whereas a linear inverse association between CDAI and insufficient sleep was observed. These findings implicate that combined intake of antioxidants could be a promising and effective approach to optimize sleep quality for public.

Pharmacokinetics of Staccato® alprazolam in healthy adult participants in two phase 1 studies: An open-label smoker study and a randomized, placebo-controlled ethnobridging study.

OBJECTIVE: Staccato® alprazolam is a single-use, drug-device combination delivering alprazolam to the deep lung that is being evaluated as treatment for rapid and early seizure termination. This article reports pharmacokinetic (PK) data from two phase 1 studies of Staccato alprazolam in healthy adult participants. METHODS: The smoker study (EPK-002/NCT03516305) was an open-label, nonrandomized, single-dose, PK study in smokers and nonsmokers aged 21-50 years, administered a single inhaled dose of 1 mg Staccato alprazolam. The ethnobridging study (UP0101/NCT04782388) was a double-blind, placebo-controlled study in Japanese, Chinese, and Caucasian participants aged 18-55 years randomized 4:1 to a single inhaled dose of Staccato alprazolam 2 mg or Staccato placebo. RESULTS: In the smoker study, 36 participants (18 smokers, 18 nonsmokers) were enrolled and received Staccato alprazolam. Following Staccato administration, alprazolam was rapidly absorbed, with a median time to peak drug plasma concentration (Tmax) of 2 min in both smokers (range = 2-30 min) and nonsmokers (range = 2-60 min). Staccato alprazolam was rapidly absorbed to a similar extent in both smokers and nonsmokers. The most commonly reported treatment-emergent adverse events (TEAEs) were somnolence and dizziness. In the ethnobridging study, 10 participants each of Japanese, Chinese, and Caucasian ethnicities were randomized 4:1 to Staccato alprazolam or Staccato placebo. Following Staccato administration, alprazolam was rapidly absorbed and distributed, with a median Tmax of 1.5-2 min in Japanese (range = 1-2 min), Chinese (range = 1-34 min), and Caucasian (range = 1-120 min) participants. Somnolence and sedation were the most commonly reported TEAEs. In both studies, there were no deaths, and no participants reported serious or severe TEAEs, or discontinued due to TEAEs. SIGNIFICANCE: Alprazolam was rapidly absorbed, and therapeutic drug levels were achieved within 2 min postdose when administered to the lung with the Staccato device. Staccato alprazolam was generally well tolerated and displayed a safety profile consistent with that known from other alprazolam applications. No new safety signals were identified.

Sleepiness should be reinvestigated through the lens of clinical neurophysiology: A mixed expertal and big-data Natural Language Processing approach.

Historically, the field of sleep medicine has revolved around electrophysiological tools. However, the use of these tools as a neurophysiological method of investigation seems to be underrepresented today, from both international recommendations and sleep centers, in contrast to behavioral and psychometric tools. The aim of this article is to combine a data-driven approach and neurophysiological and sleep medicine expertise to confirm or refute the hypothesis that neurophysiology has declined in favor of behavioral or self-reported dimensions in sleep medicine for the investigation of sleepiness, despite the use of electrophysiological tools. Using Natural Language Processing methods, we analyzed the abstracts of the 18,370 articles indexed by PubMed containing the terms 'sleepiness' or 'sleepy' in the title, abstract, or keywords. For this purpose, we examined these abstracts using two methods: a lexical network, enabling the identification of concepts (neurophysiological or clinical) related to sleepiness in these articles and their interconnections; furthermore, we analyzed the temporal evolution of these concepts to extract historical trends. These results confirm the hypothesis that neurophysiology has declined in favor of behavioral or self-reported dimensions in sleep medicine for the investigation of sleepiness. In order to bring sleepiness measurements closer to brain functioning and to reintroduce neurophysiology into sleep medicine, we discuss two strategies: the first is reanalyzing electrophysiological signals collected during the standard sleep electrophysiological test; the second takes advantage of the current trend towards dimensional models of sleepiness to situate clinical neurophysiology at the heart of the redefinition of sleepiness.

Objective evaluation of excessive daytime sleepiness.

Excessive daytime sleepiness (EDS) is multifactorial. It combines, among other things, an excessive propensity to fall asleep ("physiological sleepiness") and a continuous non-imperative sleepiness (or drowsiness/hypo-arousal) leading to difficulties remaining awake and maintaining sustained attention and vigilance over the long term ("manifest sleepiness"). There is no stand-alone biological measure of EDS. EDS measures can either capture the severity of physiological sleepiness, which corresponds to the propensity to fall asleep, or the severity of manifest sleepiness, which corresponds to behavioral consequences of sleepiness and reduced vigilance. Neuropsychological tests (The psychomotor vigilance task (PVT), Oxford Sleep Resistance Test (OSLeR), Sustained Attention to Response Task (SART)) explore manifest sleepiness through several sustained attention tests but the lack of normative values and standardized protocols make the results difficult to interpret and use in clinical practice. Neurophysiological tests explore the two main aspects of EDS, i.e. the propensity to fall asleep (Multiple sleep latency test, MSLT) and the capacity to remain awake (Maintenance of wakefulness test, MWT). The MSLT and the MWT are widely used in clinical practice. The MSLT is recognized as the "gold standard" test for measuring the severity of the propensity to fall asleep and it is a diagnostic criterion for narcolepsy. The MWT measures the ability to stay awake. The MWT is not a diagnostic test as it is recommended only to evaluate the evolution of EDS and efficacy of EDS treatment. Even if some efforts to standardize the protocols for administration of these tests have been ongoing, MSLT and MWT have numerous limitations: age effect, floor or ceiling effects, binding protocol, no normal or cutoff value (or determined in small samples), and no or low test-retest values in some pathologies. Moreover, the recommended electrophysiological set-up and the determination of sleep onset using the 30­sec epochs scoring rule show some limitations. New, more precise neurophysiological techniques should aim to detect very brief periods of physiological sleepiness and, in the future, the brain local phenomenon of sleepiness likely to underpin drowsiness, which could be called "physiological drowsiness".

Polysomnographic characteristics of excessive daytime sleepiness phenotypes in obstructive sleep apnea: results from the international sleep apnea global interdisciplinary consortium.

STUDY OBJECTIVES: Excessive daytime sleepiness (EDS) is a major symptom of obstructive sleep apnea (OSA). Traditional polysomnographic (PSG) measures only partially explain EDS in OSA. This study analyzed traditional and novel PSG characteristics of two different measures of EDS among patients with OSA. METHODS: Sleepiness was assessed using the Epworth Sleepiness Scale (>10 points defined as "risk of dozing") and a measure of general sleepiness (feeling sleepy ≥ 3 times/week defined as "feeling sleepy"). Four sleepiness phenotypes were identified: "non-sleepy," "risk of dozing only," "feeling sleepy only," and "both at risk of dozing and feeling sleepy." RESULTS: Altogether, 2083 patients with OSA (69% male) with an apnea-hypopnea index (AHI) ≥ 5 events/hour were studied; 46% were "non-sleepy," 26% at "risk of dozing only," 7% were "feeling sleepy only," and 21% reported both. The two phenotypes at "risk of dozing" had higher AHI, more severe hypoxemia (as measured by oxygen desaturation index, minimum and average oxygen saturation [SpO2], time spent < 90% SpO2, and hypoxic impacts) and they spent less time awake, had shorter sleep latency, and higher heart rate response to arousals than "non-sleepy" and "feeling sleepy only" phenotypes. While statistically significant, effect sizes were small. Sleep stages, frequency of arousals, wake after sleep onset and limb movement did not differ between sleepiness phenotypes after adjusting for confounders. CONCLUSIONS: In a large international group of patients with OSA, PSG characteristics were weakly associated with EDS. The physiological measures differed among individuals characterized as "risk of dozing" or "non-sleepy," while "feeling sleepy only" did not differ from "non-sleepy" individuals.

Predictors of blood pressure response to continuous positive airway pressure treatment in patients with sleep apnea.

BACKGROUND: Sleep apnea is associated with hypertension. Metaanalyses indicate that treatment of sleep apnea by continuous positive airway pressure (CPAP) reduces blood pressure (BP) by a mean of 3 mmHg. To date, predictors of BP response to CPAP remain incompletely understood. We hypothesized that the magnitude of CPAP-induced BP reduction depends on baseline apnea-hypopnea index (AHI) and the extent of daytime sleepiness. METHODS: We performed a retrospective study on the association of BP response to CPAP with polysomnographic readings, intensity of sleepiness (measured by Epworth Sleepiness Scale, ESS), and epidemiologic parameters in 2461 patients with obstructive sleep apnea. BP response was defined as the difference between office BP at polysomonography examinations before and after initiation of CPAP. RESULTS: Five hundred and fifty-five patients fulfilled all inclusion and exclusion criteria and were included in the analysis. Median monthly CPAP usage was 143.7 h (85.4-204.1 h). BP was significantly higher at baseline than at follow-up (129.9 ±â€Š15.5 vs. 128.3 ±â€Š15.2, P  = 0.021) resulting in mean reduction of BP of -1.5 ±â€Š19.2 mmHg. patients with a higher than median baseline AHI (median 21) showed a more pronounced reduction of BP than those with lower AHI (AHI ≥21: 130.5 ±â€Š15.3 vs. 128.6 ±â€Š14.6, P  = 0.06; AHI <21: 129.5 ±â€Š15.8 vs. 127.9 ±â€Š15.8, P  = 0.18). CPAP therapy led to a significant reduction in sleepiness (8.3 ±â€Š4.8 vs. 6.6 ±â€Š4.5, P  < 0.0001). Those subjects with higher than median sleepiness score (ESS ≥8), however, did not show a significant difference in BP response compared with those with a lower sleepiness score. Receiver-operating characteristic (ROC) curve analyses investigating the accuracy of AHI and ESS to predict a BP reduction at least 5 mmHg revealed an AUC of 0.51 and 0.52, respectively. CONCLUSION: The study confirms that CPAP therapy for sleep apnea has a mild BP lowering effect. Although this effect is slightly higher in patients with above-average AHI, neither AHI nor ESS can be used to define threshold values predicting a BP decrease at least 5 mmHg.

Fatigued but not sleepy? An empirical investigation of the differentiation between fatigue and sleepiness in sleep disorder patients in a cross-sectional study.

OBJECTIVE: Sleepiness and fatigue are common complaints among individuals with sleep disorders. The two concepts are often used interchangeably, causing difficulty with differential diagnosis and treatment decisions. The current study investigated sleep disorder patients to determine which factors best differentiated sleepiness from fatigue. METHODS: The study used a subset of participants from a multi-site study (n = 606), using a cross-sectional study design. We selected 60 variables associated with either sleepiness or fatigue, including demographic, mental health, and lifestyle factors, medical history, sleep questionnaires, rest-activity rhythms (actigraphy), polysomnographic (PSG) variables, and sleep diaries. Fatigue was measured with the Fatigue Severity Scale and sleepiness was measured with the Epworth Sleepiness Scale. A Random Forest machine learning approach was utilized for analysis. RESULTS: Participants' average age was 47.5 years (SD 14.0), 54.6% female, and the most common sleep disorder diagnosis was obstructive sleep apnea (67.4%). Sleepiness and fatigue were moderately correlated (r = 0.334). The model for fatigue (explained variance 49.5%) indicated depression was the strongest predictor (relative explained variance 42.7%), followed by insomnia severity (12.3%). The model for sleepiness (explained variance 17.9%), indicated insomnia symptoms was the strongest predictor (relative explained variance 17.6%). A post hoc receiver operating characteristic analysis indicated depression could be used to discriminate fatigue (AUC = 0.856) but not sleepiness (AUC = 0.643). CONCLUSIONS: The moderate correlation between fatigue and sleepiness supports previous literature that the two concepts are overlapping yet distinct. Importantly, depression played a more prominent role in characterizing fatigue than sleepiness, suggesting depression could be used to differentiate the two concepts.