Overnight Sleep Research Articles

Medical Devices for Pediatric Apnea Monitoring and Therapy: Past and New Trends.

Apnea in the pediatric population is associated with increased morbidity and mortality in a large number of developed as well as developing countries. It is even more prominent in preterm newborn infants and is commonly referred to as apnea of prematurity. Its current diagnosis and therapy involve the use of traditional technologies, which often result in discomfort to the infants due to the use of invasive devices attached to their sensitive skin, especially in overnight clinical sleep analysis (for over a 12- or 24-h period). Emerging trends for the point-of-care diagnosis of this sleep disorder are focused on the design of integrated devices for less complex and noninvasive monitoring. This paper presents a review of the state of the art of clinical technologies and methodologies for sleep apnea detection and their pros and cons, with particular focus on their working principles and relevance to pediatrics. Moreover, an in-depth discussion on emerging future technologies envisioned to be integral parts of the daily home-based applications is included in the paper.

Mandibular advancement appliance effects on obstructive sleep apnoea: a prospective threedimensional computed tomography study

Abstract Background The aim of this study was to determine the effects of an elastic mandibular advancement (EMA) appliance on upper airway dimensions, most constricted area (MCA) of the airway, and snoring in a sample of obstructive sleep apnoea (OSA) patients of varying severity. Methods Forty-seven male subjects were classified into two groups comprising12 controls and 35 suffering from OSA. The OSA group was further divided into three subgroups based on their apnoea-hypopnoea index (AHI). All subjects completed an Epworth questionnaire and an overnight home sleep test before (T1) and at the end of the study (T2). OSA subjects were provided with a custom-made EMA appliance. Cone beam computed tomographic images were obtained for each subject at T1 and T2. Airway parameters were measured and summarised by grouping. The differences in the measurements T1 – T2 were compared using repeated measures analysis of variance (rmANOVA) and p ≤ 0.05 was considered statistically significant. Results The use of the EMA produced a statistically significant increase in the nasopharyngeal, oropharyngeal, MCA, and total airway volume. Although sleep apnoea patients reported a reduction in snoring time, particularly in moderate and severe OSA groups, the level of improvement was not statistically significant. Patients with moderate and severe OSA demonstrated significant decreases in their AHI and Epworth scores. Conclusion EMA is effective in reducing OSA severity and changing airway dimensions in OSA patients, specifically in the moderate and severe cases.

Resistance Exercise Augments Postprandial Overnight Muscle Protein Synthesis Rates.

We have previously shown that protein ingestion before sleep increases overnight muscle protein synthesis rates. Whether prior exercise further augments the muscle protein synthetic response to presleep protein ingestion remains to be established. This study aimed to assess whether resistance-type exercise performed in the evening increases the overnight muscle protein synthetic response to presleep protein ingestion. Twenty-four healthy young men were randomly assigned to ingest 30 g intrinsically L-[1-C]-phenylalanine and L-[1-C]-leucine-labeled casein protein before going to sleep with (PRO + EX, n = 12) or without (PRO, n = 12) prior resistance-type exercise performed in the evening. Continuous intravenous L-[ring-H5]-phenylalanine, L-[1-C]-leucine, and L-[ring-H2]-tyrosine infusions were applied. Blood and muscle tissue samples were collected to assess whole-body protein balance, myofibrillar protein synthesis rates, and overnight incorporation of dietary protein-derived amino acids into de novo myofibrillar protein. A total of 57% ± 1% of the ingested protein-derived phenylalanine appeared in the circulation during overnight sleep. Overnight myofibrillar protein synthesis rates were 37% (0.055%·h ± 0.002%·h vs. 0.040%·h ± 0.003%·h, P < 0.001, based on L-[ring- H5]-phenylalanine) and 31% (0.073%·h ± 0.004%·h vs. 0.055%·h ± 0.006%·h, P = 0.024, based on L-[1-C]-leucine) higher in PRO + EX compared with PRO. Substantially more of the dietary protein-derived amino acids were incorporated into de novo myofibrillar protein during overnight sleep in PRO + EX compared with PRO (0.026 ± 0.003 vs. 0.015 ± 0.003 molar percent excess, P = 0.012). Resistance-type exercise performed in the evening augments the overnight muscle protein synthetic response to presleep protein ingestion and allows more of the ingested protein-derived amino acids to be used for de novo myofibrillar protein synthesis during overnight sleep.

Vascular stiffness determined from a nocturnal digital pulse wave signal: association with sleep, sleep-disordered breathing, and hypertension.

Reflection of the finger pulse wave form is a valid measure of arterial stiffness, which may be continuously assessed during sleep. We investigated the relationships between sleep, sleep-disordered breathing, hypertension, and pulse propagation time (PPT) in patients with suspected sleep apnea. The digital photoplethysmographic signal derived from finger pulse oximetry was recorded during overnight sleep studies in 440 patients (64% men, age 55 ± 12 years, BMI 30 ± 6 kg/m, apnea-hypopnea index 19 ± 19 n/h). PPT, defined as the time interval between the systolic and diastolic peak of the finger pulse wave, was calculated. The influence of sleep stages on PPT were assessed in patients undergoing polysomnography. Generalized linear models were used to study predictors of PPT and hypertension. Mean overnight PPT was independently associated with age (β = -1.34, P < 0.001), height (β = 0.47, P = 0.047), history of smoking (β = -9.44, P = 0.005), and apnea-hypopnea index (β = -0.18, P = 0.043). PPT was shorter in hypertensive patients compared with normotensive patients (160 ± 33 vs. 177 ± 47 ms, P < 0.001) and independently associated with a diagnosis of hypertension (P = 0.043). PPT was influenced by sleep stage (highest PPT during slow wave sleep compared with wake and all other sleep stages, all P < 0.001) and varied across sleep apnea severity groups in normotensive but not in hypertensive patients (P = 0.028 and 0.64, respectively). Overnight PPT by oximetry was strongly associated with factors known to determine daytime vascular stiffness. In addition, PTT provides information on functional and structural vascular properties during sleep. This novel technique offers new opportunities to noninvasively monitor vascular function during the sleeping period.

Pre-Sleep Protein Ingestion to Improve the Skeletal Muscle Adaptive Response to Exercise Training.

Protein ingestion following resistance-type exercise stimulates muscle protein synthesis rates, and enhances the skeletal muscle adaptive response to prolonged resistance-type exercise training. As the adaptive response to a single bout of resistance exercise extends well beyond the first couple of hours of post-exercise recovery, recent studies have begun to investigate the impact of the timing and distribution of protein ingestion during more prolonged recovery periods. Recent work has shown that overnight muscle protein synthesis rates are restricted by the level of amino acid availability. Protein ingested prior to sleep is effectively digested and absorbed, and thereby stimulates muscle protein synthesis rates during overnight recovery. When applied during a prolonged period of resistance-type exercise training, protein supplementation prior to sleep can further augment gains in muscle mass and strength. Recent studies investigating the impact of pre-sleep protein ingestion suggest that at least 40 g of protein is required to display a robust increase in muscle protein synthesis rates throughout overnight sleep. Furthermore, prior exercise allows more of the pre-sleep protein-derived amino acids to be utilized for de novo muscle protein synthesis during sleep. In short, pre-sleep protein ingestion represents an effective dietary strategy to improve overnight muscle protein synthesis, thereby improving the skeletal muscle adaptive response to exercise training.

Neuromuscular electrical stimulation prior to presleep protein feeding stimulates the use of protein-derived amino acids for overnight muscle protein synthesis.

Neuromuscular electrical stimulation (NMES) as well as presleep dietary protein ingestion represent effective strategies to stimulate muscle protein synthesis rates. Here we demonstrate that in older men after a day of bed rest, the application of NMES prior to presleep protein feeding stimulates the use of dietary protein-derived amino acids for overnight muscle protein synthesis by 18% compared with presleep protein feeding only.

A cross-sectional analysis of daytime versus nocturnal polysomnographic respiratory parameters in cystic fibrosis during early adolescence

BackgroundIn Cystic Fibrosis (CF), early detection and treatment of respiratory disease is considered the standard for respiratory care. Overnight polysomnography (PSG) may help identify respiratory deterioration in young patients with CF. MethodsA prospective cohort study of 46 patients with CF, aged 8–12years, from a specialist clinic in a tertiary paediatric hospital. Daytime pulmonary function, shuttle test exercise testing and overnight PSG were studied. ResultsOf 81 children aged 8–12years, 46 (57%) agreed to participate. FEV1 (% predicted, mean 74.6%) was normal in 23 (50%), mildly abnormal in 12 (26.1%), moderately abnormal in 10 (21.7%) and severely abnormal in 1 (2.2%). Amongst sleep study parameters, FEV1 (% predicted) showed significant correlation with the respiratory rate (RR) in slow wave sleep (SWS), CO2 change in REM, baseline SaO2, and the arousal index (h−1). Backward, stepwise linear regression modelling for FEV1 (% predicted) included the entire group with a wide spectrum of clinical severity. From sleep, variables remaining in the multivariate model for FEV1 (F=16.81, p<0.001) were the RR in SWS (min−1) and the CO2 change in REM (p=0.003, and 0.014, respectively). When daytime tests were included, the variables remaining were RR in SWS and SD score for BMI (BMIsds) (F=18.70, p<0.001). ConclusionsRespiratory abnormalities on overnight sleep studies included elevated respiratory rates during SWS and mild CO2 retention in REM sleep, and these incorporated into a model correlating with FEV1 (% predicted). Thus, mild mechanical impairment of ventilation is evident on overnight sleep studies in children with cystic fibrosis although the significance of this finding will require further investigation.

Consolidation during sleep stabilizes non-native speech sound learning

Learning to perceive non-native speech sound categories is a challenge for many adult listeners. Even after successful learning, individuals vary in the degree to which they can successfully retain and consolidate learned perceptual categories in memory. In this talk, I describe a recent line of work from our lab showing that sleep plays a greater role in perceptual learning of non-native speech sounds than previously supposed. Specifically, we find that consolidation processes during overnight sleep protect learned phonetic information from interference from similar sounds from one's native language. I will discuss the potential sources of native language interference by reviewing a series of studies that test the low-level acoustic and abstract phonological contributions to interference. Finally, overnight gains in performance can be specifically linked to the duration and quality of sleep, suggesting a key role for sleep, per se, in the retention of non-native speech categories over multiple sessions. Taken together, this line of research suggests that individual variability in non-native speech sound learning may in part be linked to individual differences in sleep behavior and differences in the degree of pre-sleep exposure to competing native-language phonetic contrasts.

EP 118. Can midday naps boost learning in older adults?

Naps as well as a night of sleep were found to improve motor learning in young individuals (Doyon et al., 2009). The capacity of older adults to learn and stabilize motor memory traces (consolidation) during over-night sleep is limited (Pan and Rickard, 2015, Backhaus et al., 2015). However a small number of studies suggested sleep-dependent consolidation in healthy older adults, immediately after sleep (Gudberg et al., 2015, Al-Sharman and Siengsukon, 2014) or after a delayed period (Tucker et al., 2011, Korman et al., 2015). Can midday naps enhance motor learning in older adults? We evaluated the performance changes of a sample of thirty-three healthy older adults (60–82 years) by implementing a napping paradigm in a motor learning setup (sequence learning and motor adaption). The participants were randomly assigned to one of three groups; short nap group (a forty-five minutes nap opportunity, 10–20 min sleep), long nap group (ninety minutes nap opportunity, 50–80 min sleep) or a forty-five minutes period of wakefulness. Three learning sessions on two consecutive days were compared for both tasks with the repeated measures mixed model approach. All older adults were able to improve their task performance in both tasks throughout all sessions. For sequence learning no differences between the nap groups could be found following the midday nap, nor after an extended period of consolidation, i.e. the following day. Similarly no significant differences between the groups could be found directly after the midday break when performing the motor adaptation task. However during the final block of the last session nappers performed significantly better (p = 0.023) than those adults staying awake. Although midday naps may have a great recuperative value (Tamaki et al., 1999, Campbell et al., 2011), these effects could not be projected on motor learning and subsequent motor performance directly after napping. Based on the current results we conclude that short daytime naps do not enhance the effects of motor learning and consolidation. Thus, deficits in consolidation apparent in older adults are not dependent of the duration of sleep but rather of the process of consolidation during sleep, which seems to be impaired in older adults. This work was supported by the Stiftung der Deutschen Wirtschaft providing a PhD Scholarship to W.B. W.B and F.C.H. hold a research grant from the Werner-Otto-Foundation (9/87).

Physical Activity Performed in the Evening Increases the Overnight Muscle Protein Synthetic Response to Presleep Protein Ingestion in Older Men

Background: The age-related decline in skeletal muscle mass is partly attributed to anabolic resistance to food intake. Dietary protein ingestion before sleep could be used as a nutritional strategy to compensate for anabolic resistance.Objective: The present study assessed whether physical activity performed in the evening can augment the overnight muscle protein synthetic response to presleep protein ingestion in older men.Methods: In a parallel group design, 23 healthy older men (mean ± SEM age: 71 ± 1 y) were randomly assigned to ingest 40 g protein intrinsically labeled with L-[1-13C]-phenylalanine and L-[1-13C]-leucine before going to sleep with (PRO+EX) or without (PRO) performing physical activity earlier in the evening. Overnight protein digestion and absorption kinetics and myofibrillar protein synthesis rates were assessed by combining primed, continuous infusions of L-[ring-2H5]-phenylalanine, L-[1-13C]-leucine, and L-[ring-2H2]-tyrosine with the ingestion of intrinsically labeled casein protein. Muscle and blood samples were collected throughout overnight sleep.Results: Protein ingested before sleep was normally digested and absorbed, with 54% ± 2% of the protein-derived amino acids appearing in the circulation throughout overnight sleep. Overnight myofibrillar protein synthesis rates were 31% (0.058% ± 0.002%/h compared with 0.044% ± 0.003%/h; P < 0.01; based on L-[ring-2H5]-phenylalanine) and 27% (0.074% ± 0.004%/h compared with 0.058% ± 0.003%/h; P < 0.01; based on L-[1-13C]-leucine) higher in the PRO+EX than in the PRO treatment. More dietary protein-derived amino acids were incorporated into de novo myofibrillar protein during overnight sleep in PRO+EX than in PRO treatment (0.042 ± 0.002 compared with 0.033 ± 0.002 mole percent excess; P < 0.05).Conclusions: Physical activity performed in the evening augments the overnight muscle protein synthetic response to presleep protein ingestion and allows more of the ingested protein-derived amino acids to be used for de novo muscle protein synthesis during overnight sleep in older men. This trial was registered at Nederlands Trial Register as NTR3885.

Exercise Enhances The Overnight Muscle Protein Synthetic Response To Pre-sleep Protein Feeding In Older Males

PURPOSE: The age-related decline in skeletal muscle mass is, at least partly, attributed to anabolic resistance to food intake. To compensate for anabolic resistance, we recently introduced the ingestion of dietary protein prior to sleep as a nutritional strategy to increase overnight muscle protein synthesis rates. Here we aimed to assess whether resistance-type exercise performed in the evening can further augment the overnight muscle protein synthetic response to pre-sleep protein ingestion in older males. METHODS: In a parallel group design, twenty-three healthy older men (71±1 y) were randomly assigned to ingest 40 g casein protein before going to sleep with (PRO+EX: n=11) or without (PRO: n=12) performing resistance-type exercise earlier that evening. Overnight protein digestion and absorption kinetics, whole body protein metabolism and muscle myofibrillar protein synthesis rates were assessed using primed, continuous infusions of L-[ring-2H5]-phenylalanine and L-[ring-2H2]-tyrosine with the ingestion of intrinsically L-[1-13C]-phenylalanine labeled casein protein. RESULTS: Exogenous phenylalanine appearance rates expressed over time did not differ between treatments. A total of 53±2 vs 55±2% of the ingested protein-derived phenylalanine appeared in the circulation during overnight sleep in the PRO+EX and PRO treatment, respectively (P=0.49). Myofibrillar protein synthesis rates were 31% higher during overnight sleep when exercise was performed earlier that day (0.058±0.002 vs 0.044±0.003 %·h-1 in PRO+EX and PRO, respectively; P<0.01; L-[ring-2H5]-phenylalanine). In line, 27% more L-[1-13C]-phenylalanine was incorporated into myofibrillar protein in PRO+EX compared with PRO (0.042±0.002 vs 0.033±0.002 MPE, respectively; P<0.05; L-[1-13C]-phenylalanine). CONCLUSIONS: Resistance-type exercise augments the overnight muscle protein synthetic response to pre-sleep protein ingestion and allows more of the ingested protein to be directed towards de novo muscle protein synthesis during overnight sleep in older males. Funding: Top Institute Food and Nutrition (TIFN)

Measures of sleep and cardiac functioning during sleep using a multi-sensory commercially-available wristband in adolescents

To validate measures of sleep and heart rate (HR) during sleep generated by a commercially-available activity tracker against those derived from polysomnography (PSG) in healthy adolescents. Sleep data were concurrently recorded using FitbitChargeHR™ and PSG, including electrocardiography (ECG), during an overnight laboratory sleep recording in 32 healthy adolescents (15 females; age, mean±SD: 17.3±2.5years). Sleep and HR measures were compared between FitbitChargeHR™ and PSG using paired t-tests and Bland-Altman plots. Epoch-by-epoch analysis showed that FitbitChargeHR™ had high overall accuracy (91%), high sensitivity (97%) in detecting sleep, and poor specificity (42%) in detecting wake on a min-to-min basis. On average, FitbitChargeHR™ significantly but negligibly overestimated total sleep time by 8min and sleep efficiency by 1.8%, and underestimated wake after sleep onset by 5.6min (p<0.05). Within FitbitChargeHR™ epochs of sleep, the average HR was 59.3±7.5bpm, which was significantly but negligibly lower than that calculated from ECG (60.2±7.6bpm, p<0.001), with no change in mean discrepancies throughout the night. FitbitChargeHR™ showed good agreement with PSG and ECG in measuring sleep and HR during sleep, supporting its use in assessing sleep and cardiac function in healthy adolescents. Further validation is needed to assess its reliability over prolonged periods of time in ecological settings and in clinical populations.

Feasibility of self-administered sleep assessment in older women in the Women's Health Initiative (WHI).

Laboratory-based polysomnography (PSG) is the gold standard assessment of sleep disordered breathing (SDB). In large cohort studies and clinical trials, however, these overnight procedures can be expensive and burdensome to participants, especially older adults. In preparation for a large observational study, we determined the feasibility of self-administering two devices mailed to participants' homes that estimate indices of SDB. In two separate studies, older women enrolled in the Women's Health Initiative (WHI) Memory Study extension aged mean (SD) 85.77 (2.98) years who were not using supplemental oxygen and consented to being in the feasibility study completed either an in-home, self-administered overnight sleep assessment using a multi-sensor device that measured oximetry, nasal pressure, chest effort, and snoring (ApneaLink(TM)) (N = 58), or a wrist-worn oximeter (NoninWristOx2(TM)) (N = 33). A follow-up questionnaire assessed the devices' acceptability and important sleep-related exposures. Although the multi-sensor device was assessed only in older women with no cognitive impairment, the proportion of completed interpretable sleep studies was low (54%) and participants reported needing help to administer the device successfully. In contrast, the wrist-worn device was used in women with either no or mild cognitive impairment (MCI), completion rates were higher (100%), and women reported being able to administer the device independently. These studies demonstrated that home-based self-administered assessments of SDB are feasible in older adults with and without cognitive impairment using wrist-worn oximetry. These data support the feasibility of using simple oximetry measurements to provide indices of overnight intermittent hypoxemia in large observational studies and clinical trials.

Early steps towards the multi-parametric and computerized sleep scoring methodology for extreme environments

Early steps towards the multi-parametric and computerized sleep scoring methodology for extreme environments

Sleep-disordered Breathing in Cardiac Rehabilitation: Prevalence, Predictors, and Influence on the Six-Minute Walk Test

Identification of non-traditional risk factors is an important component of cardiac rehabilitation (CR). However, the prevalence and predictors of sleep-disordered breathing (SDB) and its influence on exercise performance in patients attending CR remain poorly described. Patients enrolled in a national CR centre were eligible for a comprehensive SDB screening program. Screening questionnaires for SDB, overnight sleep study, and the 6-minute walk test (6MWT) were conducted. We recruited 332 patients (mean age 62±10 years, 62.4% male) attending CR for primary (29.2%) or secondary (70.8%) prevention, of which 209 successfully completed the overnight sleep study. Sleep-disordered breathing group patients (n=68, 32.5%) were older and had a higher body mass index (BMI) and neck and waist circumferences than the non-SDB group patients. After adjusting for neck and waist circumference, age (OR=1.06; 95% CI 1.02-1.10; p=0.001) and BMI (OR=1.19; 95% CI 1.10-1.30; p<0.001) remained independent predictors of SDB. A high risk of SDB based on the Berlin Questionnaire (43.4% versus 35.5%, p=0.277) or STOP-BANG questionnaire (63.2% versus 53.2%, p=0.170) and excessive daytime sleepiness (Epworth Sleepiness Scale >10, 23.9% versus 17.7%, p=0.297) were similar between the groups. The 6MWT scores were significantly lower in the SDB than non-SDB group (mean difference -32 m; 95% CI -57-7; p=0.013). The relationship was no longer significant after adjusting for age, sex, and waist circumference. Sleep-disordered breathing is prevalent in CR patients and is independently predicted by ageing and obesity. The association between SDB and poorer exercise performance may be explained by age, sex, and waist circumference.

Delayed benefit of naps on motor learning in preschool children.

Sleep benefits memory consolidation across a variety of domains in young adults. However, while declarative memories benefit from sleep in young children, such improvements are not consistently seen for procedural skill learning. Here we examined whether performance improvements on a procedural task, although not immediately observed, are evident after a longer delay when augmented by overnight sleep (24h after learning). We trained 47 children, aged 33-71months, on a serial reaction time task and, using a within-subject design, evaluated performance at three time points: immediately after learning, after a daytime nap (nap condition) or equivalent wake opportunity (wake condition), and 24h after learning. Consistent with previous studies, performance improvements following the nap did not differ from performance improvements following an equivalent interval spent awake. However, significant benefits of the nap were found when performance was assessed 24h after learning. This research demonstrates that motor skill learning is benefited by sleep, but that this benefit is only evident after an extended period of time.

Clinical Correlates of Sleep-Disordered Breathing and Nocturnal Hypoxemia in Sickle Cell Disease

Cardiopulmonary complications are the major cause of morbidity and mortality in sickle cell disease (SCD). In the general population, obstructive sleep apnea (OSA), has been associated with daytime sleepiness and increased risk for all-cause morbidity and mortality due to cardiovascular disease, systemic hypertension, pulmonary hypertension, and stroke-all of which are complications of SCD. Multiple small cohort studies have demonstrated that sleep-disordered breathing (SDB) is common among children and adolescents with SCD, but we do not understand the risk factors and clinical consequences of SDB in this population. Additionally, the prevalence of SDB in adults with SCD is unknown. We hypothesized that SDB and nocturnal hypoxemia are common across the lifespan in SCD and that the clinical presentation of SDB among SCD patients may be different from the general population without SCD. We performed a retrospective chart review of the overnight sleep studies performed at Boston Medical Center to gain greater understanding of the risk factors and clinical correlates of SDB in this population. We identified 29 patients with SCD who had a full polysomnogram for clinical purposes between 2012-2015. We obtained medical histories and steady state laboratory test results on these patients. Symptoms of SDB were assessed via the Epworth Sleepiness Scale (ESS). We evaluated the sleep studies for apneas, hypopneas, snoring, and the degree of hypoxemia. Data were analyzed using SAS, version 9.3. The 29 patients had a median age of 15.3 years (range 4 to 60), 66% were male, 43% were overweight or obese, and 86% had either the HbSS or HbSβ0 genotype 82% of these patients had at least one prior episode of the acute chest syndrome and 46% carried a diagnosis of asthma. Overall, the group had a median hemoglobin concentration of 9.7 (range 6.1-13.3) g/dL and median reticulocyte percentage of 7.3% (range 2.8-23.3%). 28% of the subjects had elevated scores on the ESS reflective of increased daytime sleepiness. Moderate to severe snoring, typically associated with OSA in the general population, was observed in 35% of patients. However, 48% of our patients met diagnostic criteria for OSA (defined as an apnea/hypopnea index [AHI] > 5), suggesting that a history of snoring may not be a sensitive marker to identify OSA risk in this population. Additionally, 17% of patients were considered to have nocturnal hypoxemia defined as greater than 5% of total sleep time with an oxygen saturation below 90%; this included 13% of those with OSA and 21% of those without OSA (p=0.65). In total, 38% of SCD patients referred for a sleep study had neither OSA nor nocturnal hypoxemia.Comparing the adults (n=14) and children (n=15) showed some differences across the lifespan. AHI and ESS scores were significantly higher in adults, while the resting oxygen saturation was lower. HbSS or HbSβ0 patients typically had lower BMIs but similar findings on sleep studies compared to those with HbSC disease. Those with moderate to severe OSA were older (p=0.006), more likely to be overweight or obese and had both significantly higher hemoglobin concentrations (p=0.04) and lower reticulocyte counts (p=0.03) compared to those without moderate-severe OSA. Nocturnal hypoxemia was associated with a history of asthma (p=0.01), an increased reticulocyte percentage (p=0.005) and white blood cell count (p=0.006), and a reduced awake oxygen saturation (p=0.002) compared to those without significant nocturnal hypoxemia. Interestingly, increased age, BMI, or ESS scores were not associated with nocturnal hypoxemia.Results from this small retrospective cohort study suggest that SDB in SCD is more complex than in the general population. SDB in SCD is common and not solely due to OSA. Additionally, traditional risk factors for OSA such as snoring and daytime sleepiness may not be present in SCD patients who have polysomnographic abnormalities. While this study needs to be confirmed with a larger prospective screening study, our findings suggest that intermittent nocturnal hypoxemia is potentially a modifiable cardiovascular risk factor in SCD. DisclosuresKlings:Pfizer: Consultancy; Actelion Pharmaceuticals: Research Funding.

Correlation between upper airway obstruction sites during sleep video fluoroscopy and natural overnight sleep

Correlation between upper airway obstruction sites during sleep video fluoroscopy and natural overnight sleep

Should you Sleep on it? The Effects of Overnight Sleep on Subjective Preference‐based Choice

AbstractConventional wisdom and studies of unconscious processing suggest that sleeping on a choice may improve decision making. Although sleep has been shown to benefit several cognitive tasks, including problem solving, its impact on everyday choices remains unclear. Here we explore the effects of ‘sleeping on it’ on preference‐based decisions among multiple options. In two studies, individuals viewed several attributes describing a set of items and were asked to select their preferred item after a 12‐hour interval that either contained sleep or was spent fully awake. After an overnight period including sleep, individuals showed increases in positive perceptions of the choice set. This finding contrasts with previous research showing that sleep selectively enhances recall for negative information. In addition, this increase in positive recall did not translate into a greater desire to purchase their preferred item or into an overall benefit for choice satisfaction. Time‐of‐day controls were used to confirm that the observed effects could not be explained by circadian influences. Thus, we show that people may feel more positive about the choice options but not more confident about the choice after ‘sleeping on’ a subjective decision. We discuss how the valence of recalled choice set information may be important in understanding the effects of sleep on multi‐attribute decision making and suggest several avenues for future research. Copyright © 2015 John Wiley &amp; Sons, Ltd.

Heightened Delta Power during Slow-Wave-Sleep in Patients with Rett Syndrome Associated with Poor Sleep Efficiency.

Sleep problems are commonly reported in Rett syndrome (RTT); however the electroencephalographic (EEG) biomarkers underlying sleep dysfunction are poorly understood. The aim of this study was to analyze the temporal evolution of quantitative EEG (qEEG) biomarkers in overnight EEGs recorded from girls (2–9 yrs. old) diagnosed with RTT using a non-traditional automated protocol. In this study, EEG spectral analysis identified high delta power cycles representing slow wave sleep (SWS) in 8–9h overnight sleep EEGs from the frontal, central and occipital leads (AP axis), comparing age-matched girls with and without RTT. Automated algorithms quantitated the area under the curve (AUC) within identified SWS cycles for each spectral frequency wave form. Both age-matched RTT and control EEGs showed similar increasing trends for recorded delta wave power in the EEG leads along the antero-posterior (AP). RTT EEGs had significantly fewer numbers of SWS sleep cycles; therefore, the overall time spent in SWS was also significantly lower in RTT. In contrast, the AUC for delta power within each SWS cycle was significantly heightened in RTT and remained heightened over consecutive cycles unlike control EEGs that showed an overnight decrement of delta power in consecutive cycles. Gamma wave power associated with these SWS cycles was similar to controls. However, the negative correlation of gamma power with age (r = -.59; p<0.01) detected in controls (2–5 yrs. vs. 6–9 yrs.) was lost in RTT. Poor % SWS (i.e., time spent in SWS overnight) in RTT was also driven by the younger age-group. Incidence of seizures in RTT was associated with significantly lower number of SWS cycles. Therefore, qEEG biomarkers of SWS in RTT evolved temporally and correlated significantly with clinical severity.