Sleep-disordered breathing in preschool children is associated with behavioral, but not cognitive, impairments

BackgroundSleep-disordered breathing (SDB) has been associated with impaired cognitive and behavioral function in school children; however, there have been limited studies in preschool children when the incidence of the disorder peaks. Thus, the aim of this study was to compare cognitive and behavioral functions of preschool children with SDB to those of non-snoring control children.MethodsA clinical sample of 3–5 year-old children (primary snoring [PS], n = 60; mild obstructive sleep apnea syndrome [OSAS], n = 32; moderate/severe [MS] OSAS, n = 24) and a community sample of non-snoring control children (n = 37) were studied with overnight polysomnography. Cognitive performance and behavioral information were collected.ResultsChildren with PS and mild OSAS had poorer behavior than controls on numerous measures (p < .05–p < .001), and on some measures they had poorer behavior than the MS OSAS group (p < .05). In contrast, all groups performed similarly on cognitive assessment. Outcomes related more to sleep than respiratory measures.ConclusionsSDB of any severity was associated with poorer behavior but not cognitive performance. The lack of significant cognitive impairment in this age group may have identified a “window of opportunity” where early treatment may prevent deficits arising later in childhood.     

Sleep architecture in school-aged children with primary snoring

ObjectiveWe aimed to examine if sleep architecture was altered in school-aged children with primary snoring (PS).MethodsChildren ages 6 to 13 years from 13 primary schools were randomly recruited. A validated obstructive sleep apnea (OSA) screening questionnaire was completed by their parents. Children at high risk for OSA and a randomly chosen low-risk group were invited to undergo overnight polysomnography (PSG) and clinical examination. Participants were classified into healthy controls, PS, mild OSA, and moderate to severe OSA (MS OSA) groups for comparison.ResultsA total of 619 participants underwent PSG (mean age, 10.0 ± 1.8 years; 396 (64.0%) boys; 524 (84.7%) prepubertal). For the cohort as a whole, there were no significant differences in measures of sleep architecture between PS and nonsnoring healthy controls. In the multiple regression model, percentage of nonrapid eye movement (NREM) stage 1 (N1) sleep had a significantly positive association, whereas percentage of slow-wave sleep (SWS) had a significantly negative association with sleep-disordered breathing (SDB) severity after controlling for age, gender, body mass index (BMI) z score, and pubertal status. In prepubertal children with PS, no significant disruption of sleep architecture was found. However, pubertal adolescent PS participants had significantly higher adjusted percentage of N1 sleep and wake after sleep onset (WASO) compared to healthy controls.ConclusionsPS did not exert significant adverse influences on normal sleep architecture in prepubertal school-aged children. Nevertheless, pubertal adolescents with PS had increased N1 sleep and WASO.     

A WASO sub-group analysis of a 6-month study of eszopiclone 3 mg

BackgroundInsomnia marked by sleep maintenance difficulty is extremely prevalent. Yet, problems staying asleep have been relatively neglected as a research focus compared to problems falling asleep. Insomnia treatment studies typically have not required participants to have a problem specifically with sleep maintenance. It is possible that exclusion of such subjects limits the detection of treatment effects in the overall trial in general, and of effects on sleep maintenance specifically. In order to address these issues we conducted a post hoc analysis of a 6-month placebo-controlled trial in which there were no inclusion criteria that specified sleep maintenance difficulties to assess the variable effects of baseline wake time after sleep onset (WASO – the primary maintenance measure) on the efficacy of eszopiclone 3 mg.MethodsPatients diagnosed with chronic primary insomnia were randomized to eszopiclone 3 mg (n = 593) or placebo (n = 195) nightly for six months. The present analyses of this study consisted of: (1) determination of the distribution of baseline WASO; (2) continuous analysis of the relationship between baseline WASO severity and drug-placebo difference at month 1 and 6; and (3) categorical efficacy analyses of subgroups delimited by the following WASO thresholds: 0, 30, 45, 60, and 90 min.ResultsThe baseline WASO distribution was: ?30 = 32.2%; >0 to ?45 = 41.5%; >30 to ?90 = 33.0%; >45 to ?90 = 23.7%; >90 = 22.6%. A relationship between greater baseline WASO severity and a significantly greater drug-placebo difference in efficacy for WASO was evident in both continuous and categorical analyses. Eszopiclone was found to have significant sleep maintenance efficacy at each time point across the entire range of WASO severity studied.ConclusionsAs illustrated in this analysis, a significant proportion of chronic insomnia patients in efficacy trials that select on the basis of sleep onset latency and total sleep time criteria may have normative-range WASO. However, even in the subgroup with minimal WASO there was a significant sleep maintenance effect. The absence of any sleep maintenance effect in a drug trial may reflect the inclusion of relatively many insomnia patients with no baseline WASO abnormality. However, treatments with therapeutic effects on sleep maintenance, can still demonstrate improvement in sleep maintenance, even in a population not selected for this type of sleep problem, if adequately powered. Future clinical trials intending to examine sleep maintenance should employ WASO selection criteria that would ensure sufficient power to detect a sleep maintenance effect. Drug-placebo difference increased as a function of baseline WASO severity, suggesting that eszopiclone’s clinical effectiveness for insomnia may be enhanced in patients with more severe sleep maintenance symptoms.     

Sleep-disordered breathing does not affect nocturnal dipping,as assessed by pulse transit time,in preschool children: evidence for early intervention to prevent adverse cardiovascular effects?

ObjectiveSleep-disordered breathing (SDB) is associated with reduced nocturnal dipping of blood pressure (BP) and sleep disruption in adults, and these features confer an increased risk of cardiovascular events. As SDB prevalence in children peaks during the preschool years, we investigated nocturnal dipping and sleep fragmentation in preschool children with SDB.MethodsChildren (3–5 years; n = 163) grouped by obstructive apnoea hypopnoea index (OAHI): control, no snoring history and OAHI ⩽1 event/h; primary snoring, OAHI ⩽1 event/h; mild SDB, >1–⩽5 events/h; moderate–severe SDB, >5 events/h. Pulse transit time (PTT), an inverse continuous indicator of BP changes, and heart rate (HR) during total sleep time and the first period of rapid eye movement (REM), non-REM (NREM)1/2 and NREM3/4 sleep were expressed as percentage change from wake before sleep onset. The sleep fragmentation index (SFI) was calculated as the number of sleep stage transitions or awakenings per hour of sleep.ResultsThere were no group differences in the change in PTT or HR from wake to total sleep time or to individual sleep stages or in the proportion of children in the quartile with the smallest change in PTT during total sleep. Children with moderate–severe SDB had higher SFI than primary snoring (PS) or mild SDB groups (p < 0.05 for both) and controls (p = 0.07).ConclusionsIn contrast to adults, nocturnal dipping is preserved in young children with SDB, despite increased sleep fragmentation. As there is evidence that nocturnal dipping is similarly preserved at the school age, childhood may pose a window of opportunity for resolution of SDB when the cardiovascular effects are less marked.     

Time course of EEG slow-wave activity in pre-school children with sleep disordered breathing: A possible mechanism for daytime deficits?

BackgroundDaytime deficits in children with sleep disordered breathing (SDB) are theorized to result from hypoxic insult to the developing brain or fragmented sleep. Yet, these do not explain why deficits occur in primary snorers (PS). The time course of slow wave EEG activity (SWA), a proxy of homeostatic regulation and cortical maturation, may provide insight.MethodsClinical and control subjects (N = 175: mean age 4.3 ± 0.9 y: 61% male) participated in overnight polysomnography (PSG). Standard sleep scoring and power spectral analyses were conducted on EEG (C4/A1; 0.5–<3.9 Hz). Univariate ANOVA’s evaluated group differences in sleep stages and respiratory parameters. Repeated-measures ANCOVA evaluated group differences in the time course of SWA.ResultsFour groups were classified: controls (OAHI ? 1 event/h; no clinical history); PS (OAHI ? 1 event/h; clinical history); mild OSA (OAHI=1–5 events/h); and moderate to severe OSA (MS OSA: OAHI > 5 events/h). Group differences were found in the percentage of time spent in NREM Stages 1 and 4 (p < 0.001) and in the time course of SWA. PS and Mild OSA children had higher SWA in the first NREM period than controls (p < 0.05). All SDB groups had higher SWA in the fourth NREM period (p < 0.01).ConclusionsThese results suggest enhanced sleep pressure but impaired restorative sleep function in pre-school children with SDB, providing new insights into the possible mechanism for daytime deficits observed in all severities of SDB.     

A four year follow-up of sleep and respiratory measures in elementary school-aged children with sleep disordered breathing

ObjectiveLittle is known of the long-term prognosis of children treated for sleep disordered breathing (SDB) and even less of children with milder forms of SDB who remain untreated. We aimed to investigate the long-term sleep and respiratory outcomes of children with a range of SDB severities.Methods41 children with SDB and 20 non snoring controls (mean age, 12.9 ± 0.2 y), underwent repeat overnight polysomnography (PSG) 4.0 ± 0.3 years after initial diagnosis. SDB severity, presence of snoring, sleep and respiratory parameters, sleep fragmentation index (SFI), the Pediatric Daytime Sleepiness Scale (PDSS), Sleep Disturbance Scale for Children (SDSC), and obstructive sleep apnea 18-item quality of life questionnaire were re assessed. Children with SDB were grouped into resolved (no snoring and obstructive apnea–hypopnea index [OAHI] <1) and unresolved (snoring or an OAHI ⩾1).ResultsAt follow-up OAHI was reduced in both SDB groups (p < 0.05); however, 54% (n = 22) of children still continued to snore, having either persistent or new OSA (n = 4). In this unresolved group, sleep was significantly disrupted; % nonrapid eye movement stage 1 (NREM1) sleep and SFI were increased (p < 0.05), and total sleep time (TST) and sleep efficiency were decreased compared to the resolved and control groups (p < 0.05). Overall, 29% of children were treated, and of these, 67% had resolved SDB. SDB groups had higher PDSS, SDSC, and OSA-18 scores compared to controls at follow-up (p < 0.01).ConclusionsOur study demonstrated that although SDB improved in the long-term, more than 50% of children had residual SDB (mostly primary snoring) and sleep disturbance. As even mild forms of SDB are known to have adverse cardiovascular, learning, and behavioral outcomes, which have implications for the health of these children.     

Sleep disordered breathing in patients with primary Sjögren's syndrome: A group controlled study

ObjectivePatients with primary Sjögren’s syndrome (pSS) have higher fatigue levels and also suffer from excessive day time sleepiness. The underlying mechanisms for this are not fully understood. Knowing that these patients have higher salivary surface tension, we postulated that sleep disordered breathing (SDB) would be more common and would be a contributor to these symptoms amongst pSS patients. We investigated the prevalence of SDB in pSS patients and its relationship to their symptoms of fatigue and excessive daytime sleepiness.MethodsThis was an observational study of 28 pSS patients (mean ± SEM age, 58.7 ± 1.9) and 18 healthy subjects (mean ± SEM age, 55.8 ± 3.4) matched for age, sex, and BMI. All the participants underwent an overnight polysomnography. The two groups were compared for fatigue, sleepiness, anxiety, and depression scores, and for the frequency of obstructive apneas and hypopneas during sleep. Correlation analyses were used to explore relationships between sleep study variables and excess sleepiness and fatigue.ResultsFatigue, sleepiness, anxiety and depression symptoms, and sleep onset latency were significantly greater in pSS patients than controls. pSS patients had twice the frequency of obstructive apneas and hypopneas compared with control subjects (median[IQR],18.6/h [10.4–40.1] vs. 9.9/h [6.5–23.4]; p = 0.032) and OSA defined as an apnea–hypopnea index >15 events/h of sleep was more prevalent amongst pSS patients than controls (64% vs. 28%; p = 0.033). While no significant correlations were found between parameters of sleep disordered breathing and sleepiness scores or fatigue scores in the pSS group, CPAP treatment in a small subset of the pSS who were more severely affected by OSA suggested significant symptomatic benefit.ConclusionOSA appears to be increased in pSS and may be a useful therapeutic target to improve the quality of life of these patients.     

Sleep disordered breathing in an elderly community-living population: Relationship to cardiac function, insomnia symptoms and daytime sleepiness

ObjectiveTo describe the prevalence of sleep disordered breathing (SDB) and its relationship to systolic function, different insomnia symptoms as well as excessive daytime sleepiness (EDS) in elderly community-living people. This has not been investigated previously.MethodThree hundred thirty-one subjects (71–87 years) healthy enough to be independently living in their own homes underwent echocardiographic examinations and sleep respiratory recordings. Questionnaires were used to evaluate insomnia symptoms and EDS.ResultsMild SDB (AHI 5–15) was found in 32%. Moderate SDB (AHI 15–30) occurred in 16%, and 7% had severe SDB (AHI > 30). Median AHI was significantly higher (p < 0.001) in those with mildly impaired systolic function (AHI 11.7) and moderately impaired systolic function (AHI 10.9) compared to those with normal systolic function (AHI 5.0). Impaired systolic function was associated with central sleep apnea (CSA) but not with obstructive sleep apnea. Concerning insomnia symptoms and EDS, only difficulties in initiating sleep correlated significantly (p < 0.05) with AHI.ConclusionSDB is common among the elderly. CSA may be related to impaired systolic function/heart failure. However, detection of SDB in this population may be problematic since insomnia symptoms and EDS correlated poorly with SDB.     

Predictors of sleep-disordered breathing in obese adults who are chronic short sleepers

BackgroundSleep disordered breathing (SDB) is common in obese adults, but not all obese adults have SDB. The aim of these analyses was to determine what predicted SDB in a sample of obese adults.MethodsWe conducted cross-sectional analysis of 139 obese men and women aged 18–50 years who are chronic short sleepers. Habitual sleep duration and sleep efficiency were estimated using two weeks of wrist actigraphy. Respiratory disturbance index (RDI) was assessed by a portable screening device. SDB was defined as RDI ? 15 events h^?1. Subjective sleep quality, sleepiness, and sociodemographic characteristics were evaluated by questionnaires.ResultsIncreased sleep duration from actigraphy was associated with reduced odds of SDB (OR 0.44 per hour, p = 0.043). Neither subjective sleep quality nor sleepiness was associated with SDB. Male sex, older age, and increased waist circumference were associated with increased odds of SDB.ConclusionsIn this sample of obese adults, subjective measures of sleep quality and sleepiness were not indicators of SDB. These results suggest that, in obese patients, physicians should not rely on subjective measures to determine who should be referred for a clinical sleep study. A wider use of portable apnea screening devices should be considered in nonsymptomatic, non-Hispanic white males.     

Psychometric properties of an omnibus sleep problems questionnaire for school-aged children

ObjectiveThere is a paucity of sleep questionnaires that have been psychometrically validated for use in school-aged children. Due to the limitation regarding the psychometric properties and the great variety in question design, there remains a need for a robust omnibus questionnaire that assesses sleep problems in community populations. This study aimed to develop such a questionnaire for school-aged children by assessing the construct validity and reliability of a questionnaire based on a combination of children’s sleep domains from two frequently used and validated questionnaires (Habits Questionnaire and Sleep Disorders Scale for Children) and author devised questions.Patients/methodsParents of 1904 children aged 5–10 years (mean 7.7 ± 1.7 years) from 32 elementary schools in Adelaide, South Australia, completed the questionnaire.ResultsPrincipal axis factoring revealed six unique sub-scales – Sleep Routine, Bedtime Anxiety, Morning Tiredness, Night Arousals, Sleep Disordered Breathing, and Restless Sleep – containing a total of 26 items. Internal consistency for sub-scales were moderate to strong (range α = 0.6–0.8) and test–retest reliability was adequate (>0.4). T-score cut-offs were devised for age and sex.ConclusionThe new questionnaire provides a robust set of sleep problem sub-scales which can be used for assessment of sleep concerns in a community sample as well as provide for optimal analysis of associations with other measures of childhood daytime functioning such as neurocognition and behaviour.     

Snoring and witnessed sleep apnea is related to diabetes mellitus in women

BackgroundGender differences in the relationship of snoring and diabetes mellitus are mainly unknown. We aimed to analyze the relationship between snoring, witnessed sleep apnea and diabetes mellitus and to analyze possible gender related differences in an unselected population.MethodsQuestions on snoring and witnessed sleep apneas were included in the Northern Sweden component of the WHO, MONICA study. Invited were 10,756 men and women aged 25–79 years, randomly selected from the population register.ResultsThere were 7905 (73%) subjects, 4047 women and 3858 men who responded to the questionnaire and attended a visit for a physical examination. Habitual snoring was related to diabetes mellitus in women, with an adjusted odds ratio (OR) = 1.58 (95% confidence interval (CI) 1.02–2.44, p = 0.041) independent of smoking, age, body mass index and waist circumference. Witnessed sleep apnea was also independently related to diabetes mellitus in women, with an adjusted OR = 3.29 (95% CI 1.20–8.32, p = 0.012). Neither snoring, nor witnessed sleep apneas were associated with diabetes mellitus among men, except for witnessed sleep apnea in men aged 25–54 years old. They had an adjusted OR = 3.84 (95% CI 1.36–10.9, p = 0.011) for diabetes mellitus.ConclusionsSnoring and witnessed sleep apneas are related to diabetes mellitus in women. Witnessed sleep apnea is related to diabetes mellitus in men younger than 55 years old.     

The discrepancy between actigraphic and sleep diary measures of sleep in adolescents

ObjectiveTo explore the discrepancy between sleep diary and actigraphic measures of sleep in adolescents and to ascertain whether these discrepancies may vary according to characteristics of the participant.MethodsParticipants were 385 adolescents aged 13–18 years (X = 15.6, standard deviation [SD] = 0.95; 60% male) from eight high schools in South Australia. Adolescents completed the School Sleep Habits Survey and Pediatric Daytime Sleepiness Scale during class time, followed by an 8-day sleep diary and wrist actigraphy. The Flinders Fatigue Scale was completed on the final day of the study. Parents completed a sleep, medical, education, and family history survey.ResultsActigraphic estimates of wake after sleep onset (WASO) were substantially greater than sleep diary estimates (74 min actigraphy vs. 7 min sleep diary) and actigraphic estimates of total sleep time were substantially less than sleep diary and parent report (6 h 51 min actigraphy vs. 8 h 16 min sleep diary vs. 8 h 51 parent report). Actigraphy displayed no significant relationship with daytime functioning and weak relationships with concomitantly recorded sleep diary variables. Sex and puberty-related differences in actigraphic scoring were found, with more WASO and less sleep scored in boys compared to girls and more WASO scored amongst pubertally-mature boys than boys of less advanced pubertal development.ConclusionsThere may be differences in the sleep of adolescents that result in less actigraphic total sleep scored than perceived, particularly in boys, possibly because of increased sleep motor activity in adolescents that actigraphic algorithms score as wake. This is a significant concern that requires further examination with polysomnography.     

Modeling caffeine concentrations with the Stanford Caffeine Questionnaire: preliminary evidence for an interaction of chronotype with the effects of caffeine on sleep

ObjectiveTo examine the validity of a novel caffeine intake questionnaire and to examine the effects of caffeine on sleep in college students.MethodsOne-week, ad libitum behavior of 50 university students (28 female, 22 male; aged 20.9 ± 1.78 years) was examined with sleep logs, wrist actigraphy, and a novel daily questionnaire assessing caffeine intake at different times of day. Saliva samples were collected for caffeine assessment (questionnaire validation) and DNA extraction, and for analysis of a single nucleotide polymorphism in the adenosine receptor 2A (ADORA2A) gene.ResultsThe caffeine questionnaire was able to accurately predict salivary concentrations of caffeine (R² = 0.41, P < 0.001). Estimations of integrated salivary caffeine concentration during sleep were correlated with wake after sleep onset (WASO) most strongly in morning-type individuals (R² = 0.49; P < 0.001, ANOVA), less so in intermediate chronotypes (R² = 0.16; P < 0.001, ANOVA), and not significantly in evening-types (R² = 0.00098; P = 0.13, ANOVA). Using multivariate modeling methods we found that the ADORA2A genotype did not moderate the effects of caffeine on WASO, but did independently alter WASO such that those with the CC genotype had nearly three-times as much WASO as those with CT or TT.ConclusionsOur questionnaire was able to accurately predict salivary caffeine concentrations and helped to describe a novel relationship between the effects of caffeine on sleep and genotype and chronotype.     

Improvement of sleep-disordered breathing in children is associated with a reduction in overnight blood pressure

ObjectiveChildhood sleep-disordered breathing (SDB) is associated with elevated blood pressure (BP); however, little is known about the long-term outcomes in this population. We aimed to assess long-term changes in overnight BP in children with SDB.MethodsForty children with previously diagnosed SDB and 20 nonsnoring control participants underwent repeat overnight polysomnography (PSG) with continuous BP measurement 4 years after the original diagnosis. At follow-up, children aged 11–16 years were categorized into 2 groups of resolved (absence of snoring and obstructive apnea–hypopnea index [OAHI]⩽1) or unresolved (continued to snore or had an OAHI >1) SDB.ResultsThere were no group differences in age, sex, or body mass index (BMI) z score. OAHI was lower at follow-up (P < .05) in both the resolved (n = 18) and unresolved (n = 22) groups. BP was elevated during wake and sleep in both SDB groups compared to the control group at baseline (P < .01 for all), but it decreased by 5–15 mmHg at follow-up during sleep for both SDB groups (P < .05 for all). BP during wake was unchanged in the SDB groups at follow-up but increased in the control group (P < .05). At follow-up, BP did not differ between the control group and the SDB groups during wake or sleep. Improved oxygen saturation (SpO₂) during sleep was a significant predictor of a reduction in BP.ConclusionsSDB improved over the 4-year follow-up and both resolved and unresolved groups exhibited a significant reduction in BP during sleep, with levels similar to the control group. Our study highlights the fact that even small improvements can improve the cardiovascular effects of SDB.     

Snoring men with daytime sleepiness drive more than others: A population-based study

ObjectiveTo investigate whether subjects with daytime sleepiness who snore or report witnessed sleep apneas drive more than others.MethodsQuestions on snoring, witnessed sleep apnea, excessive daytime sleepiness and driving distance per year were included in the Northern Sweden component of the WHO, MONICA study. Invited were 10756 subjects aged 25–79 years, randomly selected from the population register.ResultsThere were 7905 (73%) subjects, 3858 men and 4047 women who responded to the questionnaire and attended a visit for a physical examination. Habitually snoring men with daytime sleepiness drove a mean of 22566 (95% CI 18550–26582) km a year, which was significantly more than non-snoring men without excessive daytime sleepiness who drove 17751 (95% CI 17076–18427) km a year, p = 0.02, after adjustments for age, body mass index, smoking and physical activity. Men reporting witnessed sleep apnea and excessive daytime sleepiness also drove more than their counterparts in adjusted analysis, p = 0.01. Women reporting daytime sleepiness and witnessed apnea tended to drive more, while snoring women with daytime sleepiness did not.ConclusionsMen suffering from excessive daytime sleepiness who snore habitually or report witnessed sleep apneas drive significantly more than others.     

The sleep macroarchitecture of children at risk for depression recruited in sleep centers

ObjectiveThe primary aim of this study was to compare the sleep macroarchitecture of children and adolescents whose mothers have a history of depression with children and adolescents whose mothers do not.MethodPolysomnography (PSG) and Holter electroencephalogram (EEG) were used to compare the sleep architecture of 35 children whose mothers had at least one previous depressive episode (19 boys, aged 4–18 years, “high-risk” group) and 25 controls (13 males, aged 4–18 years, “low-risk” group) whose mothers had never had a depressive episode. The total sleep time, wakefulness after sleep onset (WASO), sleep latency, sleep efficiency, number of awakenings per hour of sleep, percentages of time spent in each sleep stage, rapid eye movement (REM) latency and the depressive symptoms of participants were measured.ResultsIn children (4–12 years old), the high-risk group exhibited significantly more depressive symptoms than controls (P = 0.02). However, PSG parameters were not significantly different between high-risk children and controls. In adolescents (13–18 years old), the high-risk subjects presented with significantly more depressive symptoms (P = 0.003), a significant increase in WASO (P = 0.019) and a significant decrease in sleep efficiency compared to controls (P = 0.009).ConclusionThis study shows that children and adolescents born from mothers with a history of at least one depressive episode had significantly more depressive symptoms than controls. However, only high-risk adolescents presented with concurrent alterations of sleep macroarchitecture.     

REM and NREM sleep-state distribution of respiratory events in habitually snoring school-aged community children

BackgroundStudies ascribe different functions to rapid eye movement (REM) and non-rapid eye movement (NREM) sleep, such that their disruption could result in discrepant clinical outcomes. Although sleep architecture is globally preserved in children with obstructive sleep apnoea (OSA), it is considered to be an REM sleep REMS disorder. Furthermore, body position during sleep affects the occurrence of respiratory events, while the presence of obesity has been claimed to affect sleep-state distribution of respiratory disturbance.MethodsTo explore the distribution of respiratory events during REMS and NREM sleep NREMS and its potential predictors, a cross-sectional analysis of 335 overnight sleep studies in snoring children from the community was conducted. The ratio of REMS to NREMS respiratory events was compared, and potential associations were assessed using general linear modelling (GLM).ResultsChildren were 7.3 ± 1.2 years old and had a body mass index (BMI) z-score of 1.0 ± 1.3. The obstructive apnoea–hypopnea index (OAHI) was 1.7 ± 3 and 45.8% of children had an apnoea–hypopnea index (AHI) >1 h^?1 total sleep time (TST). Obstructive respiratory events were 3.8 times more likely in REMS (2.0 h^?1) than NREMS (0.5 h^?1), and the GLM revealed distinctive predictive associations for the apnoeic and hypopneic indices separately, and for body position, the latter indicating that the REMS/NREMS distribution of respiratory events depends on body position.ConclusionObstructive respiratory events are predominantly, albeit not exclusively, present in REMS in school-aged children. NREMS respiratory events are more likely in the presence of lower oxyhaemoglobin saturations during event, side body position and in African–American children. However, REMS dominance is not affected by either BMI z-score or obesity. Our findings suggest that incorporating comprehensive respiratory event profiles of children may enhance our understanding of the pathophysiology and adverse outcomes in the context of paediatric OSA.     

Sleep instability and cognitive status in drug-resistant epilepsies

ObjectiveThe aims of this study were to evaluate the sleep habits of children with drug resistant epilepsy and to correlate sleep abnormalities with epilepsy and level of intelligence.Subjects and methodsTwenty five subjects with drug resistant epilepsy (14 males, age range 2–16.4 years) were recruited for this study. A control group was formed by 23 normal children. Two instruments to assess sleep habits were administered to the patients with epilepsy: a questionnaire on sleep habits (to preschool children) and a questionnaire on sleep behavior (for children aged more than seven years old); a cognitive test (Wechsler Intelligence Scale for Children-WISC) was also performed. Patients underwent a complete polysomnographic study and sleep parameters, including CAP, were analyzed and correlated according to cognitive-behavioral measures in children with epilepsy.ResultsChildren with drug-resistant epilepsy and severe mental retardation showed sleep abnormalities such as low sleep efficiency, high percentage of wakefulness after sleep onset, reduced slow wave sleep, and reduced REM sleep. Sleep microstructure evaluated by means of CAP analysis showed a decrease in A1 index during N3 in patients with more severe cognitive impairment. Children with epilepsy and cognitive impairment (n = 10) had higher Sleep Behavior Questionnaire for Children (SBQC) total scores (65.60 ± 18.56) compared to children with epilepsy and normal IQ (50.00 ± 10.40), p < 0.05.ConclusionsChildren with drug-resistant epilepsy have a greater incidence of sleep problems regarding qualitative aspects, macrostructure, and CAP. The decrease of CAP rate and of A1, mainly during slow wave sleep (associated to REM sleep reduction), might represent a sleep microstructural pattern of intellectual disability.     

A randomized clinical trial of valerian fails to improve self-reported, polysomnographic, and actigraphic sleep in older women with insomnia

ObjectiveTo test the effects of nightly valerian (Valeriana officinalis) extract to improve sleep of older women with insomnia.MethodsParticipants in this phase 2 randomized, double-blind, crossover controlled trial were 16 older women (mean age = 69.4 ± 8.1 years) with insomnia. Participants took 300 mg of concentrated valerian extract or placebo 30 min before bedtime for 2 weeks. Sleep was assessed in the laboratory by self-report and polysomnography (PSG) at baseline and again at the beginning and end of each treatment phase (total of nine nights in the laboratory) and at home by daily sleep logs and actigraphy.ResultsThere were no statistically significant differences between valerian and placebo after a single dose or after 2 weeks of nightly dosing on any measure of sleep latency, wake after sleep onset (WASO), sleep efficiency, and self-rated sleep quality. In comparing each treatment to baseline in separate comparisons, WASO significantly increased (+17.7 ± 25.6 min, p = .02) after 2 weeks of nightly valerian, but not after placebo (+6.8 ± 26.4 min, NS). Side effects were minor and did not differ significantly between valerian and placebo.ConclusionValerian did not improve sleep in this sample of older women with insomnia. Findings from this study add to the scientific evidence that does not support use of valerian in the clinical management of insomnia.     

Clinical significance of night-to-night sleep variability in insomnia

ObjectivesTo evaluate the clinical relevance of night-to-night variability of sleep schedules and insomnia symptoms.MethodsThe sample consisted of 455 patients (193 men, mean age = 48) seeking treatment for insomnia in a sleep medicine clinic. All participants received group cognitive behavioral therapy for insomnia (CBTI). Variability in sleep parameters was assessed using sleep diary data. Two composite scores were computed, a behavioral schedule composite score (BCS) and insomnia symptom composite score (ICS). The Insomnia Severity Index, the Beck Depression Inventory, and the Morningness–Eveningness Composite Scale were administered at baseline and post-treatment.ResultsResults revealed that greater BCS scores were significantly associated with younger age, eveningness chronotype, and greater depression severity (p < 0.001). Both depression severity and eveningness chronotype independently predicted variability in sleep schedules (p < 0.001). Finally, CBTI resulted in reduced sleep variability for all sleep diary variables except bedtime. Post-treatment symptom reductions in depression severity were greater among those with high versus low baseline BCS scores (p < 0.001).ConclusionsResults suggest that variability in sleep schedules predict reduction in insomnia and depressive severity following group CBTI. Schedule variability may be particularly important to assess and address among patients with high depression symptoms and those with the evening chronotype.