Subthalamic nucleus deep brain stimulation improves sleep in Parkinson's disease patients: a retrospective study and a meta-analysis

BackgroundMost Parkinson's patients suffered from sleep problems. There is increasing evidence that Subthalamic Nucleus Deep Brain Stimulation (STN-DBS) has a positive effect on several sleep parameters, improving overall sleep quality in patients with PD. However, the results are controversial.MethodsWe performed a retrospective study and meta-analysis to assess the Parkinson's disease sleep scale (PDSS) in Parkinson's patients.ResultsWe reviewed our data of patients who underwent STN-DBS, and then extracted five other trials to perform a meta-analysis. The pooled results showed an advantage on post-operative PDSS in both our medical center and pooled results (MD = 20.41, 95% CI = [13.03, 27.79], I² = 61%, P < 0.001). There was a significant difference in Unified Parkinson's Disease Rating Scale (UPDRS)-Ⅲ score between pre and post-operation (MD = −12.59, 95% CI = [−14.70, −10.49], I² = 90%, P < 0.001). What's more, Parkinsonian medication was significantly lower in the post-operative groups after DBS (MD = −314.71, 95% CI = [−468.13, −161.28], I² = 53%, P < 0.001).ConclusionIn the retrospective study and meta-analysis of 6 trials, we found that DBS can significantly increase sleep quality. Furthermore, motor function improved and Parkinsonian medication was significantly decreased postoperatively. The sample size was enough and no further investigations would change the conclusion.     

Effect of partial and total sleep deprivation on serum testosterone in healthy males: a systematic review and meta-analysis

BackgroundCurrently, there is no consensus on the effect of sleep deprivation on male serum testosterone. This systematic review and meta-analysis aimed to determine the association between partial/total sleep deprivation and male serum testosterone level.MethodsThe literature related to sleep deprivation and male serum testosterone in the PubMed, Embase, and Cochrane Library databases were searched from their inception to July 15, 2021. Data were pooled using the Stata 15 software. The results were presented as standard mean differences (SMDs) with their 95% confidence intervals (CIs).ResultsEighteen studies involving 252 men were included in the systematic review and meta-analysis. The findings revealed that short-term partial sleep deprivation had no significant effect on male serum testosterone (SMD = −0.22; 95% CI: −0.5, 0.06; P = 0.13), while total sleep deprivation reduced the male testosterone levels (SMD = −0.64; 95% CI: −0.87, −0.42; P < 0.001). According to the intervention duration of total sleep deprivation, subgroup analysis was conducted by a fixed-effects model. The results revealed that the serum testosterone was significantly decreased after 24 h total sleep deprivation (SMD = − 0.67; 95% CI = − 0.93, −0.42, P < 0.001), as well as 40–48 h total sleep deprivation (SMD = − 0.74; 95% CI = − 1.22, −0.26, P = 0.002).ConclusionsThis meta-analysis revealed that total sleep deprivation (more than or equal to 24 h) reduces the male testosterone levels, while short-term partial sleep deprivation has no significant effect on male serum testosterone. Sleep duration plays a pivotal role in maintaining male serum testosterone levels.     

Association between eveningness preference,socio-behavioral factors,and insomnia symptoms in Korean adolescents

Objective/BackgroundStudies focusing on insomnia in adolescents are relatively scarce compared to those on excessive daytime sleepiness. We aimed to investigate the prevalence of insomnia symptoms and associated factors in Korean high school students.Patients/methodsA total of 8565 students (girls: 4104) were investigated nationwide, across 15 South Korean districts using an online self-report questionnaire. Insomnia symptoms were evaluated using the Global Sleep Assessment Questionnaire. The participants’ mean age was 16.77 ± 0.85 years.ResultsThe prevalence of insomnia symptoms was 39.43% (n = 3377). Logistic regression was used to estimate the odds ratio (OR) of insomnia symptoms associated with sleep characteristics and social behaviors after adjusting for the relevant covariates. Evening preference (OR, 2.51, 95% CI, 2.20–2.86), perception of insufficient sleep (OR, 3.55, 95% CI, 3.11–4.06), snoring usually/always (OR, 1.25; 95% CI, 1.00–1.55), witnessed sleep apnea usually/always (OR, 1.70; 95% CI, 1.17–2.46), increased internet addiction (OR, 1.02; 95% CI, 1.02–1.03), bad sleep environment (OR, 1.77; 95% CI, 1.50–2.10), ≥3 private extra classes (OR, 1.23; 95% CI, 1.01–1.49), often coffee consumption (OR, 1.31; 95% CI, 1.10–1.56), and often nocturnal eating (OR, 1.24; 95% CI, 1.06–1.45) were associated with insomnia symptoms. Evening preference (OR, 3.48; 95% CI, 2.52–4.82) was also associated with insomnia symptoms in the perceived sufficient sleep subgroup.ConclusionInsomnia symptoms were common in Korean high school students. Evening preference was the major factor associated with insomnia symptoms. Various socio-behavioral factors were also associated with insomnia symptoms.     

A meta-analysis of the relationship between subjective sleep and depressive symptoms in adolescence

BackgroundAdolescence is a risk period for the development of mental illness, as well as a time for pronounced change in sleep behaviour. While prior studies, including several meta-analyses show a relationship between sleep and depressive symptoms, there were many inconsistences found in the literature.ObjectiveTo investigate the relationship between subjective sleep and depressive symptoms.MethodsFollowing PRISMA guidelines, we conducted a literature search that yielded forty-nine recent studies (2014–2020) with adolescent samples aged 9 to 25-year-olds, and more than double the sample size of previous meta-analyses (N = 318,256).ResultsIn a series of meta-analyses, we show that while several common categories of subjective sleep are associated with depressive symptoms in adolescents, the strength of this relationship varies. Measures of sleep perception: poor sleep quality (r = 0.41), insomnia (r = 0.37), sleep disturbances (r = 0.36), wake after sleep onset (r = 0.31), and daytime sleepiness (r = 0.30) correlated more strongly with depressive symptoms, than measures of sleep behaviour: sleep latency (r = 0.22), and sleep duration (r = −0.19).ConclusionsThese findings suggest that in studies of depressive symptoms it may be important to assess an adolescent's perception about their sleep, in addition to their sleep/wake behaviours.     

Social jetlag is associated with cardiorespiratory fitness in male but not female adolescents

IntroductionCardiorespiratory fitness (CRF) is a vital sign that can improve risk classification for adverse health outcomes. While lifestyle-related factors are associated with CRF, few have examined the influence of sleep characteristics, especially in youths. Social jetlag, a mismatch between one's biological clock and sleep schedule, is prevalent in adolescents and associated with increased adiposity, though its relationship with CRF is unclear.ObjectiveTo quantify the relationship between social jetlag and CRF, independent of other sleep characteristics.MethodsThis cross-sectional sample includes 276 New Zealand adolescents (14–18 years, 52.5% female). CRF (VO_2max) was estimated from a 20-m multi-stage shuttle run. Average sleep duration, sleep disturbances, social jetlag, physical activity, and the number of bedroom screens were estimated from validated self-report surveys. Social jetlag is the difference in hours between the midpoint of sleep during weekdays (school) and weekend days (free). Combined and sex-stratified linear regression assessed the association between sleep outcomes and CRF, controlling for relevant covariates.ResultsMales slept 17.6 min less, had less sleep disturbances, and a 25.1-min greater social jetlag than their female peers (all p < 0.05). A 1-h increase in social jetlag was associated with a 0.72 ml/kg/min decrease in VO_2max (95% CI: −1.31, −0.14), independent of other sleep variables, which were not associated with CRF. Sex-specific models indicated an association in males (B −0.93, 95% CI: −1.76, −0.09), but not females (B −0.32, 95% CI: −1.18, 0.55).ConclusionsSocial jetlag is negatively associated with CRF in adolescent males and may be a simple, measurable target for public health interventions.     

Wake-up stroke is not associated with obstructive sleep apnea

Objective/BackgroundObstructive sleep apnea is a risk factor for stroke. This study sought to assess the relationship between obstructive sleep apnea (OSA) and wake-up strokes (WUS), that is, stroke symptoms that are first noted upon awakening from sleep.Patients/methodsIn this analysis, 837 Brain Attack Surveillance in Corpus Christi (BASIC) project participants completed an interview to ascertain stroke onset during sleep (WUS) versus wakefulness (non-wake-up stroke, non-WUS). A subset of 316 participants underwent a home sleep apnea test (HSAT) shortly after ischemic stroke to assess for OSA. Regression models were used to test the association between OSA and WUS, stratified by sex.ResultsOf 837 participants who completed the interview, 251 (30%) reported WUS. Among participants who underwent an HSAT, there was no significant difference in OSA severity [respiratory event index (REI)] among participants with WUS [median REI 17, interquartile range (IQR) 10, 29] versus non-WUS (median REI 18, IQR 9, 30; p = 0.73). OSA severity was not associated with increased odds of WUS among men [unadjusted odds ratio (OR) 1.011, 95% confidence interval (95% CI) 0.995, 1.027] or women (unadjusted OR 0.987, 95% CI 0.959, 1.015). These results remained unchanged after adjustment for age, congestive heart failure, body mass index, and pre-stroke depression in men (adjusted OR 1.011, 95% CI 0.994, 1.028) and women (adjusted OR 0.988, 95% CI 0.959, 1.018).ConclusionsAlthough OSA is a risk factor for stroke, the onset of stroke during sleep is not associated with OSA in this large, population-based stroke cohort.     

Sleep positions in children with Down syndrome and obstructive sleep apnea

ObjectivesTo assess sleep positions in children with both Down syndrome (DS) and obstructive sleep apnea (OSA) and determine if there is a preferred sleep position by severity of apnea.MethodsA single-center retrospective review of patients with both DS and OSA was performed. Caregivers reported sleep position utilized greater than 50% of observed sleep time. Accuracy of this report was confirmed through review of hypnograms from polysomnography studies.ResultsEighty-two patients met inclusion criteria. Median body mass index (BMI) was 26.6 and 56% of patients had a prior tonsillectomy and/or adenoidectomy. The mean obstructive AHI (OAHI) was 25.33 with 90.4% having severe OSA, 9.6% having moderate OSA, and no patients having mild OSA. Reported sleep positions were skewed towards lateral/decubitus (82.9%) compared to prone (11.0%) and supine (6.1%). This was consistent with hypnogram data where 71% of total sleep time in lateral/decubitus positions compared to prone (13%) and supine (6%). The median changes in sleep position per patient was 5 (IQR: 3–6). Lower BMI (p < 0.001, 95% CI: 0.32–1.13) and tonsillectomy (p < 0.001, 95% CI: 7.7–18.19) were associated with lower OAHI. Sleep position was not associated with age (p = 0.19), sex (p = 0.66), race (p = 0.10), ethnicity (p = 0.68) nor history of tonsillectomy (p = 0.34). Preferred sleep position was not correlated with OAHI (p = 0.78, r = 0.03) or OSA severity (p = 0.72, r = 0.03).ConclusionsThis study highlights the possibility that children with DS may have preferential sleep positions that cater to optimized airflow in the context of OSA although further prospective study is needed.     

Everyday and major experiences of racial/ethnic discrimination and sleep health in a multiethnic population of U.S. women: findings from the Sister Study

BackgroundPerceived racial/ethnic discrimination and poor sleep occur across all races/ethnicities in the U.S., although both are most common among racial/ethnic minorities. Few studies have investigated associations between perceived racial/ethnic discrimination and various sleep dimensions in a multiethnic population.MethodsWe analyzed cross-sectional associations among 40,038 eligible Sister Study participants (enrollment: 2003–2009) who reported ever/never experiencing specific types of everyday (eg, treated unfairly at a store or restaurant) or major (eg, unfairly stopped, threatened, or searched by police) discrimination attributed to their race/ethnicity during a follow-up survey in 2008–2012. Participants also reported short sleep duration (<7 h), sleep debt (≥2-h difference between longest and shortest sleep duration), frequent napping (≥3 times/week), and insomnia. Poisson regression with robust variance estimation, adjusted for sociodemographic and health characteristics, estimated prevalence ratios (PRs) and 95% confidence intervals (CIs) for the association between each type of racial/ethnic discrimination and each sleep dimension, overall and by race/ethnicity.ResultsMean age was 55 ± 8.9 years, 89% were Non-Hispanic (NH)-white, 8% NH-black, and 3% Hispanic/Latina. NH-black participants were the most likely to report everyday (76% vs. 4% [NH-whites] and 36% [Hispanics/Latinas]) and major racial/ethnic discrimination (52% vs. 2% [NH-whites] and 18% [Hispanics/Latinas]). Participants who experienced both types versus neither were more likely to report short sleep duration (PR = 1.17 [95% CI: 1.09–1.25]) and insomnia symptoms (PR = 1.10 [1.01–1.20]) but not other poor sleep dimensions.ConclusionsRacial/ethnic minority women were most likely to experience racial/ethnic discrimination, which was associated with certain poor sleep dimensions among women of all races/ethnicities.     

Sleep time and sleep-related symptoms across two generations – results of the community-based RHINE and RHINESSA studies

Study objectivesTo analyze the association between sleep-related symptoms and sleep length in parents and their children in relation to other risk factors in both generations.MethodThe participants were parents (n = 5,855, age 54.3 ± 6.5 years, 45.2% men) who participated in the community-based Respiratory Health in Northern Europe (RHINE) study and one random member of their adult offspring (n = 5,855, age 30.2 ± 7.7 years, 41.5% men) who participated in the Respiratory Health in Northern Europe, Spain and Australia (RHINESSA) study. Both generations responded to identical questionnaires on sleep symptoms, including difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), early morning awakening (EMA), snoring, nocturnal sweating, nocturnal gastroesophageal reflux (nGER), sleep time and excessive daytime sleepiness (EDS). Insomnia was defined as either, or both, DIS and DMS in combination with EDS.ResultsAll sleep variables except nocturnal sweating were more common in offspring whose parents had reported the same symptom. After adjusting for age, gender, BMI, smoking, physical activity, education, center and parents' total number of children, there were independent associations between sleep symptoms in parents and offspring for DIS (adj. OR, 95% CI: 1.52, 1.20–1.93), DMS (1.34, 1.15–1.56), snoring (1.45, 1.15,1.83), nGER (1.65, 1.15–2.37), insomnia (1.39, 1.13–1.73), short sleep time (<6 h/night) (2.51, 1.72–3.68) and EDS (1.48, 1.26,1.72). There were no independent relationships between symptoms in parents and offspring for EMA, nocturnal sweating or long sleep time (>9 h/night).ConclusionThe familiar aggregation of many sleep disturbances was not explained by investigated lifestyle and environmental factors. This supports a heritable factor in sleep problems.     

Later bedtime is associated with angina pectoris in middle-aged and older adults: results from the Sleep Heart Health Study

ObjectivesSleep timing is related to several risk factors for angina pectoris (AP), such as obesity and diabetes. This study was designed to evaluate the relationship between sleep timing and AP, specifically whether later bedtime was associated with AP in middle-aged and older adults.MethodsThis community-based study was based on the Sleep Heart Health Study cohort and included 4710 participants (45.9% men, aged 63.3 ± 11.0 years). Lifestyle and epidemiological information were obtained from baseline records. Self-reported sleep measures provided information on bedtime and wake-up time of weekdays and weekends. Individuals were divided into three categories according to bedtime (≤22:00, 22:01–23:00, and >23:00). Odds ratios (OR) and 95% confidence intervals (CIs) of AP for bedtimes were estimated with multivariate logistic regression analysis.ResultsThe prevalence of AP was 44.2% and the distribution of weekday bedtimes ≤22:00, 22:01–23:00_, and >23:00 were 36.6%, 47.5% and 46.0%, respectively. After adjusting for potential confounders, weekday bedtimes >23:00 (OR 1.34; 95% CI 1.13–1.60; P = 0.001) and 22:01–23:00 (OR 1.54; 95% CI 1.29–1.82; P < 0.001) were significantly associated with an increased risk of AP compared with the reference group (≤22:00). In addition, weekend bedtimes >23:00 (OR 1.44; 95% CI 1.20–1.73; P < 0.001) and 22:01–23:00 (OR 1.70; 95% CI 1.40–2.05; P < 0.001) increased the risk of AP.ConclusionsLater bedtimes on both weekdays and weekends were significantly associated with an increased prevalence of AP. Early bedtimes may help people decrease the risk of AP.     

Parsing the antidepressant effects of non-invasive brain stimulation and pharmacotherapy: A symptom clustering approach on ELECT-TDCS

BackgroundTranscranial direct current stimulation (tDCS) presents small antidepressant efficacy at group level and considerable inter-individual variability of response. Its heterogeneous effects bring the need to investigate whether specific groups of patients submitted to tDCS could present comparable or larger improvement compared to pharmacotherapy. Aggregate measurements might be insufficient to address its effects.Objective/Hypothesis: To determine the efficacy of tDCS, compared to pharmacotherapy and placebo, in depressive symptom clusters.MethodsData from ELECT-TDCS (Escitalopram versus Electrical Direct-Current Therapy for Treating Depression Clinical Study, ClinicalTrials.gov, NCT01894815), in which antidepressant-free, depressed patients were randomized to receive 22 bifrontal tDCS (2 mA, 30 min) sessions (n = 94), escitalopram 20 mg/day (n = 91), or placebo (n = 60) over 10 weeks. Agglomerative hierarchical clustering identified “sleep/insomnia”, “core depressive”, “guilt/anxiety”, and “atypical” clusters that were the dependent measure. Trajectories were estimated using linear mixed regression models. Effect sizes are expressed in raw HAM-D units. P-values were adjusted for multiple comparisons.ResultsFor core depressive symptoms, escitalopram was superior to tDCS (ES = −0.56; CI_95% = -0.94 to −0.17, p = .009), which was superior to placebo (ES = 0.49; CI_95% = 0.06 to 0.92, p = .042). TDCS but not escitalopram was superior to placebo in sleep/insomnia symptoms (ES = 0.87; CI_95% = 0.22 to 1.52, p = .015). Escitalopram but not tDCS was superior to placebo in guilt/anxiety symptoms (ES = 1.66; CI_95% = 0.58 to 2.75, p = .006). No active intervention was superior to placebo for atypical symptoms.ConclusionsPharmacotherapy and non-invasive brain stimulation produce distinct effects in depressive symptoms. TDCS or escitalopram could be chosen according to specific clusters of symptoms for a bigger response.Trial registrationClinicalTrials.gov, NCT01894815     

The relationship between gross motor function impairment in cerebral palsy and sleeping issues of children and caregivers

AimTo investigate, among children and adolescents with cerebral palsy (CP), the relationship between impairment of the gross motor function and: (i) child sleep disorders; (ii) the need for nocturnal support; and (iii) the quality of sleep of their caregivers.MethodsFor children, we considered their scores on the gross motor function measure (GMFM-88) and on the sleep disturbance scale for children (SDSC), besides analyzing qualitative features about their sleep. For caregivers, we considered their scores in the Pittsburgh sleep quality index (PSQI).ResultsOur sample was comprised of 87 participants with mean age of 11.4 years old (±3.4). We observed correlations between GMFM-88 and disorders of initiating and maintaining sleep (DIMS) (r = −0.22; p = 0.039), sleep–wake transition disorders (SWTD) (r = 0.26; p = 0.017) and disorders of arousal (DA) (r = 0.23; p = 0.033). Children receiving nocturnal support presented lower scores in the GMFM-88 (p = 0.001) and higher scores in the SDSC (p = 0.029). For the caregivers, we found no correlation between GMFM-88 and PSQI. Nonetheless, their PSQI scores correlated with the SDSC scores (r = 0.24; p = 0.027).ConclusionImpairment of the gross motor function correlated with DIMS and the need for nocturnal support but might not have an impact on the caregivers’ sleep, which in turn correlated with child sleep disorders.     

Long-term effectiveness and safety of lemborexant in adults with insomnia disorder: results from a phase 3 randomized clinical trial

Objective/backgroundLemborexant is a dual orexin receptor antagonist approved in the United States, Japan, and Canada for the treatment of insomnia in adults. We report effectiveness and safety outcomes in subjects with insomnia who received up to twelve months of continuous lemborexant treatment in Study E2006-G000-303 (Study 303; SUNRISE-2).Patients/methodsStudy 303 was a twelve-month, global, multicenter, randomized, double-blind, parallel-group, Phase 3 study divided into two treatment periods. In Treatment Period 1 (first six months), subjects (n = 949, Full Analysis Set) were randomized to daily placebo, lemborexant 5 mg (LEM5) or lemborexant 10 mg (LEM10). In Treatment Period 2 (second six months), placebo subjects were rerandomized to LEM5 or LEM10, and subjects randomized to lemborexant continued their assigned treatment (LEM5, n = 251; LEM10, n = 226). Sleep onset and sleep maintenance endpoints were analyzed from daily electronic sleep diary data. Treatment-emergent adverse events (TEAEs) were monitored.ResultsFor all sleep parameters, the significant benefits observed with LEM5 and LEM10 versus placebo over six months were maintained at twelve months in subjects who received twelve continuous months of treatment. There was no evidence of rebound insomnia or withdrawal in either lemborexant group following treatment discontinuation. Over twelve months of lemborexant treatment, most TEAEs were mild/moderate; the most common TEAEs were nasopharyngitis, somnolence and headache.ConclusionsLEM5 and LEM10 had significant benefit on sleep onset and sleep maintenance compared with placebo, and importantly, lemborexant effectiveness persisted at twelve months, suggesting that lemborexant may provide long-term benefits for subjects with insomnia.Clinical trial registrationClinicalTrials.gov, NCT02952820; ClinicalTrialsRegister.eu, EudraCT Number 2015-001463-39.     

Weekend catch-up sleep and depression: results from a nationally representative sample in Korea

BackgroundThere is limited information on the association between weekend catch-up sleep (CUS), which has beneficial effects on health, and depression. This study aimed to investigate the association between CUS and depression in adults.MethodsWe used the data of the Seventh Korea National Health and Nutrition Examination Survey, 2016. Depression was defined as Patient Health Questionnaire-9 score ≥10. We categorized CUS duration as ≤0, 0 < to 1, 1 < to 2, and >2 h.ResultsOf 5550 eligible participants, 3286 (54.9%), 1033 (19.5%), 723 (14.7%) and 508 (10.9%) had CUS duration ≤0, 0 < to 1, 1 < to 2, and >2 h, respectively; of these, the prevalence of depression was 7.0%, 4.2%, 2.9%, and 6.0%, respectively. Multivariable regression analyses including covariates revealed that individuals with CUS duration 1 < to 2 h had a significantly decreased risk of depression compared to individuals with CUS duration ≤0 h (odds ratio [OR] = 0.517, 95% CI = 0.309–0.865). Individuals with CUS duration 0 < to 1 h (OR = 0.731, 95% CI = 0.505–1.060) and >2 h (OR = 1.164, 95% CI = 0.718–1.886) showed no significantly different risk of depression.ConclusionsThe risk of depression in individuals with CUS duration 1 < to 2 h was lower than for those with CUS duration ≤0 h. This finding provides a better understanding on the association between CUS and depression; and can be a basis for better management of depression.     

Bidirectional association between alopecia areata and sleep disorders: a population-based cohort study in Taiwan

BackgroundThe relationship between alopecia areata (AA) and sleep disorders remains uncertain. This study aims to investigate the bidirectional association between AA and sleep disorders.MethodsTo assess the risk of developing sleep disorders, we recruited 5648 patients with AA and 22,592 matched controls from the National Health Insurance Research Database (NHIRD) in Taiwan. Similarly, risk of developing AA was assessed in 93,130 patients with sleep disorders (including 7310 patients with obstructive sleep apnea [OSA] and 85,820 patients with non-apnea insomnia) and 372,520 matched controls. Cox regression model was used for the analysis.ResultsAA patients had a significantly increased risk of developing OSA (adjusted hazard ratio [aHR] 3.80; 95% confidence interval [CI] 2.53–5.71) and non-apnea insomnia (aHR 4.20; 95% CI 3.68–4.79). Conversely, presence of sleep disorders significantly increased the risk of AA development (aHR 4.70; 95% CI 3.99–5.54). Both OSA (aHR 3.89; 95% CI 2.46–6.16) and nonapnea insomnia (aHR 4.77; 95% CI 4.03–5.64) were associated an increased risk of developing AA.ConclusionsPatients with AA have a higher risk of developing sleep disorders compared to controls, and vice versa. Further studies are needed to investigate the shared pathogenic mechanism underlying these two conditions.     

Time for bed! Earlier sleep onset is associated with longer nighttime sleep duration during infancy

Objective/backgroundClinical recommendations include putting infants to bed using a consistent bedtime routine at an appropriate hour to promote longer nighttime sleep. Actigraphy was used in this exploratory study to examine how bedtime routines and nighttime sleep onset were associated with nighttime total sleep time (TST) and efficiency from 6 to 24 weeks of age.Patients/methodsInfants (n = 24) wore sleep actigraphs for three, one-week periods at 6, 15, and 24 weeks of age. Nighttime TST, sleep efficiency, sleep onset and offset were quantified. Mothers reported on infant bedtime routines using the Brief Infant Sleep Questionnaire at each age. Multilevel models examined between- and within-person associations.ResultsAs infants aged, sleep onset was earlier, and bedtime routines became shorter (p's < 0.05). Infants fell asleep between 7 and 8:00PM on 24% of the nights. Most mothers (70%) reported that they often fed infants to sleep for the night. For every 1 h earlier in infants' usual sleep onset, nighttime TST was 34.4 min longer that night (p < 0.01). Infants with earlier than usual sleep onset had slightly earlier sleep offset the next morning (8.4 min for every 1 h earlier in onset; p = 0.02). Between-person analyses showed similar patterns. Infants with a more consistent bedtime routine and who were not typically fed to sleep at bedtime had longer nighttime TST at 6 weeks, with a trend or no association at later ages.ConclusionInfants who fell asleep earlier also slept longer at night. Keeping infants up later in hopes of them sleeping in longer may be counterproductive.     

Racial/ethnic disparity in habitual sleep is modified by caloric intake in adolescents

Study objectivesWe investigated the moderation of caloric intake on the association between race/ethnicity and habitual sleep in adolescents.MethodsWe analyzed the data obtained from 324 adolescents who completed the follow-up examination of the Penn State Child Cohort study. We collected actigraphy-measured sleep duration on 7 consecutive nights and computed their mean and standard deviation as habitual sleep duration (HSD) and habitual sleep variability (HSV), respectively. We also measured participants’ daily intakes of total calorie, total fat, carbohydrates, and protein, through the Youth/Adolescent Food Frequency Questionnaire. Adjusted mean HSD and HSV among non-Hispanic whites and racial/ethnic minorities were compared by using analysis of covariance (ANCOVA), while controlling for age, sex, BMI percentile, total caloric intake, and socioeconomic status. The significance of the interaction between race/ethnicity and caloric intake was further tested in ANCOVA models.ResultsThe study sample consisted of 79.3% non-Hispanic whites, 13.0% African American, 4.6% Hispanics, 2.2% Asian, and 0.9% American Indian. Adolescents who are racial/ethnic minorities showed shorter HSD (mean (SE): 6.80 (0.10) vs. 7.07 (0.05) hours/night, p = 0.02) and higher HSV (mean (SE): 1.31 (0.07) vs. 1.15 (0.04) hours/night, p = 0.04) than non-Hispanic whites. Racial/ethnic differences in HSV were significantly more pronounced among adolescents with high caloric intake (p interaction = 0.01), especially from carbohydrates (p interaction = 0.03) and fat (p interaction = 0.05).ConclusionAdolescents who are racial/ethnic minorities slept objectively shorter and with greater night-to-night variability than non-Hispanic whites. The racial/ethnic disparity in habitual sleep variability was more pronounced among adolescents with high caloric intake, particularly from carbohydrates and fat.     

Delayed neonatal visual evoked potentials are associated to asymmetric growth pattern in twins

ObjectivesTo study the association between intrauterine growth and visual pathways maturation by neonatal visual evoked potentials (VEPs) in twins, in view of a possible prognostic role.MethodsSeventy-four twin neonates from 37 pregnancies were selected based on gestational age of more than 30 weeks and uneventful perinatal clinical course. Flash VEPs were recorded at the same postmenstrual age in each twin pair. The association between P2 latency and anthropometric variables at birth was analyzed by comparison within each twin pair and regarding each variable as ordered difference between the two twins.ResultsAnalysis of differences within each twin pair highlighted that inter-twin difference in P2 latency was significantly related to difference in ponderal index (PI) (p = 0.048).Expressing the difference in latency as a categorical binary variable, the correlation was significant for both difference in PI, (median difference = −0.36, 95% CI −0.54 to −0.14, p = 0.001) and difference in body mass index (BMI), (median difference = −1.06, 95% CI −1.74 to −0.29, p = 0.006).ConclusionsLower values of PI and BMI differences are associated to delayed VEP latency in twin pairs.SignificanceVEP latency suggests reduced myelination of visual pathways when difference in growth pattern occurs in twins.     

The Nexus Narcolepsy Registry: methodology,study population characteristics,and patterns and predictors of narcolepsy diagnosis

Objective/backgroundThe real-world experience of people with narcolepsy is not well understood.Patients/methodsThe Nexus Narcolepsy Registry (NCT02769780) is a longitudinal, web-based patient registry of self-reported data from adults with physician-diagnosed narcolepsy. Surveys were electronically distributed every 6 months; the current analysis reports registry population demographics, narcolepsy diagnosis journey, and predictors of diagnostic delays.ResultsThe registry population included in this analysis (N = 1024) was predominantly female (85%) and White (92%), with a mean age of 37.7 years. Most participants had education/training beyond high school (93%). Mean (median) reported ages at narcolepsy symptom onset, first consultation for symptoms, and narcolepsy diagnosis were 18.1 (16), 26.4 (24), and 30.1 (28) years, respectively. A majority (59%) of participants reported ≥1 misdiagnosis, and 29% reported consulting ≥5 physicians before narcolepsy diagnosis. More than half (56%) of participants’ first consultations for narcolepsy symptoms were with a general practitioner, whereas the diagnosing clinician was usually a sleep specialist (64%) or neurologist (27%). Pediatric symptom onset was associated with a longer mean interval to first consultation than adult symptom onset (10.7 and 4.6 years, respectively; P < 0.001) and a longer mean interval between first consultation and diagnosis (4.5 and 2.2 years, respectively; P < 0.001). Overall, mean (95% CI) time from symptom onset to diagnosis was 11.8 (11.1–12.5) years.ConclusionsThe Nexus Narcolepsy Registry data indicate that onset of narcolepsy symptoms frequently occurs in childhood or adolescence. In many individuals, the diagnostic process is long and involves multiple physicians and frequent misdiagnosis.     

The impact of obstructive sleep apnea on bronchiolitis severity in children with Down syndrome

ObjectivesAcute bronchiolitis commonly causes respiratory failure in children ≤2 years, and is particularly severe in those with Down syndrome (DS). Obstructive sleep apnea (OSA), common in DS, is also associated with respiratory complications. However, it is unknown whether OSA is associated with worse outcomes in children with and without DS, hospitalized with bronchiolitis. We hypothesized that in children with bronchiolitis, OSA is associated with worse outcomes in those with DS, independent of DS-related comorbidities.MethodsHospital discharge records of children with bronchiolitis aged ≤2 years were obtained for 1997–2012 from the Kid's Inpatient Database. The primary outcome was invasive mechanical ventilation (IMV), and secondary outcomes were non-invasive mechanical ventilation (NIMV), length of hospital stay, and inflation-adjusted cost of hospitalization (IACH). Multivariable regression was conducted to ascertain the associations between OSA and primary and secondary outcomes accounting for DS-associated comorbidities.ResultsThere were 928,961 hospitalizations for bronchiolitis. The DS group with bronchiolitis (n = 8697) was more likely to have OSA [241 (2.77%) vs 1293 (0.14%), p < 0.001] compared to the non-DS group (n = 920,264). Multivariable logistic regression showed that OSA was associated with IMV (adjusted odds ratio [OR], 3.32 [95% CI 2.54–4.35], p < 0.0001) in all children with bronchiolitis; and in those with DS, it was associated with IMV (adjusted OR, 2.34 [95% CI 1.38–3.97], p = 0.002), NIMV (adjusted OR, 8.21 [95% CI 4.48–15.04], p < 0.0001) and IACH (adjusted β, 0.18 [95% CI 0.02–0.34], p = 0.031).ConclusionsOSA is independently associated with assisted ventilation in all children hospitalized with bronchiolitis, regardless of DS-associated comorbidities in those with DS. The severity of bronchiolitis in children with DS may be driven by the high prevalence of OSA.