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.     

Association between loneliness,sleep behavior and quality: a propensity-score-matched case–control study

ObjectiveTo explore the influence of loneliness on sleep behavior and sleep quality based on propensity score-matched samples in Southwest China.MethodsIndividual-level data were obtained from a Southwest China cohort study. Participants who felt lonely were matched with those who did not with propensity scores on the basis of age, gender, socioeconomic factors, physical exercise and social connection level. Sleep behavior (onset and offset timing), sleep quality (sleep latency, nocturnal awakenings and subjective sleep quality), and daytime function (daytime sleepiness and fatigue) were assessed with the Pittsburgh Sleep Index Scale (PSQI) and compared between the two groups. The data were collected between May 2019 and December 2019, and data analyses were completed in April 2021.ResultsA total of 11,696 participants were included, and 824 out of 839 participants who felt loneliness were statistically matched with 824 participants who did not. Analyses of the matched samples showed that sleep onset and offset timing were similar between those who felt lonely and those who did not (p = 0.110 and p = 0.751, respectively). Sleep latency was longer in those who felt lonely (26.84 [0.9] vs. 35.52 [1.2] min, p < 0.001) than in those who did not. Furthermore, participants who felt lonely tended to have poor subjective sleep, a higher frequency of nocturnal awakenings, daytime sleepiness and fatigue (all p < 0.001).ConclusionsLoneliness was associated with extended sleep latency, increased nocturnal awakenings, and reduced subjective sleep quality and daytime function but was not associated with sleep behavior, including sleep onset and offset timings.     

Sleep-disordered breathing in cystic fibrosis

IntroductionCystic fibrosis (CF) is a life-shortening, genetic disease that affects approximately 30,000 Americans. Although patients frequently report snoring, mouth breathing, and insomnia, the extent to which sleep-disordered breathing (SDB) may underlie these complaints remains unknown.MethodsSingle-center retrospective review of polysomnography results from referred patients with and without CF individually-matched (1:2) for age, gender, race, and body mass index (BMI).ResultsMean ages were 8.0 ± 5.2 (sd) and 35.9 ± 12.9 years, among 29 children and 23 adults with CF respectively. The CF and non-CF groups were well-matched in age and BMI. Subjects with vs. without CF had three times greater odds of moderate-severe SDB (apnea-hypopnea index (AHI) ≥ 5 in children, ≥ 15 in adults) (p = 0.01). Nocturnal oxygen saturation nadir (Minimum SpO₂) was lower among CF vs. non-CF groups (p = 0.002). For every 1-unit increase in AHI, the decline in Minimum SpO₂ was larger for subjects with vs. without CF (p = 0.05). In subjects with CF, forced expiratory volume in 1 s percent predicted (FEV1 PPD) was associated with Minimum SpO₂ (Pearson r = 0.68, p < 0.0001) but not AHI (r = −0.19, p = 0.27). For every 1-unit increase in AHI, magnitude of decline in Minimum SpO₂ was larger for those with low vs. normal FEV1 PPD (p = 0.01).ConclusionSeverity of SDB may be worse among referred patients with vs. without CF. The SDB may modify the relationship between CF lung disease and nocturnal hypoxemia. Markers of lung disease severity including lung function do not predict SDB severity, suggesting the need for routine polysomnography to screen for this sleep disorder.     

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.     

Brain tumours result in sleep disorders in children and adolescents

Background and objectivesSleep disturbances are frequently reported in children with brain tumours. The objective of our cross-sectional study was to systematically examine sleep in these children. We hypothesised that children with tumours involving the sleep-wake-regulatory areas have an altered sleep-wake-regulation.MethodsSixty-one patients aged 0–18 years and with a diagnosis of a primary brain or cervical medullary tumour were included. They were categorised based upon tumour location into two groups – those affecting the sleep-wake regulatory regions, i.e. brain stem, basal forebrain, hypothalamus, thalamus, and posterior fossa compressing the brain stem and those that did not. Sleep history, questionnaire surveys, polysomnography, and multiple sleep latency test were used, as indicated clinically. Surveys included Pediatric Daytime Sleepiness Scale, Children's Sleep Habits Questionnaire, Strengths and Difficulties Questionnaire, and Pediatric Quality of Life Inventory, Multidimensional Fatigue Scale and Generic Core Scale.ResultsPatients with tumours involving the sleep-wake regulatory areas were sleepier/more fatigued (p = 0.03). Sleep apnoea was observed in 86% of all the patients and comorbid narcolepsy in 8%, without group differences (p ≥ 0.12). Patients with tumours involving the sleep-wake-regulatory areas had more emotional problems (p = 0.04), were more affected by mental health problems (p < 0.001), and had poorer quality of life (p ≤ 0.03).ConclusionsMany children with brain tumours suffer from disturbed sleep, poor mental health, and low quality of life. We recommend that systematic sleep evaluation is included in their routine care along with psychological and social support.     

Inflammation in children with neuromuscular disorders and sleep disordered breathing

IntroductionPaediatric obstructive sleep apnoea is associated with systemic inflammation and co-morbidities. We assessed whether sleep disordered breathing (SDB) due to neuromuscular weakness was associated with elevated airway and systemic pro-inflammatory cytokines.MethodsConsecutive neuromuscular children (age 5–18years) underwent overnight full polysomnography and morning collection of serum and breath condensate, analysed for cytokines (Interleukin-10, Interleukin-6, Interleukin-1β, Tumour Necrosis Factorα, high-sensitivity C-Reactive Protein, Intercellular and Vascular Adhesion Molecules ICAM-1, VCAM-1). Cytokine levels were related to Oxygen desaturation index (ODI), desaturation>4%/h, and levels of transcutaneous carbon dioxide overnight (tcCO2≥6.7 kPa > 2% sleep).ResultsA total of 23 patients were included, median age 12.6 years (IQR 8.7–14.6). ODI>3/h was associated with higher breath and serum IL-6 (p = 0.02). Children with elevated CO₂ overnight had higher ICAM-1 and VCAM-1. CO₂ levels correlated with serum ICAM-1 (rs0.570, p = 0.026) and VCAM-1 (rs0.76, p = 0.001).DiscussionSDB in neuromuscular children is associated with raised serum IL-6, VCAM-1, ICAM-1. This may predispose these children to future cardiovascular and other co-morbidities.     

Objective measurement of limb bradykinesia using a marker-less tracking algorithm with 2D-video in PD patients

BackgroundQuantitative measurement of parkinsonian motor symptoms is crucial in clinical practice and in research. However, the widely used Unified PD Rating Scale (UPDRS) part III is based on a semi-quantitative evaluation with high inter- and intra-rater variability. Sensor-based measurements have been widely studied but are limited for their accessibility.MethodsWe analyzed 2D-RGB videos recording finger tapping and leg agility tests in 29 PD patients with a marker-less deep-learning based tracking algorithm. The tracking performance was validated with an accelerometer. Four parameters (mean amplitude, mean interpeak interval, amplitude variability and interpeak interval variability) were calculated from the position tracking.ResultsThe performance of the video-tracking was in good agreement with the accelerometer-based tracking (Intra-class correlation coefficient > 0.9 for the peak amplitude, and >0.6 for the interpeak interval). The video-tracking successfully captured variable aspects of limb bradykinesia that have a distinct correlation with the general parkinsonian motor symptoms and gait. In the finger-tapping task, the mean amplitude (R = −0.6, p = 2.4 × 10⁻⁶), amplitude variability (R = 0.36, p = 0.0092), mean interpeak interval (R = 0.34, p = 0.014), and interpeak interval variability (R = 0.66, p = 1.4 × 10⁻⁷) was significantly correlated with the UPDRS scores. In leg agility test, the mean amplitude (R = −0.58, p = 1.7 × 10⁻⁵), mean interpeak interval (R = 0.37, p = 0.0088) and interpeak interval variability (R = 0.7, p = 6.2 × 10⁻⁸) were significantly correlated with the UPDRS scores, but not with amplitude variability (R = 0.17, p = 0.26). Limb rigidity was significantly correlated with the interpeak interval (R = 0.40, p = 0.0036) and its variability (R = 0.59, p = 4.2 × 10⁻⁶) in the leg agility test.ConclusionThe video-based tracking could objectively measure limb bradykinesia in PD patients.     

Screen exposure exacerbates ADHD symptoms indirectly through increased sleep disturbance

ObjectivesThe aim of this study was twofold. First, to confirm the deleterious aspect of evening screen exposure in school-aged children, in particular the effect of screens in the bedroom. Second, to explore the three-way association between degree of screen exposure, sleep disturbance, and ADHD symptoms. Solid evidence exists on the link between sleep disturbance and ADHD symptoms, and screen exposure and sleep disturbance. However, no studies have formally assessed the impact of screen exposure on ADHD symptoms in children, as a function of sleep disturbance.MethodsParents of 374 French children (201 girls, 173 boys, mean age of 10.8 ± 2.8 years old) completed the Sleep Disturbance Scale for Children (SDSC), the Attention-Deficit/Hyperactivity Disorder (ADHD) Rating Scale, and a questionnaire about their children's screen habits (total hours in the morning, afternoon, and evening per day). Correlational analyses between evening screen exposure, sleep quality and behavioral problems were conducted. Then, formal mediation analyses were run in order to quantify the relationship between variables.ResultsSchool-aged children with screens in their bedrooms demonstrated more sleep and behavioral problems. Evening TV exposure was associated with higher SDSC and ADHD scores. Furthermore, the Structural Equation Modelling approach confirmed that evening screen exposure is directly associated with more disrupted sleep, which in turn is directly associated with behavioral problems.ConclusionsThese findings encourage families to avoid putting screens in their children's bedrooms, and limit evening screen exposure. They furthermore demonstrate the importance of taking into account screen exposure time (morning, afternoon, evening) and location (bedroom or elsewhere) in future studies.     

The evaluation of sleep disturbances for Chinese frontline medical workers under the outbreak of COVID-19

ObjectiveTo evaluate sleep disturbances of Chinese frontline medical workers (FMW) under the outbreak of coronavirus disease 2019 (COVID-19), and make a comparison with non-FMW.MethodsThe medical workers from multiple hospitals in Hubei Province, China, volunteered to participate in this cross-sectional study. An online questionnaire, including Pittsburgh Sleep Quality Index (PSQI), Athens Insomnia Scale (AIS) and Visual Analogue Scale (VAS), was used to evaluate sleep disturbances and mental status. Sleep disturbances were defined as PSQI>6 points or/and AIS>6 points. We compared the scores of PSQI, AIS, anxiety and depression VAS, as well as prevalence of sleep disturbances between FMW and non-FMW.ResultsA total of 1306 subjects (801 FMW and 505 non-FMW) were enrolled. Compared to non-FMW, FMW had significantly higher scores of PSQI (9.3 ± 3.8 vs 7.5 ± 3.7; P < 0.001; Cohen's d = 0.47), AIS (6.9 ± 4.3 vs 5.3 ± 3.8; P < 0.001; Cohen's d = 0.38), anxiety (4.9 ± 2.7 vs 4.3 ± 2.6; P < 0.001; Cohen's d = 0.22) and depression (4.1 ± 2.5 vs 3.6 ± 2.4; P = 0.001; Cohen's d = 0.21), as well as higher prevalence of sleep disturbances according to PSQI > 6 points (78.4% vs 61.0%; relative risk [RR] = 1.29; P < 0.001) and AIS > 6 points (51.7% vs 35.6%; RR = 1.45; P < 0.001).ConclusionFMW have higher prevalence of sleep disturbances and worse sleep quality than non-FMW. Further interventions should be administrated for FMW, aiming to maintain their healthy condition and guarantee their professional performance in the battle against COVID-19.     

Sleep problems in Australian children with Down syndrome: the need for greater awareness

BackgroundChildren with Down Syndrome (DS) have a high prevalence of obstructive sleep apnoea (OSA). Non-respiratory sleep disorders also occur commonly but are less well recognised. This cross-sectional study evaluates the prevalence of sleep difficulties in a community sample of Australian children with DS (DS_comm), using the Children's Sleep Habits Questionnaire (CSHQ), and compares them to children referred to the sleep clinic (DS_ref). To our knowledge this is the first study to have reported prevalence of sleep problems in Australian children with DS and to compare a community and referred group of children with DS directly.MethodsThe CSHQ was completed by parents of children with DS recruited from the community (DS_comm) via survey distributed by Down syndrome Queensland and Australia. A second group was recruited through the tertiary sleep clinic at our institution (DS_ref) and completed the same questionnaire on enrolment. Data from these groups was compared.ResultsThere were 76 participants in the DS_comm group (57% male; median age 9.7yrs) and 42 participants in the DS_ref group (50% male; median age 6.97yrs). The overall prevalence of sleep disturbances was 90.9% in the DS_comm group, and 85.7% in the DS_ref group (p = 0.54). There was a statistically significant difference in the mean total CSHQ score, with the DS_comm having the higher score (p = 0.023).ConclusionsThis study reports a high prevalence of sleep problems in both a community and referred group of Australian children with DS and suggests that there are many children with DS with sleep problems, particularly non-respiratory difficulties, who are potentially not receiving adequate treatment.     

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.     

Relationship between high-frequency activity in the cortical sensory and the motor hand areas,and their myelin content

BackgroundThe human primary sensory (S1) and primary motor (M1) hand areas feature high-frequency neuronal responses. Electrical nerve stimulation evokes high-frequency oscillations (HFO) at around 650 Hz in the contralateral S1. Likewise, transcranial magnetic stimulation (TMS) of M1 can evoke a series of descending volleys in the corticospinal pathway that can be detected non-invasively with a paired-pulse TMS protocol, called short interval intracortical facilitation (SICF). SICF features several peaks of facilitation of motor evoked potentials in contralateral hand muscles, which are separated by inter-peak intervals resembling HFO rhythmicity.HypothesisIn this study, we tested the hypothesis that the individual expressions of HFO and SICF are tightly related to each other and to the regional myelin content in the sensorimotor cortex.MethodsIn 24 healthy volunteers, we recorded HFO and SICF, and, in a subgroup of 20 participants, we mapped the cortical myelin content using the ratio between the T1- and T2-weighted MRI signal as read-out.ResultsThe individual frequencies and magnitudes of HFO and SICF curves were tightly correlated: the intervals between the first and second peak of cortical HFO and SICF showed a positive linear relationship (r = 0.703, p < 0.001), while their amplitudes were inversely related (r = ?0.613, p = 0.001). The rhythmicity, but not the magnitude of the high-frequency responses, was related to the cortical myelin content: the higher the cortical myelin content, the shorter the inter-peak intervals of HFO and SICF.ConclusionThe results confirm a tight functional relationship between high-frequency responses in S1 (i.e., HFO) and M1 (i.e., as measured with SICF). They also establish a link between the degree of regional cortical myelination and the expression of high-frequency responses in the human sensorimotor cortex, giving further the opportunity to infer their generators.     

Social jetlag is associated with obesity-related outcomes in 9–11-year-old children,independent of other sleep characteristics

IntroductionSocial jetlag has been reported to predict obesity-related indices, independent of sleep duration, with associations in female adolescents but not males. However, such sex-specific relationships have not been investigated in pre-adolescents.ObjectivesTo examine: (i) the relationships between sleep characteristics, including social jetlag, and obesity-related outcomes during childhood, and (ii) whether these relationships are moderated by sex.MethodsThis cross-sectional study included 381 children aged 9–11 years (49.6% female). Average sleep duration, social jetlag, and physical activity were assessed via wrist-worn accelerometry. Sleep disturbances were quantified from the Children's Sleep Habits Questionnaire. Obesity-related outcomes included age-specific body mass index Z-scores (zBMI) and waist-to-height ratio. Additionally % fat, total fat mass, and fat mass index were assessed via bioelectrical impedance analysis. Linear mixed models that nested children within schools were used to identify relationships among sleep characteristics and obesity-related outcomes.ResultsPositive associations between social jetlag with zBMI, % fat, and fat mass index were seen in univariable and unadjusted multivariable analyses. Following adjustments for known confounders, social jetlag remained significantly associated with zBMI (β = 0.12, p = 0.013). Simple slopes suggested a positive association in girls (β = 0.19, p = 0.006) but not in boys (β = 0.03, p = 0.703).ConclusionsObesity prevention efforts, particularly in girls, may benefit from targeted approaches to improving the consistency of sleep timing in youth.     

Predictors of CPAP adherence following stroke and transient ischemic attack

ObjectiveContinuous positive airway pressure (CPAP) has been shown to improve functional, motor and cognitive outcomes in post-stroke obstructive sleep apnea (OSA). However, rates of CPAP adherence are often low and factors impacting CPAP adherence remain under-explored. Our objective was to determine predictors of CPAP adherence in patients who had a stroke or transient ischemic attack (TIA).MethodsWe screened 313 stroke/TIA patients for OSA using in-hospital polysomnography or the ApneaLink home sleep apnea test. Potential predictors were recorded at baseline and adherence to CPAP was recorded during a six-month follow-up visit. Selected variables from our univariate analyses were included in multivariate regression models to determine predictors of CPAP adherence. For our logistic regression analyses, CPAP adherence (CPAP use of ≥4 h per night) was the dependent outcome variable. In our linear regression analyses, total CPAP use per week (recorded in hours) was the dependent outcome variable.ResultsEighty-eight patients (mean age 67.81 ± 13.09 years, 69.32% male, mean body mass index 27.93 ± 5.23 kg/m²) were diagnosed with OSA, prescribed CPAP, and assessed for adherence at a six-month follow-up visit. In these 88 patients, 46 (52.27%) were adherent with CPAP therapy. From our regression models, two significant predictors of CPAP adherence were identified: greater functional status (p = 0.04) and not endorsing daytime tiredness (p = 0.047) post-stroke/TIA.ConclusionPatients with greater functional capacity and those with less daytime fatigue demonstrated stronger adherence to CPAP therapy. Our findings may facilitate future treatment strategies for enhancing CPAP adherence in the vulnerable stroke/TIA population.     

Developing a behavioral model of Restless Legs Syndrome utilizing mice with natural variances in ventral midbrain iron

BackgroundThe primary symptoms of Restless Legs Syndrome (RLS) are circadian-dependent, leading to increased activity or decreased rest, especially at night. The primary pathology in RLS is brain iron insufficiency despite normal systemic iron stores. Natural variances in brain and peripheral iron concentrations across recombinant inbred (RI) murine strains provide a biological model of RLS. The question is whether these RI mice strains show a behavioral analog to circadian-dependent clinical phenotype of RLS.MethodsThe home cage activity of eight female RI strains was measured over a 72-h period. The ratio of the average activity in the last 2 h of the active period relative to that in the total 12-h active period (late active period activity ratio, LAPAR) was the primary outcome variable. The relation of average LAPAR scores to measures of ventral midbrain (VMB) iron was evaluated across strains in this study.ResultsRI strain 40 (LAPAR = 1.28) and RI strain 21 (LAPAR = 1.02) were the only strains to show an increased activity in the last part of the active period. ANOVA showed the increased activity was significantly greater during the last 2 h compared to the preceding 10 h of the active phase only for the RI strain 40. Average LAPAR across the eight strains did not significantly correlate with the VMB iron content (r = −0.27, p < 0.10) but did correlate with changes in VMB iron with iron deficiency (r = 0.71, p < 0.05) and diurnal change in VMB iron (r = 0.65, p < 0.05).ConclusionThe female RI strain 40 mice exhibited a distinct end-of-active-period behavior analogous to circadian-dependent clinical phenotype of RLS.     

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.     

Age-associated differences in sleep duration in the US population: potential effects of disease burden

ObjectivesWe contrasted the relative risks (RR) of short [<7 h] and long [>8 h] sleep experienced by middle-aged (45–64 years) and older (≥65 years) adults, compared with young adults (20–44 years).MethodsWe utilized NHANES data (2005–2016), capturing sociodemographic, socioeconomic, and health-related data among US adults.ResultsThe Relative Risk (RR) of short sleep between young and middle-aged adults did not differ [RR = 1.02, NS]. However, the RR of short sleep was significantly reduced among older participants [RR = 0.81, p < 0.01]. Middle-aged adults had significantly lower RR of long sleep [RR = 0.80, p < 0.01], whereas older adults had significantly greater RR of long sleep [RR = 1.41, p < 0.01]. Compared with young adults, older adults with or without increased disease burden had significantly lower RR of short sleep [RR = 0.81, p < 0.01 and RR = 0.80, p < 0.01], respectively. However, for middle-aged adults, the RR of short sleep did not differ whether they reported a greater disease burden. Relative to young adults, older adults with or without disease burden had higher RRs of long sleep [RR = 1.39, p < 0.01] and [RR = 1.45, p < 0.01], respectively. For middle-aged adults without disease burden, the RR of long sleep was lower than among young adults [RR = 0.72, p < 0.01].ConclusionsCompared with young adults, older adults were not at increased risk for short sleep. Rather, they reported longer sleep time regardless of the presence of disease burden. Future studies should investigate longitudinal effects of aging on objective sleep time, with or without common diseases.     

Theta-burst versus 20 Hz repetitive transcranial magnetic stimulation in neuropathic pain: A head-to-head comparison

ObjectiveHigh-frequency repetitive transcranial magnetic stimulation (rTMS) has been shown to reduce neuropathic pain, but intermittent “theta-burst” stimulation (iTBS) could be a better alternative because of shorter duration and greater ability to induce cortical plasticity. Here we compared head-to-head the pain-relieving efficacy of the two modalities when applied daily for 5 days to patients with neuropathic pain.MethodsForty-six patients received 20 Hz-rTMS and/or iTBS protocols and 39 of them underwent the full two procedures in a random cross-over design. They rated pain intensity, sleep quality, fatigue and general health status daily during 5 consecutive weeks.ResultsPain relief during the month following stimulation was superior after 20 Hz-rTMS relative to iTBS (F(1,38) = 4.645; p = 0.037). Correlation between respective levels of maximal relief showed a significant deviation toward the 20 Hz-rTMS effect. A greater proportion of individuals responded to 20 Hz-rTMS (52% vs 32%, 95 %CI[0.095–3.27]; p = 0.06), and reports of fatigue significantly improved after 20 Hz-rTMS relative to iTBS (p = 0.01). General health and sleep quality scores did not differentiate both techniques.ConclusionsHigh-frequency rTMS appeared superior to iTBS for neuropathic pain relief.SignificanceAdequate matching between the oscillatory activity of motor cortex and that of rTMS may increase synaptic efficacy, thus enhancing functional connectivity of motor cortex with distant structures involved in pain regulation.     

Association of visceral adiposity and systemic inflammation with sleep disordered breathing in normal weight,never obese adolescents

Objective/backgroundWhile obesity is a known risk factor for sleep disordered breathing (SDB), a large proportion of children with SDB are not overweight as per body mass index percentile (BMI%) criteria. This study aimed to examine whether premorbid or concurrent adiposity phenotypes and inflammation are associated with SDB in normal weight youth.Patients/methodsA total of 242 persistently non-overweight (BMI%<85) subjects from the Penn State Child Cohort (PSCC, N = 421, 5-12 y at baseline and 12-23 y at follow-up), were studied. The apnea/hypopnea index (AHI) was ascertained via polysomnography (PSG) at both time points. At follow-up, a dual-energy X-ray absorptiometry (DXA) scan assessed android and gynoid distribution and subcutaneous (SAT) and visceral (VAT) adiposity composition, while a fasting blood draw was assayed for C-reactive protein (CRP) and interleukin-6 (IL-6) levels. Multivariable linear regression models with AHI at follow-up as primary outcome were adjusted for sex, race, adenotonsillectomy, age and AHI at baseline.Results and conclusionsIncreased waist circumference (β = 0.227, p = 0.001) at baseline, but not BMI%, neck or hip circumference, was significantly associated with a higher AHI at follow-up. VAT (β = 0.309, p < 0.001), IL-6 (β = 0.243, p < 0.001), SAT (β = 0.235, p = 0.013), CRP (β = 0.221, p = 0.001), and an android distribution (β = 0.196, p = 0.003) at follow-up were significantly associated with a higher AHI at follow-up. Childhood central adiposity predicts SDB in adolescence, even in individuals who have never been overweight since childhood as per BMI criteria. Visceral adiposity and inflammation are concurrent to adolescent SDB, which supports the clinical utility of these biomarkers in predicting its associated cardiometabolic risk.     

The impact of obstructive sleep apnea on endothelial function during weight loss in an obese pediatric population

BackgroundChildhood obesity is an increasing problem with substantial comorbidities such as obstructive sleep apnea (OSA) and increased cardiovascular morbidity. Endothelial dysfunction is an underlying mechanism related to both obesity and OSA.Research questionTo investigate the effect of weight loss on endothelial function and OSA in obese children and to determine whether a change in endothelial function can be linked to an improvement in OSA.MethodsObese children between 8 and 18 years of age were recruited while entering a 12-month inpatient weight loss program. Patients were followed at 3 study visits: baseline, after 10 months of weight loss, and 6 months after ending the program (18 months). Anthropometry and endothelial function (EndoPAT) were determined at all study visits. At baseline, sleep screening with a portable device (ApneaLink) was performed. This was repeated after 10 months if OSA was diagnosed at baseline.ResultsAt baseline, 130 children were included, of which 87 had OSA (67%). Seventy-two patients attended the follow-up visit at 10 months, and 28 patients attended the follow-up visit at 18 months. The BMI z-score decreased after 10 months (from 2.7 (1.4–3.4) to 1.7 (0.5–2.7); p < 0.001) and remained stable at 18 months. Endothelial function improved significantly after weight loss, evidenced by a shorter time to peak response (TPR) and higher reactive hyperemia index (p = 0.02 and p < 0.001), and remained improved after 18 months (p < 0.001 and p = 0.007). After 10 months of weight loss, 10 patients had residual OSA. These patients had a higher TPR at 10 months (225 (75–285)s) than those without OSA (135 (45–225)s) and patients with a normalized sleep study (105 (45–285)s; p = 0.02). Linear mixed models showed that more severe OSA was associated with a worse TPR at baseline and less improvement after weight loss.ConclusionWeight loss improves endothelial function in an obese pediatric population. However, even after weight loss, endothelial function improved less in the presence of OSA.