Core body temperature changes in school-age children with circadian rhythm sleep–wake disorder

Objective/backgroundCore body temperature (CBT) is considered a valuable marker for circadian rhythm. This study aimed to investigate the changes in CBT that are associated with the symptoms of circadian rhythm sleep–wake disorder (CRSWD) post-treatment in children.Patients/methodsTwenty-eight school-age children [10 boys and 18 girls; mean age (±standard deviation), 13.68 ± 0.93 years] who were admitted to our hospital with CRSWD underwent treatment for 6–8 weeks according to the following protocol: lights-out for sleep at 21:00; phototherapy for waking at 6:00 or 7:00; light exercise everyday (eg, a 20- to 30-min walk). CBT was continuously measured for 24 h on the first day of admission and on the first day after treatment.ResultsThe mean time of sleep onset/offset (±standard deviation; in hours:minutes) 1 week before admission and 1 week after treatment were 23:53 ± 2:26/9:58 ± 2:15 and 21:17 ± 0:19/6:46 ± 0:32, respectively. The mean times of sleep onset and offset measured post-treatment were significantly earlier than those measured pre-treatment (p < 0.001). The mean CBT and mean minimum CBT during sleep were significantly lower on the first day post-treatment than on the first day of admission (p = 0.011 and p < 0.001, respectively).ConclusionsSymptom improvements in patients with CRSWD were associated with a decrease in CBT during sleep, suggesting that CBT may be a biomarker for improvements in CRSWD. These results help elucidate the cause of this sleep disorder.     

Efficacy and safety of melatonin for sleep onset insomnia in children and adolescents: a meta-analysis of randomized controlled trials

ObjectiveTo evaluate the efficacy and safety of melatonin in the treatment of sleep onset insomnia in children and adolescents.MethodsElectronic databases and bibliographies of relevant reports were searched for randomized, placebo-controlled, clinical trials that used melatonin in children and adolescents with sleep onset insomnia. The quality of the included studies was assessed by the Cochrane Collaboration's risk-of-bias method. The mean differences (MD) and the odds ratios (OR) with 95% confidence interval (CI) were estimated by a random-effects model. Primary outcomes were sleep onset time (SOT), drop-out for all causes and drop-out for adverse events. Secondary outcomes included dim light melatonin onset (DLMO), sleep onset latency (SOL), total sleep time (TST), light-off time, and wake-up time.ResultsSeven trials with 387 participants were finally included after a systematic search. The overall quality of the included studies was low to moderate. SOT in patients receiving melatonin advanced more than patients receiving placebo (MD = −0.62 h, 95% CI −0.80, −0.45), as well as DLMO (MD = −0.82 h, 95% CI −1.23, −0.41). No differences were found in the outcome of drop-out for all causes (OR = 1.51, 95% CI 0.57, 4.05) or drop-out for adverse events (OR = 3.35, 95% CI 0.13, 86.03). Severe adverse events, migraine, and mild generalized epilepsy were reported in two cases. SOL decreased and TST increased, MD = −0.36 h (95% CI −0.49, −0.24) and MD = 0.38 h (95% CI 0.09, 0.66), respectively. Light-off time and wake-up time did not differ significantly.ConclusionsMelatonin was an effective and tolerable drug in the short-term treatment of sleep onset insomnia in children and adolescents. More studies, especially in adolescents, are needed to investigate the efficacy and safety of melatonin.     

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 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.     

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.     

The prevalence of sleep problems among children in mainland China: a meta-analysis and systemic-analysis

BackgroundWe conducted a meta-analysis and systematic review to identify a reliable estimate of sleep problems prevalence among children in mainland China and to describe its epidemiological characteristics.MethodsRelevant studies were searched thoroughly via electronic databases included China National Knowledge Infrastructure, Wanfang, Weipu, PubMed, Embase and Medline databases from inception until December 2020. Prevalence estimates were calculated by random-effects models. The sources of heterogeneity were explored using subgroup analyses and Meta-regression analysis, and publication bias was estimated by funnel plots and Egger's Test.ResultsOverall, 66 studies were included in this meta-analysis, which revealed that the pooled prevalence of sleep problems was 37.6% (95%CI: 34.3–40.9%) with high heterogeneity (I² = 99.6%,P < 0.001). The incidence of snoring was 7.7%, choking or gasping was 0.9%, apnea was 1.5%, restless sleep was 11.3%, mouth breathing was 4.7%, hyperhidrosis was 17.2%, leg movements was 2.7%, bruxism was 9.6%, sleep talking was 0.7%, sleep-walking was 0.8%, nightmare was 5.1%, enuresis was 3.4%, night awakening was 6.7% and trouble falling asleep was 11.1%. The prevalence rate of sleep problems among males was higher than females (OR:1.01,95%CI:1.05–1.13). In all age groups, the prevalence rates of sleep problems increased with age, including infancy or early childhood group (33.3%), pre-school group (38.9%), school-age group (43.7%). The prevalence rate in South China (30.4%, 95%CI: 23.9–36.8%) was the lowest, and the highest prevalence rate was in West China (47.4%,95%CI:35.9–58.9%), which than any other region in China. The point estimate for sleep disorders prevalence obtained using the CSHQ criterion was higher than other criteria. Meta-regression indicated that age group could influence prevalence estimation (P = 0.011).ConclusionsOver the past two decades, the prevalence rate of sleep problems among children in mainland China has increased, significantly affecting two-fifth of the school-age children. The incidence of hyperhidrosis, restless sleep and trouble falling asleep were significantly higher than other sleep prombles. The prevalence rate of sleep problems in west China was significantly higher than in any other area. There is still a lack of guidelines on children's sleep problems in mainland China, so future research should pay special attention to the sleep problems of school-age children and children in economically backward areas.     

Sleep parameters measured by accelerometry: descriptive analyses from the 22-year follow-up of the Pelotas 1993 birth cohort

ObjectiveTo describe the sleep time window (STW), total sleep time (TST), and sleep percent [SP = (TST/STW) × 100] by accelerometry in a population-based young adult cohort in Brazil.MethodsCross-sectional analysis with a 22-year sample (N = 2462). Sleep variables were measured using an accelerometer. The devices were worn on the non-dominant wrist for approximately seven days. A raw data analysis using the GGIR package was performed. The following sleep variables were extracted: TST, STW, and SP. Linear regression was used to adjust averages. All analyses were stratified according to sex. A comparison between weekday and weekend averages was also conducted.ResultsThe means of TST, STW, and SP for men were 5.9 h, 7.1 h, and 83.1%, respectively. For women, the means of TST, STW, and SP were 6.4 h, 7.6 h, and 84.6%, respectively. Women presented a higher means of all outcomes compared to men (p < 0.001). After adjusting for both sexes, white skin color and not working or studying were associated with higher TST. Individuals not working or studying presented higher means of STW and lower sleep SP. Women with children who were less than two years of age presented lower values of three evaluated outcomes. Regarding behavior and health condition variables, obesity was associated with lower STW only for men. Physical activity was associated with higher SP and risk drinking with lower TST and STW only for women.ConclusionDifferences between sexes were observed in TST, STW, and SP. In all outcomes women presented a higher means. Socioeconomic variables were associated with both sexes, but having children and behavior/health conditions differed between sexes.     

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.     

Altered REM sleep architecture in patients with Myotonic dystrophy type 1: is related to sleep apnea?

ObjectiveTo determine the sleep architecture and sleep respiratory abnormalities and to correlate with sleep symptoms in patients with Myotonic dystrophy type 1 (DM1).MethodsWe recruited a cohort of genetically confirmed patients with DM1, who attended the Neuromuscular clinic between July 2016 and December 2019. Clinical, sleep and whole night polysomnography data were collected. The analysis of sleep architecture, sleep respiratory parameters and comparison with healthy controls (HC) was performed in our sleep laboratory.ResultsA total of 59 patients with DM1 underwent sleep evaluation. Hypersomnolence in 42 (77.8%), ESS>10 in 23 (39%), and PSQI>5 in 18 (30.5%) were found in patients with DM1. Thirty-one (68.89%) patients with DM1 and 22 (95.65%) HC had more than 4-h of total sleep time (TST). More than 4 h of TST was taken to compare respiratory and sleep architecture parameters. Patients with DM1 had reduced sleep efficiency, reduced N2 sleep, and increase in N1 sleep, wake index, stage shift index, nocturnal sleep-onset REM periods compared to HC. AHI>15 was found in 16 (51.61%) DM1 and in 3 HC (13.64%). AHI had positive correlation with BMI, but not with age, ESS or disease progression (MIRS). All DM1 with AHI>15; 8(80%) and 1(33.33%) in AHI5to15, and AHI<5 groups, respectively had hypersomnolence.ConclusionIn this first study on Indian cohort, daytime hypersomnolence, poor nocturnal sleep quality, sleep architecture irregularities are identified to be common in patients with DM1. These abnormalities may be explained by sleep-related breathing disorders that are highly prevalent in these patients.     

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.     

A randomized,double blind,placebo controlled study to evaluate the effects of ashwagandha (Withania somnifera) extract on sleep quality in healthy adults

ObjectiveNon-restorative sleep (NRS) affects 10% people worldwide, leading to poor sleep quality, as well as physical and cognitive fatigue. This is the first human study in which an extract of ashwagandha (Withania somnifera Dunal L.) was evaluated for effects in improving overall sleep quality in subjects with NRS.MethodsIn this randomized, double-blind, placebo-controlled trial, 150 healthy subjects scoring high on non-restorative sleep measures were given 120 mg of standardized ashwagandha extract (Shoden®) once daily for six weeks. Subjects were evaluated using the Restorative Sleep Questionnaire-weekly version and World Health Organization Quality of Life-Bref (WHOQOL) scale. Sleep actigraphy was used to measure the onset of sleep latency, sleep efficiency, total sleep time and wake after sleep onset. Safety of the treatment was determined by testing of vitals, hematology, biochemistry and urinalysis.ResultsA total of 144 subjects completed the study, with no dropouts due to adverse events. A 72% increase in self-reported sleep quality was found for the treatment group, compared with 29% in the placebo group (p < 0.001). Based on activity monitoring data, the treatment group showed significant improvement in sleep efficiency (SE) (p < 0.01), total sleep time (p < 0.001) and sleep latency (p < 0.01) and wake after sleep onset (WASO) (p < 0.05) versus placebo after six weeks. In the ashwagandha group quality of life (QOL) scores showed significant improvement in physical (p < 0.001), psychological (p < 0.001), and environment domains (p < 0.01).ConclusionsSupplementation with the standardized ashwagandha extract for six weeks improved the overall quality of sleep by significantly improving the NRS condition in healthy subjects. No treatment related adverse events were reported in the study.Trial registrationClinical Trials Registry-India (www.ctri.nic.in). Registration number: CTRI/2017/02/007801.     

The association of sleep quality and night sleep duration with coronary heart disease in a large-scale rural population

ObjectiveThe purposes of the present study were to explore independent and interactive associations between night sleep duration, night sleep quality and coronary heart disease (CHD) based on a rural population in China.MethodsA total of 27,935 participants (11,177 men and 16,758 women) were investigated from the Henan Rural Cohort. Information about sleep was assessed by using the Pittsburgh Sleep Quality Index (PSQI). Restricted cubic splines and logistic regression were used to estimate the relationship between night sleep duration and quality with CHD.ResultAmong the 27,935 participants, 1506 participants with CHD were identified. Compared with participants with scores lower than 3, the odds ratios (ORs) and 95% confidence intervals (95% CIs) of participants with score of 3–5, 6–8, ≥9 were respectively 1.42 (1.24–1.63), 1.99 (1.70–2.33), and 2.56 (2.13–3.08) with full adjustment of covariates. Compared with night sleep duration of 7 h, men and women who slept less than 5 h were 1.55 (1.11–2.17), 1.12 (0.59–2.12) and 1.80 (1.20–2.68), after being adjusted ORs (95% CIs) of the total. Moreover, the ORs and 95% CIs of CHD increased with the shortening of sleep duration at PSQI score above the highlighted levels.ConclusionPoor sleep quality and short night sleep duration were all associated with CHD in Chinese rural areas. Moreover, the association was more obvious in women. In addition, the strongest prevalence of CHD was found in short sleepers with poor sleep quality.     

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.     

Could non-HDL-cholesterol be a better marker of atherogenic dyslipidemia in obstructive sleep apnea?

Background/objectiveObstructive sleep apnea (OSA) is independently associated with dyslipidemia, a surrogate marker of atherosclerosis. Low-density lipoprotein (LDL)-cholesterol is accepted as a major independent risk factor for cardiovascular disease. However, non-high-density lipoprotein (HDL)-cholesterol is a better marker of atherogenic dyslipidemia and recommended as a target of lipid lowering therapy. We aimed to assess the prevalence of atherogenic dyslipidemia, and relationship between OSA severity and serum LDL-cholesterol and non-HDL cholesterol levels in OSA patients.MethodsWe retrospectively evaluated treatment naïve 2361 subjects admitted to the sleep laboratory of a university hospital for polysomnography. All subjects’ lipid profile including total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, and non-HDL-cholesterol were measured.ResultsOut of 2361 patients (mean age 49.6 ± 11.9 years; 68.9% male, apnea-hypopnea index 36.6 ± 28.4/h), 185 (7.8%) had no OSA and 2176 (92.2%) had OSA. Atherogenic dyslipidemia prevalence was high (57–66%) in OSA patients, and especially increased in severe OSA compared to other groups (p < 0.05). Though total and LDL-cholesterol did not differ between those with and without OSA, non-HDL-cholesterol (p = 0.020), and triglycerides (p = 0.001) were higher and HDL-cholesterol levels (p = 0.018) were lower in OSA patients than non-OSA. Non-HDL-cholesterol was significantly correlated with OSA severity (p < 0.001) and hypoxia parameters (p < 0.01), whereas LDL-cholesterol showed no correlation.ConclusionsAtherogenic dyslipidemia is highly prevalent and non-HDL-cholesterol levels are significantly increased, predominantly in severe OSA patients. Non-HDL-cholesterol but not LDL-cholesterol, is significantly correlated with OSA severity and hypoxia parameters. Therefore, it could be better to use non-HDL-cholesterol, which is a guideline recommended target of lipid therapy, as a marker of atherosclerotic cardiovascular risk in OSA patients.     

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.     

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.     

EEG and behavioural correlates of mild sleep deprivation and vigilance

ObjectiveThe current study investigated the behavioral, cognitive, and electrophysiological impact of mild (only a few hours) and acute (one night) sleep loss via simultaneously recorded behavioural and physiological measures of vigilance.MethodsParticipants (N = 23) came into the lab for two testing days where their brain activity and vigilance were recorded and assessed. The night before the testing session, participants either slept from 12am to 9am (Normally Rested), or from 1am to 6am (Sleep Restriction).ResultsVigilance was reduced and sleepiness was increased in the Sleep Restricted vs. Normally Rested condition, and this was exacerbated over the course of performing the vigilance task. As well, sleep restriction resulted in more intense alpha bursts. Lastly, EEG spectral power differed in Sleep Restricted vs. Normally Rested conditions as sleep onset progressed, particularly for frequencies reflecting arousal (e.g., delta, alpha, beta).ConclusionsThe findings of this study suggest that only one night of mild sleep loss significantly increases sleepiness and, importantly, reduces vigilance. In addition, this sleep loss has a clear impact on the physiology of the brain in ways that reflect reduced arousal.SignificanceUnderstanding the neural correlates and cognitive processes associated with loss of sleep may lead to important advancements in identifying and preventing deleterious or potentially dangerous, sleep-related lapses in vigilance.     

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.     

Patterns of nightly CPAP usage in OSA patients with suboptimal treatment adherence

Background and objectivesLow adherence impairs the effectiveness of continuous positive airway pressure (CPAP) therapy in patients with obstructive sleep apnoea (OSA), but knowledge on CPAP usage micro-patterns is mostly lacking. Thus, the aim of this study was to analyse usage micro-patterns among patients with suboptimal CPAP adherence.MethodsWe analysed CPAP usage datasets comprising the initial 31 nights of therapy. By employing a threshold of 4 h usage in at least 70% of nights, we subdivided the patients into suboptimal and optimal users. We investigated single CPAP start- and stop-points, and introduced the parameter “interruption-rate”, by dividing the amount of therapy interruptions per night by the usage duration per night. This parameter represents the amount of interruptions per 1 h of CPAP usage. Group comparison analysis was performed via t-test, Wilcoxon rank sum-test, and via Chi²-test.ResultsWe included datasets of 48 suboptimal and 48 optimal users (55.9 ± 11.3 years, 83.3% men) in the analysis. Interruption-rate was significantly higher among suboptimal users, when compared with optimal users (median (quartiles) 0.24 (0.14/0.45) versus 0.15 (0.05/0.28), p < 0.0011). Suboptimal users were more likely to report that CPAP reduced their sleep quality, waked them up at night, and that CPAP side effects or problems with the device impaired their adherence.ConclusionsCPAP usage micro-patterns are more fragmented among OSA patients with lower overall adherence. These patterns might result from impaired sleep quality, due to CPAP side effects, and device-associated problems.