Mid-pregnancy and postpartum maternal mental health and infant sleep in the first year of life.

Perinatal depression and anxiety are common and associated with sleep problems in the offspring. Depression and anxiety are commonly comorbid, yet often studied independently. Our study used an integrative measure of anxiety and depressive symptoms to examine the associations of maternal mental health (mid-pregnancy and postnatal) with infant sleep during the first year of life. A total of 797 mother-child dyads from the 'Growing Up in Singapore Towards healthy Outcome' cohort study provided infant sleep data at 3, 6, 9 and 12 months of age, using the caregiver reported Brief Infant Sleep Questionnaire. Maternal mental health was assessed at 26-28 weeks gestation and 3 months postpartum using the Edinburgh Postnatal Depression Scale, Beck Depression Inventory and State-Trait Anxiety Inventory. Bifactor modelling with the individual questionnaire items produced a general affect factor score that provided an integrated measure of anxiety and depressive symptoms. Linear mixed models were used to model the sleep outcomes, with adjustment for maternal age, education, parity, ethnicity, sex of the child and maternal sleep quality concurrent with maternal mental health assessment. We found that poorer mid-pregnancy, but not postpartum, maternal mental health was associated with longer wake after sleep onset duration across the first year of life (ß = 49, 95% confidence interval 13-85 min). Poor maternal mental health during mid-pregnancy is linked to longer period of night awakening in the offspring during infancy. Interventions that aim to improve maternal antenatal mental health should examine infant sleep outcomes.

Comparison of Sleep Characteristics, Patterns, and Problems in Young Children Within the Southeast Asian Region.

BACKGROUND AND OBJECTIVES: Optimal sleeping habits are important for health development of infants. The role of culture in sleep habits cannot be underestimated. We aimed to characterize sleep patterns, sleep practices, and sleep problems; and assess the sleep settings and parental perceptions of sleep problems in children from birth to 36 months in countries in the Southeast Asian (SEA) region. PARTICIPANTS: Parents and caregivers of infants and toddlers (birth to 36 months old) from countries in Southeast Asia participated in this study. METHODS: Data was collected using the Brief Infant Sleep Questionnaire for a total of 5,987 children from 6 countries in the SEA region (967 Indonesia/ID, 997 Malaysia/MY, 1,034 Philippines/PH, 1,001 Singapore/SG, 988 Thailand/TH, and 1,000 Vietnam/VN). RESULTS: The sleep variables varied among SEA children studied. Bedtimes and nighttime sleep varied across the region by as much as 1 hr 34 min and 1 hr 15 min respectively. CONCLUSIONS: Despite being geographically very close together and having some common sociocultural characteristics, sleep variables in the young child within the SEA region do differ in significant ways.

Establishment of the nasal microbiota in the first 18 months of life: Correlation with early-onset rhinitis and wheezing.

BACKGROUND: Dynamic establishment of the nasal microbiota in early life influences local mucosal immune responses and susceptibility to childhood respiratory disorders. OBJECTIVE: The aim of this case-control study was to monitor, evaluate, and compare development of the nasal microbiota of infants with rhinitis and wheeze in the first 18 months of life with those of healthy control subjects. METHODS: Anterior nasal swabs of 122 subjects belonging to the Growing Up in Singapore Towards Healthy Outcomes (GUSTO) birth cohort were collected longitudinally over 7 time points in the first 18 months of life. Nasal microbiota signatures were analyzed by using 16S rRNA multiplexed pair-end sequencing from 3 clinical groups: (1) patients with rhinitis alone (n = 28), (2) patients with rhinitis with concomitant wheeze (n = 34), and (3) healthy control subjects (n = 60). RESULTS: Maturation of the nasal microbiome followed distinctive patterns in infants from both rhinitis groups compared with control subjects. Bacterial diversity increased over the period of 18 months of life in control infants, whereas infants with rhinitis showed a decreasing trend (P < .05). An increase in abundance of the Oxalobacteraceae family (Proteobacteria phylum) and Aerococcaceae family (Firmicutes phylum) was associated with rhinitis and concomitant wheeze (adjusted P < .01), whereas the Corynebacteriaceae family (Actinobacteria phylum) and early colonization with the Staphylococcaceae family (Firmicutes phylum; 3 weeks until 9 months) were associated with control subjects (adjusted P < .05). The only difference between the rhinitis and control groups was a reduced abundance of the Corynebacteriaceae family (adjusted P < .05). Determinants of nasal microbiota succession included sex, mode of delivery, presence of siblings, and infant care attendance. CONCLUSION: Our results support the hypothesis that the nasal microbiome is involved in development of early-onset rhinitis and wheeze in infants.

The genetic variation rs6903956 in the novel androgen-dependent tissue factor pathway inhibitor regulating protein (ADTRP) gene is not associated with levels of plasma coagulation factors in the Singaporean Chinese.

BACKGROUND: Genome-wide association study (GWAS) has reported that rs6903956 within the first intron of androgen-dependent tissue factor pathway inhibitor (TFPI) regulating protein (ADTRP) gene is associated with coronary artery disease (CAD) risk in the Chinese population. Although ADTRP is believed to be involved in the upregulation of TFPI, the underlying mechanism involved is largely unknown. This study investigated the association of rs6903956 with plasma Factor VII coagulant activity (FVIIc) and fibrinogen levels, which are regulated by TFPI and are independent risk predictors for CAD. METHODS: We conducted the analysis in both Chinese adult (N = 309) and neonatal cohorts (N = 447). The genotypes of the rs6903956 single nucleotide polymorphism (SNP) were determined by the polymerase chain reaction restriction fragment length polymorphism method (PCR-RFLP). FVIIc and fibrinogen level were measured from citrated plasma. The association between rs6903956 and coagulation factors was tested by linear regression with adjustment for possible confounders. Analysis was carried out in adults and neonates separately. RESULTS: No significant association was observed between rs6903956 and plasma FVIIc nor fibrinogen levels with adjustment for age, gender, body mass index (BMI) and cigarette smoking in adults (P for FVIIc = 0.464; P for fibrinogen = 0.349). The SNP was also not associated with these two coagulation factors in the neonates (P for FVIIc = 0.579; P for fibrinogen = 0.359) after adjusting for gestational age, gender and birth weight. CONCLUSIONS: SNP rs6903956 on ADTRP gene was not associated with plasma FVIIc nor fibrinogen levels.

Interaction Between Peroxisome Proliferator Activated Receptor δ and Epithelial Membrane Protein 2 Polymorphisms Influences HDL-C Levels in the Chinese Population.

Peroxisome proliferator activated receptors (PPARs) are transcription factors involved in the regulation of key metabolic pathways. Numerous in vivo and in vitro studies have established their important roles in lipid metabolism. A few SNPs in PPAR genes have been reported to be associated with lipid levels. In this study, we aimed to investigate the interactive effects between single nucleotide polymorphisms (SNPs) in three PPAR isoforms α/δ/γ and other genetic variants across the genome on plasma high-density lipoprotein-cholesterol (HDL-C) levels. Study subjects (N = 2003) were genotyped using Illumina HumanOmniZhongHua-8 Beadchip. Fifty-three tag SNPs ± 100 kb of PPAR α, δ, and γ (r(2) < 0.2) were selected. The effect of interactions between PPAR SNPs and those across the genome on HDL-C was tested using linear regression models. One statistically significant interaction influencing HDL-C was detected between PPARδ SNP rs2267668 and epithelial membrane protein 2 (EMP2) downstream SNP rs7191411 (N = 1993, ß = 0.74, adjusted P = 0.022). This interaction was successfully replicated in the meta-analysis of two additional Chinese cohorts (N = 3948, P = 0.01). The present study showed a novel SNP × SNP interaction between rs2267668 in PPARδ and rs7191411 in EMP2 that has significant impact on circulating HDL-C levels in the Singaporean Chinese population.

Long-term Follow-up of Pulmonary Function and Scoliosis in Patients With Duchenne's Muscular Dystrophy and Spinal Muscular Atrophy.

BACKGROUND: Spine surgery for neuromuscular scoliosis in patients with Duchenne's Muscular Dystrophy (DMD) and Spinal Muscular Atrophy (SMA) remained controversial. This study aimed to review the long-term results of spine surgery and its effect on pulmonary function in these patients. METHODS: A retrospective review was conducted for the above patients who had undergone surgery from 1990 to 2006 in a tertiary hospital. Their yearly lung function tests, clinical records, and x-ray films before and after surgery were reviewed. All patients had at least 2 lung function tests performed before surgery and at least 3 lung function tests performed after surgery. Records of perioperative pulmonary infections that resulted in hospital admissions were also retrieved from the hospital computer system. RESULTS: Forty patients were reviewed: 29 with DMD, 11 with SMA. The mean follow-up period was 11.6 years. For patients with DMD, the mean correction of Cobb's angle from surgery was 34.1 degrees. The rate of decline of the predicted forced vital capacity preoperatively was 7.80% per year, and was reduced to 4.26% per year postoperatively (P<0.001). For patients with SMA, the mean correction of Cobb's angle from surgery was 44.1 degrees. The rate of decline of the predicted forced vital capacity preoperatively was 5.31% per year, and was reduced to 1.77% per year postoperatively (P<0.001). For both DMD and SMA patients, the difference between the rate of preoperative and postoperative pulmonary infections that resulted in hospital admission were, however, not significant (P=0.433 and 0.452, respectively). CONCLUSIONS: Scoliosis surgery in patients with DMD and SMA results in a long-term decreased rate of decline in pulmonary function over a follow-up period of more than 10 years. The level of the apical vertebrae of the scoliosis did not demonstrate a significant trend on the pulmonary function. The frequency of chest infections did not improve by scoliosis surgery. LEVEL OF SIGNIFICANCE: Level III­Retrospective study.

Rhinitis in the first 18 months of life: exploring the role of respiratory viruses.

BACKGROUND: Rhinitis is common in early childhood, but allergic rhinitis is considered a later manifestation of the atopic march. This study aimed to evaluate rhinitis (allergic and non-allergic) in the first 18 months of life, its link with other atopic manifestations and the role of respiratory viruses. METHODS: Subjects (n = 1237) of the Singapore GUSTO birth cohort were followed up quarterly until 18 months of age with questionnaires to screen for rhinitis symptoms lasting at least 2 wk and with monthly calls to positive subjects to detect prolonged/recurrent rhinitis symptoms (total duration ≥ 4 wk). Anterior nasal swabbing for molecular-based virus detection was conducted during these visits and near (within a month) rhinitis episodes. Skin prick testing to common environmental and food allergens was conducted at the 18 month visit. RESULTS: Prolonged/recurrent rhinitis was significantly associated with history of parental atopy (mother: aOR = 2.17; father: aOR = 1.82) and atopic comorbidities of eczema (aOR = 2.53) and wheeze (aOR = 4.63) (p < 0.05), though not with allergen sensitization. Although the frequency of nasal respiratory virus detection during scheduled quarterly visits did not differ between prolonged/recurrent rhinitis and matched controls (p > 0.05), virus detection was higher in swabs obtained within a month following rhinitis episodes in prolonged/recurrent rhinitis subjects compared with scheduled visits (adjusted p = 0.04). CONCLUSIONS: Based on the duration of rhinitis symptoms, this study defined a subset of early childhood rhinitis which was associated with atopic predisposition and comorbidities. Persistent respiratory viral shedding may contribute to the symptomatology. Whether this entity is a precursor of subsequent childhood allergic rhinitis will require longer follow-up.

Relationship Between Child and Maternal Sleep: A Developmental and Cross-Cultural Comparison.

The aim of this study was to assess the relationship between young children's sleep and maternal sleep from both a developmental and a cross-cultural perspective. Mothers of 10,085 young children completed the Brief Infant/Child Sleep Questionnaire and the Pittsburgh Sleep Quality Index. Overall, there were significant relationships between maternal and child sleep for bedtime, waketime, number of night wakings, and total nighttime sleep time across ages and cultures, although these relationships were stronger with younger children than preschool-aged children. Mothers report that their child's sleep pattern significantly impacts their sleep and daytime function, and they do not feel confident in managing their child's sleep pattern. Thus, interventions to improve children's sleep and develop good sleep habits, especially in early childhood, are likely to improve the quality of life of the whole family.

Prevalence of habitual snoring and its correlates in young children across the Asia Pacific.

AIMS: To evaluate: (i) the prevalence of habitual snoring (HS) in a large sample of children aged from birth to 36 months in 14 countries across Asia Pacific; and (ii) the different correlates associated with HS in Caucasians, Chinese and non-Chinese, non-Caucasian Asians. METHODS: This was a multi-centre, cross-sectional survey conducted across Asia Pacific. Parents/caregivers of 23,481 infants and toddlers completed an expanded version of the Brief Infant Sleep Questionnaire. We defined HS as snoring more than three nights per week. RESULTS: Chinese and non-Caucasian non-Chinese (NCNC) children had a lower prevalence of HS across the age range from birth to 3 years than their Caucasian counterparts (6.2% and 5.1% vs. 11%, P < 0.01). Boys had a higher prevalence of HS compared to girls (χ(2) = 98.5, P < 0.0001). History of prematurity (OR = 1.37-1.56, CI (1.1-2.17), P < 0.01) and gender (OR = 1.53-1.54, CI (1.26-1.85), P < 0.0001) were found to be significant predictors for HS. Current breastfeeding (OR = 0.69, CI (0.54-0.88), P < 0.005) and greater parental age (OR = 0.86, CI (0.78-0.96), P < 0.01) were protective against HS among NCNC children. HS was less prevalent in younger Chinese subjects (OR = 0.88, CI (0.84-0.93), P < 0.0001). In Caucasians, parents' education (OR = 0.78, CI (0.67-0.91), P < 0.005) and their not sleeping in the same room as their child (OR = 0.62, CI (0.45-0.86), P < 0.005) were negatively associated with parental report of HS. CONCLUSIONS: Prevalence of HS shows racial differences among countries across Asia Pacific. Future studies should assess craniofacial structure and body fat distribution as contributory factors for this differential prevalence.

ASVAC2022 : 8th Asian Vaccine Conference.

Aiming to further the Immunization Partners in Asia Pacific (IPAP)'s vision of a world where no one suffers from a vaccine preventable disease, the 8th Asian Vaccine Conference (ASVAC 2022) was held in Colombo, Sri Lanka and virtually from 15 to 18, September 2022 (www.asianvaccine.com). This conference followed those held in Siem Reap, Cambodia (2009), Manila, Philippines (2010), Jakarta, Indonesia (2011), Cebu, Philippines (2013), Hanoi, Vietnam (2015), Singapore (2017) and Naypyidaw and Yangon, Myanmar (2019). The ASVAC2022 themed "Immunization: in Era of Pandemics," commenced with the EPI Managers' Workshop, followed by pre-conference workshops and Vaccinology Masterclass, followed by the main conference featuring 5 plenary lectures, 6 partner-led symposia, free paper and poster presentations, and industry-supported lunch and evening sessions. There were over 1830 registered participants, with 112 attending in person and 998 virtually from 63 countries. The conference was organized by IPAP and hosted by the Vaccine and Infectious Disease Forum of Sri Lanka, Sri Lanka College of Pediatricians, Sri Lanka College of Microbiologists and College of General Practitioners of Sri Lanka, with the support of the Ministry of Health, Sri Lanka. The 9th ASVAC is scheduled to be held in Davao City, Philippines in late 2023.

Chronotype and time-of-day effects on spatial working memory in preschool children.

STUDY OBJECTIVES: Spatial working memory (SWM) capacity subserves complex cognitive functions, yet it is unclear whether individual diurnal preferences and time-of-day influence SWM in preschool children. The main and interaction effects of chronotype and time-of-day on SWM and SWM differences in preschoolers with different chronotypes within each time-of-day group will be examined. METHODS: We studied a subset of typically developing 4.5-year-olds taking part in a birth cohort study (n = 359). The Children's Chronotype Questionnaire categorized children into morning-, intermediate-, and evening-types. Using a computerized neuropsychological test (Cambridge Neuropsychological Test Automated Battery), SWM was determined from the total number of between-search errors (ie, between search-total errors) and Strategy scores. Higher between search-total errors or lower Strategy scores indicated worse SWM. Time-of-day was categorized into late morning (10:00 am to 11:59 am), afternoon (12:00 pm to 3:59 pm), and late afternoon (4:00 pm to 6:30 pm). In a subsample (n = 199), caregiver-reported chronotype was validated using actigraphy-measured sleep midpoint. RESULTS: After controlling for ethnicity, no significant main and interaction effects of chronotype and time-of-day on between search-total errors and Strategy scores were seen (all P > .05). However, evening-types outperformed morning-types (ie, lower mean between search-total errors) in the late afternoon (P = .013) but not in the late morning and afternoon (all P > .05). Actigraphy data in the subsample confirmed that evening-types had later sleep midpoints during weekdays and weekends (P < .001). CONCLUSIONS: Since evening-type preschoolers had better SWM in the late afternoon compared to morning-type preschoolers, this gives insights into optimal learning opportunities in early childhood education. CITATION: Abdul Jafar NK, Tham EKH, Eng DZH, et al. Chronotype and time-of-day effects on spatial working memory in preschool children. J Clin Sleep Med. 2023;19(10):1717-1726.

Caregiver perceptions of sleep problems and desired areas of change in young children.

OBJECTIVE: To explore the prevalence of and relationship between caregiver-reported sleep problems and sleep-related desired areas of change in young children (0-36 months) in a multinational sample. METHODS: Caregivers (96.5% mothers) of 2219 young children (birth to 3 years; M = 13.7 mos; 49.8% male) completed an online survey including an abbreviated Brief Infant Sleep Questionnaire-Revised (BISQ-R) and questions about desired areas of change regarding their child's sleep. Data were collected in six countries (Indonesia, Japan, New Zealand, Singapore, Thailand, and United States). RESULTS: Overall, 35% of caregivers reported a sleep problem and nearly all (96%) indicated a desired area of change, with 76% endorsing changes in 3 or more categories (bedtime/falling asleep, overnight, morning, and naps). Desiring a change in their child's sleep was universal across age group and country, with those perceiving a sleep problem more likely to endorse an area of change than those without a sleep problem. Overall, the top change categories were bedtime (80%), naps (74%), and overnight (67%). Top specific areas of change related to sleeping for longer stretches, waking up later in the morning, and having an earlier bedtime. CONCLUSIONS: Although one-third of caregivers perceived that their child had a sleep problem, nearly all caregivers identified desired areas of change related to their child's sleep, across the first three years of life and all countries. Sleep education, such as normalizing sleep challenges that are developmentally appropriate, is warranted for all families of young children, regardless of whether sleep problems are endorsed.

Variations in longitudinal sleep duration trajectories from infancy to early childhood.

OBJECTIVE: This study investigates variations in night, day, and total sleep trajectories across infancy and childhood in Asian children. PARTICIPANTS: Participants consisted of a subset of 901 children, within the Growing Up in Singapore Towards healthy Outcomes cohort, which recruited 1247 pregnant women between June 2009 and September 2010. DESIGN: We used a novel conditional probabilistic trajectory model: a probabilistic model for mixture distribution, allowing different trajectory curves and model variances among groups to cluster longitudinal observations. Longitudinal sleep duration data for the trajectory analyses were collected from caregiver-reported questionnaires at 3, 6, 9, 12, 18, 24, and 54 months. RESULTS: We found 3 patterns of night sleep trajectories (n = 356): long consistent (31%), moderate consistent (41%), and short variable (28%); and 4 patterns of day sleep trajectories (n = 347): long variable (21%), long consistent (20%), moderate consistent (34%), and short consistent (25%). We also identified 4 patterns of total sleep trajectories (n = 345): long variable (19%), long consistent (26%), moderate consistent (28%), and short variable (27%). Short, moderate, and long trajectories differed significantly in duration. Children with consistent trajectories also displayed sleep patterns that were significantly more representative of typical developmental sleep patterns than children with variable trajectories. CONCLUSIONS: This is the first study to describe multiple sleep trajectories in Singaporean children and identify between-individual variability within the trajectory groups. Compared to predominantly Caucasian samples, night/total sleep trajectories were generally shorter, while day sleep trajectories were longer. Future studies should investigate how these variations are linked to different developmental outcomes.

Association between breastfeeding and sleep patterns in infants and preschool children.

BACKGROUND: Although most studies have reported unfavorable short-term effects of breastfeeding on early-childhood sleep-wake behaviors that potentially attenuate over time, findings have remained inconsistent. OBJECTIVES: We assessed associations of breastfeeding with longitudinal day-, night-, and total-sleep trajectories and with sleep-wake behaviors in healthy infants and preschoolers. METHODS: Caregivers of naturally conceived, term, singleton infants (n = 654) completed the Brief Infant Sleep Questionnaire (3, 6, 9, 12, 18, and 24 mo) and/or Children's Sleep Habits Questionnaire (54 mo), and provided information on their infants' breastfeeding status at 3 mo. Trajectory analyses derived 4 day- (n = 243), 3 night- (n = 248), and/or 4 total- (n = 241) sleep trajectories, each differing in length of sleep duration (short/moderate/long) and variability (variable/consistent). Sleep-wake behaviors from 3 to 24 mo (day/night/total-sleep durations and duration/number of night awakenings) were also assessed for associations with breastfeeding. RESULTS: After adjusting for potential covariates, formula-fed infants, relative to fully breastfed (predominant or exclusive) infants, were significantly less likely to exhibit moderate (OR: 0.28; 95% CI: 0.11, 0.70) and long consistent (OR: 0.18; 95% CI: 0.07, 0.50) night-sleep trajectories and less likely to exhibit moderate (OR: 0.21; 95% CI: 0.07, 0.61) and long consistent (OR: 0.12; 95% CI: 0.04, 0.38) and long variable (OR: 0.16; 95% CI: 0.05, 0.56) total-sleep trajectories, instead of short variable night- and total-sleep trajectories. Partially breastfed infants did not differ from fully breastfed infants for both night- and total-sleep trajectories. No significant differences were found between all groups for day-sleep trajectories. Fully breastfed infants had longer night- (6, 9, 12, and 24 mo) and total- (3 and 12 mo) sleep durations than formula-fed infants, albeit a greater number of night awakenings (from 6 to 12 mo). CONCLUSIONS: Despite more night awakenings, fully breastfed infants have overall longer night- and total-sleep durations (sleep trajectories) than formula-fed infants.

Time trends of co-existing atopic conditions in Singapore school children: prevalence and related factors.

Atopic diseases are known to co-exist and are interrelated. Their co-existence in a patient increases disease burden and morbidity. We sought to study the prevalence of co-existing atopic conditions over time and its associated risk factors among Singapore children. Data was collected from two respective The International Study of Asthma and Allergies in Childhood surveys conducted in 1994 and 2001. Data on asthma, rhinitis and eczema were obtained from the responses to questions about wheezing, exercise-induced wheezing, nocturnal cough, rhinitis symptoms, rash, and diagnoses of asthma, rhinitis and eczema in the last 12 months. Data on demographic and known risk factors were also obtained. The prevalence of children who have had more than one atopic disorder increased significantly from 6.0% in 1994 to 10.2% in 2001 (p < 0.001). Parental history of atopic disease, maternal educational level, male gender and smoke exposure were significantly associated with co-existent atopic symptoms in the child. Among Singapore schoolchildren, there was a significant prevalence of co-existent atopic disease and this prevalence was rising. The influences of both genetic and environmental factors were likely to have contributed to these observations.

Compliance with topical nasal medication--an evaluation in children with rhinitis.

It is our impression that children with rhinitis often dislike or struggle with the administration of topical nasal sprays and drops. This study aims to investigate children's acceptance of topical nasal sprays/drops, and to identify patient factors that may affect their acceptance. An interview (by WYZI) questionnaire survey was carried out on parents/guardians of children aged 1-15 with rhinitis, where information on the diagnosis and treatment, patients' use and responses to these medications, and their preferred treatment routes were collected. Two hundred questionnaires were completed, of which 194 were valid for analysis. The mean age of patients was 7.54 yr; male to female ratio was 1:1.6, and Chinese made up the majority (62.4%). About one quarter (24.7%) of children disliked the use of topical nasal sprays/drops sufficiently to affect compliance with the medication. Furthermore, of those who could indicate their preferred route of drug administration (n = 75), 73% indicated a preference for oral medication, while only 11% preferred the nasal route. Topical nasal sprays/drops were more acceptable in older children (7-15 yr) compared to the younger ones (1-6 yr) (OR = 2.383, CI 1.223-4.644). The acceptance of nasal sprays/drops was not associated with gender, ethnic group, concurrent use by other family members, length and amount of usage, and the response to therapy. A substantial proportion of children prescribed topical nasal sprays/drops did not find it acceptable. Age played a significant factor to the acceptance of the use of topical nasal sprays/drops.

Variations in habitual sleep and relational memory in 6-month-olds.

OBJECTIVES: Adequate sleep duration and good sleep quality are considered essential for development, especially during periods of major neurodevelopmental change. Still, relations between parent-reported habitual sleep and emerging cognitive abilities within the first year of life are not well studied. Here, we examined relations between habitual sleep measures and an aspect of cognitive functioning, relational memory, which emerges as early as 6 months of age, as compared to other abilities (ie, recognition memory and attentional orienting), both of which are considered to emerge earlier in development. PARTICIPANTS: Participants were a subset of 267 healthy typically developing 6-month-olds taking part in the Growing Up in Singapore towards Healthy Outcomes cohort study. MEASUREMENTS: Sleep duration, sleep latency, and number and duration of night awakenings were derived from the Brief Infant Sleep Questionnaire (BISQ). Short sleep was defined as <10 hours per day, categorized as "not recommended" based on the National Sleep Foundation recommendations. Associations between sleep variables and infants' performance on 2 relational memory tests (deferred imitation and relational binding) were examined independently using hierarchical (blockwise entry) linear regression. Associations between sleep and recognition memory and attentional orienting were also explored. RESULTS: Habitual short sleepers had poorer relational memory recall in the deferred imitation task compared with 'typical' sleepers (10-18 hours per day). Shorter sleep latency was related to a greater proportion of correct responses for certain aspects of relational binding. There were no associations between sleep and recognition memory or attention. CONCLUSIONS: Our findings suggest that habitual sleep duration and short sleep latency associate with 6-month-olds' relational memory, suggesting a preferential association with memory tasks that are sensitive to development during the second half of the first year.

Obstructive Sleep Apnea Detection Using Difference in Feature and Modified Minimum Distance Classifier.

The current gold standard of Obstructive Sleep Apnea (OSA) diagnosis involves the use of a Polysomnography (PSG) system which requires the patient to stay in the hospital for overnight recording. The process is uncomfortable for the patient and it disturbs the patient's sleep pattern. On the other hand, it is well known that some acoustic features of the snoring sounds are good indicators of the presence of OSA, and a variety of acoustic OSA detection algorithms have been reported in the literature. Typically, these algorithms use multiple features and a relatively complex classifier, which are not ideal for handling the huge over-night data. In this paper, we propose an algorithm that uses a single feature and a relatively simple classifier. The proposed feature is the difference between two carefully selected Mel-frequency cepstral coefficients (MFCCs) of the snoring sound samples. The proposed classifier is derived based on a modified minimum distance criterion. The proposed algorithm has been tested with patient data. The results show that the proposed algorithm outperforms existing algorithms and is able to achieve up to 97.1% detection accuracy.

Relation of plasma tryptophan concentrations during pregnancy to maternal sleep and mental well-being: The GUSTO cohort.

BACKGROUND: Evidence suggests a relation between plasma tryptophan concentrations and sleep and mental well-being. As no studies have been performed in pregnant women, we studied the relation of plasma tryptophan concentrations during pregnancy with sleep quality, and mood during and after pregnancy. METHODS: Pregnant women (n = 572) from the Growing Up in Singapore Towards healthy Outcomes study completed the Pittsburgh Sleep Quality Index (PSQI), the Edinburgh Postnatal Depression Scale (EPDS) and the State-Trait Anxiety Inventory (STAI) at 26-28 weeks gestation and three months post-delivery. Plasma tryptophan concentrations were measured at 26-28 weeks gestation. Poisson regressions estimated prevalence ratios (PR) for the association between tryptophan and poor sleep quality (PSQI global score > 5), probable antenatal depression (EPDS ≥ 15) and probable anxiety (STAI-state ≥ 41) were calculated adjusting for covariates. RESULTS: Mean plasma tryptophan concentrations was 48.0µmol/L (SD: 8.09). Higher plasma tryptophan concentrations were associated with a lower prevalence of antenatal poor sleep quality adjusting for covariates [PR: 0.88 (95% CI 0.80, 0.97) per 10µmol/L], especially in those participants who also suffered from anxiety symptoms [PR: 0.80 (95% CI 0.67, 0.95)]. No associations were observed between tryptophan concentrations during pregnancy and postnatal sleep quality or mental well-being. LIMITATION: Subjective measures were used to assess sleep and mental well-being. CONCLUSIONS: We observed that higher plasma tryptophan concentrations were associated with a 12% lower prevalence of poor sleep quality during pregnancy, in particular among those with anxiety symptoms. These findings suggest the importance of having adequate tryptophan concentrations during pregnancy.

Prospective multinational study of pertussis infection in hospitalized infants and their household contacts.

BACKGROUND: Increased incidence of pertussis has been noted among infants too young to be immunized. We studied the disease burden of pertussis in pediatric intensive care units and the source of infection in several Asian, European and Latin American countries. METHODS: The study was conducted in 7 countries from September 2001 to January 2004. Children <1 year of age were enrolled from pediatric intensive care units (PICU) and pediatric wards if they presented with respiratory failure, apnea, bradycardia, or cough accompanied by paroxysms, vomiting, whoop or cyanosis. Household members of pertussis-positive index cases were asked to answer a questionnaire and provide diagnostic specimens. RESULTS: Pertussis was confirmed in 99 infants (12%) of 823 infants included in the analysis: 10 of 90 (11%) in Brazil, 9 of 88 (10%) in Costa Rica, 11 of 145 (8%) in Germany, 13 of 147 (9%) in Singapore, 29 of 67 (43%) in Spain, 2 of 86 (2%) in Taiwan and 25 of 200 (13%) in Uruguay. However, sensitivity analysis indicated that these figures were conservative. The mean (+/- SD) average age of infection was 2.6 +/- 2.2 months. Pertussis was found among 96 of 269 (36%) of household contacts investigated. At least one household contact was identified as the source of infection in 24 of 88 (27%) of the PICU cases and mothers were identified as being the most frequent source of infection. CONCLUSION: Although regional differences exist, severe pertussis represents a considerable global disease burden. Since most infants are infected before vaccination and concomitant protection is completed, household contacts should be targeted for booster vaccination to reduce the pertussis reservoir.