Sleep disturbance has the largest impact on children's behavior and emotions.

Objective: Children's behavior and emotions are affected by sleep disturbances, the parent-child relationship, media viewing time, and the social status of parents and caregivers. We conducted a questionnaire survey to identify the factors that have the greatest impact on children's behavior and emotions and how these factors relate to each other. Methods: A parental questionnaire survey was performed at a public elementary school. The questionnaire comprised questions on the family environment (e.g., family structure, media and game exposure, after-school lessons, and caregiver's work schedule) and physical information, the Strengths and Difficulties Questionnaire (SDQ), the Children's Sleep Habits Questionnaire (CSHQ), and the Pittsburgh Sleep Quality Index (PSQI) for parents' sleep condition. A path diagram was drawn to hypothesize the complex interrelationships among factors, and structural equation modeling was used to estimate the path coefficients. Result: We identified several factors that significantly affected the SDQ score. The CSHQ total score had the largest impact, followed by after-school lessons, single-mother families, and children's sex. In addition, several indirect pathways that led to the CSHQ score (i.e., a pathway from time spent watching television to CSHQ score via children's bedtime and a pathway from single-mother family to CSHQ score via PSQI total score) significantly affected the SDQ score. Conclusion: Children's sleep habits that were influenced by several environmental factors had the greatest impact on children's behavior and emotions, which suggested that children's behavioral problems can be improved by interventions focused on sleep habits, such as sleep hygiene instructions.

Increased cortisol awakening response after completing the summer treatment program in children with ADHD.

OBJECTIVE: Little is known about the cortisol awakening response (CAR) in children with attention deficit hyperactivity disorder (ADHD). Here, we examined the CAR in children with ADHD and their mothers before, immediately after, and 4months after an intensive summer treatment program (STP). METHODS: Participants were 37 children aged 7-12years who completed the STP in 2009 and 2010, and their mothers. Daily saliva samples for cortisol measurement were collected twice daily at awakening and 30min afterwards at pre-STP, post-STP, and during a follow-up measurement period. ADHD symptom scores were evaluated by parents, and participants completed the Kid-KINDLR QOL questionnaire. RESULTS: CAR was low in children with ADHD before the STP, and increased to the control range 4months after STP. Maternal CAR also tended to increase after STP. Changes in the CAR in children tended to correlate with an improved ADHD inattention scores (p=0.091), physical health (p=0.070), and school life subscales scores in the Kid-KINDLR (p=0.079). CONCLUSION: We demonstrated that STP improved the behavior and QOL of children with ADHD. Our results indicate that STP could lead to improvements in HPA axis function, as reflected by increased CAR after STP.

Influence of sleep-onset time on the development of 18-month-old infants: Japan Children's cohort study.

OBJECTIVE: We report here the influence of sleep patterns on the development of infants in Japan. A total of 479 infants were registered in two different Japanese cities. Direct neurological observations were performed by licensed pediatric neurologists. METHOD: We designed a prospective cohort study and identified the sleep factors of children showing atypical development. The Kinder Infant Developmental Scale (KIDS) was used to evaluate the infant developmental quotient (DQ); we also applied a neurobehavioral screening battery. Neurobehavioral observations in 18-month-old infants were designed to check all developmental categories within the three areas of motor function, language, and social function. Based on the observations, each infant was classified as having "atypical development" or "typical development". RESULT: We found that later sleep onset time (>22:00 h), and longer naps during the day each had significant positive correlations with atypical development patterns in 18-month-old infants. For each hour the infant sleep-onset time extended past 22:00 h, the infants showed worse neurodevelopmental outcomes, at an odds ratio increase of 2.944. CONCLUSION: Although our results may be confounded by sleep problems resulting from pre-existing developmental disabilities, we can safely conclude that appropriate sleeping habits are important for healthy development in 18-month-old infants.

High incidence of sleep problems in children with developmental disorders: results of a questionnaire survey in a Japanese elementary school.

OBJECTIVE: The aim of the present school-based questionnaire was to analyze the sleep problems of children with developmental disorders, such as pervasive developmental disorder and attention deficit hyperactivity disorder. METHODS: The sleep problems of 43 children with developmental disorders were compared with those of 372 healthy children (control group). All children attended one public elementary school in Kurume, Japan; thus, the study avoided the potential bias associated with hospital-based surveys (i.e. a high prevalence of sleep disturbance) and provided a more complete picture of the children's academic performance and family situation compared with a control group under identical conditions. Children's sleep problems were measured with the Japanese version of the Children's Sleep Habits Questionnaire (CSHQ). RESULTS: Children with developmental disorders had significantly higher total CSHQ scores, as well as mean scores on the parasomnias and sleep breathing subscales, than children in the control group. The total CSHQ score, bedtime resistance, sleep onset delay, and daytime sleepiness worsened with increasing age in children with developmental disorders; in contrast, these parameters were unchanged or became better with age in the control group. In children with developmental disorders, there was a significant association between a higher total CSHQ score and lower academic performance, but no such association was found in the control group. For both groups, children's sleep problems affected their parents' quality of sleep. There were no significant differences in physical, lifestyle, and sleep environmental factors, or in sleep/wake patterns, between the two groups. CONCLUSIONS: Children with developmental disorders have poor sleep quality, which may affect academic performance. It is important for physicians to be aware of age-related differences in sleep problems in children with developmental disorders. Further studies are needed to identify the association between sleep quality and school behavioral performance.

Sleep architecture in healthy 5-year-old preschool children: associations between sleep schedule and quality variables.

AIM: Although disturbed sleep quality such as night awakenings and difficulties in falling asleep are common symptoms during sleep in preschool children, relationships between sleep quality and sleep schedule are mostly unknown. This study aimed to evaluate the relationships between sleep schedule and quality variables in preschool children. METHODS: Sleep-wake patterns of 48 healthy 5-year-old children were assessed over 7 consecutive days using actigraphy. RESULTS: Children with longer sleep latency had a lower sleep quality, a later bedtime, a later sleep onset time, a shorter nocturnal sleep period and a longer daytime nap. Children with a longer nocturnal sleep period on weekends compared with weekdays had longer sleep latency and a later sleep onset time on weekdays, resulting in a lower sleep quality on weekends. An irregular bedtime on weekdays was associated with a later sleep onset time and a shorter sleep period on weekends. CONCLUSION: Sleep quality and schedule were linked with each other, which may explain why sleep problems tend to aggregate and form a wider syndrome of disturbed sleep even in young children. Strategies solely targeting the improvement of sleep quantity may not promote ideal sleep; simultaneous considerations for the sleep rhythm and quality may be required.

Determinants of sleep patterns in healthy Japanese 5-year-old children.

BACKGROUND: Early childhood is an important period for the development of sleep patterns; studies of sleep patterns in young preschool children may help elucidate the mechanism of associated mental/physical conditions and later sleep problems. AIM AND METHODS: The aim of this study was to investigate intrinsic and extrinsic independent variables associated with sleep patterns in preschool children using actigraphy. Forty-eight 5-year-old children from two types of nurseries, which accommodate children with (Type A) or without (Type B) in-home caregivers, were invited to undergo a 7-day actigraphic sleep study. RESULTS: Compared with weekdays, both sleep onset time and sleep end time were later on weekends (28 and 17 min later in average, respectively). On weekdays, cultural lessons were associated with a later sleep onset time (22 min later); female gender, sports lessons and fixed bathing times were related with an earlier sleep end time (17, 21 and 17 min earlier, respectively); sports lessons were also associated with higher sleep efficiency (3.7% higher). During weekends, unfixed bedtimes and daytime naps were related with a later sleep onset time (73 and 54 min later, respectively); male gender, Type A nursery and daytime naps were associated with a later sleep end time (33, 37 and 34 min later, respectively); sports lessons were associated with higher sleep efficiency (3.6% higher). CONCLUSIONS: Our current findings suggested that both intrinsic and extrinsic factors, such as gender, child care, lifestyle and after-nursery lessons, influence the establishment of sleep patterns in young preschool children. Further investigation of these independent variables may help establish a strategy for predicting and preventing sleep disorders later in life.

Utility of subjective sleep assessment tools for healthy preschool children: a comparative study between sleep logs, questionnaires, and actigraphy.

BACKGROUND: Sleep pattern is an important factor in a child's mental, behavioural and physical status. To evaluate the sleep patterns of children, subjective tools such as sleep logs and questionnaires are still widely used in addition to objective methods of sleep assessment. Despite the established correlation between subjective and objective sleep variables, the characteristic features of subjective assessment have not been elucidated. METHODS: To investigate the characteristics of parental sleep assessment (daily sleep log and brief questionnaire) in preschool children, a 7-day actigraphic sleep study was conducted in 48 healthy 5-year-old children. RESULTS: Sleep schedule variables in the parental reports generally correlated well with actigraphic assessment of sleep patterns; however, sleep periods were longer in parental reports than in actigraphic recordings. Although the daily sleep log was better correlated with actigraphy, the brief questionnaire showed a good correlation with sleep pattern on weekday actigraphic assessments. Parental reports recorded fewer than 10% of the night wakings recorded by actigraphy. CONCLUSIONS: Subjective sleep assessments remain useful, although their utility depends on the purpose and size of the study in question. However, knowledge of the potential biases and characteristics of such assessments is essential for correct interpretation of the data.

A novel subjective sleep assessment tool for healthy elementary school children in Japan.

BACKGROUND: A child's sleep pattern is important in defining his or her mental and physical well-being. Although we have reported previously on the utility of collecting 2 weeks of daily sleep logs, this type of record keeping is often onerous for the parents. Therefore, we established a new questionnaire, called the Japan Children's Study Sleep Questionnaire (JCSSQ), which is used to collect sleep pattern data over 4 weeks, including weekdays, Saturdays, Sundays, and holidays. METHODS: Two parent-administered sleep assessment tools, the JCSSQ and a daily sleep log, were used to examine the sleeping patterns of 105 school children (58 boys and 47 girls; age range, 6-12 years) in Fukuoka, Japan. Parents were requested to record sleep logs for 14 days after the JCSSQ. Sleep/wake status was recorded on the sleep log, from which data on the parameters of "sleep onset time", "waking time", "sleep period", and "number of nights waking" were extracted. RESULTS: There were no significant differences between the JCSSQ and the logs for waking time data collected on weekdays, Saturdays, and Sundays. However, there was a significant difference (P = 0.03) between the JCSSQ and the sleep logs with respect to the sleep onset time data collected on Saturdays. CONCLUSIONS: The JCSSQ was easy to fill out, and the data collected using the JCSSQ on weekdays were both valid and generally consistent with those collected using sleep logs. However, for sampling on Saturdays and Sundays, the JCSSQ data did not correlate with the sleep log data.

Relationship of head lean mass to regional bone mineral density in elderly postmenopausal women.

OBJECTIVES: This study investigated the relationship of head lean mass to bone mineral density (BMD). METHOD: Subjects were 102 elderly women (> or =65-years-old) and 123 middle-aged postmenopausal women (<65-years-old) with right-side dominance. Age, height, weight, and years since menopause (YSM) were recorded. Lean mass of the head, arm, trunk, leg, and total body were measured by dual-energy X-ray absorptiometry (DEXA). BMD of the same regions were measured by DEXA. RESULTS: In elderly women, head lean mass was positively correlated with BMD of the head (r=0.389, P<0.01), left arm (r=0.235, P<0.05), right arm (r=0.280, P<0.05), lumbar spine (L2-4) (r=0.411, P<0.001), pelvis (r=0.490, P<0.001), left leg (r=0.572, P<0.001), right leg (r=0.558, P<0.001), and total body (r=0.529, P<0.001). These relationships remained significant after adjusting for age, height, and YSM. In addition, the strength of correlation of head lean mass with BMD was higher than those of other regional lean mass with respective BMD. In middle-aged women, strength of correlation of head lean mass with BMD was loose (r< or =0.238), while regional lean mass was more correlated with respective regional BMD. CONCLUSION: Factors related to lifestyle associated with higher (lower) head lean mass may contribute to higher (lower) BMD in elderly postmenopausal women.