Daily mood and sleep: reciprocal relations and links with adjustment problems

Children's sleep problems are common and associated with increased risk for adjustment problems. We examined daily links between children's sleep and mood, using a daily diary method and actigraphy. We also tested children's daily mood as a mediator of relations among sleep and children's broader internalizing and externalizing symptoms. A community sample of 142 children (mean age = 10.69 years; 57% girls; 69% European American, 31% African American) and their parents participated. For 1 week, children wore actigraphs and parents completed a daily telephone interview about their child's mood. Following the week of actigraphy, mothers and fathers reported on their child's adjustment. Multi‐level models indicated within‐person relations between children's mood and subsequent sleep fragmentation (indicated by increased activity) and sleep latency, and between‐person relations between sleep latency and subsequent mood on the next day. Significant indirect effects were found such that a more negative daily mood (aggregated across diary days) mediated relations between poor sleep efficiency and longer sleep latency and parent‐reported internalizing and externalizing symptoms. Findings extend previous research by highlighting disruptions to children's daily mood as a potential mechanism linking sleep problems to children's mental health.     

A Prospective Cohort Study on the Relationship of Sleep Duration With All-cause and Disease-specific Mortality in the Korean Multi-center Cancer Cohort Study

Objectives

Emerging evidence indicates that sleep duration is associated with health outcomes. However, the relationship of sleep duration with long-term health is unclear. This study was designed to determine the relationship of sleep duration with mortality as a parameter for long-term health in a large prospective cohort study in Korea.

Methods

The study population included 13 164 participants aged over 20 years from the Korean Multi-center Cancer Cohort study. Information on sleep duration was obtained through a structured questionnaire interview. The hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality were estimated using a Cox regression model. The non-linear relationship between sleep duration and mortality was examined non-parametrically using restricted cubic splines.

Results

The HRs for all-cause mortality showed a U-shape, with the lowest point at sleep duration of 7 to 8 hours. There was an increased risk of death among persons with sleep duration of ≤5 hours (HR, 1.21; 95% CI, 1.03 to 1.41) and of ≥10 hours (HR, 1.36; 95% CI, 1.07 to 1.72). In stratified analysis, this relationship of HR was seen in women and in participants aged ≥60 years. Risk of cardiovascular disease-specific mortality was associated with a sleep duration of ≤5 hours (HR, 1.40; 95% CI, 1.02 to 1.93). Risk of death from respiratory disease was associated with sleep duration at both extremes (≤5 and ≥10 hours).

Conclusions

Sleep durations of 7 to 8 hours may be recommended to the public for a general healthy lifestyle in Korea.     

Polysomnographically determined sleep and body mass index in patients with insomnia

We assessed associations between polysomnographically determined sleep, especially the amount of slow-wave sleep (SWS), and body mass index (BMI) in patients with insomnia. One hundred and forty-one insomniacs and 55 healthy volunteers completed overnight polysomnographic recordings, and we measured height and body weight. No significant correlations were obtained between total sleep time and BMI among insomniacs. Compared with normal volunteers, insomnia patients exhibited longer sleep latency and shorter total sleep duration. While the two groups had no significant differences in BMI, insomniacs presented with more N1 but less time spend in SWS and rapid eye movement sleep (REMS). Based on their SWS time, we divided insomnia patients into three groups: short (26.99±13.88), intermediate (59.24±8.12), and long (102.21±26.17) SWS groups. The short-SWS group had significantly greater BMI than the long-SWS group. Further analyses with multiple linear regression showed a significant negative correlation between the amount of SWS and BMI scores in insomniacs, whereas no such correlation was found in healthy volunteers after controlling for potential confounds (e.g., age, sex and AHI). Our study suggests that low amounts of SWS may be associated with higher BMI in patients with insomnia.     

Association between short sleeping hours and overweight in adolescents: results from a US Suburban High School survey

Insufficient sleep may lead to adverse health effects, influencing body weight. This study quantified the prevalence of short sleep and the association between sleep duration and overweight in a sample of suburban students. Cross-sectional study was conducted in 2004, involving 529 students from Bay High School, Bay Village, OH, USA, using self-administered questionnaires assessing lifestyle and sleep behaviors. Students with a body mass index Z Score >85th percentile for sex and age were deemed overweight. Ninety percent of students reported average sleep time less than 8 h on school nights, with 19% reported less than 6 h of sleep per night. Twenty percent of the sample were overweight. Overweight was significantly associated with the male gender, increased caffeine consumption, and short sleep duration. Compared with students sleeping >8 h, the age and gender-adjusted odds ratio of overweight was 8.53 (95% CI: 2.26, 32.14) for those with <5 h sleep (P = 0.0036); 2.79 (1.03, 7.55) for those with 5–6 h sleep; 2.81 (1.14, 6.91) for those with 6–7 h sleep; and 1.29 (0.52, 3.26) for those with 7–8 h sleep. Short sleep duration was common and associated with overweight with evidence of a “dose–response” relationship. These results confirm a high prevalence of short sleep among suburban high school students and provide additional support suggesting significant association between short sleeping hours and overweight. There are no financial disclosures from any of the authors.     

Meta-analysis of short sleep duration and obesity in children and adults

BACKGROUND: Recent epidemiological studies suggest that short sleep duration may be associated with the development of obesity from childhood to adulthood. OBJECTIVES: To assess whether the evidence supports the presence of a relationship between short sleep duration and obesity at different ages, and to obtain an estimate of the risk. METHODS: We performed a systematic search of publications using MEDLINE (1996-2007 wk 40), EMBASE (from 1988), AMED (from 1985), CINHAL (from 1982) and PsycINFO (from 1985) and manual searches without language restrictions. When necessary, authors were contacted. Criteria for inclusion were: report of duration of sleep as exposure, BMI as continuous outcome and prevalence of obesity as categorical outcome, number of participants, age, and gender. Results were pooled using a random effect model. Sensitivity analysis was performed, heterogeneity and publication bias were also checked. Results are expressed as pooled odds ratios (OR [95% confidence intervals, CIs]) and as pooled regression coefficients (beta; 95% CIs). RESULTS: Of 696 studies identified, 45 met the inclusion criteria (19 in children and 26 in adults) and 30 (12 and 18, respectively) were pooled in the meta-analysis for a total of 36 population samples. They included 634,511 participants (30,002 children and 604,509 adults) from around the world. Age ranged from 2 to 102 years and included boys, girls, men and women. In children the pooled OR for short duration of sleep and obesity was 1.89 (1.46 to 2.43; P < 0.0001). In adults the pooled OR was 1.55 (1.43 to 1.68; P < 0.0001). There was no evidence of publication bias. In adults, the pooled beta for short sleep duration was -0.35 (-0.57 to -0.12) unit change in BMI per hour of sleep change. CONCLUSIONS: Cross-sectional studies from around the world show a consistent increased risk of obesity amongst short sleepers in children and adults. Causal inference is difficult due to lack of control for important confounders and inconsistent evidence of temporal sequence in prospective studies.     

Short sleep duration in middle childhood: risk factors and consequences

STUDY OBJECTIVES: To measure sleep duration in 7-year-old children; identify the determinants of sleep duration; and assess the association between short sleep duration and obesity, cognitive functioning, and behaviour. DESIGN: Longitudinal study with disproportionate sampling of the participants. SETTING: Community. PARTICIPANTS: 591 seven-year-old children, of whom 519 had complete sleep data. INTERVENTIONS: Not applicable. MEASUREMENTS: Sleep duration was assessed by actigraphy. Other measurements included height, weight, BMI, percentage body fat as assessed by bioimpedance assay, intelligence (WISC-III) and behaviour (Strengths & Difficulties questionnaire, parent and teachers Conners Rating Scales). RESULTS: Mean time in bed according to parental report was 10.9 hours (SD 0.8). Mean sleep duration by actigraphy was 10.1 (SD 0.8) hours. In multivariable analysis, sleep duration was longer on weekdays vs. weekend nights (31.5 min, P = 0.002), in winter (40.5 min), autumn (31.1 min), and spring (14.8 min) compared with summer (P <0.0001), and in those with younger siblings (11.7 min, P = 0.03). Sleep duration was shorter when bedtime was after 21:00 (-41.1 min, P <0.0001). In multivariable analysis, sleep duration <9 hours was associated with being overweight/ obese (BMI: OR = 3.32; 95% CI = 1.40, 7.87) with an increase of 3.34% body fat (P = 0.03), and this was not explained by physical activity or television watching. Short sleep duration was also associated with higher emotional lability scores (Conners Rating Scale Parent Form; P = 0.03). IQ (WISC-III) and attention deficit / hyperactivity disorder scores (both parent and teachers Conners Rating Scales) did not differ with sleep duration. CONCLUSIONS: Sleep duration in 7-year-old children varies considerably among individuals. The duration is affected by weekday, season, and having younger siblings. Importantly, short sleep duration was shown to be an independent risk factor for obesity/overweight.     

Sleep characteristics and risk of dementia and Alzheimer's disease: The Atherosclerosis Risk in Communities Study

Introduction

This study tested the hypotheses that late-midlife obstructive sleep apnea (OSA) and short and long sleep duration are associated with dementia over 15 years of follow-up.

重庆沙坪坝中小学生睡眠时间与超重肥胖的相关性分析

目的 探讨中小学生睡眠时间与超重肥胖的关系，为制定干预措施提供依据。方法 利用多阶段整群抽样方法，于2018年12月至2019年1月，对重庆沙坪坝8所中小学，共5306名在校学生，进行睡眠时间与超重肥胖的调查分析。结果 该区中小学生平均睡眠时间为9.21h，不同性别、学段和区域的学生，睡眠时间差异均有统计学意义；学生睡眠时间在<8h，8~8.9h，9~9.9h和≥10h的构成，分别为13.47%，25.63%，29.95%和30.95%，差异有统计学意义。工作日平均入睡时间为21:00，周末节假日为22:00；工作日平均睡眠时间为8.87h小时，周末为10.05h，差异均有统计学意义。中小学生超重与肥胖检出率分别为15.49%和9.18%，超重肥胖检出率随睡眠时间的缩短而升高，差异有统计学意义。调整了性别、学段和区域等因素后，以睡眠时间≥10h作参照，发现周末节假日睡眠不足是肥胖的危险因素，睡眠时间<8h的OR值为1.81（1.09~2.86），<9h的OR值为1.58（1.12~2.19）。结论 周末节假日睡眠不足是肥胖的危险因素，应重点改善学生周末节假日的睡眠状况，保证充足的睡眠时间。     

2017年北京市成年人睡眠与血清TG/HDL-C的关联性研究

背景　血清三酰甘油（TG）与高密度脂蛋白胆固醇（HDL-C）的比值（TG/HDL-C）是系统性反映血脂水平的指标，不良的睡眠状况可能是血脂异常的危险因素，探索睡眠问题对TG/HDL-C的影响并识别危险人群，有助于有针对性地通过改善睡眠减少血脂异常的发生。目的　了解2017年北京市成年人睡眠问题现状及其与血清TG/HDL-C的关联，旨在为改善睡眠质量及控制血脂水平提供依据。方法　数据来源于2017年北京市成年人慢性病与危险因素监测，在北京市16区采用多阶段分层整群抽样方法抽取18~79岁常住居民，收集调查对象年龄、性别、婚姻状况、受教育程度等人口学信息，高血压、糖尿病、血脂异常等慢性病患病情况，吸烟、饮酒等生活行为方式，睡眠时长及打鼾/窒息、入睡困难、中间觉醒≥2次、早醒、服用安眠药等睡眠问题，测量身高、体质量、腰围、血压，抽取空腹静脉血进行血脂四项检测。采用t检验、非参数Kruskal-Wallis H检验、Mann-Whitney U检验、χ2检验、多因素Logistic回归分析睡眠与TG/HDL-C的关联。结果　13 240例调查对象平均年龄为（44.79±15.47）岁，平均睡眠时长为（7.47±1.30）h/d，中位TG/HDL-C为0.99（0.84），6 490例（49.02%）30 d内存在睡眠问题。睡眠处于9 h/d者TG/HDL-C水平最低，中位数为0.95（0.82），不同睡眠时长的女性人群TG/HDL-C比较，差异有统计学意义（χ2=37.14，P<0.01）。按是否存在睡眠问题进行分组，组间TG/HDL-C水平比较，差异有统计学意义（P<0.01）。在控制性别、年龄、婚姻状况、城乡、受教育程度、现在吸烟、30 d内饮酒、身体活动不足、高血压、糖尿病、BMI等协变量之后，多因素Logistic回归分析结果显示，存在≥1种睡眠问题是TG/HDL-C升高的影响因素〔OR（95%CI）=1.05（1.01，1.08）〕；相比于无睡眠问题的人群，男性或18~44岁人群存在≥1种睡眠问题是高TG/HDL-C的影响因素〔OR男（95%CI）=1.05（1.01，1.09）；OR18~44岁（95%CI）=1.06（1.01，1.10）〕。结论　北京市18~79岁成年人睡眠时长过长或过短，打鼾/窒息/入睡困难、服用安眠药等睡眠问题可能影响血清TG/HDL-C，男性及45岁以下人群作为高危人群应采取改善睡眠的措施。