Sleep During Pregnancy: The nuMoM2b Pregnancy and Sleep Duration and Continuity Study

Study Objectives: To characterize sleep duration, timing and continuity measures in pregnancy and their association with key demographic variables. Methods: Multisite prospective cohort study. Women enrolled in the nuMoM2b study (nulliparous women with a singleton gestation) were recruited at the second study visit (16-21 weeks of gestation) to participate in the Sleep Duration and Continuity substudy. Women <18 years of age or with pregestational diabetes or chronic hypertension were excluded from participation. Women wore a wrist activity monitor and completed a sleep log for 7 consecutive days. Time in bed, sleep duration, fragmentation index, sleep efficiency, wake after sleep onset, and sleep midpoint were averaged across valid primary sleep periods for each participant. Results: Valid data were available from 782 women with mean age of 27.3 (5.5) years. Median sleep duration was 7.4 hours. Approximately 27.9% of women had a sleep duration of 9 hours. In multivariable models including age, race/ethnicity, body mass index, insurance status, and recent smoking history, sleep duration was significantly associated with race/ethnicity and insurance status, while time in bed was only associated with insurance status. Sleep continuity measures and sleep midpoint were significantly associated with all covariates in the model, with the exception of age for fragmentation index and smoking for wake after sleep onset. Conclusions: Our results demonstrate the relationship between sleep and important demographic characteristics during pregnancy

The association between sleep patterns and obesity in older adults.

BackgroundReduced sleep duration has been increasingly reported to predict obesity. However, timing and regularity of sleep may also be important. In this study, the cross-sectional association between objectively measured sleep patterns and obesity was assessed in two large cohorts of older individuals.MethodsWrist actigraphy was performed in 3053 men (mean age: 76.4 years) participating in the Osteoporotic Fractures in Men Study and 2985 women (mean age: 83.5 years) participating in the Study of Osteoporotic Fractures. Timing and regularity of sleep patterns were assessed across nights, as well as daytime napping.ResultsGreater night-to-night variability in sleep duration and daytime napping were associated with obesity independent of mean nocturnal sleep duration in both men and women. Each 1 h increase in the standard deviation of nocturnal sleep duration increased the odds of obesity 1.63-fold (95% confidence interval: 1.31-2.02) among men and 1.22-fold (95% confidence interval: 1.01-1.47) among women. Each 1 h increase in napping increased the odds of obesity 1.23-fold (95% confidence interval: 1.12-1.37) in men and 1.29-fold (95% confidence interval: 1.17-1.41) in women. In contrast, associations between later sleep timing and night-to-night variability in sleep timing with obesity were less consistent.ConclusionsIn both older men and women, variability in nightly sleep duration and daytime napping were associated with obesity, independent of mean sleep duration. These findings suggest that characteristics of sleep beyond mean sleep duration may have a role in weight homeostasis, highlighting the complex relationship between sleep and metabolism

THE ASSOCIATION BETWEEN SLEEP DURATION AND DEMENTIA: A META-ANALYSIS

In the United States, the current cases of Alzheimer’s disease will double by 2050. Therefore, it is important to study risk factors associated with dementia such as sleep duration. This meta-analysis was conducted to understand the discrepancy in study results since some demonstrated a V shaped association between duration of sleep and dementia while others found no association. If there truly is an association then sleep duration could be targeted to decrease the burdens caused by dementia. A meta-analysis of published studies was conducted to assess the association between sleep duration and the different forms of dementia. The articles were found using PubMed, Embase, Scopus, and EBSCO with the search terms (“Sleep Duration” OR “Change in Sleep Duration”) AND (Alzheimer* OR Dementia) and reviewing bibliographies. Studies were included in the analysis if they met the following criteria 1) a longitudinal study 2) a cohort, case-control, or clinical trial 3) assessed the exposure and outcome of interest 4) diagnosed dementia using established diagnostic criteria 5) provided a risk estimate and 95% confidence interval (CI) 6) in English 7) a published paper. Analyses such as test of heterogeneity, sensitivity analysis, and tests of publication bias were done using STATA15. The analysis included 11 cohort studies with a total of 48,360 participants. No significant association was found between short or long sleep duration and any form of dementia. However, there was a significant association between increase in sleep and dementia but there were only two published papers that examined this association. This study suggests that there is likely no association between sleep duration and any form of dementia which differs from results of previous meta-analyses

Reduced sleep duration affects body composition, dietary intake and quality of life in obese subjects.

Purpose Sleep duration has emerged as a crucial factor affecting body weight and feeding behaviour. The aim of our study was to explore the relationship among sleep duration, body composition, dietary intake, and quality of life (QoL) in obese subjects. Methods Body composition was assessed by DXA. ‘‘Sensewear Armband’’ was used to evaluate sleep duration. SF-36 questionnaire was used to evaluate quality of life (QoL). A 3-day dietary record was administered. Subjects were divided into 2 groups: sleep duration[and B300 min/day. Results 137 subjects (105 women and 32 men), age: 49.8 ± 12.4 years, BMI: 38.6 ± 6.7 kg/m2, were enrolled. Sleep duration was B300 min in 30.6 % of subjects. Absolute and relative fat mass (FM) (40.5 ± 9 vs. 36.5 ± 9.1 kg; 40.2 ± 4.7 vs. 36.9 ± 5.6 %), and truncal fat mass (19.2 ± 6.1 vs. 16.6 ± 5 kg; 38.6 ± 5.3 vs. 35.2 ± 5.5 %) were higher in subjects sleeping B300 min when compared to their counterparts (all p.05), whereas just a tendency towards a higher BMI was observed (p = 0.077). Even though energy intake was not different between groups, subjects sleeping B300 min reported a higher carbohydrate consumption per day (51.8 ± 5.1 vs. 48.4 ± 9.2 %, p = 0.038). SF-36 total score was lower in subjects sleeping B300 min (34.2 ± 17.8 vs. 41.4 ± 12.9, p = 0.025). Sleep duration was negatively associated with FM (r = -0.25, p = 0.01) and SF-36 total score (r = -0.31, p.001). The inverse association between sleep duration and SF-36 total score was confirmed by the regression analysis after adjustment for BMI and fat mass (R = 0.43, R2 = 0.19, p = 0.012). Conclusion Reduced sleep duration negatively influences body composition, macronutrient intake, and QoL in obese subjects

Associations between objectively measured and self‐reported sleep with academic and cognitive performance in adolescents: DADOS study

Adequate sleep has been positively related with health and school achievement out-comes during adolescence. The aim of this study was to investigate the associations ofobjectively measured and self‐reported sleep duration and quality with academic andcognitive performance in adolescents. This study was conducted with 257 adolescents(13.9 ± 0.3 years) from the DADOS study (Deporte, ADOlescencia y Salud). Objec-tively measured and self‐reported sleep duration and quality were obtained by a wrist‐worn GENEActiv accelerometer and the Spanish version of Pittsburgh Sleep QualityIndex questionnaire, respectively. Academic performance was analysed through schoolrecords using four indicators: math, language, science and grade point average score.Cognitive performance was measured using the Spanish version of the“SRA Test ofEducational Ability”. After Benjamini–Hochberg correction for the false discovery rate,objectively measured sleep duration was negatively associated with verbal ability (β=−0.179,p= .004), whilst self‐reported sleep quality was positively associated withacademic performance (βranging from 0.209 to 0.273; allp<.001). These associationsremained significant after further controlling for physical fitness and physical activity.Conversely, there were no associations between self‐reported sleep duration andobjective sleep quality with academic and cognitive performance. Our findings fit inline with previous research showing that sleep quality may play an important role onadolescents’academic performance. Further interventional research is needed to clar-ify the mechanisms by which sleep is related to academic performance in youth

Sleep duration and patterns in Chinese older adults: A comprehensive meta-analysis

This meta-analysis examined the mean sleep duration and patterns in Chinese older adult population. A literature search was systematically conducted covering major English (PubMed, Embase and PsycINFO) and Chinese (Chinese National Knowledge Infrastructure (CNKI), WanFang and SinoMed) databases. Data in studies with the mean and standard deviation of sleep duration and/or the proportion of short and long sleep durations in Chinese older adults were extracted and pooled using random-effects models. Subgroup analyses were conducted according to gender, region, area, survey time and sample size. A total of 36 studies with 150,616 subjects were included for analyses. The pooled mean sleep duration of 21 studies with available data was 6.82 hours/day (95% CI: 6.59–7.05 hours/day). The estimated proportions of sleep duration \u3c5 hours/day, \u3c6 hours/day, \u3c7 hours/day were 18.8% (95% CI: 1.7%–35.9%), 26.7% (95% CI: 19.7%–33.7%) and 42.3% (95% CI: 34.8%–49.8%), respectively. The pooled proportions for long sleepers were 22.6% (95% CI: 13.9%–31.4%) (\u3e8 hours/day) and 17.6% (95% CI: 12.4%–22.9%) (\u3e9 hours/day). Given the adverse effects of unhealthy sleep patterns, health professionals should pay more attention to sleep patterns in this population in China

Sleep Duration and Overweight among Elementary Schoolchildren:A Population-based Study in Japan

Although a number of studies have investigated the relationship of sleep duration to overweight and obesity, studies conducted among population-based elementary schoolchildren have been limited in Japan. The aim of the present study was to investigate the relationship between sleep duration and overweight among elementary schoolchildren in Japan. The study subjects were all fourth-grade schoolchildren (9 or 10 years of age) in Ina-town, Saitama Prefecture, Japan from 1999 to 2008. Information concerning each subjectʼs sex, age, and lifestyle was obtained using a self-administered questionnaire, while measurements of his or her height and weight were carried out. Childhood overweight was determined according to the definition established by the International Obesity Task Force. Data from 3,433 children were analyzed. In logistic regression analysis, a statistically significant dose-response relationship was observed between sleep duration and overweight among boys (p for trend＝0.014) but not among girls (p for trend＝0.149). Short sleep duration was associated with childhood overweight, and the sex difference in the association was observed. These findings suggested that it is important to consider sleep duration as part of any program to prevent overweight among elementary schoolchildren, especially among boys

Quantifying sleep architecture dynamics and individual differences using big data and Bayesian networks

The pattern of sleep stages across a night (sleep architecture) is influenced by biological, behavioral, and clinical variables. However, traditional measures of sleep architecture such as stage proportions, fail to capture sleep dynamics. Here we quantify the impact of individual differences on the dynamics of sleep architecture and determine which factors or set of factors best predict the next sleep stage from current stage information. We investigated the influence of age, sex, body mass index, time of day, and sleep time on static (e.g. minutes in stage, sleep efficiency) and dynamic measures of sleep architecture (e.g. transition probabilities and stage duration distributions) using a large dataset of 3202 nights from a non-clinical population. Multi-level regressions show that sex effects duration of all Non-Rapid Eye Movement (NREM) stages, and age has a curvilinear relationship for Wake After Sleep Onset (WASO) and slow wave sleep (SWS) minutes. Bayesian network modeling reveals sleep architecture depends on time of day, total sleep time, age and sex, but not BMI. Older adults, and particularly males, have shorter bouts (more fragmentation) of Stage 2, SWS, and they transition less frequently to these stages. Additionally, we showed that the next sleep stage and its duration can be optimally predicted by the prior 2 stages and age. Our results demonstrate the potential benefit of big data and Bayesian network approaches in quantifying static and dynamic architecture of normal sleep