UNASSIGNED: Gestational diabetes mellitus (GDM) is associated with several adverse maternal and neonatal outcomes. Previous studies reported a link between altered sleep and risk of GDM. This systematic review aims to collate evidence on the association between impaired sleep quality and duration, and the risk of GDM.
UNASSIGNED: PubMed, Embase, Web of Science, and Scopus databases were searched up to January 20, 2024. Studies reporting the association between impaired sleep quality and duration and risk of GDM were included. Sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI). Random-effects meta-analysis was performed, and the results were reported as hazard ratio (HR) with 95% confidence interval (CI).
UNASSIGNED: 19 studies were included. Meta-analysis revealed a significant increase in the risk of GDM in pregnant women with poor sleep quality (i.e. <5 PSQI) (HR: 1.50, 95% CI: 1.26 - 1.78, p < .001). Sleep duration of <7 h (HR: 1.56, 95% CI.: 1.20 - 2.01, p < .001), and >8 h (HR: 2.32, 95% CI.: 1.19 - 4.50, p = .01) were also associated with a significantly higher incidence of GDM.
UNASSIGNED: Sleep quality and duration emerge as critical risk factors of GDM. Healthcare practitioners should consider targeted interventions to improve sleep hygiene as a potential measure for GDM prevention.

OBJECTIVE: The effect of various sleep traits on the risk of lung cancer differs among pre-existing studies. This study aims to systematically review and synthesise the association between sleep duration and insomnia with the incidence of lung cancer.
METHODS: PubMed, Embase and The Cochrane Library were searched from inception to 23 April 2023 for observational studies examining the effect of sleep quantity or insomnia on lung cancer incidence. We pooled maximally-adjusted hazard ratios and odds ratios separately using random effects inverse variance weighted models. The risk of bias of observational studies was assessed using the Newcastle-Ottawa Scale.
RESULTS: We included 11 observational studies with a pooled cohort of 5,049,141 patients. The mean age of the patients was 49.5 ± 17.7 years, and 51.4% were males. The risk of bias ranged from low-moderate. Individuals who slept for a shorter or longer duration than the reference range of sleep per night showed an increased risk of lung cancer by 11% (HR:1.11; 95%CI:1.00-1.23) and 16% (HR:1.16; 95%CI:1.06-1.27) respectively. Furthermore, individuals with insomnia symptoms had a 9% greater risk of lung cancer than those without symptoms (HR:1.09; 95%CI:1.05-1.13).
CONCLUSIONS: This study suggests that insufficient sleep, excessive sleep and insomnia may be associated with an increased risk of lung cancer. Physicians should be mindful of this association and encourage healthy sleep practises among patients. Given the observed heterogeneity among some pre-existing studies, future research with longer periods of follow-up, greater control for covariates and objective testing of sleep parameters may add value to this topic.

Two researchers independently assessed studies published up to February 5, 2023, across PubMed, Web of Science, Embase, and Cochrane Library, to investigate the associations of sleep traits with cardiometabolic risk factors, as well as with cardiovascular diseases. Fourteen systematic reviews consisting of 23 meta-analyses, and 11 Mendelian randomization (MR) studies were included in this study. Short sleep duration was associated with a higher risk of obesity, type 2 diabetes (T2D), hypertension, stroke, and coronary heart disease (CHD) in observational studies, while a causal role was only demonstrated in obesity, hypertension, and CHD by MR. Similarly, long sleep duration showed connections with a higher risk of obesity, T2D, hypertension, stroke, and CHD in observational studies, none was supported by MR analysis. Both observational and MR studies indicated heightened risks of hypertension, stroke, and CHD in relation to insomnia. Napping was linked to elevated risks of T2D and CHD in observational studies, with MR analysis confirming a causal role in T2D. Additionally, snoring was correlated with increased risks of stroke and CHD in both observational and MR studies. This work consolidates existing evidence on a causal relationship between sleep characteristics and cardiometabolic risk factors, as well as cardiovascular diseases.

OBJECTIVE: To consolidate adolescents\' perspectives regarding various aspects of sleep and offer insights to promote healthier sleep habits during their critical developmental years.
METHODS: Six electronic databases (PubMed, CINAHL, Embase, Scopus, PsycINFO and Web of Science) were searched from their inception dates to June 2023. Data were extracted and meta-summarised using Sandelowski and Barroso\'s approach and synthesised using Thomas and Harden\'s thematic analysis framework.
RESULTS: Meta-synthesis from 11 peer-reviewed published studies identified four main themes: (1) Awareness and understanding of sleep\'s significance, (2) The shadows and radiance of slumber, (3) Traversing the sleepscape: trouble bubbles and (4) Illuminating the path: Guiding lights to enhanced sleep.
CONCLUSIONS: Our review findings suggest a lack of awareness and guidance regarding the significance of sleep and the cultivation of good sleep habits among adolescents. Identified barriers to adequate sleep encompass various factors, including overthinking, poor habits, family/environmental influences, extensive technology use, peer pressure, the fear of missing out, academic demands and involvement in extracurricular activities. Strategies to improve adolescents\' sleep health involve multiple sleep strategies, including sleep education, workshops/seminars, parental involvement, incorporating digital well-being practices, the promotion of relaxation techniques and the provision of essential resources. Prioritising sleep health and implementing targeted interventions are key steps to empower adolescents, create supportive environments and shape a healthier future generation. Future research endeavours should focus on evaluating the effectiveness of interventions and exploring the influence of cultural factors.
CONCLUSIONS: There exists a notable lack of awareness and guidance regarding the significance of sleep and the cultivation of good sleep habits among adolescents. Barriers to achieving adequate sleep among adolescents include overthinking, poor habits, family/environmental influences, extensive technology use, peer pressure, the fear of missing out, academic demands and involvement in extracurricular activities. The collaboration between healthcare institutions, professionals and educational institutions is crucial to facilitate (1) the implementation of sleep education workshops/seminars targeting adolescents, (2) increased parental involvement and role-modelling to instil good sleep practices among adolescents and (3) enhanced integration of digital well-being practices, the promotion of relaxation techniques and accessibility to essential sleep hygiene resources.
UNASSIGNED: Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.
UNASSIGNED: No patient or public contribution.
UNASSIGNED: This review was registered on the Prospective Register of Systematic Reviews (CRD42023403775).

Adolescents\' late chronotypes colliding with early school start times (SSTs) are associated with students\' unhealthy sleep habits. Most studies comparing different SSTs associate later SSTs with longer sleep duration and lower social jetlag. However, the magnitude of the effect varies between studies and the effect of different SSTs on chronotype is not well established. Importantly, although human circadian rhythms are entrained by sunlight, when studying the effect of different SSTs on adolescents\' sleep habits usually only the social clock, and not the solar clock, is considered. This meta-analysis investigates whether later SSTs affect adolescents\' sleep habits and chronotype and it assesses factors that can modulate this effect, including the relative importance of social and solar clocks. Here, through a database search we identify 37 studies comparing the effect of different SSTs on adolescents\' sleep habits and/or chronotype. Random effect meta-analyses showed that later SSTs are associated with later sleep timings and longer sleep duration on weekdays, lower levels of social jetlag, and later chronotypes. Several meta-regressions reveal that the distance between compared SSTs and the interplay between SSTs and the solar clock modulate the effect of different SSTs on sleep timings and duration on weekdays.

OBJECTIVE: Obesity is a leading contributor to global morbidity and mortality. Short sleep duration is significantly associated with the incidence of obesity, however, it remains unclear whether this relationship is influenced by sex. The purpose of this meta-analysis was to systematically evaluate the evidence of whether the association between short sleep duration and obesity differs between males and females.
RESULTS: The protocol was registered with PROSPERO (CRD42023374205). From inception through June 2023, Medline, Embase and Web of Science databases were searched for longitudinal cohort studies with minimum 12 months of observation. The quality of studies was assessed using the Newcastle-Ottawa Quality Assessment for Cohort Studies. Results were pooled using a random effects model. Results are expressed as ratio of odds ratios (ROR) with 95% confidence interval (CI). ROR directly estimates the relative strength of the association of interest (measured as odds ratio [OR] between females and males). Sensitivity analysis was performed and inconsistency between studies was assessed using I2 statistics. A total of 4582 articles were retrieved with the search strategy, of which 6 were included. The meta-analysis indicated that the association between short sleep duration and obesity incidence was statistically significant in both men [OR 1.26 (95% CI 1.13-1.40)] and women [OR 1.36 (95% CI 1.16-1.59)]. However, it did not differ significantly between sexes ROR (women/men) 1.04 (95%CI 0.79-1.36; I2 20.1%).
CONCLUSIONS: This meta-analysis indicates that women and men who subjectively report short sleep duration have similarly increased risks of incident obesity.

OBJECTIVE: Sleep duration has been suggested to be associated with hypertension (HTN). However, evidence of the nature of the relationship and its direction has been inconsistent. Therefore, we performed a meta-analysis to assess the relationship between sleep duration and risk of HTN incidence, and to distinguish more susceptible populations.
METHODS: PubMed, Embase, Scopus, Web of Science, and ProQuest were searched from January 2000 to May 2023 for cohort studies comparing short and long sleep durations with 7-8 hours of sleep for the risk of HTN incidence. Random-effect model (the DerSimonian-Laird method) was applied to pool risk ratios (RR) and 95% confidence interval (CI).
RESULTS: We included sixteen studies ranging from 2.4 to 18 years of follow-up duration evaluating HTN incidence in 1,044,035 people. Short sleep duration was significantly associated with a higher risk of developing HTN (HR: 1.07, 95% CI: 1.06-1.09). The association was stronger when the sleep duration was less than 5 hours (HR: 1.11, 95% CI: 1.08-1.14). In contrast to males, females (HR: 1.07, 95% CI: 1.04-1.09) were more vulnerable to developing HTN due to short sleep duration. No significant difference between different follow-up durations and age subgroups was observed. Long sleep duration was not associated with an increased incidence of HTN.
CONCLUSIONS: Short sleep duration was associated with higher risk of HTN incidence, however, there was no association between long sleep duration and incidence of HTN. These findings highlight the importance of implementing target-specific preventive and interventional strategies for vulnerable populations with short sleep duration to reduce the risk of HTN.

Sleep duration has been proposed as a potential and important modifiable risk factor, yet its precise relationship with hypertension among Asian adults remains unclear. This meta-analysis aims to elucidate the impact of short sleep duration on hypertension risk within the adult Asian population. A systematic search of databases, including PubMed, Scopus, and ScienceDirect, was conducted to identify relevant studies published up to January 4, 2024. Eligible studies comprised observational cohort studies and cross-sectional studies that compared short sleep duration to normal sleep duration in relation to hypertension risk among Asian adults. The definitions for short and normal sleep durations were derived from the respective studies. The random effects model was utilized to pool effect estimates, and all statistical analyses were conducted using Review Manager 5.4 software (RevMan) (Cochrane Collaboration, Oxford, UK). Results from a systematic search obtained seven studies assessing sleep duration and hypertension risk in Asian populations. Based on a meta-analysis of six studies, short sleep duration is associated with a higher hypertension risk when compared to normal sleep duration (OR: 1.36; 95% CI: 1.13-1.64; p: 0.0010; I2: 75%). Subgroup analysis based on sex showed that the association is evident across males (OR: 1.12; 95% CI: 1.01-1.25; p: 0.03; I2: 64%) and females (OR: 1.22; 95% CI: 1.10-1.35; p: 0.0003; I2: 82%). In conclusion, based on the analyzed studies, short sleep duration is associated with a higher mild risk of hypertension, irrespective of sex. Thus, short sleep duration can be a modifiable risk factor that can be prevented to reduce the risk of hypertension. By incorporating sleep hygiene practices and promoting healthy sleep habits, significant improvement in cardiovascular health can be made, especially in hypertension risk at a population level. Further studies on the effect of sleep duration in different age populations should be conducted to confirm the impact of short sleep duration.

BACKGROUND: Dietary components or its overall properties can influence an individual\'s sleep status.
OBJECTIVE: The aim for this study was to critically search, appraise, and synthesize research evidence on the association between dietary inflammatory index (DII) and sleep quality and its parameters.
METHODS: Original published studies on adults were obtained from the PubMed, SCOPUS, ScienceDirect, Cochrane Library, and Google Scholar databases.
METHODS: The search was conducted without date limitation until April 2023. Duplicated and irrelevant investigations were screened out, and the results of the remaining articles were descriptively summarized, then critically appraised and analyzed. Possible mechanistic pathways regarding diet, systemic inflammation, and sleep status were discussed.
METHODS: Of the 102 studies searched, 23 articles (n = 4 cohort studies, 18 cross-sectional studies, and 1 intervention study) were included in the final review. The association between DII and sleep status was investigated subjectively in 21 studies and objectively in 6 studies. The main studied sleep outcomes were sleep quality, duration, latency, efficiency, apnea, disturbances, the use of sleeping medications, daytime dysfunctions, wakefulness after sleep onset, and rapid eye movement.
CONCLUSIONS: According to most of the evidence, DII may not be related to overall sleep quality, sleep duration, latency, efficiency, and the use of sleeping medications. The evidence of positive association was greater between a high DII score (pro-inflammatory diet) with daytime dysfunctions, wakefulness after sleep onset, and sleep apnea. There is insufficient evidence to make any conclusion regarding sleep disturbances and rapid eye movement.

UNASSIGNED: The relationship between sleep duration and obesity has been the focus of numerous investigations. This systematic review and meta-analysis of prospective cohort studies aimed to assess the relationship between sleep duration, abdominal obesity, and body composition.
UNASSIGNED: PubMed, Scopus, and Web of Science were searched until February 2024. Cohort studies that assessed the relationship between sleep duration at night and central obesity measures or body composition indices in adults were included. The quality of studies was assessed using the Newcastle-Ottawa scale. Random-effects meta-analysis was conducted on studies that reported risk ratio (RR) and 95% confidence intervals (CIs).
UNASSIGNED: Eighteen studies were eligible to be included. Eleven out of the 18 studies were not included in the analysis as 10 studies did not report RR, and in one study, the definition of short and normal sleep duration was different from others. The results of the meta-analysis indicated that short sleep duration was significantly associated with abdominal obesity (RR = 1.08; 95% CI: 1.04-1.12; I 2 = 49.1%, n = 7), but long sleep duration was not (RR = 1.02; 95% CI: 0.83-1.24; I 2 = 98.2%, n = 6).
UNASSIGNED: Short sleep duration was associated with a slightly higher risk of central obesity, while long sleep duration was not.