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Objective: Genetic risks can accelerate ageing, yet better quality sleep may slow down it. We thus examined the interaction and combined effects of genetic predisposition and sleep quality on the risk of accelerate aging., Methods: This study included 407,027 participants from the UK Biobank. Sleep index of each participant was retrieved from the following seven sleep behaviors: snoring, chronotype, daytime sleepiness, sleep duration, insomnia, nap and difficulties in getting up. The biological age (PhenoAge) were estimated by corresponding algorithms based on clinical traits, and their residual discrepancies with chronological age were defined as the age accelerations (PhenoAgeaccel). We explored the interaction and combined effects of genetic risk and sleep quality on accelerated ageing by constructing a linear model., Results: Compared with participants in low sleep quality group, those in medium and high sleep quality group decreased 0.727 (95%CI, 0.653 to 0.801) and 1.056 (95%CI, 0.982 to 1.130) years of PhenoAgeaccel, respectively. Compared with participants in low genetic risk group, those in medium and high genetic risk group increased 0.833 (95%CI, 0.792 to 0.874) and 1.543 (95%CI, 1.494 to 1.592) years of PhenoAgeaccel, respectively. There was interaction between the genetic risk and sleep quality (P-interaction<0.001). For combined effect, compared to the group with high sleep quality and lower genetic risk, people with low sleep quality and high genetic risk had 2.747 (95%CI, 2.602 to 2.892) years higher PhenoAgeaccel., Conclusion: Our findings elucidate that better sleep quality could lessen accelerated biological ageing especially among population with high genetic risk., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Immune dysregulation has been observed in individuals with sleep disturbance, with HLA molecules play a crucial role in the immune response. This study aimed to investigate the associations between HLA alleles and sleep behaviours, considering several environmental factors. Data were sourced from the UK Biobank. Logistic regression analyses were performed to explore the associations between 359 HLA alleles and 4 sleep behaviours, including chronotype (n = 204,636), insomnia (n = 227,553), snoring (n = 214,350) and daytime dozing (n = 227,197). Furthermore, gene-environmental interaction studies (GEIS) were conducted to evaluate the interactions of HLA alleles with environmental factors on sleep behaviours. This study analysed a total sample and subgroups stratified by sex to elucidate the impact of HLA alleles on sleep behaviours. Our findings revealed several associations between specific HLA alleles and sleep behaviours. Notably, HLA-A*23:01 was associated with evening chronotype in the total sample (OR = 0.918, 95%CI: 0.872-0.965), while HLA-A*32:01 was associated with evening chronotype in males (OR = 1.089, 95%CI: 1.037-1.144). Furthermore, GEIS identified multiple sets of interactions associated with sleep behaviours. For example, the interaction of HLA-DPA1*01:04 with alcohol consumption was associated with daytime dozing in the total sample (OR = 1.993, 95%CI: 1.351-2.941), while the interaction of HLA-DQB1*05:04 with ever suffered mental distress preventing usual activities was associated with insomnia in males (OR = 0.409, 95%CI: 0.254-0.658). Our findings highlight the involvement of HLA in sleep regulation and underscore the potential interactions between HLA alleles and environmental factors in modulating susceptibility to sleep behaviours., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Although healthy sleep patterns have been linked to a lower risk of cardiovascular disease in earlier research, it is unclear how beneficial they are for venous thromboembolism (VTE)., Aim: This research aimed to examine the correlation between sleep patterns, genetic susceptibility, and VTE., Methods: In the UK Biobank cohort, healthy sleep behaviors were defined as early chronotype, 7-8 hours of sleep each day, no snoring, infrequent insomnia, and infrequent daytime sleepiness. Each of the five criteria was given 1 point, creating a healthy sleep score ranging from 0 to 5. Cox proportional hazards regression models were utilized to examine the associations between genetic susceptibility, healthy sleep score and VTE., Results: The UK Biobank study included 384,758 participants aged 56.6 ± 8.0 years. After a median of 11.9 years of follow-up, 8,885 (2.3%) participants were diagnosed with VTE. A healthy sleep score inversely affected VTE risk. For participants with a score of 5, the hazard ratio of VTE was 0.813 (95% confidence interval: 0.758-0.873, P<0.001) compared to those with a score ≤2. Early chronotype, sleeping 7-8 hours each day, infrequent insomnia, and infrequent daytime sleepiness were significantly associated with a 7.9%, 8.3%, 5.1%, and 20.7% lower risk of VTE, respectively. In addition, the correlation between sleep pattern and the incidence of VTE was consistent, regardless of genetic susceptibility (P for interaction = 0.366)., Conclusions: Our secondary analysis of a large-scale prospectively gathered registry revealed that individuals with a healthy sleep pattern are significantly correlated with lower risk of developing VTE, irrespective of genetic susceptibility., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Bai et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Sleep problems are prevalent. However, the impact of sleep patterns on digestive diseases remains uncertain. Moreover, the interaction between sleep patterns and genetic predisposition with digestive diseases has not been comprehensively explored., Methods: Four hundred ten thousand five hundred eighty-six participants from UK Biobank with complete sleep information were included in the analysis. Sleep patterns were measured by sleep scores as the primary exposure, based on five healthy sleep behaviors. Individual sleep behaviors were secondary exposures. Genetic risk of the digestive diseases was characterized by polygenic risk score. Primary outcome was incidence of 16 digestive diseases., Results: Healthy sleep scores showed dose-response associations with reduced risks of digestive diseases. Compared to participants scoring 0-1, those scoring 5 showed a 28% reduced risk of any digestive disease, including a 50% decrease in irritable bowel syndrome, 37% in non-alcoholic fatty liver disease, 35% in peptic ulcer, 34% in dyspepsia, 32% in gastroesophageal reflux disease, 28% in constipation, 25% in diverticulosis, 24% in severe liver disease, and 18% in gallbladder disease, whereas no correlation was observed with inflammatory bowel disease and pancreatic disease. Participants with poor sleep and high genetic risk exhibited approximately a 60% increase in the risk of digestive diseases. A healthy sleep pattern is linked to lower digestive disease risk in participants of all genetic risk levels., Conclusions: In this large population-based cohort, a healthy sleep pattern was associated with a reduced risk of digestive diseases, regardless of genetic susceptibility. The authors' findings underscore the potential impact of healthy sleep traits in mitigating the risk of digestive diseases., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Background: The associations between sleep patterns or behaviors and the risk of cirrhosis and the influence of genetic susceptibility on these associations among NAFLD participants remain inadequately elucidated., Methods: This study conducted a prospective follow-up of 112,196 NAFLD participants diagnosed at baseline from the UK Biobank cohort study. Five sleep behaviors were collected to measure a healthy sleep score. Five genetic variants were used to construct a polygenic risk score. We used Cox proportional hazard model to assess hazard ratios (HR) and 95% confidence intervals (CIs) for incidence of cirrhosis., Results: During the follow-up, 592 incident cirrhosis cases were documented. Healthy sleep pattern was associated with reduced risk of cirrhosis in a dose-response manner (p trend  < 0.001). Participants with favourable sleep score (versus unfavourable sleep score) had an HR of 0.55 for cirrhosis risk (95% CI 0.39-0.78). Multivariable-adjusted HRs (95% CIs) of cirrhosis incidence for NAFLDs with no frequent insomnia, sleeping for 7-8 h per day, and no excessive daytime dozing behaviors were 0.73 (0.61-0.87), 0.79 (0.66-0.93), and 0.69 (0.50-0.95), respectively. Compared with participants with favourable sleep pattern and low genetic risk, those with unfavourable sleep pattern and high genetic risk had higher risks of cirrhosis incidence (HR 3.16, 95% CI 1.88-5.33). In addition, a significant interaction between chronotype and genetic risk was detected for the incidence of cirrhosis (p for multiplicative interaction = 0.004)., Conclusion: An association was observed between healthy sleep pattern and decreased risk of cirrhosis among NAFLD participants, regardless of low or high genetic risk., (© 2024. Asian Pacific Association for the Study of the Liver.)

Objectives: To explore the relationship between sleep duration and cognitive functions in older adults using NHANES, a national US population study dataset, and to explore the causal association with Mendelian randomization (MR) using the UK Biobank., Methods: First, an observational study was conducted with the NHANES database with participants ≥60 years. Sleep duration was measured with accelerometers for 7 consecutive days. Participants were divided into habitual short sleep (<7 h) and long sleep (>9 h) groups. Cognitive functions were measured with the CERAD Word Learning sub-set, Animal Fluency, and Digit Symbol Substitution test (DSST). Multivariate regression models were used to explore relationships between sleep duration and cognitive functions. Second, bidirectional MR was conducted with data for self-reported sleep duration, which came from a genome-wide association study (GWAS) comprising 446,118 adults from the UK Biobank, and general cognitive performance, which was obtained from a recent GWAS study ( N = 257,841). Inverse-variance weighted (IVW) was used as the primary estimation of the outcome., Results: In the observational study, 2687 participants were included. Sleep duration was associated with cognitive functions in a non-linear way. Habitual long sleep (>9°h) was associated with lower scores on DSST (OR = 0.01, p = .003) in the fully-adjusted model. The association between habitual short sleep and cognitive functions was insignificant. For the MR, genetically predicted lower general cognitive performance was causally associated with a higher prevalence of habitual short sleep (OR = 0.97, p = 5.1 × 10 -7 ) and long sleep (OR = 0.97, p = 8.87 × 10 -16 )., Discussion: Short and long sleep duration might be both causally associated with worse outcomes of cognitive functions in older adults, highlighting the importance of maintaining sleep health., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Few prospective studies have investigated the joint effect of lifestyle factors and genetic susceptibility on the risk of irritable bowel syndrome (IBS). This study aims to evaluate the associations of lifestyle and genetic factors with incident IBS in the UK Biobank. We analyzed data from 481,057 participants (54% female) without prevalent IBS at enrollment in the UK Biobank. An overall healthy lifestyle was defined using six modifiable lifestyle factors, including smoking, body mass index (BMI), sleep duration, diet, physical activity, and alcohol consumption, and hence categorized into 'favorable', 'intermediate', and 'unfavorable' lifestyles. A Cox proportional hazard model was used to investigate the association between a healthy lifestyle and incident IBS. Furthermore, we constructed a polygenic risk score (PRS) for IBS and assessed whether lifestyle modified the effect of genetics on the development of IBS. During a median follow-up of 12.1 years, 8645 incident IBS were ascertained. Specifically, among the six modifiable lifestyle factors, adequate sleep demonstrates the greatest protective effect (hazard ratio [HR]: 0.72, 95% CI: 0.69,0.75) against IBS. Compared with a favorable lifestyle, an unfavorable lifestyle was associated with a 56% (95% CI: 46%-67%) increased risk of IBS (P = 8.99 × 10 -40 ). The risk of incident IBS was 12% (95% CI: 4%-21%) higher among those at high genetic risk compared with those at low genetic risk (P = 0.005). When considering the joint effect of lifestyle and genetic susceptibility, the HR nearly doubled among individuals with high genetic risk and unfavorable lifestyle (HR: 1.80; 95% CI:1.51-2.15; P = 3.50 × 10 -11 ) compared to those with low genetic risk and favorable lifestyle. No multiplicative or addictive interaction was observed between lifestyle and genetics. The findings from this study indicated that lifestyle and genetic factors were independently associated with the risk of incident IBS. All these results implicated a possible clinical strategy of lowering the incidence of IBS by advocating a healthy lifestyle., Competing Interests: Conflict of interest The authors declare that they have no competing interests., (Copyright © 2024 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.)

Background: Numerous individuals opt for napping to achieve adequate rest, and several studies have linked napping to various health conditions. Consequently, we aimed to investigate the potential effect of napping on the development of deep vein thrombosis (DVT)., Methods: We used the publicly available summary statistics data sets of genome-wide association studies (GWAS) meta-analyses for napping in individuals included in the UK Biobank as the exposure and a GWAS for DVT from the individuals included in the FinnGen Biobank as the outcome. The two-sample MR research approach was utilized to explore the causative link between napping and DVT. Single nucleotide polymorphisms (SNPs) data strongly related to napping were found and used as instrumental factors. Inverse variance weighting (IVW), weighted median and MR-Egger regression, and weighted mode approaches were four statistical techniques., Results: There were 86 SNPs in all that were discovered to be strongly related to napping (P < 5 × 10 -8 , linkage disequilibrium r 2  < 0.1). Consistent association between napping and DVT (IVW: odds ratio (OR) 0.508, 95% confidence interval (CI) 0.280-0.921; MR-Egger regression: OR 0.988, 95% CI 0.118-8.303; weighted median estimates: OR 0.419, 95% CI 0.181-0.974; weighted mode: OR 0.442, 95% CI 0.080-2.427) suggested that napping correlated with decreased risk of DVT. There was no evidence that genetic pleiotropy affected the link between napping and DVT (MR-Egger intercept - 6.7 × 10 -3 ; P = 0.525)., Conclusion: The results of the Mendelian randomization study suggested a potential causal relationship between napping and a reduced incidence of DVT., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background: Although the association between sleep behavior and morbidity and mortality risk has been reported before, there is still uncertainty whether the observed associations are causal or confounding. Therefore, we investigated the causal relationships between sleep-behavioral traits and terminated healthspan risk using Mendelian randomization (MR)., Methods: We conducted a one-sample MR analysis to evaluate causality between six sleep-behavioral traits (sleep duration, chronotype/morningness, napping, sleeplessness/insomnia, and getting up from bed) and risk of healthspan termination among 388, 909 UK Biobank (UKB) participants. Instrumental variables for sleep behaviors (N = 590) were obtained from recent genome-wide association studies (GWAS). We defined healthspan based on eight predominant health-terminating events associated with longevity (congestive heart failure, myocardial infarction, chronic obstructive pulmonary disease, stroke, dementia, diabetes, cancer, and death). We further constructed a sleep score and a weighted genetic risk score to increase the predictive ability of the sleep-behavioral traits. Cox regression models and Inverse Probability Treatment Weighting (IPTW) were implemented, followed by MR to assess causation. We used inverse-variance-weighted MR to estimate causal effects, and weighted-median and MR-egger for sensitivity analysis to test the pleiotropic effects., Results: In IPTW, we observed a decreased risk of terminated healthspan for healthy sleep behaviors such as 'sleep duration 7-8h/d' (Hazard ratio, HR = 0.93; 95 % confidence interval, CI: 0.92-0.96; P < 0.001); 'morningness' (HR = 0.95; 95%CI: 0.93-0.98; P < 0.01); 'napping' (HR = 0.93; 95%CI: 0.91-0.94; P < 0.001); 'easy getting up from bed' (HR = 0.91; 95%CI: 0.88-0.93; P < 0.001); and, 'never/rarely experience sleeplessness/insomnia' (HR = 0.94; 95%CI: 0.92-0.96; P < 0.001). MR results further indicated causal associations between healthy sleep duration (OR = 0.98; 95%CI: 0.97-1.00; P = 0.036) and insomnia (OR = 1.02; 95%CI: 1.01-1.03; P < 0.001) with terminated healthspan. MR-egger did not suggest any potential pleiotropy., Conclusion: This study supports abnormal sleep duration and insomnia as potential causal risk factors for terminated healthspan. Thus, healthy sleep behavior is valuable for the extension of healthspan, and well-designed and tailored sleep health interventions are warranted., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Previous studies have shown that excessive alcohol consumption is associated with poor sleep. However, the health risks of light-to-moderate alcohol consumption in relation to sleep traits (e.g., insomnia, snoring, sleep duration and chronotype) remain undefined, and their causality is still unclear in the general population. To identify the association between alcohol consumption and multiple sleep traits using an observational and Mendelian randomization (MR) design. Observational analyses and one-sample MR (linear and nonlinear) were performed using clinical and individual-level genetic data from the UK Biobank (UKB). Two-sample MR was assessed using summary data from genome-wide association studies from the UKB and other external consortia. Phenotype analyses were externally validated using data from the National Health and Nutrition Examination Survey (2017-2018). Data analysis was conducted from January 2022 to October 2022. The association between alcohol consumption and six self-reported sleep traits (short sleep duration, long sleep duration, chronotype, snoring, waking up in the morning, and insomnia) were analysed. This study included 383,357 UKB participants (mean [SD] age, 57.0 [8.0] years; 46% male) who consumed a mean (SD) of 9.0 (10.0) standard drinks (one standard drink equivalent to 14 g of alcohol) per week. In the observational analyses, alcohol consumption was significantly associated with all sleep traits. Light-moderate-heavy alcohol consumption was linearly linked to snoring and the evening chronotype but nonlinearly associated with insomnia, sleep duration, and napping. In linear MR analyses, a 1-SD (14 g) increase in genetically predicted alcohol consumption was associated with a 1.14-fold (95% CI, 1.07-1.22) higher risk of snoring (P < 0.001), a 1.28-fold (95% CI, 1.20-1.37) higher risk of evening chronotype (P < 0.001) and a 1.24-fold (95% CI, 1.13-1.36) higher risk of difficulty waking up in the morning (P < 0.001). Nonlinear MR analyses did not reveal significant results after Bonferroni adjustment. The results of the two-sample MR analyses were consistent with those of the one-sample MR analyses, but with a slightly attenuated overall estimate. Our findings suggest that even low levels of alcohol consumption may affect sleep health, particularly by increasing the risk of snoring and evening chronotypes. The negative effects of alcohol consumption on sleep should be made clear to the public in order to promote public health., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Objectives: The association between sleep pattern and chronic kidney disease (CKD) incidence, and whether the association is dependent on the genetic backgrounds has not been addressed. We sought to investigate the association of multidimensional sleep pattern with CKD in consideration of genetic polymorphisms., Methods: In this prospective cohort study of 157,175 participants from the UK Biobank, sleep patterns were derived by multiple correspondence analysis (MCA) and k-means clustering of individual sleep traits (sleep duration, insomnia, chronotype, daytime sleepiness, snoring, and night shift status). Cox proportional hazard regression was used to estimate the association between sleep patterns and CKD incidence. Gene-environment-wide interaction study (GEWIS) was performed to detect whether gene polymorphisms were modifiers on this association., Results: Compared with "healthy sleep" pattern, increased CKD incidence was observed in the clusters with "long sleep duration" (hazard ratios (HR) 1.42, 95% confidence intervals (CI), 1.18-1.72) and "night shift" (HR 1.23, 95% CI, 1.05-1.45) patterns, but not with the "short sleep duration" pattern. By GEWIS, we identified 167 SNPs as suggestive effect modifiers that interacted with unhealthy sleep patterns and affected the risk of CKD., Conclusions: Unhealthy sleep patterns, with features of long sleep duration and night shift, may increase the risk of CKD. The study highlights the interaction of sleep and individual genetic risk to affect health outcomes., Competing Interests: Declaration of Competing Interest All authors declare no competing interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: The bidirectional relationship between sleep disturbances and depression is well documented, yet the biology of sleep is not fully understood. Mitochondria have become of interest not only because of the connection between sleep and metabolism but also because of mitochondria's involvement in the production of reactive oxygen species, which are largely scavenged during sleep., Methods: Genome-wide association studies (GWAS) of eight accelerometry-derived sleep measures were performed across both the autosomal and mitochondrial DNA (mtDNA) among two severity levels of depression in UK Biobank participants. We calculated SNP heritability for each of the sleep measures. Linear regression was performed to test associations and mitochondrial haplogroups., Results: Variants included in the GWAS accounted for moderate heritability of bedtime (19.6%, p = 4.75 × 10 -7 ), sleep duration (16.6%, p = 8.58 × 10 -6 ) and duration of longest sleep bout (22.6%, p = 4.64 × 10 -4 ). No variants passed genome-wide significance in the autosomal genome. The top hit in the severe depression sample was rs145019802, near GOLGA8B, for sleep efficiency (p = 1.17 × 10 -7 ), and the top hit in the broad depression sample was rs7100859, an intergenic SNP, and nap duration (p = 1.25 × 10 -7 ). Top mtDNA loci were m.12633C > A of MT-ND5 with bedtime (p = 0.002) in the severe sample and m.16186C > T of the control region with nap duration (p = 0.002) in the broad sample., Conclusion: SNP heritability estimates support the involvement of common SNPs in specific sleep measures among depressed individuals. This is the first study to analyze mtDNA variance in sleep measures in depressed individuals. Our mtDNA findings, although nominally significant, provide preliminary suggestion that mitochondria are involved in sleep., Competing Interests: Declaration of competing interest The authors have no competing interests to disclose., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background: Alzheimer's disease (AD) is the most frequently occurring type of dementia. Concurrently, inadequate sleep has been recognized as a public health epidemic. Notably, genetic and environmental factors are now considered contributors to AD progression., Objective: To assess the association between sleep duration, genetic susceptibility, and AD., Methods and Results: Based on 483,507 participants from the UK Biobank (UKB) with an average follow-up of 11.3 years, there was a non-linear relationship between AD incidence and sleep duration (P for non-linear < 0.001) by restricted cubic splines (RCS). Sleep duration was categorized into short sleep duration (< 6 h/night), normal sleep duration (6-9 h/night), and long sleep duration (> 9 h/night). No statistically significant interaction was identified between sleep duration and the AD-GRS (Alzheimer's disease genetic risk score, P for interaction = 0.45) using Cox proportional risk model. Compared with the participants who had a low AD-GRS and normal sleep duration, there was associated with a higher risk of AD in participants with a low AD-GRS and long sleep duration (HR = 3.4806; 95% CI 2.0011-6.054, p < 0.001), participants with an intermediate AD-GRS and long sleep duration (HR = 2.0485; 95% CI 1.3491-3.1105, p < 0.001), participants with a high AD-GRS and normal sleep duration (HR = 1.9272; 95% CI 1.5361-2.4176, p < 0.001), and participants with a high AD-GRS and long sleep duration (HR = 5.4548; 95% CI 3.1367-9.4863, p < 0.001).In addition, there was no causal association between AD and sleep duration using Two Sample Mendelian randomization (MR)., Conclusion: In the UKB population, though there was no causal association between AD and sleep duration analyzed using Two Sample MR, long sleep duration (> 9 h/night) was significantly associated with a higher risk of AD, regardless of high, intermediate or low AD-GRS. Prolonged sleep duration may be one of the clinical predictors of a higher risk of AD., (© 2022. The Author(s).)

Study Objectives: Sleep and circadian phenotypes are associated with several diseases. The present study aimed to investigate whether sleep and circadian phenotypes were causally linked with coronavirus disease 2019 (COVID-19)-related outcomes., Methods: Habitual sleep duration, insomnia, excessive daytime sleepiness, daytime napping, and chronotype were selected as exposures. Key outcomes included positivity and hospitalization for COVID-19. In the observation cohort study, multivariable risk ratios (RRs) and their 95% confidence intervals (CIs) were calculated. Two-sample Mendelian randomization (MR) analyses were conducted to estimate the causal effects of the significant findings in the observation analyses. Odds ratios (ORs) and the corresponding 95% CIs were calculated and compared using the inverse variance weighting, weighted median, and MR-Egger methods., Results: In the UK Biobank cohort study, both often excessive daytime sleepiness and sometimes daytime napping were associated with hospitalized COVID-19 (excessive daytime sleepiness [often vs. never]: RR = 1.24, 95% CI = 1.02-1.5; daytime napping [sometimes vs. never]: RR = 1.12, 95% CI = 1.02-1.22). In addition, sometimes daytime napping was also associated with an increased risk of COVID-19 susceptibility (sometimes vs. never: RR = 1.04, 95% CI = 1.01-1.28). In the MR analyses, excessive daytime sleepiness was found to increase the risk of hospitalized COVID-19 (MR IVW method: OR = 4.53, 95% CI = 1.04-19.82), whereas little evidence supported a causal link between daytime napping and COVID-19 outcomes., Conclusions: Observational and genetic evidence supports a potential causal link between excessive daytime sleepiness and an increased risk of COVID-19 hospitalization, suggesting that interventions targeting excessive daytime sleepiness symptoms might decrease severe COVID-19 rate., (© The Author(s) 2022. Published by Oxford University Press on behalf of Sleep Research Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Studies of sleep duration in relation to the risk of site-specific cancers other than breast cancer are scarce. Furthermore, the available results are inconclusive and the causality remains unclear. We aimed to investigate the potential causal associations of sleep duration with overall and site-specific cancers using the Mendelian randomization (MR) design. Single-nucleotide polymorphisms associated with the sleep traits identified from a genome-wide association study were used as instrumental variables to estimate the association with overall cancer and 22 site-specific cancers among 367 586 UK Biobank participants. A replication analysis was performed using data from the FinnGen consortium (up to 121 579 individuals). There was suggestive evidence that genetic liability to short-sleep duration was associated with higher odds of cancers of the stomach (odds ratio [OR], 2.22; 95% confidence interval [CI], 1.15-4.30; P = .018), pancreas (OR, 2.18; 95% CI, 1.32-3.62; P = .002) and colorectum (OR, 1.48; 95% CI, 1.12-1.95; P = .006), but with lower odds of multiple myeloma (OR, 0.47; 95% CI, 0.22-0.99; P = .047). Suggestive evidence of association of genetic liability to long-sleep duration with lower odds of pancreatic cancer (OR, 0.44; 95% CI, 0.25-0.79; P = .005) and kidney cancer (OR, 0.44; 95% CI, 0.21-0.90; P = .025) was observed. However, none of these associations passed the multiple comparison threshold and two-sample MR analysis using FinnGen data did not confirm these findings. In conclusion, this MR study does not provide strong evidence to support causal associations of sleep duration with risk of overall and site-specific cancers. Further MR studies are required., (© 2020 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of Union for International Cancer Control.)

Background: Despite a growing body of evidence suggesting that short sleep duration may be linked to adverse metabolic outcomes, how these associations differ between age groups remains unclear. We use eight years of data from the UK National Diet and Nutritional Survey (NDNS) (2008-2016) to analyse cross-sectional relationships between sleep duration and metabolic risk in participants aged 11-70 years., Methods: Participants (n = 2008) who provided both metabolic risk and sleep duration data were included. Self-reported sleep duration was standardised by age, to account for differences in age-related sleep requirements. A standardised metabolic risk score was constructed, comprising: waist circumference, blood pressure, serum triglycerides, serum high-density lipoprotein cholesterol, and fasting plasma glucose. Regression models were constructed across four age groups from adolescents to older adults., Results: Overall, decreased sleep duration (hrs) was associated with an increased metabolic risk (standard deviations) with significant quadratic (B:0.028 [95%CI: 0.007, 0.050]) and linear (B:-0.061 [95%CI: -0.111, -0.011]) sleep duration coefficients. When separated by age group, stronger associations were seen among mid-aged adults (36-50y) (quadratic coefficient: 0.038 [95%CI: 0.002, 0.074]) compared to other age groups (e.g. adolescents (11-18y), quadratic coefficient: -0.009 [95%CI: -0.042, 0.025]). An increased difference between weekend and weekday sleep was only associated with increased metabolic risk in adults aged 51-70 years (B:0.18 [95%CI: 0.005, 0.348])., Conclusions: Our results indicate that sleep duration is linked to adverse metabolic risk and suggest heterogeneity between age groups. Longitudinal studies with larger sample sizes are required to explore long-term effects of abnormal sleep and potential remedial benefits., Competing Interests: The authors have declared that no competing interests exist.

Background: Short and long sleep duration have been linked with poorer cognitive outcomes, but it remains unclear whether these associations are causal., Methods: We conducted the first Mendelian randomization (MR) study with 77 single-nucleotide polymorphisms (SNPs) for sleep duration using individual-participant data from the UK Biobank cohort (N = 395 803) and summary statistics from the International Genomics of Alzheimer's Project (N cases/controls = 17 008/37 154) to investigate the potential impact of sleep duration on cognitive outcomes., Results: Linear MR suggested that each additional hour/day of sleep was associated with 1% [95% confidence interval (CI) = 0-2%; P = 0.008] slower reaction time and 3% more errors in visual-memory test (95% CI = 0-6%; P = 0.05). There was little evidence to support associations of increased sleep duration with decline in visual memory [odds ratio (OR) per additional hour/day of sleep = 1.10 (95% CI = 0.76-1.57); P = 0.62], decline in reaction time [OR = 1.28 (95% CI = 0.49-3.35); P = 0.61], all-cause dementia [OR = 1.19 (95% CI = 0.65-2.19); P = 0.57] or Alzheimer's disease risk [OR = 0.89 (95% CI = 0.67-1.18); P = 0.41]. Non-linear MR suggested that both short and long sleep duration were associated with poorer visual memory (P for non-linearity = 3.44e-9) and reaction time (P for non-linearity = 6.66e-16)., Conclusions: Linear increase in sleep duration has a small negative effect on reaction time and visual memory, but the true association might be non-linear, with evidence of associations for both short and long sleep duration. These findings suggest that sleep duration may represent a potential causal pathway for cognition., (© The Author(s) 2019. Published by Oxford University Press on behalf of the International Epidemiological Association.)

Sleep is an essential state of decreased activity and alertness but molecular factors regulating sleep duration remain unknown. Through genome-wide association analysis in 446,118 adults of European ancestry from the UK Biobank, we identify 78 loci for self-reported habitual sleep duration (p < 5 × 10 -8 ; 43 loci at p < 6 × 10 -9 ). Replication is observed for PAX8, VRK2, and FBXL12/UBL5/PIN1 loci in the CHARGE study (n = 47,180; p < 6.3 × 10 -4 ), and 55 signals show sign-concordant effects. The 78 loci further associate with accelerometer-derived sleep duration, daytime inactivity, sleep efficiency and number of sleep bouts in secondary analysis (n = 85,499). Loci are enriched for pathways including striatum and subpallium development, mechanosensory response, dopamine binding, synaptic neurotransmission and plasticity, among others. Genetic correlation indicates shared links with anthropometric, cognitive, metabolic, and psychiatric traits and two-sample Mendelian randomization highlights a bidirectional causal link with schizophrenia. This work provides insights into the genetic basis for inter-individual variation in sleep duration implicating multiple biological pathways.

Short sleep duration has been linked to negative health effects, but is a complex phenotype with many contributing factors, including genetic. We evaluated 27 common single nucleotide polymorphisms (SNPs) in candidate genes previously reported to be associated with other sleep variables for association with self-reported habitual sleep duration in the UK Biobank in 111 975 individuals of European ancestry. Genetic variation in DAT1 (rs464049) was significantly associated with sleep duration after correction for multiple testing (p = 4.00 × 10-5), whereas SNPs correlated to a previously studied variable number tandem repeat (VNTR) in DAT1 were not significant in this population. We also replicated a previously reported association in DRD2. Independent replication of these associations and a second signal in DRD2 (rs11214607) was observed in an additional 261 870 participants of European ancestry from the UK Biobank. Meta-analysis confirmed genome-wide significant association of DAT1 rs464049 (G, beta [standard error, SE] = -0.96 [0.18] minutes/allele, p = 5.71 × 10-10) and study-wide significant association of DRD2 (rs17601612, C, beta [SE] = -0.66 [0.18] minutes/allele, p = 1.77 × 10-5; rs11214607, C, beta [SE] = 1.08 (0.24) minutes/allele, p = 1.39 × 10-6). Overall, SNPs in two dopamine-related genes were significantly associated with sleep duration, highlighting the important link of the dopamine system with adult sleep duration in humans.

Sleep and circadian rhythms are intrinsically linked, with several sleep traits, including sleep timing and duration, influenced by both sleep homeostasis and the circadian phase. Genetic variation in several circadian genes has been associated with diurnal preference (preference in timing of sleep), although there has been limited research on whether they are associated with other sleep measurements. We investigated whether these genetic variations were associated with diurnal preference (Morningness-Eveningness Questionnaire) and various sleep measures, including: the global Pittsburgh Sleep Quality index score; sleep duration; and sleep latency and sleep quality. We genotyped 10 polymorphisms in genes with circadian expression in participants from the G1219 sample (n = 966), a British longitudinal population sample of young adults. We conducted linear regressions using dominant, additive and recessive models of inheritance to test for associations between these polymorphisms and the sleep measures. We found a significant association between diurnal preference and a polymorphism in period homologue 3 (PER3) (P < 0.005, recessive model) and a novel nominally significant association between diurnal preference and a polymorphism in aryl hydrocarbon receptor nuclear translocator-like 2 (ARNTL2) (P < 0.05, additive model). We found that a polymorphism in guanine nucleotide binding protein beta 3 (GNβ3) was associated significantly with global sleep quality (P < 0.005, recessive model), and that a rare polymorphism in period homologue 2 (PER2) was associated significantly with both sleep duration and quality (P < 0.0005, recessive model). These findings suggest that genes with circadian expression may play a role in regulating both the circadian clock and sleep homeostasis, and highlight the importance of further studies aimed at dissecting the specific roles that circadian genes play in these two interrelated but unique behaviours., (© 2014 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of the European Sleep Research Society.)