Introduction and application of quantile regression method in medical reserach / 复旦学报（医学版）

This article introduced the basic theory of quantile regression and its application in medical and public health research for methodological reference.We fit the quantile regression model to cross-sectional data from the National Health and Nutrition Examination Survey to estimate the association between sleep duration and depression levels at different quantiles of depression levels.The method showed that among people with low levels of depression,sleep duration was not significantly associated with depression level.While among people with higher levels of depression,the association of sleep duration with depression level became much more pronounced.The real data analysis shows that quantile regression can provide a comprehensive analysis of association between exposure and continuous outcome,and identify subgroups that are more sensitive to exposure,providing recommendations for targeted interventions.The method showed promising application value in medical and public health research.

Sleep characteristics and risk of osteoarthritis:a two-sample and multivariate Mendelian randomization study / 中国组织工程研究

BACKGROUND:In recent years,epidemiological studies have shown that sleep patterns are risk factors for osteoarthritis,but the causal relationship between sleep characteristics and osteoarthritis remains unknown. OBJECTIVE:To investigate the causal relationship between seven sleep phenotypes and osteoarthritis,thereby providing a theoretical foundation for clinical prevention and intervention of osteoarthritis. METHODS:Seven sleep-related features,namely sleep duration,wake-up time,daytime napping,morning/evening preference,snoring,insomnia,and hypersomnia,were selected from published genome-wide association studies.Instrumental variables for these sleep-related features were extracted.Instrumental variables for knee osteoarthritis and hip osteoarthritis were obtained from publicly available genome-wide association studies.Causal relationships between sleep characteristics and outcome risks were evaluated using two-sample and multivariable Mendelian randomization analyses.The inverse variance weighted method was employed as the primary Mendelian randomization approach.Various methods,including weighted median,weighted mode,Mendelian randomization-Egger regression,Mendelian randomization pleiotropy-residual sum and outlier,were utilized to detect and correct for the presence of pleiotropy. RESULTS AND CONCLUSION:The results of the inverse variance-weighted method in the two-sample Mendelian randomization study revealed a detrimental causal association between the duration of sleep and the incidence risk of knee osteoarthritis[odds ratio(OR)=0.621,95%confidence interval(CI):0.470-0.822,P=0.001].Concurrently,insomnia displayed a positive causal connection with hip osteoarthritis risk(OR=2.016,95%CI:1.249-3.254,P=0.005).Sensitivity analysis affirmed the robustness of these causal relationships,and Mendelian randomization-Egger intercept analysis found no evidence of potential horizontal pleiotropy(knee osteoarthritis:P=0.468,hip osteoarthritis:P=0.551).Moreover,the results from the multivariable Mendelian randomization analysis showed that the causal association between insomnia and hip osteoarthritis lacked statistical significance(P=0.715).In contrast,sleep duration exhibited a direct negative causal relationship with the incidence risk of knee osteoarthritis(OR=0.526,95%CI:0.336-0.824,P=0.005).Reverse Mendelian randomization analysis indicated that knee osteoarthritis did not influence sleep duration(P=0.757).These findings indicate a negative correlation between sleep duration and incidence risk of knee osteoarthritis,suggesting that correcting insufficient sleep might mitigate the incidence risk of knee osteoarthritis.

Sleep duration, insomnia and cognitive performance in the Elsa-Brasil cohort: a cross-sectional analysis / Duração do sono, insônia e desempenho cognitivo na coorte Elsa-Brasil: uma análise transversal

ABSTRACT Objective: To investigate the single and combined associations between sleep disturbances (sleep duration, insomnia symptoms in the last 30 nights, and daytime tiredness) and performance in cognitive tests. Methods: Cross-sectional analysis of data from visit 2 (2012-2014) of the Longitudinal Study of Adult Health from a cohort of active and retired civil servants from six Brazilian capitals. Polynomial regression with quadratic term and multiple linear regression models were performed to assess single and combined associations between sleep disturbances and memory performance, fluency, executive functions, and global cognition. Results: A total of 7,248 participants were included, with a mean age of 62.7 years (standard deviation [SD]=5.9), and 55.2% were women. Inverted U-shaped associations were observed between sleep duration and performance on all cognitive abilities, suggesting that durations shorter or longer than seven hours are associated with worse performance, regardless of age. Reported insomnia was associated with worse executive function (β: -0.08; 95% confidence interval [CI]: -0.15 to -0.01), and the magnitudes of associations were higher for individuals with insomnia at two or more moments (β: -0.12; 95%CI -0.19 to -0.05) or, especially, insomnia combined with short sleep (β: -0.18; 95%CI -0.24 to -0.11). Insomnia in two or more periods was also associated with lower memory and global cognition. There was no association between any sleep disturbance tested and verbal fluency. Isolated daytime tiredness was not associated with performance in the evaluated tests. Conclusion: The results suggest that extreme sleep durations are detrimental to almost all cognitive abilities investigated, whereas insomnia appears to affect more severely the executive function.

RESUMO Objetivo: Investigar a associação isolada e combinada entre distúrbios do sono (duração do sono, sintomas de insônia nas últimas 30 noites e cansaço diurno) e desempenho em testes cognitivos. Métodos: Análise transversal dos dados da visita 2 (2012-2014) do Estudo Longitudinal de Saúde do Adulto de coorte de servidores públicos ativos e aposentados de seis capitais brasileiras. Regressão polinomial com termo quadrático e modelos de regressão linear múltipla foram realizados para avaliar associações isoladas e combinadas entre distúrbios do sono e desempenho na memória, fluência, funções executivas e cognição global. Resultados: Foram incluídos um total de 7.248 participantes, com média etária de 62,7 anos (desvio padrão [DP]=5,9), sendo 55,2% mulheres. Associações em forma de U invertido foram observadas entre duração do sono e desempenho em todas as habilidades cognitivas, sugerindo que durações menores ou maiores que sete horas estão associadas ao pior desempenho, independentemente da idade. O relato de insônia foi associado à pior função executiva (β: -0.08; IC95% -0.15 a -0.01), sendo as magnitudes das associações maiores para indivíduos com insônia em dois ou mais momentos (β: -0.12; intervalo de confiança [IC]95% -0.19 a -0.05) ou, especialmente, insônia combinada com sono curto (β: -0.18; IC95% -0.24 a -0.11). Insônia em dois ou mais períodos também foi associada à menor memória e cognição global. Não houve associação entre qualquer distúrbio do sono testado e fluência verbal. Cansaço diurno isolado não foi associado ao desempenho nos testes avaliados. Conclusão: Os resultados sugerem que a duração extrema do sono é prejudicial para quase todas as funções cognitivas investigadas, enquanto a insônia parece afetar mais fortemente a função executiva.

A segregação residencial socioeconômica está associada aos problemas do sono? Insights do ELSA-Brasil / Is socioeconomic residential segregation associated with sleep problems? Insights from ELSA-Brasil / ¿Está asociada la segregación residencial socioeconómica con problemas de sueño? Insights de ELSA-Brasil

Resumo: O sono é influenciado por diversos fatores e é essencial para a saúde. O papel do contexto socioeconômico da vizinhança na saúde do sono foi estudado nos últimos anos, mas os resultados são inconsistentes. O objetivo deste estudo foi investigar a associação entre a segregação residencial socioeconômica e os problemas do sono. Utilizou-se dados da 2ª avaliação (2012-2014) de 9.918 servidores públicos participantes do Estudo Longitudinal de Saúde do Adulto (ELSA-Brasil). A segregação residencial socioeconômica foi avaliada por meio da estatística Getis-Ord Local Gi*, e a duração e privação do sono, as queixas de insônia e a sonolência diurna foram obtidas por meio de entrevistas. Para as estimativas da odds ratio (OR), foram utilizados modelos de regressão logística binomial e multinomial. Em relação ao sono, 49% tinham curta duração e 3% longa duração, 23% relataram queixas de insônia, 45% relataram privação do sono, 42% relataram sonolência diurna e 48% relataram ≥ 2 problemas do sono. No modelo ajustado por variáveis demográficas e socioeconômicas, houve associação entre alta segregação residencial socioeconômica e duração curta do sono (OR = 1,22; IC95%: 1,07; 1,40), privação do sono (OR = 1,20; IC95%: 1,05; 1,37), sonolência diurna (OR = 1,17; IC95%: 1,03; 1,34) e ≥ 2 problemas associados do sono (OR = 1,24; IC95%: 1,08; 1,41). Indivíduos que vivem em vizinhanças com alta segregação residencial socioeconômica apresentam maior chance de terem curta duração, privação do sono, sonolência diurna e ≥ 2 problemas associados ao sono. Essas informações reforçam que políticas públicas para reduzir as desigualdades socioeconômicas podem contribuir para melhorar a saúde do sono da população.

Abstract: Several factors influence sleep, which is essential for health. While the role of neighborhood socioeconomic context on sleep health has been studied in recent years, results are inconsistent. The study aimed to investigate the association between socioeconomic residential segregation and sleep problems, using data from the second evaluation (2012-2014) of 9,918 public servants participating in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Socioeconomic residential segregation was assessed using the Getis-Ord Local Gi* statistic. Sleep duration and deprivation, complaints of insomnia, and daytime sleepiness were obtained through interviews. Binomial and multinomial logistic regression models were used to estimate the odds ratio (OR). Regarding sleep, 49% had short duration and 3% long duration, 23% reported complaints of insomnia, 45% sleep deprivation, 42% daytime sleepiness, and 48% reported ≥ 2 sleep problems. In the model adjusted for demographic and socioeconomic variables, there was an association between high socioeconomic residential segregation and short sleep duration (OR = 1.22; 95%CI: 1.07; 1.40), sleep deprivation (OR = 1.20; 95%CI: 1.05; 1.37), daytime sleepiness (OR = 1.17; 95%CI: 1.03; 1.34) and ≥ 2 associated sleep problems (OR = 1.24; 95%CI: 1.08; 1.41). Individuals living in neighborhoods with high socioeconomic residential segregation are more likely to have short sleep duration, sleep deprivation, daytime sleepiness, and ≥ 2 associated sleep problems. This information reinforces that public policy measures to reduce socioeconomic inequalities can improve the population's sleep health.

Resumen: El sueño se influye por varios factores y es esencial para la salud. Se estudió el papel del contexto socioeconómico del barrio en la salud del sueño en los últimos años, pero los resultados son inconsistentes. El objetivo del estudio fue investigar la asociación entre la segregación residencial socioeconómica y los problemas de sueño. Se utilizó datos de la 2ª evaluación (2012-2014) de 9918 servidores públicos participantes del Estudio Longitudinal de Salud del Adulto (ELSA-Brasil). Se evaluó la segregación residencial socioeconómica a través de la estadística Getis-Ord Local Gi*. La duración y privación del sueño, las quejas de insomnio y somnolencia diurna se obtuvieron a través de entrevista. Se utilizaron modelos de regresión logística binomial y multinominal para estimar el odds ratio (OR). Con respecto al sueño, el 49% tenía una duración corta y el 3% tenía una duración larga, el 23% relató quejas de insomnio, el 45% relató privación de sueño, el 42% relató somnolencia diurna y el 48% relató ≥ 2 problemas de sueño. En el modelo ajustado por variables demográficas y socioeconómicas, hubo una asociación entre la alta segregación residencial socioeconómica y la duración corta de sueño (OR = 1,22; IC95%: 1,07; 1,40), la privación de sueño (OR = 1,20; IC95%: 1,05; 1,37), la somnolencia diurna (OR = 1,17; IC95%: 1,03; 1,34) y ≥ 2 problemas asociados con el sueño (OR = 1,24; IC95%: 1,08; 1,41). Personas que viven en barrios con una alta segregación residencial socioeconómica presentan una mayor probabilidad de tener duración corta del sueño, privación de sueño, somnolencia diurna y ≥ 2 problemas asociados con el sueño. Estas informaciones resaltan que medidas de políticas públicas para reducir las desigualdades socioeconómicas pueden contribuir a mejorar la salud del sueño en la población.

Duração do Sono e Risco de Aterosclerose: Um Estudo Mendeliano de Randomização / Sleep Duration and the Risk of Atherosclerosis: A Mendelian Randomization Study

Resumo Fundamento: A associação entre a duração do sono e a aterosclerose foi relatada em muitos estudos observacionais. No entanto, pouco se sabe sobre a sua importância como fator de risco para aterosclerose ou como consequência negativa da aterosclerose. Objetivo: Este estudo teve como objetivo avaliar a associação causal entre a duração do sono e o risco de aterosclerose usando estatísticas resumidas de estudos de associação genômica ampla (GWAS) disponíveis publicamente. Métodos: Empregamos um método de randomização mendeliana (RM) de duas amostras com 2 coortes do MRC-IEU (n = 460.099) e do UK Biobank (n = 361.194) para investigar a associação causal entre a duração do sono e o risco de aterosclerose. Três métodos, incluindo a técnica de variância inversa ponderada (IVW), escore de perfil ajustado robusto (RAPS) e abordagem de mediana simples e ponderada, foram usados para obter resultados confiáveis, e uma razão de chances com intervalo de confiança (IC) de 95% foi calculada. P<0,05 foi considerado diferença estatística. Além disso, foram utilizadas análises de regressão: MR-Egger regression, Radial MR, MR-PRESSO e leave-one-out para avaliar os possíveis efeitos de pleiotropia. Resultados: Não foi encontrada associação causal entre duração do sono e aterosclerose [OR (IC95%): 0,90 (0,98-1,00), p = 0,186]. As análises Leave-one-out, MR-Egger, e MR-PRESSO não conseguiram detectar pleiotropia horizontal. Conclusões: Esta análise de RM não indicou nenhuma associação causal entre a duração do sono geneticamente prevista e a aterosclerose nas populações europeias.

Abstract Background: The association between the length of sleep and atherosclerosis has been reported in many observational studies. However, little is known about its significance as a risk factor for atherosclerosis or as a negative consequence of atherosclerosis. Objective: This study aimed to assess the causal association between sleep duration and the risk of atherosclerosis using publicly available genome-wide association studies (GWAS) summary statistics. Methods: We employed a two-sample Mendelian randomization (MR) method with 2 cohorts from MRC-IEU (n=460,099) and UK Biobank (n=361,194) to investigate the causal association between sleep duration and the risk of atherosclerosis. Three methods including the inverse-variance weighted (IVW) technique, Robust adjusted profile score (RAPS), and simple-and weighted-median approach were used to obtain reliable results, and an odds ratio with a 95% confidence interval (CI) was calculated. P<0.05 was considered as a statistical difference. In addition, MR-Egger regression, Radial MR, MR-PRESSO, and leave-one-out analyses were used to assess the possible pleiotropy effects. Results: No causal association of sleep duration with atherosclerosis was found [OR (95%CI): 0.90 (0.98-1.00), p = 0.186]. Leave-one-out, MR-Egger, and MR-PRESSO analyses failed to detect horizontal pleiotropy. Conclusions: This MR analysis indicated no causal association between genetically predicted sleep duration and atherosclerosis across European populations.

A study of sleep duration, body mass index and blood pressure in an adult Kashmiri population

Background: Sleep is influenced by the circadian rhythms (regular body changes in mental and physical characteristics that occur in the course of about 24 hours). Lack of a good night’s sleep results in a variety of negative health and cognitive issues, which makes it critical to study the prevalence of sleep deficiency and its effects on an individual’s physical and mental health. Aim of study was to access the association of sleep duration with body mass index and blood pressure in an adult Kashmiri population. Methods: The present study was done in the Postgraduate Department of Physiology, Government Medical College and Associated Hospitals, Srinagar. This study was done on 500 subjects and it was an observational, cross sectional study. Results: The prevalence of overweight/obese among short sleepers was quite high at 34.4% as compared to 11.7% and 15.2% among normal sleepers and long sleepers respectively. Among short sleepers 0% participants were hypotensive 47.5% were normotensive, 52.4% were prehypertensive/hypertensive. Conclusions: In conclusion, this study showed a statistically significant increase in the prevalence of elevated blood pressure and overweight/obese subjects among short sleepers. There was an inverse relationship of prevalence of overweight/obesity and elevated blood pressure with short sleep duration. Our study also showed a statistically significant increase in the percentage of prehypertension/hypertension among overweight/obese people with a p value of <0.001 and CHI square of 43.964.

Sleep pattern and sleep disorders in school-going children aged 6-12 years and its association with screen time: a cross-sectional study from South Kerala during the COVID-19 pandemic

Background: Poor sleep quality in school children can negatively impact their neurocognitive abilities and academic achievement. Increased screen time was shown to interfere with children’s sleep habits and disrupts their sleep pattern. This study aimed to understand the sleep patterns and sleep disorders in school children and the influence of screen time on sleep in children during the COVID-19 pandemic.Methods: This cross-sectional observational school-based study was done on 443 children aged 6-12 years. Data was collected through parent filled online questionnaire having a proforma and child sleep habit questionnaire (CSHQ), a validated questionnaire to assess sleep disorders in childrenResults: Out of 443 children studied, the average sleep duration of the study population was 9:06 hours ±42:18 min and, 34.3% of the children slept less than 9 hours per day. The prevalence of sleep disorders was found to be 76.52%. Significant screen time after 8 PM was observed in 65.9% and 62.2 % of children had a total screen time of more than 2 hours. Increased screen time after 8 PM, delayed bedtime and wake-up time in children and also contributed to sleep disorders. Bedtime resistance and daytime sleepiness were more commonly observed in children with increased screen time.Conclusions: Sleep disorders in children are more predominant than sleep deprivation. Increased screen time before bed was found to alter sleep patterns in children and increases bedtime resistance, daytime sleepiness, and sleep disorders.

Vitamin D and sleep duration: a possible link

Background: Normal-range sleep duration is an important factor for general health and metabolism. Insufficient or excessive sleep duration is associated with various chronic physical or mental illness, such as obesity, hypertension, diabetes, metabolic syndrome, depression, and other psychiatric diseases. Sleep duration is mainly affected by circadian rhythm, and circadian rhythm is affected by the melatonin level controlled by the light exposure. Therefore, sun exposure has an important role for determining sleep time. Aim and objective was to find an association between self-reported sleep duration with serum vitamin D levels in healthy adults. Methods: A cross sectional study was carried out on 150 first professional MBBS students. They were asked about their sleep duration via a questionnaire and their morning samples of serum vitamin D was taken. All the data was put in SPSS software and analyzed. Results: There was a definite positive correlation between sleep duration and the concentration of 25(OH)D in this study (r=0.11, p<0.05). Conclusions: The present study revealed that vitamin D [25(OH)D] deficiency was an independent predictor of insufficient sleep among healthy adults.

Vitamin D and sleep duration: a possible link

Background: Normal-range sleep duration is an important factor for general health and metabolism. Insufficient or excessive sleep duration is associated with various chronic physical or mental illness, such as obesity, hypertension, diabetes, metabolic syndrome, depression, and other psychiatric diseases. Sleep duration is mainly affected by circadian rhythm, and circadian rhythm is affected by the melatonin level controlled by the light exposure. Therefore, sun exposure has an important role for determining sleep time. Aim and objective was to find an association between self-reported sleep duration with serum vitamin D levels in healthy adults. Methods: A cross sectional study was carried out on 150 first professional MBBS students. They were asked about their sleep duration via a questionnaire and their morning samples of serum vitamin D was taken. All the data was put in SPSS software and analyzed. Results: There was a definite positive correlation between sleep duration and the concentration of 25(OH)D in this study (r=0.11, p<0.05). Conclusions: The present study revealed that vitamin D [25(OH)D] deficiency was an independent predictor of insufficient sleep among healthy adults.

Genetically predicted insomnia causally increases the risk of erectile dysfunction / 亚洲男科学杂志(英文版)

Sleep has attracted extensive attention due to its significance in health. However, its association with erectile dysfunction (ED) is insufficiently investigated. To investigate the potential causal links between sleep traits (insomnia, sleep duration, and chronotype) and ED, this study was performed. The single-nucleotide polymorphisms (SNPs) associated with insomnia, sleep duration, and chronotype were retrieved from previous genome-wide association studies (GWAS). A conventional two-sample Mendelian randomization (MR) was used to estimate the causal links between sleep traits and ED. The summary statistics of ED were from individuals of European ancestry (6175 cases vs 217 630 controls). As shown by the random effect inverse-variance-weighting (IVW) estimator, genetically predicted insomnia was causally associated with a 1.15-fold risk of ED (95% confidence interval: 1.07-1.23, P < 0.001). Sleep duration and morningness were not causally associated with ED, as indicated by the IVW (all P > 0.05). These findings were consistent with the results of sensitivity analyses. Based on genetic data, this study provides causal evidence that genetically predicted insomnia increases the risk of ED, whereas sleep duration and chronotype do not.

Association between sleep duration and depressive symptoms inthe elderly / 四川精神卫生

BackgroundDepression presents a significant risk to the physical and mental health of the elderly. The relationship between sleep and depressive symptoms has become a major research focus. However， previous research findings on this relationship have yielded inconsistent conclusions. ObjectiveTo explore the relationship between sleep duration and depressive symptoms in the elderly， in order to provide insights into the prevention of depressive symptoms and delaying their progression in the elderly. MethodsData analysis involved 8 210 adults aged 60 years or older， utilizing data from the 2018 China Health and Retirement Longitudinal Study （CHARLS） survey. Participants were categorized into two groups those with depressive symptoms and those without- based on the Center for Epidemiologic Studies Depression-10 Scale （CESD-10） criteria. Logistic regression and restricted cubic spline models were used to analyze the association between sleep duration and depressive symptoms. ResultsThe 318 people with depressive symptoms were detected among the 8 210 elderly participants， with an average sleep duration of （6.14±2.05） hours per night. Restricted cubic spline models showed a non-linear association between sleep duration and depressive symptoms （χ2=412.670，P<0.01）. After adjusting for confounding factors， compared to the elderly with a sleep duration 7~7.9 hours， the risk of depressive symptoms in the elderly was 2.971 times higher （95% CI： 2.560~3.449， P<0.01） in those with a sleep duration <6 hours， 1.372 times higher （95% CI： 1.161~1.621， P<0.01） in those with 6~6.9 hours， and 1 185 times higher （95% CI： 1.009~1.393， P<0.05） in those with ≥8 hours. Subgroup analysis showed no correlation between sleep duration ≥8 hours and the risk of depressive symptoms across genders and the 60~69 age group （P>0.05）. ConclusionThere was an approximately nonlinear association between sleep duration and depressive symptoms， with differences by gender and age.［Funded by Sichuan Applied Psychology Research Center， Chengdu Medical College （number， CSXL-22226）］

Obesity: A mediator between cardiorespiratory fitness and self-reported sleep pattern among future physicians

Background: Obesity in relation to physical fitness is of major concern nowadays, as the prevalence of obesity is increasing rapidly worldwide and India is no exception to it. Lack of fitness results in stress as well as increased burnout, which ultimately contributes to mortality from cardiovascular disease. Physicians who are having poor exercise habits are also less likely to counsel patients about exercise. Aim and Objectives: Hence, in this study, we aim to evaluate the body mass index (BMI) as well as cardiorespiratory fitness and self-reported sleep pattern among the resident doctors of MMIMSR, Mullana, Ambala, Haryana. Materials and Methods: Data were collected for the cross-sectional study. Sleep pattern was determined using a validated Pittsburgh sleep quality index questionnaire. Body weight and height were measured and BMI was calculated using Quetelet index. Queen’s College Step Test method was used to estimate cardiorespiratory fitness by calculating VO2max. VO2max is internationally accepted parameter and is the first choice in measuring a person’s cardiopulmonary status. Results: The result of our study showed highly positive significant (P < 0.01) association and correlation between obesity and sleep patterns and highly significant (P < 0.01) correlation between obesity and cardiorespiratory fitness among the resident doctors. Residents with relatively disturbed sleep pattern and with shorter sleep durations were either overweight or obese. Preliminary findings are consistent with the hypothesis that disturbance in sleep pattern may be one of the factors which influences BMI and also influences long-term cardiorespiratory health. Residents attributed time constraints due to training as a key barrier to physical activity. Conclusion: Proper awareness at early stage is extremely important to impress the consequences disturbed sleep pattern and in prevention of the development of obesity and improvement in the cardiorespiratory fitness.

Correlation between depressive symptoms and sleep quality among middle school students in Shanghai / 环境与职业医学

Background The correlation between depression and sleep quality is well established in adults, but similar evidence is lacking in adolescents. Objective To study the sleep quality, the positive rate of depressive symptoms, and their correlation among middle school students in Shanghai, so as to provide a basis for providing mental health and sleep management to this group of students. Methods From September to November 2020, using multi-stage stratified cluster random sampling method, a total of 7796 students from 32 middle schools in 16 districts of Shanghai were selected to conduct a questionnaire survey. The questionnaire for middle school students of the 2020 Shanghai Students’ Common Diseases and Health Influencing Factors Surveillance was used to collect students' demographic information, history of smoking, history of drinking, and history of chronic diseases; the Pittsburgh Sleep Quality Index was used to assess sleep quality; and the Center for Epidemiological Studies Depression Scale was used to evaluate depressive symptoms. χ2 test was used to compare qualitative data between groups. Binary logistic regression was used to analyze the correlation between sleep quality and depressive symptoms among middle school students in Shanghai. Results After excluding incomplete questionnaires, a total of 7160 valid questionnaires were collected. The average sleep time of middle school students in Shanghai was (7.54±1.15) h. Among them, 84.8% reported insufficient sleep time < 9 h, and only 15.2% reported sleep time ≥9 h. In addition, 9.2% of the students had poor sleep quality (Pittsburgh Sleep Quality Index ≥8 points). The sleep quality of urban students was worse than that of suburban students. The sleep quality of girls was worse than that of boys. The sleep quality of students in the third grade of middle school was worse than that of students in the first and second grades of middle school. Students with smoking history, drinking history, and chronic disease history had worse sleep quality than those without (P<0.05). The positive rate of depressive symptoms among middle school students in Shanghai was 22.2%, among which 7.0% reported possible depressive symptoms and 15.2% reported definite depressive symptoms. The positive rate of depressive symptoms in female students (26.1%) was higher than that in male students (18.5%); among different grades of middle school, the positive rate of depressive symptoms of the third grade middle school students was the highest (24.1%); the positive rates of depressive symptoms in students with smoking history, drinking history, and chronic disease history were higher than those without; the positive rate of depressive symptoms was higher in students with poor sleep quality (P<0.05). The results of logistic regression analysis indicated that the students with poor sleep quality showed higher risks of reporting depressive symptoms, and the OR (95%CI) was 17.064 (14.024-20.764). Conclusion The positive rates of poor sleep quality and depressive symptoms of middle school students in Shanghai are high, and there is a significant correlation between these two indicators. For students’ mental health and sleep management, more attention should be paid to the quality in addition to the quantity of sleep.

Associations of Daytime Napping with Incident Cardiovascular Diseases and Hypertension in Chinese Adults: A Nationwide Cohort Study / 生物医学与环境科学（英文）

OBJECTIVE@#This study aimed to examine the associations of daytime napping with incident risks of cardiovascular diseases (CVDs) and hypertension (HTN).@*METHODS@#Data for napping and CVD outcomes in 25 provinces were collected from baseline (2010) and three waves of follow-up (2012-2017) investigations of the China Family Panel Studies. Cox frailty models with random intercepts for the surveyed provinces were used to assess the longitudinal effects of daytime napping on CVD and HTN.@*RESULTS@#Compared with non-nappers, 30+ min nappers had higher risks of CVD and HTN, while no significant associations were observed among < 30 min nappers. Incident risks among 30- to < 60-min nappers increased by 22% [hazard ratio (HR) 1.22, 95% confidence interval ( CI) 1.08-1.39] for CVD and 21% (1.21, 1.04-1.41) for HTN, respectively, with corresponding HRs of CVD and HTN of 1.27 (1.09-1.47) and 1.38 (1.16-1.65) among ≥ 60 min nappers. Nap-associated CVD risks varied by subgroups, with stronger associations in participants with lower body mass index (< 24 kg/m 2), physically inactive persons, smokers, and participants with longer nighttime sleep (≥ 7 h/night). Significant effects of daytime napping were observed on rural and northern residents only, highlighting great regional variations in CVD risks associated with napping habits.@*CONCLUSIONS@#This cohort study revealed strong evidence that long daytime napping (≥ 30 min) is associated with an increased incidence of cardiovascular events.

Relationship between sleep duration, sleep time and brachial-ankle pulse wave velocity / 中华内分泌代谢杂志

Objective:Explore the relationship between sleep duration, sleep time and brachial-ankle pulse wave velocity(baPWV) in community population.Methods:Questionnaire, physical examination, blood tests, and baPWV detection were applied to a community based population. Finally, 3 912 subjects with complete data were included in the study. The relationship between sleep duration, time to fall asleep and PWV was evaluated with binary logistic regression analysis. Results:Being adjusted for age, sex, prevalence of diabetes, sleep condition, body mass index, blood glucose, blood pressure, dyslipidemia, ankle-brachial index, sleep duration and time to fall asleep were correlated with PWV. The risk of PWV abnormalities was increased in the≥8 h group compared to the 6-8 h group( OR=1.155, 95% CI 0.995-1.367, P=0.037). The risk of abnormalities PWV was higher in the group with sleep time after 00: 00 than in the group -23: 00( OR=1.482, 95% CI 1.008-2.179, P=0.045). Conclusion:Long sleep duration(≥8 h) and late sleep time(after 00: 00) may be associated with higher risk of atherosclerosis.

Association between nocturnal sleep duration combined with snoring exposure and SGA，LGA in the first trimester of pregnancy based on birth cohort / 安徽医科大学学报

Objective @#To investigate the correlation between nocturnal sleep duration combined with snoring in the first trimester of pregnancyand small for gestational age(SGA) ，large for gestational age(LGA) ．@*Methods @#Multi- variate Logistic regression model was used to analyze the association between nocturnal sleep duration ，snoring， their combined effects and SGA，LGA. @*Results @#Compared to nocturnal sleep duration 7 to 9 h in the first trimester of pregnancy，sleep duration＜7 h was positively correlated with SGA in male newborn( OR = 4. 22，95% CI : 1. 69 - 10. 52) ; After stratified by snoring，the sleep duration of snoring women＜7 h was positively correlated with SGA ( OR = 5. 68，95% CI : 1. 02－31. 51) ，and the sleep duration of non-snoring women＜7 h was positively correlated with LGA ( OR = 2. 10，95% CI : 1. 16 －3. 81) ．@*Conclusion @#Sleep duration＜7 h in the first trimester of preg- nancy is a risk factor for SGA and LGA，and snoring may enhance the association between sleep duration＜7 h in the first trimester of pregnancy and SGA．Pregnant women should keep adequate nocturnal sleep duration to reduce the risk of abnormal neonatal weight.

Associations of sleep duration with childhood obesity:findings from a national cohort study in China / 《全球健康杂志（英文）》

Objective:Examine effect of sleep duration on children's risk of overweight and obesity;and study associations between activities in the last hour before bedtime and sleep outcomes(sleep duration,sleep quality,and sleep onset latency).Methods:Children's data were recruited using a questionnaire survey from a nationally representative sample of children(n=10 279)in China in 2013-2016.Mixed-effects models were used to test associations among variables stratified by sex.Results:Sleep duration was positively associated with BMI in boys(p=0.04,P=0.021).Girls with short sleep durations(＜8 h/d)tended to have higher BMI values than those with normal sleep durations(8-9 h/d)(β=0.12,P=0.063).The top three activities were playing electronic devices(Factor 1),doing homework,and reading(combined as Factor 2).Factors 1 and 2 were both significantly associated with sleep duration(β=0.17,P＜0.001;β=-0.26,P＜0.001,respectively).Conclusion:Sleep duration seems to affect BMI in Chinese children.Using electronic devices and reading before bedtime influenced sleep duration.Good bedtime habits and sleep duration can help weight management in children.

Relación entre la duración del sueño y la presión arterial elevada en estudiantes universitarios / Relationship between sleep duration and high blood pressure in university students

RESUMEN Introducción: Los estudiantes universitarios presentan alteraciones en la duración del sueño. Estudios previos revelaron que la duración del sueño puede estar asociada a un aumento de la presión arterial (PA) Objetivo: Analizar la posible relación entre duración del sueño y la PA en estudiantes de Medicina. Material y métodos: Estudio analítico, de corte transversal en 728 estudiantes de Medicina. Se consideró PA elevada a la PA ≥ a la categoría de PA limítrofe (PA sistólica ≥130 mmHg y/o diastólica ≥85 mmHg). La duración del sueño se clasificó en: <6, 6-8 y >8 horas/día. Para determinar los riesgos asociados se realizaron comparaciones bivariadas (chi cuadrado) y multivariadas (regresión logística) ajustadas por factores de riesgo. Resultados: El 33,6% de los estudiantes presentó PA elevada. La duración media del sueño para los que presentaron PA elevada fue de 6,92 ± 0,92 horas, mientras que para los estudiantes con PA normal fue de 6,97 ± 0,95 horas. El 12,4% dormían <6 horas, el 74,6% entre 6-8 horas y 13,0% más de 8 horas. El análisis bivariado mostró que las horas de sueño no estuvieron asociados a PA elevada. El análisis multivariado ajustado no mostró asociación significativa entre las horas de sueño y la PA. Conclusión: La duración del sueño para los estudiantes con PA elevada fue la misma que para los estudiantes con PA normal. Hay un bajo porcentaje de estudiantes que duermen menos de 6 horas y más de 8 hs. No se encontró asociación significativa entre la duración del sueño corto o largo y la prevalencia de PA elevada.

ABSTRACT Background: University students present alterations in the duration of sleep. Previous studies revealed that the duration of sleep may be associated with an increase in blood pressure (BP). Objective: Analyze the possible relationship between sleep duration and BP in medical students. Methods: Analytical, cross-sectional study in medical students. High BP was considered to be BP ≥ to the borderline BP category (SBP ≥130 mmHg and / or DBP ≥85 mmHg). The duration of sleep was classified as: <6, 6-8 and >8 h / d. To determine the associated risks, bivariate (chi square) and multivariate (logistic regression) comparisons were made adjusted for risk factors. Results: 33.6% of the students presented high BP. The mean duration of sleep for those with high BP was 6.92 ± 0.92 hours, while for students with normal BP it was 6.97 ± 0.95. 12.4% slept <6 hours, 74.6% between 6-8 hours and 13.0% more than 8 hours. The bivariate analysis showed that hours of sleep were not associated with high BP. The adjusted multivariate analysis did not show a significant association between hours of sleep and BP. Conclusion: The duration of sleep for students with high BP was the same as for students with normal BP. There is a low percentage of students who sleep less than 6 hours and more than 8 hours. No significant association was found between the duration of short or long sleep and the prevalence of elevated BP.

Association between low vision and sleep duration among primary and middle school students / 预防医学

Objective @#To understand the relationship between sleep duration and low vision among primary and middle school students, so as to provide the reference for promoting eye health of primary and middle school students.@* Methods @#Using stratified cluster sampling method, the students were selected from four primary schools, four junior high schools and three senior high schools in Dinghai, Putuo, Daishan and Shengsi of Zhoushan. The questionnaire for the influencing factors of myopia in the national monitoring and intervention project of common diseases and influencing factors among students in 2019 was used to collect their demography, video display terminal use, outdoor activity, parents'myopia and sleep duration. The multivariate logistic regression model was established to analyze the relationship between sleep duration and low vision among the students. @*Results @#A total of 3 016 questionnaires were sent out, and 2 932 valid ones were returned. The effective rate was 97.21%. There were 1 537 ( 52.42% ) males and 1 395 females ( 47.58% ); 947 ( 32.30% ) primary school students and 1 985 ( 67.70% ) middle school students; 2 328 ( 79.40% ) students with low vision. There were 1 022 ( 34.85% ), 903 (30.80%), 697 ( 23.77% ) and 310 ( 10.57% ) students with the daily sleep duration of <8 hours, 8-<9 hours, 9-<10 hours and ≥10 hours, respectively. The multivariate logistic regression analysis showed that the risk of low vision was lower when the daily sleep duration of students was 8-<9 hours ( OR=0.735, 95%CI: 0.561-0.963 ) and 9-<10 hours ( OR=0.605, 95%CI: 0.446-0.825 ). @*Conclusion @#Adequate sleep duration is conducive to reduce the risk of low vision among primary and middle school students.

Predicted 10-year Cardiovascular Disease Risk and Its Association with Sleep Duration among Adults in Beijing-Tianjin-Hebei Region, China / 生物医学与环境科学（英文）

Objective@#The study aims to predict 10-year cardiovascular disease (CVD) risk and explore its association with sleep duration among Chinese urban adults.@*Methods@#We analyzed part of the baseline data of a cohort that recruited adults for health screening by cluster sampling. The simplified Pittsburgh Sleep Quality Index (PSQI) and Framingham 10-year risk score (FRS) were used to measure sleep duration and CVD risk. Demographic characteristics, personal history of chronic diseases, lifestyle factors were collected using a questionnaire. Height, weight, total cholesterol (TC), and high-density lipoprotein cholesterol (HDL-C) were also measured. Multiple logistic regression models were performed to explore the association of sleep duration with the predicted CVD risk.@*Results@#We included 31, 135 participants (median age 44 years, 53.02% males) free of CVD, cerebral stroke, and not taking lipid-lowering agents. Overall, 14.05%, and 25.55% of participants were at medium and high predicted CVD risk, respectively. Short sleep was independently associated with increased odds of medium to high risk of predicted 10-year CVD among males ( @*Conclusion@#A substantial number of adults free of CVD were at high 10-year CVD risk. Short sleep was associated with increased odds of predicted CVD risk.