Sleep and mortality: a population-based 22-year follow-up study

STUDY OBJECTIVES: Long and short sleep have been associated with increased mortality. We assessed mortality and 3 aspects of sleep behavior in a large cohort with 22-year follow-up. DESIGN/SETTING: Prospective, population-based cohort study. PARTICIPANTS: 21,268 twins aged > or =18 years responding to questionnaires administered to the Finnish Twin Cohort in 1975 (response rate 89%), and 1981 (84%). INTERVENTIONS: N/A. MEASUREMENTS: Subjects were categorized as short (<7 h), average, or long (>8 h) sleepers; sleeping well, fairly well, or fairly poorly/poorly; no, infrequent, or frequent users of hypnotics and/or tranquilizers. Cox proportional hazard models were used to obtain hazard ratios (HR) for mortality during 1982-2003 by sleep variable categories and their combinations. Adjustments were done for 10 sociodemographic and lifestyle covariates known to affect risk of death. RESULTS: Significantly increased risk of mortality was observed both for short sleep in men (+26%) and in women (+21%), and for long sleep (+24% and +17%), respectively, and also frequent use of hypnotics/tranquilizers (+31% in men and +39% in women). Snoring as a covariate did not change the results. The effect of sleep on mortality varied between age groups, with strongest effects in young men. Between 1975 and 1981, sleep length and sleep quality changed in one-third of subjects. In men there was a significant increase for stable short (1.34) and stable long (1.29) sleep for natural deaths, and for external causes in stable short sleepers (1.62). CONCLUSIONS: Our results show complicated associations between sleep and mortality, with increased risk in short and long sleep.     

Exhaled nitric oxide in a population-based study of asthma and allergy in schoolchildren

Exhaled nitric oxide (NO) reflects inflammation in the lower airways and is well adapted for use in children. The aims of this study were to investigate the distribution of the fraction of expired NO (FENO) in school children and to compare FENO and spirometry in relation to the International Study of Asthma and Allergies in Childhood questionnaire. The study was performed in 959 randomly selected 13-14-year-old school children in Uppsala, Sweden. Exhaled NO was measured at an inhalation rate of 0.1 l/s (FENO0.1) and a spirometric test was performed and data from these measurements were related to questionnaire data. Exhaled NO was measured according to American Thoracic Society recommendations, except the use of a mouth wash and an exhalation flow rate of 0.1 l/s. The distribution of the mean FENO0.1 values was skewed, with a preponderance of very low levels and a widespread tail of values ranging up to 102 parts per billion (ppb). Boys exhibited significantly higher mean FENO0.1 values than girls, 5.2 (4.7-5.7) vs 4.4 (4.0-4.8) ppb (geometric mean and 95% CI), P <0.01). Children who reported wheezing in the last year had higher FENO0.1 values than children that had not, 8.5 (7.1-10.2) vs 4.3 (4.0-4.6) ppb, P <0.001). The same association was found to most symptoms indicating hay fever and eczema. In contrast to this, only weak or inconsistent associations were found between asthma and spirometric indices. Exhaled NO levels were found to be independently related to male gender, wheeze and rhinoconjuctivitis but not to current eczema. In conclusion, exhaled NO was closely associated with reported asthma and allergy symptoms whereas spirometric indices such as percent predicted forced expiratory volume in 1 s were not. As most asthma cases in a population are mild, the findings suggest that exhaled NO is a sensitive marker of asthma and allergy.     

Prevalence of Japanese cedar pollinosis among schoolchildren in Japan

BACKGROUND: Japanese cedar pollinosis is an important allergic rhinoconjunctivitis in Japan in spring. We investigated the relationship between the amount of pollen in the air and the prevalence of the disease and sensitization to Japanese cedar pollen in this ecological study. METHODS: The IgE antibody to Japanese cedar pollen (JCP-IgE) was determined in human serum and rhinoconjunctival symptoms were surveyed in 407-510 children in May or June every year from 1995 to 2001. Japanese cedar pollinosis was defined as being JCP-IgE >or=1.5 IU/ml and having any rhinoconjunctival symptom lasting 3 weeks or longer in March or April. RESULTS: Prevalence rates of Japanese cedar pollinosis were 13.8-22.9%. Prevalence rates of being JCP-IgE >or=1.5 IU/ml were 39.0-50.1%, and those of being JCP-IgE >or=15.01 IU/ml were 11.4-23.2%. All prevalence rates were significantly related to the amount of pollen in the air. The proportion of subjects with rhinoconjunctival symptoms was relatively constant in each stratum of low JCP-IgE levels (<0.35, 1.50-2.99, 3.0-14.9 IU/ml). CONCLUSION: High exposure to Japanese cedar pollen was associated with higher levels of JCP-IgE antibody and a high prevalence of Japanese cedar pollinosis. The relationship between the level of JCP-IgE and the proportion of subjects with symptoms was relatively constant.     

Pre-pregnancy sleep duration and postpartum depression: a multicenter study in Japan

Postpartum depression (PPD) is as a major public health issue and clinical priority worldwide. This study aimed to investigate the association between pre-pregnancy sleep duration and PPD. A multicenter retrospective study was conducted using clinical data of women who delivered at term between 2014 and 2018 at 12 maternity care hospitals in Japan. A total of 15,314 women were stratified into five groups according to their pre-pregnancy sleep duration: < 6, 6–7, 7–8, 8–9, and ≥ 9 h. Univariate and multivariate regression analyses were conducted to determine whether pre-pregnancy sleep duration affects the Edinburgh Postnatal Depression Scale (EPDS) scores at 1 month postpartum. We also evaluated whether the risk for PPD differs between primipara and multipara women classified according to pre-pregnancy sleep duration. The adjusted odds ratio for high EPDS scores (≥ 9) among women who slept for < 6 h and 6–7 h was 2.08 (95% confidence interval [CI]: 1.60–2.70) and 1.41 (95% CI: 1.18–1.68), respectively, relative to that in women with 7–8 h of sleep as the reference group. A 1-h increase in sleep duration was associated with an approximately 14% reduction in the risk for high EPDS scores. The association between short sleep duration and high EPDS scores was more remarkable in multipara women than in primipara women. Short pre-pregnancy sleep duration is associated with high EPDS scores, and this association is more significant in multipara women than in primipara women. Our findings emphasize the importance of collecting information on pre-pregnancy sleep duration to identify women at a high risk for PPD.

     

Racial differences in self-reports of sleep duration in a population-based study

STUDY OBJECTIVES: Racial and ethnic differences in sleep duration are not well understood. Research shows that short (< or =6 hours) and long (> or =9 hours) sleepers have higher mortality risks than mid-range sleepers. We investigated whether sleep duration varies by racial and ethnic characteristics and if some of these associations may be explained by residential context. DESIGN: Cross-sectional National Health Interview Survey. SETTING: Non-institutionalized adults living in the United States in 1990. PARTICIPANTS: 32,749 people aged 18 years or older. MEASUREMENT AND RESULTS: We estimate a multinomial logistic regression that predicts short, mid-range, and long sleep duration; including covariates for race/ethnicity, among other demographic, health, and neighborhood characteristics. Black respondents had an increased risk of being short and long sleepers (OR=1.41, 95% CI=1.27-1.57 and OR=1.62, 95% CI=1.40-1.88, respectively) relative to white respondents. Hispanics (excluding Mexican Americans) and non-Hispanic "Others" were also associated with increased risk of short sleeping (OR=1.26, 95% CI= 1.07-1.49 and OR=1.35, 95% CI= 1.11-1.64, respectively). Living in an inner city was associated with increased risk of short sleeping and reduced risk of long sleeping, compared to non-urban areas. Some of the higher risk of short sleeping among blacks can be explained by higher prevalence of blacks living in the inner city. CONCLUSIONS: Blacks and other racial minorities are more likely to have sleep durations that are associated with increased mortality. The results are consistent with the hypothesis that unhealthy sleep patterns among minorities may contribute to health differentials.     

Sleep habits and disorders in Finnish schoolchildren

SUMMARY  A variety of epidemiological sleep parameters was evaluated in 574 Finnish schoolchildren (age 7 to 17 years) and in their parents (454 mothers and 390 fathers). Three questionnaire forms were set, one for the pupil and two for his/her parents including information of sleep habits, disorders, and social background of the pupil and his/her family. The pupils were grouped by age (two preadolescent groups: 7.1–9.3 y and 9.4–13 y, adolescents 13.1–17.1 y) and sex. It was found that bedtime was more often after 22.00 hours among adolescents than preadolescents both at weekends and on weekdays. At weekends the wake-up time was later in adolescents than preadolescents but on weekdays it was opposite in boys. On weekdays girls went earlier to bed than boys and woke up earlier than boys. Total sleep durations both on weekdays and at weekends were longer in preadolescent than in adolescent groups, and longer during weekend nights than on weekday nights in all groups. Girls experienced more dreaming and night waking, but boys snored more. Daytime sleepiness patterns were more common in adolescents than in preadolescents. Children who experienced daytime sleepiness more often had fathers with daily sleep urges.
An association was found between age and sleep habits and some daytime sleepiness patterns; adolescents went to bed later and slept less, and had more problems with alertness during daytime than preadolescents. Some differences were also found between boys and girls. The daytime sleepiness of pupils correlated with the same symptom in fathers.     

Sleep duration and mortality: a systematic review and meta-analysis

Epidemiologic studies have shown that sleep duration is associated with overall mortality. We conducted a systematic review of the associations between sleep duration and all-cause and cause-specific mortality. PubMed was systematically searched up to January, 2008 to identify studies examining the association between sleep duration and mortality (both all-cause and cause-specific) among adults. Data were abstracted serially in a standardized manner by two reviewers and analyzed using random-effects meta-analysis. Twenty-three studies assessing the associations between sleep duration and mortality were identified. All examined sleep duration measured using participant self-report. Among the 16 studies which had similar reference categories and reported sufficient data on short sleep and mortality for meta-analyses, the pooled relative risk (RR) for all-cause mortality for short sleep duration was 1.10 [95% confidence interval (CI): 1.06, 1.15]. For cardiovascular-related and cancer-related mortality, the RRs associated with short sleep were 1.06 (95% CI: 0.94, 1.18) and 0.99 (95% CI: 0.88, 1.13), respectively. Similarly, among the 17 studies reporting data on long sleep duration and mortality, the pooled RRs comparing the long sleepers with medium sleepers were 1.23 (95% CI: 1.17, 1.30) for all-cause mortality, 1.38 (95% CI: 1.13, 1.69) for cardiovascular-related mortality, and 1.21 (95% CI: 1.11, 1.32) for cancer-related mortality. Our findings indicate that both short sleepers and long sleepers are at increased risk of all-cause mortality. Further research using objective measures of sleep duration is needed to fully characterize these associations.     

Sitting habits in elementary schoolchildren: a traditional versus a "Moving school"

This study evaluated differences in sitting habits in the classroom between the project "Moving school" and a traditional school in 8-year-old children. Twenty-two children, since 1.5 years involved in the project were compared to 25 children in a traditional school. Making use of the Portable Ergonomic Observation (PEO) method, it was observed that children from a traditional school spend an average of 97% of the lesson time sitting statically, from which one-third with the trunk bend over 45 degrees. In the "Moving school" this posture was replaced by dynamic sitting (53%), standing (31%) and walking around (10%), while trunk flexion over 45 degrees was nearly not observed. Children from the "Moving school" also showed significantly less neck and trunk rotation. Additionally, accelerometric data showed significantly more physical activity in lessons of the "Moving school". Rates of self-reported back or neck pain did not differ significantly between both study groups. Results show that sitting habits are more favourable in a "Moving school". Further research is needed to study the impact of implementing "Moving school" concepts in traditional schools on sitting habits.     

Preventing disruptive behavior in elementary schoolchildren: impact of a universal classroom-based intervention

A population-based, randomized universal classroom intervention trial for the prevention of disruptive behavior (i.e., attention-deficit/hyperactivity problems, oppositional defiant problems, and conduct problems) is described. Impact on developmental trajectories in young elementary schoolchildren was studied. Three trajectories were identified in children with high, intermediate, or low levels of problems on all 3 disruptive behaviors at baseline. The intervention had a positive impact on the development of all disruptive behavior problems in children with intermediate levels of these problems at baseline. Effect sizes of mean difference at outcome were medium or small. In children with the highest levels of disruptive behavior at baseline, a positive impact of the intervention was found for conduct problems.     

Relation of socioeconomic status to overweight and obesity: a large population-based study of Chinese adults

Background: China has been going through significant changes in social and economical aspects and with great socioeconomic disparity in different regions. However, data on the association between socioeconomic status (SES) and obesity are not available in Tianjin, China.

Aim: This study aimed to investigate the association between SES and high adiposity among the adult population in Tianjin.

Subjects and methods: A total of 7351 individuals aged 20–79 were included in this study. Socioeconomic information was collected through an interview following a structured questionnaire. Waist circumference, body weight and height were measured following standard procedures. Overweight and obesity were defined according to the criteria of the Working Group on Obesity in China. Data were analysed using multinomial logistic regression with adjustment for potential confounders.

Results: Stratified analysis showed that higher monthly income and education were related to decreased odds of abdominal overweight/obesity in women, while high education was associated with increased odds of general overweight/obesity in men. Retirement increased the odds of abdominal overweight and obesity and non-manual work was associated with low odds of abdominal obesity in women.

Conclusions: SES was associated with general and abdominal overweight/obesity and sex may play a role in such an association.     

Sleep duration and history of stroke among adults from the USA

Although short sleep duration is related to chronic conditions, such as hypertension, diabetes and obesity, the association with stroke is less well known. Using 2006–2011 National Health Interview Surveys, we assessed the association between self‐reported duration of sleep and prevalence of stroke stratifying by age and sex. Of the 154 599 participants aged 18 years or older, 29.2%, 61.8% and 9.0% reported they sleep ≤6, 7–8 and ≥9 h per day, respectively. Corresponding age‐standardized prevalence of stroke were 2.78%, 1.99% and 5.21% (P < 0.001). Logistic regression models showed a higher prevalence of stroke among those who slept ≤6 or ≥9 h a day compared with those who slept 7–8 h, after adjusting for sociodemographic, behavioural and health characteristics. Further stratifying by age and sex showed that the association of duration of sleep and stroke differed among different age or sex groups. Among young adults (18–44 years), a higher prevalence of stroke was found among women with short sleep. Higher prevalence of stroke was found among middle‐aged men and women reporting short or long sleep duration. Among older adults (≥65 years), higher prevalence of stroke was found only among those who slept ≥9 h. In this national sample of adults, the association between duration of sleep and stroke varied by sex and age. Although there was an association of short sleep duration with stroke, we also observed the association of long sleep duration with stroke, especially among those aged 65 years or older.     

Individual measurement of exposure to everyday violence among elementary schoolchildren across various settings

One hundred and thirty‐four second‐ and fourth‐grade students from two schools in Israel were measured individually using a Hebrew adaptation of the Violence Exposure Scale—Revised (VEX‐R), a self‐report scale measuring children's exposure to everyday violence. Children reported exposure as a function of situation (witness or victim) and setting (home, school, or neighborhood). They also reported on their own distress symptoms. The children's mothers also completed the VEX‐R, indicating how they expected their child would report, and the Child Behavior Checklist. Children reported more exposure to violence at school compared to either the home or neighborhood, and more as witnesses than victims. Most of the violence reported was mild (e.g., pushing, chasing), while severe violence (e.g., shooting, stabbing) was rare in all settings. Children who reported themselves as frequent victims of violence were rated by their mothers as exhibiting more behavior problems than those reporting less victimization. The results support the validity of the VEX‐R as a measure of exposure to violence for young children. © 2001 John Wiley & Sons, Inc.     

Predictors of smoking initiation among schoolchildren in Tunisia: a 4 years cohort study

Objective

To identify predictors of smoking initiation among non smoking Tunisian school children; and to propose efficient antismoking strategies in order to prevent smoking initiation.

Methods

It was a cohort study surveying prospectively for four years pupils attending schools in Sousse city in Tunisia. 441 non smoking pupils aged 13–15 years attending secondary schools in Sousse.Data were collected by a self administered questionnaire during class session. Two ways cross tabulation, univariate and multivariate logistic regression analyses were the main analytical methods.

Results

57.1% of the surveyed population were girls, 42.9 % were boys. 63% had at least one of their peers who smoked. Before 1999, 16.6% had already tried to smoke, 29.5% had already experienced alcohol. In 2003, smoking prevalence was 17%. 4.8% were girls; 33.3% of boys; p<0,001). 69.9 % of these smokers declared that they would carry on smoking during the following five years. Predictors which were highly associated with smoking initiation were previous experimentation with alcohol and tobacco, having a smoking best friend, lack of sensitization from the part of the school, believing that smoking makes one feel cool and that tobacco shouldn''t be forbidden in public places.

Conclusion

Intervention programs should target young children to avoid experiencing the first cigarette. Multidisciplinary management including community and school based intervention highlighted by mass media campaigns may provide schoolchildren with skills to resist smoking peers prompts to adopt unhealthy habits such as smoking.     

Sleep problems and internet addiction among children and adolescents: a longitudinal study

Although the literature has documented associations between sleep problems and internet addiction, the temporal direction of these relationships has not been established. The purpose of this study is to evaluate the bidirectional relationships between sleep problems and internet addiction among children and adolescents longitudinally. A four‐wave longitudinal study was conducted with 1253 children and adolescents in grades 3, 5 and 8 from March 2013 to January 2014. The sleep problems of the student participants were measured by parental reports on the Sleep Habit Questionnaire, which catalogues early insomnia, middle insomnia, disturbed circadian rhythm, periodic leg movements, sleep terrors, sleepwalking, sleep talking, nightmares, bruxism, snoring and sleep apnoea. The severity of internet addiction was measured by students’ self‐reports on the Chen Internet Addiction Scale. Based on the results of time‐lag models, dyssomnias (odds ratio = 1.31), especially early and middle insomnias (odds ratio = 1.74 and 2.24), sequentially predicted internet addiction, and internet addiction sequentially predicted disturbed circadian rhythm (odds ratio = 2.40), regardless of adjustment for gender and age. This is the first study to demonstrate the temporal relationship of early and middle insomnia predicting internet addiction, which subsequently predicts disturbed circadian rhythm. These findings imply that treatment strategies for sleep problems and internet addiction should vary according to the order of their occurrence.     

Sleep habits and accident risk among truck drivers: a cross-sectional study in Argentina

Road accidents are a major cause of death, and sleep deprivation affects driving skills. We conducted a cross-sectional study to evaluate sleep habits and accident risk in long-haul truck drivers in Buenos Aires, Argentina. Questionnaires regarding sleep habits, snoring, and daytime sleepiness were administered, and a limited physical examination was performed. We obtained 738 complete answers (response rate 85%). Mean sleep hours during working days was 3.76 (SD 2.40). Mean driving hours was 15.9 (SD 5.60) per day. Frequent sleepiness while driving was reported by 43.7% of responders. Sleepiness while driving was associated with Epworth Sleepiness Scale values >10 (odds ratio 1.85, 95% confidence interval = 1.20-2.85). Snoring was reportea by 71% of drivers and was frequent in 43.8%. Snoring more than 3 times a week (odds ratio 1.73, 95% confidence interval = 1.23-2.44), sleepiness while driving (OR 1.92, 95% confidence interval = 1.08-1.96), and Epworth Sleepiness Scale score > 10 (odds ratio 2.53, 95% confidence interval = 1.61-3.97) were independently associated with reporting of accidents or near accidents. Sleep deprivation and long driving shifts were prevalent in our study. Accident risk was associated with frequent snoring, daytime sleepiness, and reporting of sleepiness at the wheel. This study highlights the need of improving working conditions in this highly exposed population.     

Sleep duration among black and white Americans: results of the National Health Interview Survey

INTRODUCTION: Epidemiologic studies have shown the importance of habitual sleep duration as an index of health and mortality risks. However, little has been done to ascertain ethnic differences in sleep duration in a national sample. This study compares sleep duration in a sample of black and white participants in the National Health Interview Survey (NHIS). METHOD: Data were collected from 29,818 Americans (age range 18-85 years) who participated in the 2005 NHIS. The NHIS is a cross-sectional household interview survey that uses a multistage area probability design, thus permitting representative sampling of U.S. households. During face-to-face interviews conducted by trained interviewers from the U.S. Census Bureau, respondents provided demographic data and information about physician-diagnosed chronic conditions, estimated habitual sleep duration and functional capacity, and rated their mood. RESULTS: Fisher's exact test results indicated that blacks were less likely than whites to report sleeping 7 hours (23% vs. 30%; chi2 = 94, p < 0.0001). Blacks were more likely to experience both short sleep (< or = 5 hours) (12% vs. 8%, chi2 = 44, p < 0.0001) and long sleep (> or = 9 hours) (11% vs. 9%, chi2 = 23, p < 0.0001). Logistic regression analysis, adjusting for differences in sociodemographic factors, depression, functional capacity and medical illnesses, demonstrated that black ethnicity was a significant predictor of extreme sleep duration (Wald = 46, p < 0.0001; OR = 1.35, 95% CI: 1.24-1.47). DISCUSSION: Independent of several sociodemographic and medical factors, blacks had more prevalent short and long sleep durations, suggesting greater variation in habitual sleep time. Therefore, blacks might be at increased risks of developing medical conditions associated with short and long sleep.     

Sleep duration and metabolic syndrome

Extremes in duration of sleep have been associated with adverse health, specifically with the symptomatology characteristic of the metabolic syndrome. Body homeostasis and circadian rhythm are thought to interact and to influence energy metabolism. Environmental cues, such as time of year and amplitude of seasonal changes (changes in photoperiod length) influence both sleep behavior and energy metabolism, supporting a link between these two systems. However, little is known about the molecular mechanism underlying the relationships of sleep and the metabolic syndrome symptoms, or the sleep–circadian phenotypes per se. In genetic association studies on sleep duration (candidate clock genes approach and genome-wide association studies), we identified genes that are functionally involved in the development of the metabolic syndrome symptomatology. Although the relationship between sleep duration and body mass index may partly be caused by environmental influences such as voluntary sleep restriction and circadian misalignment, the association of sleep duration with genes related to metabolism indicates that genetic factors are central to it. In this article, the latest evidence of a gene–environment influence on the relationship of sleep duration with the metabolic syndrome symptomatology is discussed. Greater understanding of a common genetic pathway linking sleep duration to metabolic dysfunction, and the role of environment in the mediation of this relationship, will lead to the development of new guidelines for treatment of obesity, which is a major health issues in our society.