Chronotype and sleep duration are associated with stimulant consumption and BMI among Chinese undergraduates

The study sought to identify the association between stimulant consumption and social jetlag, chronotype as well as sleep duration among undergraduate students. A cross-sectional survey was conducted in the university town in Chongqing, China. Data were collected on 977 participants, age 20.06 (SD = 1.25) years old, using the Munich Chronotype Questionnaire (MCTQ) to measure social jetlag, chronotype and average sleep duration. A self-reported questionnaire was used to collect the information: BMI, demographic data, outdoor activity time, smoking status, alcohol consumption, coffee consumption and sugar-sweetened beverage consumption. The positive significant association was found between late chronotype and alcohol consumption (OR = 1.26, 95% CI [1.05–1.52]), being a current smoker (OR = 1.62, 95% CI [1.26–2.07]) and sugar-sweetened beverage consumption (OR = 1.42, 95% CI [1.17–1.72]). Average sleep duration was negatively associated with BMI (OR = 0.84, 95% CI [0.71–0.98]). Social jetlag did not find any association between stimulant consumption and BMI in the adjusted model. The results showed that Chinese undergraduate students had a negative significant association between average sleep duration and BMI, and late chronotype might affect the stimulant consumption among the group. This study may provide some implications for health management of obesity among undergraduate students in China.

     

The impact of a delayed sleep–wake schedule on depression is greater in women – A web-based cross-sectional study in Japanese young adults

Sleep-related problems, such as symptoms of insomnia, daytime sleepiness, shorter sleep duration, or a delayed sleep–wake schedule, are known to be risk factors for depression. In general, depression is more prevalent in women than in men, but sleep-related problems do not necessarily show similar gender predominance. Hence, it can be speculated that the impact of sleep-related problems on the development process of depression differs between genders; however, so far, few studies have focused on this issue. The aim of this study was to clarify gender differences in the rates of depression of people with the above sleep-related problems, and to examine gender differences in factors associated with depression in Japanese young adults. A web-based questionnaire survey comprising assessments of demographic variables, sleep-related variables (bed time, wake time, sleep onset latency, frequency of difficulty in initiating sleep and that in maintaining sleep, i.e. symptom components of insomnia, and daytime sleepiness), and the 12-item version of the Center for Epidemiologic Studies Depression Scale was administered to 2502 participants (males:females?=?1144:1358, age range?=?19–25 years). Female predominance in the rate of depression was observed only in subjects with a delayed sleep–wake schedule (χ²₍₁₎?=?15.44, p?<?0.001). In men, daytime sleepiness and difficulty in initiating sleep were significantly associated with depression (odds ratio [OR]?=?2.39, 95% confidence interval [CI]?=?[1.69, 3.39], p?<?0.001; OR?=?3.50, 95% CI?=?[2.29, 5.35], p?<?0.001, respectively), whereas in women, significant associations were found between depression and a delayed sleep–wake schedule (OR?=?1.75, 95% CI?=?[1.28, 2.39], p?<?0.001), daytime sleepiness (OR?=?2.13, 95% CI?=?[1.60, 2.85], p?<?0.001), and difficulty in initiating sleep (OR?=?4.37, 95% CI?=?[3.17, 6.03], p?<?0.001). These results indicate that in younger generations, the impact of a delayed sleep–wake schedule on the development of depression is greater in women; specifically, women are vulnerable to depression when they have an eveningness-type lifestyle, which is possibly attributable to the female-specific intrinsic earlier and shorter circadian rhythm. These results suggest the necessity of gender-based approaches to treating sleep-related problems for alleviating or preventing depressive symptoms in young adults.     

Pooling analysis reveals that galectin-1 is a reliable prognostic biomarker in various cancers

Galectin-1 is reported to be upregulated in various human cancers. However, the relationship between galectin-1 expression and cancer prognosis has not been systematically assessed. In this study, we searched PubMed, Web of Science, and Embase to collect all relevant studies and a meta-analysis was performed. We found that increased galectin-1 expression was associated with tumor size (odds ratio [OR] = 1.75; 95% confidence interval [CI]: 1.06–2.89; p = 0.029), clinical stage (OR = 3.89; 95% CI: 2.40–6.31; p < 0.001), and poorer differentiation (OR = 1.39; 95% CI: 1.14–1.69; p = 0.001), but not with age (OR = 1.07; 95% CI: 0.82–1.39; p = 0.597), sex (OR = 0.89; 95% CI: 0.74–1.07; p = 0.202), or lymph node metastasis (OR = 2.57; 95% CI: 0.98–6.78; p = 0.056). In addition, we found that high galectin-1 expression levels were associated with poor overall survival (HR = 2.12; 95% CI: 1.71–2.64; p < 0.001). The results were further validated using The Cancer Genome Atlas data set. Moreover, high galectin-1 expression was significantly associated with disease-free survival (hazard ratio [HR] = 1.60; 95% CI: 1.17–2.19; p = 0.003), progression-free survival (HR = 1.93; 95% CI: 1.65–2.25; p < 0.001), and cancer-specific survival (HR = 1.82; 95% CI: 1.30–2.55; p < 0.001). Our meta-analysis demonstrated that galectin-1 might be a useful common biomarker for predicting prognosis in patients with cancer.     

Associations of chronotype with social jetlag and behavioral problems in preschool children

The timing, duration, and intensity of sleep are determined by the interaction between a sleep-wake-dependent homeostatic process and a sleep-wake-independent, intrinsic, clock-like circadian process. Chronotype represents individual differences in diurnal preferences, which are not only genetically determined but also influenced by social and environmental factors. Thus, the discrepancy between biological and social clocks, so-called “social jetlag”, occurs. Chronotype, social jetlag, and the links between chronotype and behavioral problems are well documented in adults and adolescents. However, such studies on young children are limited. We conducted a survey of sleep and health for preschool children attending kindergarten or childcare centers in Wako, Okayama and Kurashiki cities, Japan, between May and July 2012. A total of 654 children aged 4–6 years (342 boys and 312 girls, with an average age of 4.7 years) were assessed using the Children’s ChronoType Questionnaire and the Strength and Difficulties Questionnaire. Morning (M)-type, neither (N)-type and evening (E)-type accounted for 36.2%, 54.0% and 9.8% of the participants, respectively. The weekday-to-weekend differences in midsleep time – originally proposed as the concept of social jetlag – were 11, 25 and 35?min for M-, N- and E-types, respectively. There was a negative correlation between chronotype and sleep period during weekdays (p?<?0.001) and a positive correlation on weekends (p?<?0.001). The weekday-to-weekend difference in sleep period was 0.5?h for E-types, whereas there was no difference for M-types. Binomial logistic regression analyses were used to examine the links between chronotype and behavioral problems, adjusted for participants’ sex, age, childcare programs and locations. Chronotype was significantly associated with hyperactivity/inattention: N-type (adjusted OR?=?1.74, 95% CI?=?1.03–2.95, p?<?0.05) and E-type (adjusted OR?=?2.47, 95% CI?=?1.18–5.20, p?<?0.05). E-type was significantly associated with conduct problems (adjusted OR?=?2.11, 95% CI?=?1.03–4.31, p?<?0.05) and peer problems (adjusted OR?=?2.75, 95% CI?=?1.18–6.44, p?<?0.05). The results suggest that E-type children are vulnerable to higher social jetlag and more behavioral problems. The immature adjustment function of their endogenous circadian pacemakers may not be able to correct a small but significant social jetlag to synchronize with their social clocks. Furthermore, guidance based on chronobiological evidence is required for parents, teachers and health professionals to help children achieve optimal sleep and reduce behavioral problems.     

Correlations between sleep patterns and cardiovascular diseases in a Chinese middle-aged population

Epidemiological and animal studies have suggested an association between habitual sleep patterns and cardiovascular (CV) disease, but the results are still controversial. Therefore, the aims of this study are to investigate the relationships between habitual sleep patterns and CV disease based on Prospective Urban Rural Epidemiology (PURE) China study. PURE China study recruited 46 285 participants, aged 35–70, from 12 provinces and 115 communities in China. Habitual sleep patterns and CV disease were self-reported. Multilevel logistic regression was used in our analysis. In this study, 39 515 participants were eligible in our analysis, including 23 345 (59.1%) women and 16 170 (40.9%) men. Sleeping ≥9 h per day was associated with increased odds of CV disease (OR = 1.16, 95% CI: 1.01–1.32, p = 0.033) compared with sleeping 7–8 h per day. Taking daytime naps was also associated with an increased odds of CV disease, and the CV odds increased with increasing napping duration (p for trend < 0.001). For the sleeping < 6 h per day, we only found an association with coronary artery disease (CAD) (OR = 1.58, 95% CI: 1.01–2.48, p = 0.046). Participants with only 7–8 h sleep per night had lowest prevalence of CV disease (OR = 0.77, 95% CI: 0.65–0.90, p = 0.001) compared with other sleep patterns. Napping, long and short duration of habitual sleep may increase the odds of CV disease. Only participants sleeping 7–8 hours at night are recommended in this study, and large longitudinal studies are needed to confirm these results.     

Incidence and outcomes of chronic total occlusion percutaneous coronary intervention in the Netherlands: data from a nationwide registry

Background

Patients with chronic total coronary occlusions (CTO) are at increased risk for poor clinical outcomes. We aimed to determine the incidence of CTO percutaneous coronary intervention (PCI) and to identify CTO patients at risk for cardiac events in the nationwide Netherlands Heart Registration (NHR).

Methods

We included all PCI procedures with ≥1 CTO registered in the NHR from January 2015 to December 2018, excluding acute interventions. We used multivariable logistic regression of baseline characteristics to calculate the risk for events as odds ratios (OR) with 95% confidence intervals (CI).

Results

Of the PCIs performed during the study period, 6.3% (8,343/133,042) were for CTOs, with the percentage increasing significantly over time from 5.9% in 2015 to 6.6% in 2018 (p < 0.001). Coronary artery bypass grafting <24 h was carried out in 0.3%, and the only significant predictor was diabetes mellitus (OR 2.97, 95% CI 1.04–8.49, p = 0.042). Myocardial infarction (MI) <30 days occurred in 0.5%, and renal insufficiency (i.e. estimated glomerular filtration rate <30 ml/min per 1.73 m²) was identified as an independent predictor (OR 4.70, 95% CI 1.07–20.61, p = 0.040). Among patients undergoing CTO-PCI, 1‑year mortality was 3.7%, and independent predictors included renal insufficiency (OR 5.59, 95% CI 3.25–9.59, p < 0.001), left ventricular ejection fraction <30% (OR 3.43, 95% CI 2.00–5.90, p < 0.001), previous MI (OR 1.62, 95% CI 1.14–2.31, p = 0.007) and age (OR 1.06 per year increment, 95% CI 1.04–1.07, p < 0.001). Target-vessel revascularisation <1 year occurred in 11.3%.

Conclusion

CTO-PCI is still infrequently performed in the Netherlands. The most important predictor of mortality after CTO-PCI was renal insufficiency. Identification of patients at risk may help improve the prognosis of CTO patients in the future.

     

Permanent night workers´ sleep and psychosocial factors in hospital work. A comparison to day and shift work

ABSTRACT

We aimed to study whether permanent night workers sleep and psychosocial factors differ from day workers and shift workers. The participants (n = 9 312, 92% females, average age 45 years, most commonly nurses and departmental secretaries) were day workers (DW, n = 2 672), shift workers (SW, n = 6 486) and permanent night workers (PNW, n = 154). The Finnish Public Sector survey responses from six hospital districts from 2012 were combined to payroll data from 91 days preceding the survey. The data were analyzed using Pearson χ²-test, one-way ANOVA and multinomial logistic regression analysis. The PNWs reported slightly longer average sleep length than the SWs or the DWs (7:27 vs. 7:13 and 7:10 h, p < 0.001). The PNWs reported least often difficulties in maintaining sleep (p < 0.001) compared to the SWs and the DWs. The PNWs reported most often difficulties to fall asleep and fatigue during free-time (p-values <0.001). The DWs and PNWs experienced less often work-life conflict than the SWs (25 and 26 vs. 38%, p < 0.001). The PNWs were more often satisfied with autonomy at work and appreciation and fair treatment by colleagues than the DWs or the SWs (p < 0.001). The SWs and PNWs reported remarkably higher occurrence of verbal (p < 0.001, OR 3.71, 95% CI 3.23–4.27 and OR 7.67, 95% CI 5.35–10.99, respectively) and physical workplace violence (p < 0.001, OR 9.24, 95% CI 7.17–11.90 and OR 28.34, 95% CI 16.64–43.06, respectively) compared to DWs. Conclusively, PNWs reported contradictory differences in sleep quality compared to DWs and SWs. PNWs are more often satisfied with their colleagues and autonomy at work than DWs or SWs but face workplace violence remarkably more often.     

Associations between chronotype,morbidity and mortality in the UK Biobank cohort

Later chronotype (i.e. evening preference) and later timing of sleep have been associated with greater morbidity, including higher rates of metabolic dysfunction and cardiovascular disease (CVD). However, no one has examined whether chronotype is associated with mortality risk to date. Our objective was to test the hypothesis that being an evening type is associated with increased mortality in a large cohort study, the UK Biobank. Our analysis included 433 268 adults aged 38–73 at the time of enrolment and an average 6.5-year follow-up. The primary exposure was chronotype, as assessed through a single self-reported question-defining participants as definite morning types, moderate morning types, moderate evening types or definite evening types. The primary outcomes were all-cause mortality and mortality due to CVD. Prevalent disease was also compared among the chronotype groups. Analyses were adjusted for age, sex, ethnicity, smoking, body mass index, sleep duration, socioeconomic status and comorbidities. Greater eveningness, particularly being a definite evening type, was significantly associated with a higher prevalence of all comorbidities. Comparing definite evening type to definite morning type, the associations were strongest for psychological disorders (OR 1.94, 95% CI 1.86–2.02, p = < 0.001), followed by diabetes (OR 1.30, 95% CI 1.24–1.36, p = < 0.001), neurological disorders (OR 1.25, 95% CI 1.20–1.30, p = < 0.001), gastrointestinal/abdominal disorders (OR 1.23, 95% CI 1.19–1.27, p = < 0.001) and respiratory disorders (OR 1.22, 95% CI 1.18–1.26, p = < 0.001). The total number of deaths was 10 534, out of which 2127 were due to CVD. Greater eveningness, based on chronotype as an ordinal variable, was associated with a small increased risk of all-cause mortality (HR 1.02, 95% CI 1.004–1.05, p = 0.017) and CVD mortality (HR 1.04, 95% CI 1.00–1.09, p = 0.06). Compared to definite morning types, definite evening types had significantly increased risk of all-cause mortality (HR 1.10, 95% CI 1.02–1.18, p = 0.012). This first report of increased mortality in evening types is consistent with previous reports of increased levels of cardiometabolic risk factors in this group. Mortality risk in evening types may be due to behavioural, psychological and physiological risk factors, many of which may be attributable to chronic misalignment between internal physiological timing and externally imposed timing of work and social activities. These findings suggest the need for researching possible interventions aimed at either modifying circadian rhythms in individuals or at allowing evening types greater working hour flexibility.     

High Risk for Obstructive Sleep Apnea in Truck Drivers Estimated by the Berlin Questionnaire: Prevalence and Associated Factors

The health issues that attract our attention when analyzing the truck driver population are the high prevalence of sedentary habits, inadequate diet, obesity, and proportion of hypertensive. All these are either considered risk factors for or a consequence of Obstructive Sleep Apnea (OSA). The objective of this study was to investigate the risk for OSA among 10,101 truck drivers and to correlate it with potentially related factors, such as serum glucose and cholesterol levels, smoking habits, alcohol and drug consumption, and self-reported physical activity. The drivers were invited to participate in the campaign “Saúde na Boléia” (Health Behind the Wheel) promoted by a Brazilian company responsible for the maintenance of approximately 360 km of roads in the country. Drivers who spontaneously stopped at the campaign booths placed along the roads were invited to answer a questionnaire covering sociodemographic data such as age, alcohol, and drug consumption. All participants completed a Berlin Questionnaire and were classified as low- or high-risk subjects for OSA based on questions about snoring, tiredness during the day, and the presence of hypertension or obesity. Blood collection was accomplished at the same site by nurses and/or nursing students collaborating with the campaign for subsequent laboratory studies. Approximately 26% of the truck drivers were found to be at high-risk group for OSA. An adjusted multiple logistic model found the independent risk factors of smoking (OR = 1.16; p = 0.014) and drug use (OR = 1.32; p < 0.0001) were associated with high risk for OSA. The presence of self-reported occasional (OR = 0.62; p < 0.0001) and regular (OR = 0.53; p < 0.0001) physical activity was found to be an independent factor protective of OSA. Educational programs, including ones aimed at improving one's health habits, such as engagement in physical exercise, should be considered in the development of initiatives to reduce the risk for OSA among the truck driver population.     

Factors affecting prevalence of overweight among 12- to 17-year-old urban adolescents in Hyderabad, India

Objective: The problem of overweight and obesity is not confined only to developed countries but is also widely prevalent in developing countries. The objective of this study was to assess the prevalence of overweight and obesity as defined by the International Obesity Task Force (IOTF) among school‐age children in Hyderabad, India, and identify its associated factors. Research Methods and Procedures: A cross‐sectional and institutional study, adopting a multistage stratified cluster sampling procedure, was carried out during 2003 on adolescents 12 to 17 years of age of both sexes from Hyderabad, India. Results: The overall prevalence of overweight was 6.1% [95% confidence interval (CI): 4.2, 8.0] among boys and 8.2% among girls (CI: 6.0, 10.4); 1.6% and 1.0% were obese, respectively. The prevalence was significantly higher (p < 0.05) among adolescents who watched television ≥3 h/d (10.4%) or belonged to a high socioeconomic background (14.9%, p < 0.001), whereas it was significantly lower among those participating regularly in outdoor games ≥6 h/wk (3.1%, p < 0.004) and household activities ≥3 h/d (4.7%, p < 0.001). The logistic regression analysis revealed that the prevalence of overweight was 4 times higher among the adolescents of high socioeconomic status [odds ratio (OR): 4.1; CI: 2.25, 7.52], 3 times higher in those not participating in outdoor games (OR: 2.75; CI: 1.56, 4.72), and 1.92 times higher in those watching television ≥3 h/d (OR: 1.92; CI: 1.16, 3.18). Discussion: This study confirmed the findings of earlier studies carried out in Western countries and emphasizes that regular physical exercise, doing household activities, regulated television viewing, and healthy eating behaviors could contribute to controlling overweight and obesity.     

Differences in morning–evening type and sleep duration between Black and White adults: Results from a propensity-matched UK Biobank sample

Biological evidence suggests that ethno-racial differences in morning–evening type are possible, whereby Blacks may be more likely to be morning type compared to Whites. However, population-level evidence of ethno-racial difference in morning–evening type is limited. In an earlier study, we reported that morning type was more prevalent in Blacks compared to Whites in the United Kingdom (UK) Biobank cohort (N = 439 933). This study aimed to determine if these ethno-racial differences persisted after accounting for an even broader range of social, environmental and individual characteristics and employing an analytic approach that simulates randomization in observational data, propensity score modeling. Data from UK Biobank participants whose self-identified race/ethnicity was Black/Black British or White; who did not report daytime napping, shift work or night shift work; who provided full mental health information; and who were identified using propensity score matching were used (N = 2044). Each sample was strongly matched across all social, environmental and individual characteristics as indicated by absolute standardized mean differences <0.09 for all variables. The prevalence of reporting nocturnal short, adequate and long sleep as well as morning, intermediate and evening type among Blacks (n = 1022) was compared with a matched sample of Whites (n = 1022) using multinomial logistic regression models. Blacks had a 62% greater odds of being morning type [odds ratio (OR) = 1.620, 95% confidence interval (CI): 1.336–1.964, p < .0001] and a more than threefold greater odds of reporting nocturnal short sleep (OR = 3.453, 95% CI: 2.846–4.190, p < .0001) than Whites. These data indicate that the greater prevalence of morning type and short nocturnal sleep in Blacks compared to Whites is not fully explained by a wide range of social and environmental factors. If sleep is an upstream determinant of health, these data suggest that ethno-racially targeted public health sleep intervention strategies are needed.     

Making errors at work due to sleepiness or sleep problems is not confined to non-standard work hours: results of the 2016 Sleep Health Foundation national survey

Almost one-third of Australians report having made errors at work that are related to sleep issues. While there is significant literature investigating the role of sleep in workplace health and safety in shiftworking and nightwork operations, long working hours, work-family conflict, and commute times getting longer also impact day workers’ sleep behaviors and opportunities. The aim of this study was to examine the relationship between sleep duration and disorders, sleep health and hygiene factors, work-related factors and errors at work in Australian workers. From a sample of 1011 Australian adults, age-adjusted binary logistic regression analyses were conducted in 512 workers who provided responses to the question “Thinking about the past three months, how many days did you make errors at work because you were too sleepy or you had a sleep problem?” A number of sleep behaviors and poor sleep hygiene factors were linked with work errors related to sleepiness or sleep problems, with age-adjusted odds of errors (confidence intervals) up to 11.6 times higher (5.4–25.1, p < 0.001) in those that snored, 7.7 (4.6–12.9) times higher in those reporting more than three sleep issues (p < 0.001), 7.0 times higher (3.4–14.8) in short (≤5 hours/night) sleepers (p < 0.021), 6.1 times higher (2.9–12.7) in those staying up later than planned most nights of the week (p< 0.001) and 2.4 times higher (1.6–3.7) in those drinking alcohol ≥3 nights/week before bed (p < 0.001). More than 40% of participants working non-standard hours reported making errors at work, and they were more likely to be young (compared to the main sample of workers) and more likely to engage in work activities in the hour before bed. Sleep factors (other than clinical sleep disorders) were associated with an increased likelihood of sleep-related work errors. Both day workers and those working non-standard hours engage in work, sleep and health behaviors that do not support good sleep health, which may be impacting safety and productivity in the workplace through increased sleepiness-related errors.     

Bullying,sleep/wake patterns and subjective sleep disorders: Findings from a cross-sectional survey

The aim of this study was to explore: (a) sleep patterns and disorders possibly associated with adolescent bullying profiles (pure bully, pure victim, bully/victim and neutral) and (b) the effect of sleep on psychosocial problems (externalized and internalized) related to bullying. The sample consisted of 1422 students aged 10–18 (mean?=?14.3, SD?=?2.7; 57% male) from five socioeconomically diverse schools in France. Bullying profiles were obtained using the revised Bully–Victim Questionnaire. Subjective sleep disorders were assessed using the Athens Insomnia Scale. School-week and weekend sleep/wake patterns were recorded. Internalizing problems were investigated using a Perceived Social Disintegration Scale and a Psychological Distress Scale. Externalizing behaviors were assessed using a General Aggressiveness Scale and an Antisocial Behavior Scale. These questionnaires were administered during individual interviews at school. After controlling for effects of gender and age, victims of bullying showed significantly more subjective sleep disturbances than the pure-bully or neutral groups (p?<?0.001). Bullies’ sleep schedules were more irregular (p?<?0.001 for bedtime irregularity and p<0.01 for wake-up time irregularity) and their sleep duration was shorter than their schoolmates (p?<?0.001 for the school week and p?<?0.05 for the weekend). There was an effect of sleep on psychosocial problems related to bullying, and our results indicate that sleep has a moderating effect on aggression in bullies (p?<?0.001). This would suggest a higher vulnerability of bullies to sleep deprivation. These results show differences in sleep problems and patterns in school-bullying profiles. Findings of this study open up new perspectives for understanding and preventing bullying in schools, with implications for research and clinical applications.     

Social jet lag,chronotype and body mass index in 14–17-year-old adolescents

The relationship between sleep duration and obesity in adolescents is inconclusive. This may stem from a more complex relationship between sleep and obesity than previously considered. Shifts toward evening preferences, later sleep–wake times and irregular sleep–wake patterns are typical during adolescence but their relationship to body mass index (BMI) has been relatively unexplored. This cross-sectional study examined associations between sleep duration, midpoint of sleep and social jet lag (estimated from 7 days of continuous actigraphy monitoring), and morningness/eveningness with BMIs (BMI z-scores) and waist-to-height ratios in 14–17-year-old adolescents. Seventy participants were recruited from ninth and tenth grades at a public high school. Participants’ characteristics were as follows: 74% female, 75% post-pubertal, 36% Hispanic, 38% White, 22% Black, 4% Asian and 64% free/reduced lunch participants with a mean age of 15.5 (SD, 0.7). Forty-one percent of the participants were obese (BMI ≥ 95th percentile); 54% were abdominally obese (waist-to-height ratio ≥ 0.5). Multivariable general linear models were used to estimate the association between the independent variables (school night sleep duration, free night sleep duration, midpoint of sleep (corrected), social jet lag and morningness/eveningness) and the dependent variables (BMI z-scores and waist-to-height ratios). Social jet lag is positively associated with BMI z-scores (p < 0.01) and waist-to-height ratios (p = 0.01). Midpoint of sleep (corrected) is positively associated with waist-to-height ratios (p = 0.01). After adjusting for social jet lag, school night sleep duration was not associated with waist-to-height ratios or BMI z-scores. Morningness/eveningness did not moderate the association between sleep duration and BMI z-scores. Findings from this study suggest that chronobiological approaches to preventing and treating obesity may be important for accelerating progress in reducing obesity rates in adolescents.     

Independent Effects of Sleep Duration and Body Mass Index on the Risk of a Work-Related Injury: Evidence From the US National Health Interview Survey (2004–2010)

Fatigue has been linked to adverse safety outcomes, and poor quality or decreased sleep has been associated with obesity (higher body mass index, BMI). Additionally, higher BMI is related to an increased risk for injury; however, it is unclear whether BMI modifies the effect of short sleep or has an independent effect on work-related injury risk. To answer this question, the authors examined the risk of a work-related injury as a function of total daily sleep time and BMI using the US National Health Interview Survey (NHIS). The NHIS is an in-person household survey using a multistage, stratified, clustered sample design representing the US civilian population. Data were pooled for the 7-yr survey period from 2004 to 2010 for 101 891 “employed” adult subjects (51.7%; 41.1?±?yrs of age [mean?±?SEM]) with data on both sleep and BMI. Weighted annualized work-related injury rates were estimated across a priori defined categories of BMI: healthy weight (BMI: <25), overweight (BMI: 25–29.99), and obese (BMI: ≥30) and also categories of usual daily sleep duration: <6, 6–6.99, 7–7.99, 8–8.99, and ≥9?h. To account for the complex sampling design, including stratification, clustering, and unequal weighting, weighted multiple logistic regression was used to estimate the risk of a work-related injury. The initial model examined the interaction among daily sleep duration and BMI, controlling for weekly working hours, age, sex, race/ethnicity, education, type of pay, industry, and occupation. No significant interaction was found between usual daily sleep duration and BMI (p?=?.72); thus, the interaction term of the final logistic model included these two variables as independent predictors of injury, along with the aforementioned covariates. Statistically significant covariates (p?≤?.05) included age, sex, weekly work hours, occupation, and if the worker was paid hourly. The lowest categories of usual sleep duration (<6 and 6–6.9?h) showed significantly (p?≤?.05) elevated injury risks than the referent category (7–8?h sleep), whereas sleeping >7–8?h did not significantly elevate risk. The adjusted injury risk odds ratio (OR) for a worker with a usual daily sleep of <6?h was 1.86 (95% confidence interval [CI]: 1.37–2.52), and for 6–6.9?h it was 1.46 (95% CI: 1.18–1.80). With regards to BMI, the adjusted injury risk OR comparing workers who were obese (BMI: ≥30) to healthy weight workers (BMI: <25) was 1.34 (95% CI: 1.09–1.66), whereas the risk in comparing overweight workers (BMI: 25–29.99) to healthy weight risk was elevated, but not statistically significant (OR?=?1.08; 95% CI: .88–1.33). These results from a large representative sample of US workers suggest increase in work-related injury risk for reduced sleep regardless of worker's body mass. However, being an overweight worker also increases work-injury risk regardless of usual daily sleep duration. The independent additive risk of these factors on work-related injury suggests a substantial, but at least partially preventable, risk. (Author correspondence: david.lombardi@libertymutual.com)     

Relationship of BMI,Waist Circumference,and Weight Change with Use of Health Services by Older Adults

Objective: To examine the relationship of BMI, waist circumference (WC), and weight change with use of health care services by older adults. Research Methods and Procedures: This was a prospective cohort study conducted from 2001 to 2003 among 2919 persons representative of the non‐institutionalized Spanish population ≥60 years of age. Analyses were performed using logistic regression, with adjustment for age, educational level, size of place of residence, tobacco use, alcohol consumption, and presence of chronic disease. Results: Obesity (BMI ≥ 30 kg/m²) and abdominal obesity (WC >102 cm in men and >88 cm in women) in 2001 were associated with greater use of certain health care services among men and women in the period 2001–2003. Compared with women with WC ≤ 88 cm, women with abdominal obesity were more likely to visit primary care physicians [odds ratio (OR): 1.36; 95% confidence limit (CL): 1.06–1.73] and receive influenza vaccination (OR: 1.30; 95% CL: 1.03–1.63). Weight gain was not associated with greater health service use by either sex, regardless of baseline BMI. Weight loss was associated with greater health service use by obese and non‐obese subjects of both sexes. In comparison with those who reported no important weight change, non‐obese women who lost weight were more likely to visit hospital specialists (OR: 1.45; 95% CL: 1.02–2.06), receive home medical visits (OR: 1.61; 95% CL: 1.06–2.45), be hospitalized (OR: 1.88; 95% CL: 1.29–2.74), and have more than one hospital admission (OR: 2.31; 95% CL: 1.19–4.47). Discussion: Obesity and weight loss are associated with greater health service use among the elderly.     

Electronic Games and Environmental Factors Associated with Childhood Obesity in Switzerland

Objective: Environmental factors and behaviors associated with obesity have not been well described in children living in Europe. Although television watching has been repeatedly associated with obesity, it is unclear whether other sedentary activities, such as use of electronic games, are independently associated with obesity in children. The hypothesis was that various types of sedentary activities are associated with obesity in children living in Switzerland. Research Methods and Procedures: This was a cross‐sectional study of children (grades one to three) from four communities in the Greater Zurich Area (Switzerland). Obesity was defined as a combination of overweight (BMI) and overfat (skinfold thicknesses). Environmental factors were assessed by questionnaire. The children's physical activity was estimated by their teacher (scale 0 to 10). Results: Of 922 eligible subjects, 872 (94.6%) took part in the study. Use of electronic games [odds ratio (OR) = 2.03 per hour per day, 95% confidence interval (CI): 1.57 to 2.61, p < 0.001], television (OR = 2.83 per hour per day, 95% CI: 2.08 to 3.86, p < 0.001), physical activity (OR = 0.80 per unit, 95% CI: 0.72 to 0.88, p < 0.001), maternal work (OR = 1.93, 95% CI: 1.13 to 3.29, p = 0.02), and paternal smoking (OR = 1.78, 95% CI: 1.07 to 2.96, p = 0.03) were independently associated with obesity. Further adjustment for socioeconomic status, when available, did not change these results. Discussion: In this sample of children living in Switzerland, the use of electronic games was significantly associated with obesity, independently of confounding factors. The association of obesity with television use and lack of physical activity confirms results from other populations and points to potential strategies for obesity prevention.     

Evening chronotype is associated with poor cardiovascular health and adverse health behaviors in a diverse population of women

ABSTRACT

Chronotype reflects time of day preferences for performing daily activities. Previous research within Asian and European cohorts indicates evening chronotype is associated with elevated cardiometabolic risk. However, evidence is limited from population-based US cohorts, particularly among women in whom evening chronotype prevalence may become higher after middle-age, coinciding with life stages associated with higher cardiovascular disease (CVD) risk. This cross-sectional study evaluated associations of chronotype with overall cardiovascular health (CVH), health behaviors, and cardiometabolic risk factors among 506 women (mean age = 37 ± 16y, 62% racial/ethnic minority) in the American Heart Association (AHA)’s Go Red for Women Strategically-Focused Research Network cohort at Columbia University (New York City, NY, USA). Chronotype was assessed using the validated Morningness-Eveningness Questionnaire (MEQ) and categorized as “evening”, “intermediate”, and “morning” chronotypes. Health behaviors (diet, physical activity, and sleep) were assessed using validated questionnaires. Anthropometrics, clinical blood pressure, and blood biomarkers were assessed at the clinic visit. CVH was evaluated using the AHA Life’s Simple 7 (LS7) metrics; LS7 scores of 0–8 and 9–14 were considered indicative of poor and moderate-to-high CVH, respectively. Linear and logistic regression models adjusted for age, race/ethnicity, education, health insurance, and menopausal status were used to examine associations of MEQ scores and chronotype categories with overall CVH, clinical cardiometabolic risk factors, and health behaviors. Overall, 13% of women identified as evening chronotypes, while 55% and 32% reported being intermediate and morning types. In linear models, higher MEQ scores were associated with higher AHA LS7 scores (β(SE) = 0.02(0.01); p = .014), indicative of more favorable CVH, and with health behaviors not included in the LS7. Higher MEQ scores were also associated with lower Pittsburgh Sleep Quality Index, i.e. better sleep quality, (β(SE) = ?0.07(0.02), p < .0001), lower insomnia severity (β(SE) = ?0.14(0.01), p < .0001), shorter time to fall asleep (β(SE) = ?0.28(0.14), p = .044), and less sedentary time (β(SE) = ?0.11(0.03), p = .001). In logistic regression models, evening chronotype, compared to intermediate/morning type, was associated with higher odds of having poor CVH (OR(95%CI):2.41(1.20–4.85)), not meeting AHA diet (OR(95%CI):2.89(1.59–5.23)) and physical activity guidelines (OR(95%CI):1.78(1.03–3.07)), and having short sleep (OR(95%CI):2.15(1.24–3.73)) or insomnia (OR(95%CI):2.69(1.53–4.75)). The evening type compared to morning type was also associated with being a current smoker (OR(95%CI):2.14(1.02–4.52)) and having poor sleep quality (OR(95%CI:2.35(1.27–4.37)) and long sleep onset latency (OR(95%CI:1.89(1.00–3.56)). In our cohort of women, evening chronotype was related to poor CVH, likely driven by its influence on health behaviors. These findings, although warranting confirmation prospectively in other populations, suggest chronotype is an important factor to consider and possibly target when designing lifestyle interventions for CVD prevention.     

The Association of Plasma Cysteine and γ‐Glutamyltransferase With BMI and Obesity

We recently reported a strong positive association of plasma total cysteine (tCys) with fat mass in over 5,000 subjects. As γ‐glutamyltransferase (GGT) enzyme increases cysteine availability by catalyzing glutathione breakdown and is positively associated with BMI and adiposity, we hypothesized that GGT might explain the association of tCys with adiposity. To study whether the associations of tCys and serum GGT with BMI and obesity were interrelated we conducted a cross‐sectional study using data from 1,550 subjects recruited from nine European countries in the COMAC project. Multiple linear and logistic regression models and concentration‐response curves were used. In age and sex‐adjusted analyses, tCys showed strong positive associations with BMI (partial r = 0.19, P < 0.001), and obesity (odds ratio (OR) for 4th vs. 1st tCys quartile: 2.8; 95% confidence interval: 1.6–5.0, P < 0.001), both of which remained robust after adjustment for GGT and other metabolic and lifestyle confounders. Serum GGT was also a positive predictor of BMI (partial r = 0.17, P < 0.001) and obesity (OR for 4th vs. 1st GGT quartile: 4.8; 95% confidence interval: 2.5–9.2, P < 0.001), independent of tCys. However, the associations of GGT with BMI and obesity were weakened by adjustment for obesity‐related factors such as serum lipids and blood pressure. These results indicate that tCys is a strong positive predictor of BMI and obesity, independent of GGT and other obesity‐related factors. We also suggest that the association of serum GGT with BMI and obesity is unrelated to the role of GGT in cysteine turnover. The potential link between cysteine and fat metabolism should be further evaluated.