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We aim to examine the association of sleep duration, sleep quality, late chronotype, and circadian misalignment with glycemic control and risk of complications in young adults with youth-onset type 2 diabetes followed in the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study. Self-reported sleep duration, quality, timing, and circadian misalignment were assessed via a modified Pittsburgh Sleep Quality Index (PSQI) questionnaire, and chronotype was assessed via the Morningness-Eveningness Questionnaire (MEQ). We examined diabetes complications including loss of glycemic control (defined as hemoglobin A1c ≥8%), hypertension, dyslipidemia, albuminuria, and diabetic peripheral neuropathy. Multivariable logistic regression models were constructed to assess associations between sleep and circadian measures with outcomes of interest, such as loss of glycemic control and diabetes complications. A total of 421 participants (34.2% male), mean age 23.6 ± 2.5 yr, mean body mass index (BMI) of 36.1 ± 8.3 kg/m 2 , and mean diabetes duration of 10.0 ± 1.5 yr were evaluated. Self-reported short sleep duration, daytime sleepiness, and sleep quality were not associated with loss of glycemic control or diabetes complications. Late self-reported bedtime (after midnight) on work/school nights, rather than self-expressed chronotype or circadian misalignment, was independently associated with loss of glycemic control. An association was seen between late bedtimes and albuminuria but was attenuated after adjusting for depression. In conclusion, late bedtime on work/school days, rather than short sleep duration, daytime sleepiness, or poor sleep quality, was independently associated with loss of glycemic control in this longitudinal cohort of young adults with youth-onset type 2 diabetes. NEW & NOTEWORTHY The prevalence of type 2 diabetes in youth is increasing at an alarming rate. Identifying potentially modifiable factors modulating glycemic control is critically important to reduce micro and macrovascular complications. In a large cohort of youth-onset type 2 diabetes, self-reported late bedtime on work/school days was independently associated with loss of glycemic control in this longitudinal cohort of young adults with youth-onset type 2 diabetes.

Previous research has demonstrated that experiences of discrimination contribute to racial disparities in sleep, and that psychological distress mediates these relationships. However, previous research has not included race as part of the mediation pathway and has had limited dimensions of sleep health and psychological mediators. In the current study, we examine serial mediation pathways by which race and sleep health are mediated through discrimination and subsequently through psychological distress (i.e., depressive symptoms, chronic stress, and loneliness). Data were from the 2010 wave of the Health Retirement Study (HRS). The analytic sample (n = 7,749) included Black and White participants who were included in the enhanced face-to-face interview in 2010 and who completed the psychosocial questionnaire. Race was reported as either Black or White. Sleep health was assessed with a 4-item questionnaire. Depressive symptoms were assessed with the shortened CES-D, chronic stress via the ongoing chronic stressor scale, and loneliness via the UCLA loneliness scale. Covariates were included in all serial mediation models. Relative to White participants, Black participants reported increased experiences of discrimination, which was associated with increased psychological distress, and poorer sleep health. Findings demonstrate the significant adverse impact that discrimination has on both psychological well-being and sleep health., (© 2022. W. Montague Cobb-NMA Health Institute.)

Previous research has demonstrated that exposure to light preceding and during sleep is associated with poor sleep, but most research to date has utilized either experimental or cross-sectional designs. The current study expands upon prior studies by using a microlongitudinal design that examines the night-to-night associations between light and sleep health in a diverse sample of adults (pre-registered at osf.io/k5zgv). US adults aged 18-87 years from two parent studies (N = 124) wore an actiwatch for up to 10 nights. Light variables estimated from actigraphy include both average exposure and time above light threshold of 10 (TALT 10 ) and 40 (TALT 40 ) lux both during sleep and for the 1-hr preceding sleep. Actigraphy-based sleep variables included sleep offset, duration, percentage and fragmentation index. Higher average light exposure during sleep was associated with a later sleep-offset time, lower sleep percentage and higher fragmentation index (all p < 0.01). More minutes of TALT 10 during sleep was associated with later sleep timing, lower sleep percentage and higher fragmentation index (all p < 0.01), and greater TALT 40 during sleep was associated with lower sleep percentage. Light exposure was not related to sleep duration. In summary, greater light exposure during sleep was related to poorer sleep continuity and later wake time. The lack of association between light and sleep duration may be the result of compensating for sleep disruption by delaying wake time. Multi-level interventions to consistently reduce light levels during sleep should be considered., (© 2022 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.)

Studying communities at different stages of urbanisation and industrialisation can teach us how timing and intensity of light affect the circadian clock under real-life conditions. We have previously described a strong tendency towards morningness in the Baependi Heart Study, located in a small rural town in Brazil. Here, we tested the hypothesis that this morningness tendency is associated with early circadian phase based on objective measurements (as determined by dim light melatonin onset, DLMO, and activity) and light exposure. We also analysed how well the previously collected chronotype questionnaire data were able to predict these DLMO values. The average DLMO observed in 73 participants (40 female) was 20:03 ± 01:21, SD, with an earlier average onset in men (19:38 ± 01:16) than in women (20:24 ± 01:21; P ≤ .01). However, men presented larger phase angle between DLMO and sleep onset time as measured by actigraphy (4.11 hours vs 3.16 hours; P ≤ .01). Correlational analysis indicated associations between light exposure, activity rhythms and DLMO, such that early DLMO was observed in participants with higher exposure to light, higher activity and earlier light exposure. The strongest significant predictor of DLMO was morningness-eveningness questionnaire (MEQ) (beta=-0.35, P ≤ .05), followed by age (beta = -0.47, P ≤ .01). Sex, light exposure and variables derived from the Munich chronotype questionnaire were not significant predictors. Our observations demonstrate that both early sleep patterns and earlier circadian phase have been retained in this small rural town in spite of availability of electrification, in contrast to metropolitan postindustrial areas., (© 2020 The Authors. Journal of Pineal Research published by John Wiley & Sons Ltd.)

Optimism is associated with better health outcomes with hypothesized effects due in part to optimism's association with restorative health processes. Limited work has examined whether optimism is associated with better quality sleep, a major restorative process. We test the hypothesis that greater optimism is associated with more favorable sleep quality and duration. Main analyses included adults aged 32-51 who participated in the Coronary Artery Risk Development in Young Adults ( CARDIA ) study (n = 3,548) during the fifth (Year 15: 2000-2001) and sixth (Year 20: 2005-2006) follow-up visits. Optimism was assessed using the revised Life-Orientation Test. Self-report measures of sleep quality and duration were obtained twice 5 years apart. A subset of CARDIA participants (2003-2005) additionally provided actigraphic data and completed the Pittsburgh Sleep Quality Index ( PSQI ) and Epworth Sleepiness Scale ( ESS ). Multivariate regression analyses were used to examine associations of optimism and sleep indicators. In cross-sectional analyses of 3548 participants, each standard deviation (SD) higher optimism score resulted in 78% higher odds of self-reporting very good sleep quality. Prospectively, a 1-SD higher optimism score was related to higher odds of reporting persistently good sleep quality across 5-years relative to those with persistently poor sleep [OR = 1.31; 95%CI:1.10,1.56]. In participant with supplementary data, each SD higher optimism score was marginally associated with 22% greater odds of favorable sleep quality [OR = 1.22; 95%CI:1.00,1.49] as measured by the PSQI, with possible mediation by depressive symptoms. Optimism was unrelated to objective actigraphic sleep data. Findings support a positive cross-sectional and prospective association between optimism and self-reported sleep behavior.

Study Objectives: Although sleep disturbance is common in acutely ill patients during and after a hospitalization, how hospitalization affects sleep in general medicine patients has not been well characterized. We describe how sleep and activity patterns vary during and after hospitalization in a small population of older, predominately African American general medicine patients., Methods: Patients wore a wrist accelerometer during hospitalization and post-discharge to provide objective measurements of sleep duration, efficiency, and physical activity. Random effects linear regression models clustered by subject were used to test associations between sleep and activity parameters across study days from hospitalization through post-discharge., Results: We recorded 404 nights and 384 days from 54 patients. Neither nighttime sleep duration nor sleep efficiency increased from hospitalization through post-discharge (320.2 vs. 320.2 min, p = 0.99; 74.0% vs. 71.7%, p = 0.24). Daytime sleep duration also showed no significant change (26.3 vs. 25.8 min/day, p = 0.5). Daytime physical activity was significantly less in-hospital compared to post-discharge (128.6 vs. 173.2 counts/min, p < 0.01) and increased 23.3 counts/min (95% CI = 16.5 to 30.6, p < 0.01) per hospital day. A study day and post-discharge period interaction was observed demonstrating slowed recovery of activity post-discharge (β 3 = -20.8, 95% CI = -28.8 to -12.8, p < 0.01)., Conclusions: Nighttime sleep duration and efficiency and daytime sleep duration were similar in-hospital and post-discharge. Daytime physical activity, however, was greater post-discharge and increased more rapidly during hospitalization than post-discharge. Interventions, both in hospital and at home, to restore patient sleep and sustain activity improvements may improve patient recovery from illness., (© Sleep Research Society 2019. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.)

Introduction: False beliefs about sleep can persist despite contradicting scientific evidence, potentially impairing population health. Identifying commonly held false beliefs lacking an evidence base ("myths") can inform efforts to promote population sleep health., Method: We compiled a list of potential myths using Internet searches of popular press and scientific literature. We used a Delphi process with sleep experts (n = 10) from the fields of sleep medicine and research. Selection and refinement of myths by sleep experts proceeded in 3 phases, including focus groups (Phase 1); email-based feedback to edit, add, or remove myths (Phase 2); and closed-ended questionnaires (Phase 3) where experts rated myths on 2 dimensions, falseness and public health significance, using 5-point Likert scale from 1 ("not at all") to 5 ("extremely false")., Results: The current study identified 20 sleep myths. Mean expert ratings of falseness ranged from 5.00 (SD = 0.00) for the statement "during sleep the brain is not active" to 2.50 (SD = 1.07) for the statement "sleeping in during the weekends is a good way to ensure you get adequate sleep." Mean responses to public health significance ranged from 4.63 (SD = 0.74) for debunking the statement that "many adults need only 5 or less hours of sleep for general health" to 1.71 (SD = 0.49) for the statement that "remembering your dreams is a sign of a good night's sleep.", Conclusion: The current study identified commonly held sleep myths that have a limited or questionable evidence base. Ratings provided by experts suggest areas that may benefit from public health education to correct myths and promote healthy sleep., (Copyright © 2019 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.)

Aim: To test the association between cardiometabolic risk factors and subjective sleep quality assessed by the Pittsburgh sleep quality index (PSQI), independent of obstructive sleep apnea (OSA) and sleep duration., Methods: A total of 573 participants from the Baependi Heart Study, a rural cohort from Brazil, completed sleep questionnaires and underwent polygraphy for OSA evaluation. Multivariable linear regression analysis tested the association between cardiovascular risk factors (outcome variables) and sleep quality measured by PSQI, adjusting for OSA and other potential confounders (age, sex, race, salary/wage, education, marital status, alcohol intake, obesity, smoking, hypertension, and sleep duration)., Results: The sample mean age was 43 ± 16 years, 66% were female, and mean body mass index (BMI) was 26 ± 5 kg/m 2 . Only 20% were classified as obese (BMI ≥30). Overall, 50% of participants reported poor sleep quality as defined by a PSQI score ≥5. A high PSQI score was significantly associated with higher very-low-density lipoprotein (VLDL) cholesterol levels (beta = 0.392, p = 0.012) and higher triglyceride levels (beta = 0.017, p = 0.006), even after adjustments, including the apnea-hypopnea index. Further adjustments accounting for marital status, alcohol intake, and medication use did not change these findings. No significant association was observed between PSQI scores and glucose or blood pressure. According to PSQI components, sleep disturbances (beta = 1.976, p = 0.027), sleep medication use (beta = 1.121, p = 0.019), and daytime dysfunction (beta = 1.290, p = 0.024) were significantly associated with higher VLDL serum levels. Only the daytime dysfunction domain of the PSQI components was significantly associated with higher triglyceride levels (beta = 0.066, p = 0.004)., Conclusion: Poorer lipid profile was independently associated with poor sleep quality, assessed by the PSQI questionnaire, regardless of a normal sleep duration and accounting for OSA and socio-economic status., (Copyright © 2019 Elsevier B.V. All rights reserved.)

We created Sleep for Inpatients: Empowering Staff to Act (SIESTA), which combines electronic "nudges" to forgo nocturnal vitals and medications with interprofessional education on improving patient sleep. In one "SIESTAenhanced unit," nurses received coaching and integrated SIESTA into daily huddles; a standard unit did not. Six months pre- and post-SIESTA, sleep-friendly orders rose in both units (foregoing vital signs: SIESTA unit, 4% to 34%; standard, 3% to 22%, P < .001 both; sleeppromoting VTE prophylaxis: SIESTA, 15% to 42%; standard, 12% to 28%, P < .001 both). In the SIESTAenhanced unit, nighttime room entries dropped by 44% (-6.3 disruptions/room, P < .001), and patients were more likely to report no disruptions for nighttime vital signs (70% vs 41%, P = .05) or medications (84% vs 57%, P = .031) than those in the standard unit. The standard unit was not changed. Although sleep-friendly orders were adopted in both units, a unit-based nursing empowerment approach was associated with fewer nighttime room entries and improved patient experience., (© 2019 Society of Hospital Medicine.)

Physiological evidence suggests that sleep modulates kidney function. Our objective was to examine the cross-sectional association between kidney function and objectively-estimated habitual sleep duration, quality and timing in a cohort of patients with mild to moderate chronic kidney disease. This study involved two US clinical centers of the Chronic Renal Insufficiency Cohort (CRIC) study, including 432 participants in a CRIC ancillary sleep study. Habitual sleep duration, quality and timing were measured using wrist actigraphy for 5-7 days. Validated sleep questionnaires assessed subjective sleep quality, daytime sleepiness and risk of sleep apnea. Kidney function was assessed with the estimated glomerular filtration rate using the Chronic Kidney Disease Epidemiology Collaboration equation, and the urinary protein to creatinine ratio. Lower estimated glomerular filtration rate was associated with shorter sleep duration (-1.1 mL min -1  1.73 m -2 per hour less sleep, P = 0.03), greater sleep fragmentation (-2.6 mL min -1  1.73 m -2 per 10% higher fragmentation, P < 0.001) and later timing of sleep (-0.9 mL min -1  1.73 m -2 per hour later, P = 0.05). Higher protein to creatinine ratio was also associated with greater sleep fragmentation (approximately 28% higher per 10% higher fragmentation, P < 0.001). Subjective sleep quality, sleepiness and persistent snoring were not associated with estimated glomerular filtration rate or protein to creatinine ratio. Thus, worse objective sleep quality was associated with lower estimated glomerular filtration rate and higher protein to creatinine ratio. Shorter sleep duration and later sleep timing were also associated with lower estimated glomerular filtration rate. Physicians treating patients with chronic kidney disease should consider inquiring about sleep and possibly sending for clinical sleep assessment. Longitudinal and interventional trials are needed to understand causal direction., (© 2017 European Sleep Research Society.)

Objectives: A validated survey instrument to assess general sleep health would be a useful research tool, particularly when objective measures of sleep are not feasible. Thus, the National Sleep Foundation spearheaded the development of the Sleep Health Index (SHI)., Design: The development of the SHI began with a task force of experts who identified key sleep domains and questions. An initial draft of the survey was created and questions were refined using cognitive testing and pretesting. The resulting 28-question survey was administered via random-sample telephone interviews to nationally representative samples of adults in 2014 (n=1253) and 2015 (n=1250). These data were combined to create the index. A factor analysis linked 14 questions to 3 discrete domains: sleep quality, sleep duration, and disordered sleep. These were assembled as sub-indices, then combined to form the overall SHI, with scores ranging from 0 to 100 (higher score reflects better sleep health)., Results: Americans earned an overall SHI score of 76/100, with sub-index scores of 81/100 in disordered sleep, 79/100 in sleep duration, and 68/100 in sleep quality. In regression analyses, the strongest independent predictors of sleep health were self-reported stress (β=-0.26) and overall health (β=0.26), which were also the strongest predictors of sleep quality (β=-0.32 and β=0.27 respectively)., Conclusions: The current 12-item SHI is a valid, reliable research tool that robustly measures 3 separate but related elements of sleep health-duration, quality, and disorders-and assesses the sleep health status of adults in the United States., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

The well-established negative health outcomes of sleep deprivation, and the suggestion that availability of electricity may enable later bed times without compensating sleep extension in the morning, have stimulated interest in studying communities whose sleep pattern may resemble a pre-industrial state. Here, we describe sleep and activity in two neighbouring communities, one urban (Milange) and one rural (Tengua), in a region of Mozambique where urbanisation is an ongoing process. The two communities differ in the amount and timing of daily activity and of light exposure, with later bedtimes (≈1 h) associated with more evening and less daytime light exposure seen in the town of Milange. In contrast to previous reports comparing communities with and without electricity, sleep duration did not differ between Milange (7.28 h) and Tengua (7.23 h). Notably, calculated sleep quality was significantly poorer in rural Tengua than in Milange, and poor sleep quality was associated with a number of attributes more characteristic of rural areas, including more intense physical labour and less comfortable sleeping arrangements. Thus, whilst our data support the hypothesis that access to electricity delays sleep timing, the higher sleep quality in the urban population also suggests that some aspects of industrialisation are beneficial to sleep.

In recent years, strong evidence has emerged suggesting that insufficient duration, quality, and/or timing of sleep are associated with cardiovascular disease (CVD), and various mechanisms for this association have been proposed. Such associations may be related to endophenotypic features of the sleep homeostat and the circadian oscillator, or may be state-like effects of the environment. Here, we review recent literature on sleep, circadian rhythms and CVD with a specific emphasis on differences between racial/ethnic groups. We discuss the reported differences, mainly between individuals of European and African descent, in parameters related to sleep (architecture, duration, quality) and circadian rhythms (period length and phase shifting). We further review racial/ethnic differences in cardiovascular disease and its risk factors, and develop the hypothesis that racial/ethnic health disparities may, to a greater or smaller degree, relate to differences in parameters related to sleep and circadian rhythms. When humans left Africa some 100,000 years ago, some genetic differences between different races/ethnicities were acquired. These genetic differences have been proposed as a possible predictor of CVD disparities, but concomitant differences in culture and lifestyle between different groups may equally explain CVD disparities. We discuss the evidence for genetic and environmental causes of these differences in sleep and circadian rhythms, and their usefulness as health intervention targets., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Objectives: To investigate the association of sleep characteristics with prevalent hypertension, diabetes, and obesity in a multiethnic cohort., Design: This study used a population-based cross-sectional study design., Setting: Participants were recruited between 2009 and 2011 from Chicago, Illinois, and the surrounding suburbs., Participants: Participants were 492 adults aged 35 to 64years who self-reported as white, black, Hispanic, or Asian and who had a low likelihood of sleep apnea based on the apnea screening questionnaires and 1 night of apnea screening using an in-home device (apnea hypopnea index <15 or oxygen desaturation index <10)., Measurements: Participants wore a wrist actigraphy monitor (Actiwatch™) for 7days. During a clinical examination, participants completed questionnaires about sleep, other health behaviors, and medical history and had their blood pressure, anthropometric measures, and fasting blood glucose measured; metabolic risk factors were determined based on standard clinical guidelines., Results: The prevalence of hypertension, obesity, and diabetes was 17.1%, 5.5%, and 35.4%, respectively. Sleep duration was not associated with any cardiovascular risk factor. There was a significantly increased odds for hypertension (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.01-1.08) and obesity (OR, 1.03; 95% CI, 1.00-1.05) associated with higher sleep fragmentation (per 1%). There was also a significantly increased odds for hypertension associated with poorer self-reported sleep quality (OR, 1.14 [95% CI, 1.05-1.24] per 1-unit higher Pittsburgh Sleep Quality Index global score)., Conclusion: Objective and self-reported sleep quality may be more important than duration in relation to prevalent hypertension., (Copyright © 2017 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.)

Study Objectives: Recent studies implicate inadequate sleep duration and quality in metabolic disease. Fewer studies have examined the timing of sleep, which may be important because of its potential impact on circadian rhythms of metabolic function. We examined the association between sleep timing and metabolic risk among Hispanic/Latino adults., Methods: Cross-sectional data from community-based study of 13429 participants aged 18-74 years. People taking diabetic medications were excluded. Sleep timing was determined from self-reported bedtimes and wake times. Chronotype was defined as the midpoint of sleep on weekends adjusted for sleep duration on weekdays. Other measurements included body mass index (BMI), fasting glucose levels, estimated insulin resistance (HOMA-IR), glucose levels 2 hours post oral glucose ingestion, and hemoglobin A1c. Survey linear regression models tested associations between sleep timing and metabolic measures. Analyses were stratified by diabetes status and age-group when significant interactions were observed., Results: Among participants with diabetes, fasting glucose levels were positively associated with bedtime (approximately +3%/hour later, p < .01) and midpoint of sleep (approximately +2%/hour later, p < .05). In participants with and without diabetes combined, HOMA-IR was positively associated with midpoint of sleep (+1.5%/hr later, p < .05), and chronotype (+1.2%/hour later, p < .05). Associations differed by age-group. Among those < 36 years, later sleep timing was associated with lower BMI, lower fasting glucose, and lower HbA1c, but the opposite association was observed among older participants., Conclusions: Later sleep timing was associated with higher estimated insulin resistance across all groups. Some associations between sleep timing and metabolic measures may be age-dependent., (© Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.)

The circadian system is known to play a role in glucose metabolism. Chronotype reflects the interindividual variability in the phase of entrainment. Those with later chronotype typically prefer later times in the day for different activities such as sleep or meals. Later chronotype has been shown to be associated with metabolic syndrome, increased diabetes risk and poorer glycemic control in type 2 diabetes patients. In addition, "social jetlag", a form of circadian misalignment due to a mismatch between social rhythms and the circadian clock, has been shown to be associated with insulin resistance. Other sleep disturbances (insufficient sleep, poor sleep quality and sleep apnea) have also been shown to affect glucose metabolism. In this study, we explored whether there was a relationship between chronotype, social jetlag and hemoglobin A1c (HbA1c) levels in prediabetes patients, independent of other sleep disturbances. A cross-sectional study was conducted at the Department of Family Medicine, Ramathibodi Hospital, Bangkok, from October 2014 to March 2016 in 1014 non-shift working adults with prediabetes. Mid-sleep time on free day adjusted for sleep debt (MSFsc) was used as an indicator of chronotype. Social jetlag was calculated based on the absolute difference between mid-sleep time on weekdays and weekends. The most recent HbA1c values and lipid levels were retrieved from clinical laboratory databases. Univariate analyses revealed that later MSFsc (p = 0.028) but not social jetlag (p = 0.48) was significantly associated with higher HbA1c levels. Multivariate linear regression analysis was applied to determine whether an independent association between MSFsc and HbA1c level existed. After adjusting for age, sex, alcohol use, body mass index (BMI), social jetlag, sleep duration, sleep quality and sleep apnea risk, later MSFsc was significantly associated with higher HbA1c level (B = 0.019, 95% CI: 0.00001, 0.038, p = 0.049). The effect size of one hour later MSFsc on HbA1c (standardized coefficient = 0.065) was approximately 74% of that of the effect of one unit (kg/m 2 ) increase in BMI (standardized coefficient = 0.087). In summary, later chronotype is associated with higher HbA1c levels in patients with prediabetes, independent of social jetlag and other sleep disturbances. Further research regarding the potential role of chronotype in diabetes prevention should be explored.

Background: Racial disparities in hypertension prevalence in the United States are established. Given our understanding of racial and ethnic disparities in sleep characteristics and demonstrated associations between sleep characteristics and hypertension, we tested whether sleep characteristics mediated racial disparities in hypertension., Methods: Analyses were performed in the Chicago Area Sleep Study, a population-based cohort study of 154 Blacks, 128 Whites, 103 Hispanics, and 109 Asians without obstructive sleep apnea. Participants underwent 7 days of wrist actigraphy monitoring. Algorithms were used to determine sleep duration and sleep maintenance (the percent of sleep in the sleep period). Hypertension was determined as systolic blood pressure >140mm Hg or diastolic blood pressure >90mm Hg or the use of antihypertensive medications. We estimated sample prevalence ratios for hypertension before and after adjustment for sleep characteristics and also conducted mediation analysis., Results: The sample prevalence of hypertension was highest in Blacks (36%), followed by Hispanics (14%), Asians (8%), and Whites (5%). The sample prevalence ratio for hypertension for Blacks vs. Whites was 5.52 (95% confidence interval (CI): 2.36, 13.23) after adjusting for age, sex, and education. Adjustment for sleep duration had no influence on the effect estimate, but adjustment for sleep maintenance attenuated the sample prevalence ratio to 4.55 (95% CI: 1.91, 11.14). Sleep maintenance mediated 11.4% of the difference in hypertension prevalence between Blacks and Whites in this sample., Conclusions: Sleep maintenance mediated a small but significant portion of the disparity in hypertension between Blacks and Whites. Future research should investigate the mechanisms underlying these findings., (© American Journal of Hypertension, Ltd 2016. All rights reserved. For Permissions, please email: journals.permissions@oup.com)

Study Objectives: Sleep duration has been associated with risk of dementia and stroke, but few studies have investigated the relationship between sleep duration and brain MRI measures, particularly in middle age., Methods: In a prospective cohort of 613 black and white adults (mean age = 45.4 years) enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study, participants reported typical sleep duration, dichotomized into moderate sleep duration (> 6 to ≤ 8 h) and short sleep duration (≤ 6 h) at baseline (2005-2006). Five years later, we obtained brain MRI markers of white matter including fractional anisotropy, mean diffusivity, and white matter hyperintensities., Results: Compared to moderate sleepers, short sleepers had an elevated ratio of white matter hyperintensities to normal tissue in the parietal region (OR = 2.31, 95% CI: 1.47, 3.61) adjusted for age, race/sex, education, hypertension, stroke/TIA, depression, smoking status, and physical activity. White matter diffusivity was also higher, approximately a 0.2 standard deviation difference, in frontal, parietal, and temporal white matter regions, among those reporting shorter sleep duration in (P < 0.05 for all)., Conclusions: Short sleep duration was associated with worse markers of white matter integrity in midlife. These mid-life differences in white matter may underlie the link between poor sleep and risk of dementia and stroke., (© 2016 Associated Professional Sleep Societies, LLC.)

Objectives: The association between inadequate sleep and type 2 diabetes has garnered much attention, but little is known about sleep and type 1 diabetes (T1D). Our objectives were to conduct a systematic review and meta-analysis comparing sleep in persons with and without T1D, and to explore relationships between sleep and glycemic control in T1D., Methods: Studies were identified from Medline and Scopus. Studies reporting measures of sleep in T1D patients and controls, and/or associations between sleep and glycemic control, were selected., Results: A total of 22 studies were eligible for the meta-analysis. Children with T1D had shorter sleep duration (mean difference [MD] = -26.4 minutes; 95% confidence interval [CI] = -35.4, -17.7) than controls. Adults with T1D reported poorer sleep quality (MD in standardized sleep quality score = 0.51; 95% CI = 0.33, 0.70), with higher scores reflecting worse sleep quality) than controls, but there was no difference in self-reported sleep duration. Adults with TID who reported sleeping >6 hours had lower hemoglobin A1c (HbA1c) levels than those sleeping ≤6 hours (MD = -0.24%; 95% CI = -0.47, -0.02), and participants reporting good sleep quality had lower HbA1c than those with poor sleep quality (MD = -0.19%; 95% CI = -0.30, -0.08). The estimated prevalence of obstructive sleep apnea (OSA) in adults with TID was 51.9% (95% CI = 31.2, 72.6). Patients with moderate-to-severe OSA had a trend toward higher HbA1c (MD = 0.39%, 95% CI = -0.08, 0.87)., Conclusion: T1D was associated with poorer sleep and high prevalence of OSA. Poor sleep quality, shorter sleep duration, and OSA were associated with suboptimal glycemic control in T1D patients., (Copyright © 2016 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Prior studies report less favorable sleep characteristics among non-Whites as compared with non-Hispanic Whites. However, few population-based studies have used objective measures of sleep duration, especially in more than two racial/ethnic groups. We tested whether objectively estimated sleep duration and self-reported sleep quality varied by race and whether differences were at least partially explained by the variability in clinical, psychological, and behavioral covariates., Methods: Adults aged 35-64 years who self-identified as White, Black, Asian, or Hispanic were randomly sampled from Chicago, IL, and the surrounding suburbs. Our analytic sample included adults who had an apnea-hypopnea index <15 after one night of screening and who completed seven nights of wrist actigraphy for determination of sleep duration, sleep percentage, minutes of wake after sleep onset, and sleep fragmentation (n = 495). Daytime sleepiness was estimated using the Epworth Sleepiness Scale (ESS), and sleep quality was estimated from the Pittsburgh Sleep Quality Index (PSQI)., Results: Following statistical adjustment for age, gender, education, work schedule (ie, day vs. night shift), smoking status, depressive symptoms, body mass index (BMI), hypertension, and diabetes, sleep duration (minutes) was significantly (all p < 0.01) shorter in Black (mean = 399.5), Hispanic (mean = 411.7), and Asian (mean = 409.6) participants than in White participants (mean = 447.4). All remaining sleep characteristics were significantly less favorable among Black participants as compared with White participants. Asian participants also reported significantly more daytime sleepiness than did White participants., Conclusions: Differences in sleep characteristics by race/ethnicity are apparent in a sample of adults with a low probability of sleep apnea and following adjustment for known confounders., (Copyright © 2015 Elsevier B.V. All rights reserved.)

The popularity of energy drinks has increased rapidly in the past decade. One of the main reasons people use energy drinks is to counteract effects of insufficient sleep or sleepiness. Risks associated with energy drink use, including those related to sleep loss, may be disproportionately borne by racial minorities and those of lower socioeconomic status. In this review, a brief introduction to the issue of health disparities is provided, population-level disparities and inequalities in sleep are described, and the social-ecological model of sleep and health is presented. Social and demographic patterns of energy drink use are then presented, followed by discussion of the potential ways in which energy drink use may contribute to health disparities, including the following: 1) effects of excessive caffeine in energy drinks, 2) effects of energy drinks as sugar-sweetened beverages, 3) association between energy drinks and risk-taking behaviors when mixed with alcohol, 4) association between energy drink use and short sleep duration, and 5) role of energy drinks in cardiometabolic disease. The review concludes with a research agenda of critical unanswered questions., (© 2014 International Life Sciences Institute.)

Objective: To determine the association between objectively measured sleep and 10-year changes in estimated glomerular filtration rate (eGFR)., Methods: From 2003 to 2005, an ancillary sleep study was conducted at the Chicago site of the Coronary Artery Risk Development in Young Adults (CARDIA) study. Community-based black and white adults (aged 32-51 years) wore a wrist actigraph for up to six nights to record sleep duration and fragmentation. Sleep quality was measured with the Pittsburgh Sleep Quality Index (PSQI). Participants without history of cardiovascular or chronic kidney diseases, proteinuria, or hypertension at the 2000-2001 CARDIA examination were followed over 10 years (n = 463). eGFR was estimated from serum creatinine (eGFRCr) at the 2000-2001, 2005-2006, and 2010-2011 CARDIA examinations, whereas cystatin-C-estimated eGFR (eGFRCys) was measured at the 2000-2001 and 2005-2006 examinations. Generalized estimating equation regression and linear models estimated the associations of each sleep parameter with changes in eGFRCr and eGFRCys, controlling for cardiovascular and renal risk., Results: Sleep parameters were not related to 5-year change in eGFRCys. However, each 1 h decrease in sleep duration was significantly associated with a 1.5 mL/min/1.73 m2 higher eGFRCr [95% confidence interval (CI), 0.2-2.7], and each one-point increase in PSQI was significantly associated with a 0.5 mL/min/1.73 m2 higher eGFRCr (95% CI, 0.04-0.9) over 10 years., Conclusion: In this community-based sample, shorter sleep and poorer sleep quality were related to higher kidney filtration rates over 10 years., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Sleep symptoms are associated with weight gain and cardiometabolic disease. The potential role of diet has been largely unexplored. Data from the 2007-2008 National Health and Nutrition Examination Survey (NHANES) were used (n = 4552) to determine which nutrients were associated with sleep symptoms in a nationally representative sample. Survey items assessed difficulty falling asleep, sleep maintenance difficulties, non-restorative sleep and daytime sleepiness. Analyses were adjusted for energy intake, other dietary factors, exercise, body mass index (BMI) and sociodemographics. Population-weighted, logistic regression, with backwards-stepwise selection, examined which nutrients were associated with sleep symptoms. Odds ratios (ORs) reflect the difference in odds of sleep symptoms associated with a doubling in nutrient. Nutrients that were associated independently with difficulty falling asleep included (in order): alpha-carotene (OR = 0.96), selenium (OR = 0.80), dodecanoic acid (OR = 0.91), calcium (OR = 0.83) and hexadecanoic acid (OR = 1.10). Nutrients that were associated independently with sleep maintenance difficulties included: salt (OR = 1.19), butanoic acid (0.81), carbohydrate (OR = 0.71), dodecanoic acid (OR = 0.90), vitamin D (OR = 0.84), lycopene (OR = 0.98), hexanoic acid (OR = 1.25) and moisture (OR = 1.27). Nutrients that were associated independently with non-restorative sleep included butanoic acid (OR = 1.09), calcium (OR = 0.81), vitamin C (OR = 0.92), water (OR = 0.98), moisture (OR = 1.41) and cholesterol (OR = 1.10). Nutrients that were associated independently with sleepiness included: moisture (OR = 1.20), theobromine (OR = 1.04), potassium (OR = 0.70) and water (OR = 0.97). These results suggest novel associations between sleep symptoms and diet/metabolism, potentially explaining associations between sleep and cardiometabolic diseases., (© 2013 European Sleep Research Society.)

Objectives: Sleep comprises one-third of one's life, yet little is known about sleep in developing countries. Furthermore, many studies in industrialized countries have reported that sleep duration and quality decline with aging, but whether this association persists globally is unknown. This study's objectives were to characterize sleep in a community without electricity in Haiti and to examine associations between measures of sleep and age., Methods: Fifty-eight Haiti residents (50% women) in four age groups, 18-30, 31-50, 51-64, and ≥ 65 years participated. Three days of wrist actigraphy were used to estimate sleep patterns., Results: Mean (standard deviation) values of sleep measures were: 20:57 (0:40) for sleep onset, 4:54 (0:43) for sleep end, 9.3 (1.2) h for time in bed, 7.0 (1.0) h for sleep duration, 54 (24) min awake after sleep onset, and 88.7 (5.4)% for sleep maintenance (percentage of sleep period actually spent sleeping). There were no significant differences in the sleep measures between men and women. Regression analyses adjusting for sex, household size, and number of people sleeping in the same room indicated that only sleep fragmentation differed by age group. Specifically, mean fragmentation was higher in the youngest age group than all other age groups, which did not differ from one another., Conclusions: Average time in bed in this Haitian sample was greater than previously reported for industrialized countries like the United States (9.3 versus. 7-8 h);, however, actual sleep duration averaged only 7 h. No age-related decline in sleep duration or quality was observed in Haiti., (Copyright © 2013 Wiley Periodicals, Inc.)

Short sleep duration is associated with weight gain and obesity, diabetes, cardiovascular disease, psychiatric illness, and performance deficits. Likewise, long sleep duration is also associated with poor physical and mental health. The role of a healthy diet in habitual sleep duration represents a largely unexplored pathway linking sleep and health. This study evaluated associations between habitual sleep parameters and dietary/nutritional variables obtained via the National Health and Nutrition Examination Survey (NHANES), 2007-2008. We hypothesized that habitual very short (<5h) short (5-6h) and long (9+h) sleep durations are associated with intake of a number of dietary nutrient variables. Overall, energy intake varied across very short (2036kcal), short (2201kcal), and long (1926kcal) sleep duration, relative to normal (2151kcal) sleep duration (p=0.001). Normal sleep duration was associated with the greatest food variety (17.8), compared to very short (14.0), short (16.5) and long (16.3) sleep duration (p<0.001). Associations between sleep duration were found across nutrient categories, with significant associations between habitual sleep duration and proteins, carbohydrates, vitamins and minerals. In stepwise analyses, significant contributors of unique variance included theobromine (long sleep RR=0.910, p<0.05), vitamin C (short sleep RR=0.890, p<0.05), tap water (short sleep RR=0.952, p<0.001; very short (<5h) sleep RR=0.941, p<0.05), lutein+zeaxanthin (short sleep RR=1.123, p<0.05), dodecanoic acid (long sleep RR=0.812, p<0.05), choline (long sleep RR=0.450, p=0.001), lycopene (very short (<5h) sleep RR=0.950, p<0.05), total carbohydrate (very short (<5h) sleep RR=0.494, p<0.05; long sleep RR=0.509, p<0.05), selenium (short sleep RR=0.670, p<0.01) and alcohol (long sleep RR=1.172, p<0.01). Overall, many nutrient variables were associated with short and/or long sleep duration, which may be explained by differences in food variety. Future studies should assess whether these associations are due to appetite dysregulation, due to short/long sleep and/or whether these nutrients have physiologic effects on sleep regulation. In addition, these data may help us better understand the complex relationship between diet and sleep and the potential role of diet in the relationship between sleep and obesity and other cardiometabolic risks., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Background/objectives: To examine the associations between perceived control over sleep, noise levels, sleep duration, and noise complaints in a cohort of hospitalized adults., Design: Prospective cohort study., Setting: General medicine ward in an academic medical center., Participants: One hundred eighteen hospitalized patients age 50 years and over (mean age, 65 years; 57% female; 67% African American)., Measurements: Sleep duration was measured via wrist actigraphy, and noise levels in patient rooms were measured via sound monitors. Validated questionnaires were used to assess sleep characteristics at baseline and sleep quality for each night. Perceived control over sleep was measured at baseline using the Sleep Self-Efficacy (SSE) scale (range 9-45)., Results: The mean SSE score was 32.1 (standard deviation, 9.4), and the median score was 34 (interquartile range, 24-41). Average sleep duration for patients in the hospital was 333 minutes (5.5 hours). Forty-two percent of patients complained of noise disrupting their sleep. Linear regression clustered by subject showed that above median SSE was associated with longer sleep duration (+55 minutes 95% confidence interval [CI]: 14, 97; P = 0.010). This association remained significant after controlling for objective noise levels and patient demographics (+50 minutes 95% CI: 11, 90; P = 0.014). In logistic regression controlling for noise level and patient demographics, those patients with high SSE were 51% less likely to complain of noise disruptions (odds ratio: 0.49; 95% CI: 0.25, 0.96; P = 0.039)., Conclusion: Higher perceived control over sleep is associated with longer sleep duration, better sleep quality, and fewer reports of noise disruptions. In addition to noise control, interventions to boost perceived control may improve in-hospital sleep., (Copyright © 2013 Society of Hospital Medicine.)

Background and Purpose: Carotid intima-media thickness (CIMT) is a subclinical marker of cardiovascular disease. Recent studies suggest that shorter sleep duration is a risk factor for cardiovascular disease, but there is limited evidence regarding this association using high-quality, objective assessments of sleep. The aim of this study is to determine whether sleep duration is associated with CIMT., Methods: The study used an observational cohort consisting of 617 black and white middle-aged healthy participants (37-52 years; 58% female) in the Coronary Artery Risk Development in Young Adults (CARDIA) Study. Multivariable-adjusted linear regression analyses were performed. Sleep duration was measured using wrist actigraphy monitors. CIMT was calculated using the average of 20 measurements of the mean common carotid, bulb, and internal CIMT, which was assessed using ultrasound images., Results: After adjusting for covariates, 1 hour of longer sleep duration was associated with 0.026 mm less CIMT among men (P=0.02; 95% CI, -0.047 to -0.005) and 0.001 mm less CIMT among women (P=0.91; 95% CI, -0.020 to 0.022). Segment-specific analyses indicated that the carotid bulb was a key driver of the observed association., Conclusions: Shorter objectively assessed sleep duration was associated with greater CIMT among men but not women.

Slow-wave sleep has been associated with several physiological phenomena, including glucose metabolism, sympathetic nervous system activity, hormonal secretion and blood pressure regulation. The aim of these analyses was to determine which sociodemographic and medical factors were associated with slow-wave sleep duration in a large clinical sample. We conducted cross-sectional analysis of clinical data from 1019 consecutive adults over a 10-month period who had their first in-laboratory polysomnogram for suspicion of obstructive sleep apnea. Patients either underwent in-laboratory full-night polysomnogram followed by full-night continuous positive airway pressure titration or split-night polysomnogram. Patients also completed questionnaires to assess race, education, marital status and medical co-morbidities. A multiple linear regression model that predicted the natural log of slow-wave sleep in minutes indicated that African Americans had approximately 48% less slow-wave sleep than non-African Americans. Increasing age and male gender were also associated with less slow-wave sleep. Overweight and obese individuals had significantly less slow-wave sleep than those not overweight, even after adjustment for obstructive sleep apnea severity. Finally, those with severe obstructive sleep apnea had significantly less slow-wave sleep than those with less severe obstructive sleep apnea even after adjustment for obesity. Results remained unchanged when patients who had a split-night polysomnogram were excluded. We observed less slow-wave sleep in African Americans, a group at increased risk of diabetes and hypertension compared with Caucasians, and in those who are overweight and obese and those with severe obstructive sleep apnea. Future research needs to explore potential reasons for reduced slow-wave sleep in these individuals., (© 2011 European Sleep Research Society.)

Background: Polysomnograms (PSGs) are routinely ordered by nonsleep specialists. However, it is unknown whether a sleep specialist consultation prior to a diagnostic PSG influences adherence to continuous positive airway pressure (CPAP) therapy., Methods: This study was done at the University of Chicago Sleep Disorders Center and included 403 patients with obstructive sleep apnea who had CPAP adherence data available. CPAP was set up at home, and objective adherence was remotely monitored during the first 30 days of therapy. Physicians who ordered PSGs were divided into two groups: sleep specialists and nonsleep specialists., Results: Patients were aged 52.5 ± 14 years, 47% were men, and 54% were African American. Mean daily CPAP use was greater in patients who were referred by sleep specialists (n = 105, 279 ± 179 min/d) than in patients referred by nonsleep specialists (n = 298, 219 ± 152 min/d, P = .005). In the linear regression model adjusting for several covariates, only two predictors were significantly associated with CPAP adherence. A sleep specialist consultation prior to the diagnostic PSG was associated with 58.2 min more per day (P = .002), and African American race was associated with 56.0 min less per day (P = .002) of CPAP use., Conclusions: In this cohort study, CPAP adherence was significantly higher with a sleep specialist consultation prior to the diagnostic PSG. In addition, African American race was associated with worse adherence to therapy. A better understanding of predictors of CPAP adherence may be useful in identifying patients who may benefit from a sleep specialist consultation prior to ordering a diagnostic PSG.

Previous research in lean subjects has found lower leptin levels associated with shorter sleep duration. Since leptin levels are higher and some of the actions of leptin are impaired in obese individuals, one cannot assume that sleep will be similarly associated with leptin in obese individuals. The aim of this paper was to examine the cross-sectional association between habitual sleep duration and quality and plasma leptin levels in a sample of 80 obese men and premenopausal women aged 18-50 years. Leptin levels (ng/ml) were assayed on a fasting blood sample taken in the morning. We calculated a relative leptin level by dividing leptin by body fat percentage. Sleep duration and sleep efficiency were measured by 2 weeks of wrist actigraphy and respiratory disturbance index (RDI), a measure of sleep disordered breathing, was assessed by a portable screening device on a single night. Mean leptin levels and body fat percentage were higher in women than men (P < 0.001), however, mean RDI was higher in men (P = 0.01). There were no significant associations between relative leptin level and any of the sleep measures, including sleep duration, sleep efficiency, and sleep disordered breathing. There was also no difference between men and women in the association between sleep and leptin. In conclusion, contrary to what has been reported in other studies, measures of sleep duration and quality were not associated with leptin levels in our sample of obese adults.

Objective: To examine whether sleep duration and quality are associated with fasting glucose, fasting insulin, or estimated insulin resistance in a community-based sample of early middle-aged adults., Research Design and Methods: This was an ancillary study to the Coronary Artery Risk Development in Young Adults (CARDIA) Study. Habitual sleep duration and fragmentation were estimated from 6 days of wrist actigraphy collected in 2003-2005. Insomnia was defined as self-reported difficulty falling asleep or waking up in the night three or more times per week plus average sleep efficiency of <80% based on actigraphy. Fasting blood samples to measure glucose and insulin were collected after the sleep measures during the CARDIA clinical examination in 2005-2006. Insulin resistance was estimated using the homeostatic model assessment (HOMA) method. Analyses were cross-sectional and stratified by the presence of diabetes., Results: There was no association between sleep measures and fasting glucose, insulin, or HOMA in the 115 subjects without diabetes. Among the 40 subjects with diabetes, after adjustment for covariates, 10% higher sleep fragmentation was associated with a 9% higher fasting glucose level, a 30% higher fasting insulin level, and a 43% higher HOMA level. Insomnia was associated with a 23% higher fasting glucose level, a 48% higher fasting insulin level, and an 82% higher HOMA level., Conclusions: The observed association between poor sleep quality and higher glucose, insulin, and estimated insulin resistance among subjects with diabetes warrants further examination of the effect of sleep disturbances on glucose control in type 2 diabetes.

Objectives: Although numerous studies have reported negative associations between sleep duration and body size, no studies of this association have focused on Hispanic groups, which was the goal of this work., Methods: Data are from adults in the 1982-1984 Hispanic Health and Nutrition Examination Survey (HHANES), which enrolled Cuban-Americans, Mexican-Americans, and Puerto Ricans. HHANES included self-reported sleep duration and several anthropometric measures. Principle component analysis extracted a single variable to represent body size. Linear regression models stratified by Hispanic group predicted body size from sleep duration adjusting for age, sex, education, income, marital status, household size, and acculturation., Results: Average age was 36-44 years and 52-64% were women. Average sleep duration was 7.3-7.7 h. Shorter sleep duration was associated with larger body size in Mexican-Americans only. The regression coefficient indicated that on average a Mexican-American adult who reported sleeping for 4 h would have a body size that was larger by 0.12 times the standard deviation for body size than a Mexican-American adult reporting 8 h of sleep (all other covariates being equal). This effect was similar to the effect of 10 years of age, which would be associated with an increase in body size by 0.10 times the standard deviation of body size., Conclusions: These results underscore the importance of examining factors associated with obesity in different ethnic groups. It may be inappropriate to combine different Hispanic ethnicities together., (© 2010 Wiley-Liss, Inc.)

Laboratory studies have found that short-term sleep restriction is associated with impairments in glucose metabolism, appetite regulation and blood pressure regulation. This chapter reviews the epidemiologic evidence for an association between habitual sleep duration and quality and risk of cardiometabolic diseases including obesity, diabetes and hypertension. Multiple studies observed a cross-sectional association between short sleep duration (generally <6 h per night) and increased body mass index or obesity, prevalent diabetes and prevalent hypertension. Many studies also reported an association between self-reported long sleep duration (generally >8 h per night) and cardiometabolic disease. There have been a few prospective studies and several, but not all, have found an association between short sleep and incident diabetes, hypertension and markers of cardiovascular disease. Future prospective epidemiologic studies need to include objective measures of sleep, and intervention studies are needed in order to establish a causal link between impaired or insufficient sleep and cardiometabolic disease risk., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Numerous studies have found an association between shorter sleep duration and higher body mass index (BMI) in adults. Most previous studies have been cross-sectional and relied on self-reported sleep duration, which may not be very accurate. In the Coronary Artery Risk Development in Young Adults (CARDIA) Sleep Study (2000-2006), the authors examine whether objectively measured sleep is associated with BMI and change in BMI. They use several nights of wrist actigraphy to measure sleep among participants in an ongoing cohort of middle-aged adults. By use of linear regression, the authors examine whether average sleep duration or fragmentation is associated with BMI and 5-year change in BMI, adjusting for confounders. Among 612 participants, sleep duration averaged 6.1 hours and was grouped into 4 categories. Both shorter sleep and greater fragmentation were strongly associated with higher BMI in unadjusted cross-sectional analysis. After adjustment, BMI decreased by 0.78 kg/m(2) (95% confidence interval: -1.6, -0.002) for each increasing sleep category. The association was very strong in persons who reported snoring and weak in those who did not. There were no longitudinal associations between sleep measurements and change in BMI. The authors confirmed a cross-sectional association between sleep duration and BMI using objective sleep measures, but they did not find that sleep predicted change in BMI. The mechanism underlying the cross-sectional association is not clear.

Background: Epidemiological studies have reported an association between self-reported short sleep duration and high blood pressure (BP). Our objective was to examine both cross-sectional and longitudinal associations between objectively measured sleep and BP., Methods: This study is ancillary to the Coronary Artery Risk Development in Young Adults (CARDIA) cohort study. Blood pressure was measured in 2000 and 2001 and in 2005 and 2006. Sleep was measured twice using wrist actigraphy for 3 consecutive days between 2003 and 2005. Sleep duration and sleep maintenance (a component of sleep quality) were calculated. Analyses included 578 African Americans and whites aged 33 to 45 years at baseline. Outcome measures were systolic BP (SBP) and diastolic BP (DBP) levels, 5-year change in BP, and incident hypertension., Results: After we excluded the patients who were taking antihypertensive medications and adjusted for age, race, and sex, shorter sleep duration and lower sleep maintenance predicted significantly higher SBP and DBP levels cross-sectionally as well as more adverse changes in SBP and DBP levels over 5 years (all P < .05). Short sleep duration also predicted significantly increased odds of incident hypertension (odds ratio, 1.37; 95% confidence interval, 1.05-1.78). Adjustment for 16 additional covariates, including snoring and daytime sleepiness, slightly attenuated the associations between sleep and BP. Sleep duration appeared to mediate the difference between African Americans and whites in DBP change over time (P = .02)., Conclusion: Reduced sleep duration and consolidation predicted higher BP levels and adverse changes in BP, suggesting the need for studies to investigate whether interventions to optimize sleep may reduce BP.

Objective: To examine bed times and wake times in US adolescents aged 15 to 17 years using time diaries to determine whether adolescent sleep has changed in recent years and what factors determine bed times and wake times., Study Design: Time diary analysis using 2 national probability samples: 1981 Time Use Longitudinal Panel Study (n = 130) and 2003-2006 American Time Use Survey (n = 2978)., Results: Average time in bed on school days was about 8 hours and was 1 to 2 hours longer on non-school days. Bed times and wake times were similar in 1981 and 2003-2006. Sociodemographic factors and daytime activities, specifically computer use and social activities, predicted bed time. On school days, school start time was the strongest predictor of wake time. Every hour earlier that school started, wake time was about 25 minutes earlier., Conclusions: Adolescents spent less than the recommended 9 hours in bed on school days. There is no evidence that this is a recent change in bed times and wake times, however. Although many factors influence bed time, school start time is the strongest determinant of wake time on school days. Increased computer use and earlier school days may be contributing to insufficient sleep in adolescents.

Context: Coronary artery calcification is a subclinical predictor of coronary heart disease. Recent studies have found that sleep duration is correlated with established risk factors for calcification including glucose regulation, blood pressure, sex, age, education, and body mass index., Objective: To determine whether objective and subjective measures of sleep duration and quality are associated with incidence of calcification over 5 years and whether calcification risk factors mediate the association., Design, Setting, and Participants: Observational cohort of home monitoring in a healthy middle-aged population of 495 participants from the Coronary Artery Risk Development in Young Adults (CARDIA) cohort Chicago site (black and white men and women aged 35-47 years at year 15 of the study in 2000-2001 with follow-up data at year 20 in 2005-2006). Potential confounders (age, sex, race, education, apnea risk, smoking status) and mediators (lipids, blood pressure, body mass index, diabetes, inflammatory markers, alcohol consumption, depression, hostility, self-reported medical conditions) were measured at both baseline and follow-up. Sleep metrics (wrist actigraphy measured duration and fragmentation, daytime sleepiness, overall quality, self-reported duration) were examined for association with incident calcification. Participants had no detectable calcification at baseline., Main Outcome Measure: Coronary artery calcification was measured by computed tomography in 2000-2001 and 2005-2006 and incidence of new calcification over that time was the primary outcome., Results: Five-year calcification incidence was 12.3% (n = 61). Longer measured sleep duration was significantly associated with reduced calcification incidence (adjusted odds ratio, 0.67 per hour [95% confidence interval, 0.49-0.91 per hour]; P = .01). No potential mediators appreciably altered the magnitude or significance of sleep (adjusted odds ratio estimates ranged from 0.64 to 0.68 per sleep hour; maximum P = .02). Alternative sleep metrics were not significantly associated with calcification., Conclusion: Longer measured sleep is associated with lower calcification incidence independent of examined potential mediators and confounders.

Background: Recent epidemiologic studies have found that self-reported duration of sleep is associated with obesity, diabetes, hypertension, and mortality. The extent to which self reports of sleep duration are similar to objective measures and whether individual characteristics influence the degree of similarity are not known., Methods: Eligible participants at the Chicago site of the Coronary Artery Risk Development in Young Adults Study were invited to participate in a 2003-2005 ancillary sleep study; 82% (n = 669) agreed. Sleep measurements collected in 2 waves included 3 days each of wrist actigraphy, a sleep log, and questions about usual sleep duration. We estimate the average difference and correlation between subjectively and objectively measured sleep by using errors-in-variables regression models., Results: Average measured sleep was 6 hours, whereas the average from subjective reports was 6.8 hours. Subjective reports increased on average by 34 minutes for each additional hour of measured sleep. Overall, the correlation between reported and measured sleep duration was 0.47. Our model suggests that persons sleeping 5 hours over-reported their sleep duration by 1.2 hours, and those sleeping 7 hours over-reported by 0.4 hours. The correlations and average differences between self-reports and measured sleep varied by health, sociodemographic, and sleep characteristics., Conclusion: In a population-based sample of middle-aged adults, subjective reports of habitual sleep are moderately correlated with actigraph-measured sleep, but are biased by systematic over-reporting. The true associations between sleep duration and health may differ from previously reported associations between self-reported sleep and health.

Objective: Studies of children have found an inverse association between sleep duration and overweight on the basis of parental report of sleep duration. Studies in adolescents have been inconsistent but used varied measures of sleep. We used a nationally representative sample of adolescents that included 2 different measures of sleep duration (24-hour time diaries and self-reported usual sleep hours) to examine whether the association with overweight is sensitive to how sleep is measured in a single study population. We expected that the 2 measures of sleep would be strongly correlated and that the time-diary sleep would be more strongly associated with overweight risk because it is likely the more accurate measure of sleep., Methods: In 2001-2002, adolescents from the Child Development Supplement of the Panel Study of Income Dynamics completed 24-hour time diaries on a random weekday and weekend. Adolescents also self-reported average sleep duration. Both sleep measures were categorized into quartiles. Height and weight were measured, and a BMI z score for age and gender was calculated. Overweight was defined as above the 95th percentile., Results: The final sample included 767 male and 779 female subjects who were aged 10 to 19 years. Mean time-diary sleep was nearly 9 hours on weekdays and >10 hours on weekends. Mean self-reported sleep duration was 8 hours. Time-diary sleep and self-reported sleep were weakly correlated. Time-diary sleep was not significantly associated with overweight. Self-reported sleep was associated with overweight, but the association was not linear. When both sleep measures were included in the same model, their effects on overweight were independent., Conclusions: The weak correlation between self-reported sleep and time-diary sleep and the independence of their associations with overweight raise questions about what different measures of sleep duration in adolescents represent.

Background: Evidence from laboratory and epidemiologic studies suggests that decreased sleep duration or quality may increase diabetes risk. We examined whether short or poor sleep is associated with glycemic control in African Americans with type 2 diabetes mellitus., Methods: We conducted a cross-sectional study of volunteers with type 2 diabetes interviewed at the University of Chicago Hospitals, Chicago, Ill. The final analysis included 161 participants. Glycemic control was assessed by hemoglobin A1c (HbA1c) level obtained from medical charts. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Perceived sleep debt was calculated as the difference between preferred and actual weekday sleep duration., Results: The mean +/- SD sleep duration was 6.0 +/- 1.6 hours, and 71% of the participants were classified as having poor quality sleep (PSQI score >5). We excluded patients with sleep frequently disrupted by pain (n = 39). In patients without diabetic complications, glycemic control was associated with perceived sleep debt but not PSQI score. The predicted increase in HbA1c level for a perceived sleep debt of 3 hours per night was 1.1% above the median. In patients with at least 1 complication, HbA1c level was associated with PSQI score but not perceived sleep debt. The predicted increase in HbA1c level for a 5-point increase in PSQI was 1.9% above the median., Conclusions: In our sample, sleep duration and quality were significant predictors of HbA1c, a key marker of glycemic control. Combined with existing evidence linking sleep loss to increased diabetes risk, these data suggest that optimizing sleep duration and quality should be tested as an intervention to improve glucose control in patients with type 2 diabetes.

Despite mounting evidence that sleep duration is a risk factor across diverse health and functional domains, little is known about the distribution and determinants of sleep. In 2003-2004, the authors used wrist activity monitoring and sleep logs to measure time in bed, sleep latency (time required to fall asleep), sleep duration, and sleep efficiency (percentage of time in bed spent sleeping) over 3 days for 669 participants at one of the four sites of the Coronary Artery Risk Development in Young Adults (CARDIA) study (Chicago, Illinois). Participants were aged 38-50 years, 58% were women, and 44% were Black. For the entire sample, mean time in bed was 7.5 (standard deviation (SD), 1.2) hours, mean sleep latency was 21.9 (SD, 29.0) minutes, mean sleep duration was 6.1 (SD, 1.2) hours, and mean sleep efficiency was 80.9 (SD, 11.3)%. All four parameters varied by race-sex group. Average sleep duration was 6.7 hours for White women, 6.1 hours for White men, 5.9 hours for Black women, and 5.1 hours for Black men. Race-sex differences (p < 0.001) remained after adjustment for socioeconomic, employment, household, and lifestyle factors and for apnea risk. Income was independently associated with sleep latency and efficiency. Sleep duration and quality, which have consequences for health, are strongly associated with race, sex, and socioeconomic status.

Objective: To determine whether an association between short sleep duration and increased body mass index (BMI) exists in a sample of U.S. adolescents., Study Design: Public-use dataset of the National Longitudinal Study of Adolescent Health. Final sample included 4486 adolescents (51% female). Main outcome was BMI transformed into z-scores for age and sex using reference values from the Centers for Disease Control/National Center for Health Statistics. Overweight was defined as > or =95th percentile. Linear and logistic regression models were calculated. Sleep duration was self-reported in hours. A quadratic term for sleep was added to test curvilinear association. Covariates included age, race, parental education, activity and inactivity scores., Results: Among males, linear regression indicated that sleep duration significantly predicted BMI z-score (Beta = -0.08, 95% CI: -0.12, -0.03). Logistic regression indicated that sleep duration predicted risk of overweight among males (OR = 0.90, 95% CI: 0.82, 1.00). Sleep duration was not a significant predictor among females in either regression model. Quadratic term for sleep was not significant for either sex., Conclusions: Longer sleep duration was weakly associated with lower BMI and risk of overweight among male adolescents only. This sex-related difference may be due to differences in the physiology of puberty or in sleep characteristics.

Many hormones play important roles in both pubertal development and sleep regulation. Because of the possible consequences of impaired sleep, including impaired health and cognition, it is important to examine whether an association between pubertal stage and sleep exists. The aim of this analysis is to examine the association between sleep and adolescent growth and developmental stage in a large sample of adolescents ages 12-16 years from a nationally representative longitudinal study. This analysis used the public-use data set of the National Longitudinal Study of Adolescent Health, an extensive survey of health and behavior among adolescents in the United States. The study included two interviews approximately 1 year apart. Pubertal development, sleep variables, and height are self-reported. Pubertal development scores were calculated by summing responses to three questions for each sex. The sleep variables include sleep duration, frequent insomnia (once/week or more), frequently waking tired (once/week or more), and insufficient sleep. The results indicate a sex difference in the association between sleep problems and pubertal development. Among females, there was a significant increase in sleep problems with increasing pubertal development score, but not among males. The negative association between sleep duration and pubertal development score, however, was significant in both males and females. There is no association between sleep duration and height velocity (inches/year) in this sample. The results, which are based on a large sample size, warrant further examination with more objective measures into the association between sleep and growth and development among adolescents., (Copyright 2005 Wiley-Liss, Inc)

Sleep hygiene recommendations discourage eating before bedtime; however, the impact of mealtime on sleep has been inconsistent. We examined gender-stratified associations between eating or drinking <1, <2 and <3 h before bedtime, sleep duration and wake after sleep onset (WASO >30 min). This study utilised 2003–2018 data from the American Time Use Survey, a nationally representative sample of USA residents aged ≥15 years. Participants recorded weekday/weekend activities during a 24-h period. Age-specific sleep duration and WASO were estimated categorically and continuously. Eating or drinking were identified from all activities recorded <1, <2 and <3 h before bedtime. Mean ± se sleep duration was 8·0 ± 0·006 h, and 6% of participants ate or drank <1 h prior to weekdays bedtime. Overall, eating or drinking <1 h prior to bedtime was associated with longer weekdays sleep duration. Women and men who ate or drank <1 h before bedtime, v. those who did not, had 35 min (95% CI (30,39)) and 25 min (95 % CI (21,29)) longer sleep duration, respectively, as well as increased odds of WASO; women (OR=2·03, 95% CI (1·66,2·49)) and men (OR=2·64, 95% CI (2·08,3·36)). As the interval of eating or drinking prior to bedtime expanded, odds of short and long sleep durations and WASO decreased. This population-based data linked eating or drinking <1 h before bedtime to longer sleep duration, but increased WASO. Eating or drinking further from bedtime lowers the odds of short and long sleep duration and WASO. Causal pathways are difficult to discern, though inefficient sleep after late-night eating could increase WASO and trigger compensatory increases in sleep duration. [ABSTRACT FROM AUTHOR]