Association between long sleep duration and increased risk of obesity and type 2 diabetes: A review of possible mechanisms

No association between a common type 2 diabetes risk gene variant in the melatonin receptor gene (MTNR1B) and mortality among type 2 diabetes patients

The minor G risk allele in the common melatonin receptor gene (MTNR1B, rs10830963) has been associated with an increased risk of myocardial infarction among patients with type 2 diabetes (T2D). Furthermore, activating the melatonin receptor 1B through melatonin has been shown to promote cell proliferation, which could be hypothesized to increase cancer risk. Cardiovascular disease (CVD) and cancer are common causes of death among patients with T2D. Using data from 14 736  patients with T2D who participated in the UK Biobank investigation, we hypothesized an additive effect of the G risk allele on all-cause mortality, CVD mortality, and cancer mortality. As shown by Cox regression adjusted for confounders such as age, glucose-lowering medication, and socioeconomic status, no significant trend between the number of G risk alleles and mortality outcomes was found during the follow-up period of 11.1 years. Our negative findings do not speak against the role of this gene variant in the development of T2D, as repeatedly shown by previous large-scale studies. Instead, they may suggest that rs10830963 is less relevant for mortality risk in patients with T2D.

Environmental risk factors of type 2 diabetes-an exposome approach

Type 2 diabetes is one of the major chronic diseases accounting for a substantial proportion of disease burden in Western countries. The majority of the burden of type 2 diabetes is attributed to environmental risks and modifiable risk factors such as lifestyle. The environment we live in, and changes to it, can thus contribute substantially to the prevention of type 2 diabetes at a population level. The 'exposome' represents the (measurable) totality of environmental, i.e. nongenetic, drivers of health and disease. The external exposome comprises aspects of the built environment, the social environment, the physico-chemical environment and the lifestyle/food environment. The internal exposome comprises measurements at the epigenetic, transcript, proteome, microbiome or metabolome level to study either the exposures directly, the imprints these exposures leave in the biological system, the potential of the body to combat environmental insults and/or the biology itself. In this review, we describe the evidence for environmental risk factors of type 2 diabetes, focusing on both the general external exposome and imprints of this on the internal exposome. Studies provided established associations of air pollution, residential noise and area-level socioeconomic deprivation with an increased risk of type 2 diabetes, while neighbourhood walkability and green space are consistently associated with a reduced risk of type 2 diabetes. There is little or inconsistent evidence on the contribution of the food environment, other aspects of the social environment and outdoor temperature. These environmental factors are thought to affect type 2 diabetes risk mainly through mechanisms incorporating lifestyle factors such as physical activity or diet, the microbiome, inflammation or chronic stress. To further assess causality of these associations, future studies should focus on investigating the longitudinal effects of our environment (and changes to it) in relation to type 2 diabetes risk and whether these associations are explained by these proposed mechanisms.

Obese Patients Experience More Severe CSA than Non-Obese Patients

Objective: To investigate whether central sleep apnea (CSA) is associated with an increased risk of obesity. Materials and methods: From 1 January 2000 to 31 December 2015, we screened 24,363 obese patients from the 2005 longitudinal health insurance database, which is part of the Taiwan National Health Insurance Research Database. From the same database, 97,452 non-obese patients were also screened out. Age, gender, and index dates were matched. Multiple logistic regression was used to analyze the previous exposure risk of obese and CSA patients. A p-value of <0.05 was considered significant. Results: Obese patients were more likely to be exposed to CSA than non-obese patients would (AOR = 2.234, 95% CI = 1.483–4.380, p < 0.001). In addition, the closeness of the exposure time to the index time is positively correlated with the severity of obesity and has a dose–response effect (CSA exposure < 1 year, AOR = 2.386; CSA exposure ≥ 1 year and <5 years, AOR = 1.725; CSA exposure time ≥ 5 years, AOR = 1.422). The CSA exposure time of obese patients was 1.693 times that of non-obese patients. Longer exposure time is associated with more severe obesity and has a dose-response effect (CSA exposure < 1 year, AOR = 1.420; CSA exposure ≥ 1 year and <5 years, AOR = 2.240; CSA ≥ 5 years, AOR = 2.863). Conclusions: In this case-control study, patients with CSA had a significantly increased risk of obesity. Long-term exposure to CSA and obesity is more likely and has a dose-response effect.

Association between sleep duration on workdays and blood pressure in non-overweight/obese population in NHANES: a public database research

This study aimed to explore the association between sleep duration on workdays and blood pressure (BP) including systolic blood pressure (SBP) and diastolic blood pressure (DBP) in non-overweight/obese population. A cross-sectional study composed of 2887 individuals from NHANES was conducted. Subjective sleep duration on workdays were evaluated by the questionnaire. Multiple linear regression analyses were done to explore the relationship between sleep duration and BP. Compared with sleep duration of 6-8 h, both sleep duration < 6 h and ≥ 8 h on workdays were significantly associated with increased SBP (β, 3.58 [95% CI 1.60, 5.56] and 1.70 [95% CI 0.76, 2.64], respectively). However, the significant association was not founded in DBP. The stratified analyses showed that in females, sleep duration (< 6 h or ≥ 8 h) on workdays were associated with SBP (β = 5.99 and 2.41, respectively, both P < 0.0005). In addition, the SBP levels were much higher among participants aged (≥ 60) with sleep duration < 6 h. The effect size was 7.23 (P = 0.0217). In the subgroup classified by race, a significantly positive association between sleep duration (< 6 h, ≥ 8 h) and SBP can be seen in the White population (β = 6.64 (P = 0.0007) and 1.91 (P = 0.0215), respectively). In non-overweight/obese population, both short sleep duration (< 6 h) and long sleep duration (≥ 8 h) on workdays were correlated with higher level of SBP.

Association of elevated glycated hemoglobin and obesity with afternoon napping for more than 1 h in young and middle-aged healthy adults

INTRODUCTION

Sleep has different patterns followed worldwide and can be influenced by social, cultural, and environmental factors. Daytime napping is commonly practiced in different parts of the world with controversial results of its effect on glucose metabolism. The current study aims to examine the association of afternoon napping and night sleep duration with metabolic derangements.

METHODS

This is a cross-sectional study involving young adults and middle-aged subjects. Anthropometric measurements were taken for height and weight and hip and waist ratio. Consented subjects were asked to wear actigraphy for 1 week and run their usual daily activities. Home sleep apnea testing was performed to exclude obstructive sleep apnea. Subjects had been asked to come fasting on day seven for blood collection to test for fasting glucose, glycated hemoglobin, lipid profile, and insulin.

RESULTS

A total of 405 subjects were involved to complete the study (52% male, 48% female). The mean age of participants was 32.8 ± 11.5 years. The study indicated that the duration of afternoon napping was significantly associated with abnormal glycated hemoglobin (HbA1c > 5.7%) (p = 0.01) and body mass index (p = 0.046) independent of age, gender, and nocturnal sleep duration. Nocturnal sleep duration was associated with increased insulin level (p = 0.04).

CONCLUSION

Afternoon napping is associated with an increased level of glycated hemoglobin and obesity and that may predispose to the development of type 2 diabetes mellitus.

Self-Reported Sleeping Time Effects on Physical Performance and Body Composition Among Spanish Older Adults: EXERNET-Elder 3.0 study

Objective: To determine the link between physical fitness and body composition with nocturnal and nap time in Spanish older adults. Methods: Eight hundred thirty older adults underwent several tests. Sleep was measured using Jenkins Sleep Scale. Nocturnal sleep was categorized (<7, 7-9, and >9 hours), and nap time (no nap, 1-30 minutes, and >30 minutes).Physical fitness was evaluated using validated tests, and body composition by electric bioimpedance. Results: 75.1% of participants were female, mean age 77.7 ± 5.1 years. Mean nocturnal sleep and nap time was 6.7 hours and 23.3 minutes, respectively. Models showed nocturnal sleep >9 hours was significant and positively associated with body shape index (Odds ratio[OR] = 4.07 (p = .011)) and waist circumference OR = 1.04 (p = .024) in females. Males' waist and hip circumference were positively significantly related to nap time between 1 and 30 minutes, OR = 1.08, p = .009 and OR = 1.08, p = .048, respectively. In females, nap time >30 minutes was associated with greater fat mass and body shape index OR = 1.22, p = .032 and OR = 3.95, p = .027, respectively. Physical fitness showed no associations with sleep outcomes. Conclusions: Sleep patterns do not influence physical fitness but body composition, being more related to female body composition as nocturnal and nap sleep were associated with higher fat mass, waist circumference and body shape index, while only short nap times were related to higher waist and hip circumference in males.

Gender differences in the association between sleep duration and body mass index, percentage of body fat and visceral fat area among chinese adults: a cross-sectional study

BACKGROUND

The relationship between sleep duration and anthropometric indices are still unclear. This study aimed to explore the association between sleep duration and body mass index (BMI), percentage of body fat (PBF) and visceral fat area (VFA) among Chinese adults, further to explore gender difference in it.

METHODS

We analyzed part of the baseline data of a cohort study among adult attendees at two health-screening centers in China. Sleep duration was self-reported and categorized into short (< 7 h/day), optimal (7-9 h/day) and long sleep (≥ 9 h/day). BMI, PBF and VFA were assessed by bioelectric impedance analysis. Demographic characteristics, chronic diseases and medication history, physical activity, smoking and alcohol drinking behaviors were measured by an investigator-administrated questionnaire.

RESULTS

A total of 9059 adult participants (63.08% were females) were included in the analysis. The participants aged from 19 to 91 years with the mean age of 45.0 ± 14.6 years. Short sleep was independently associated with elevated odds of general obesity (defined using BMI) and visceral obesity (defined using VFA) among the total study population, and gender differences were observed in these associations. Among women, short sleep was associated with 62% increased odds of general obesity (OR = 1.62, 95% CI: 1.24-2.12) and 22% increased odds of visceral obesity (OR = 1.22, 95% CI: 1.02-1.45). Among men, long sleep duration was associated with 21% decreased odds of visceral obesity (OR = 0.79, 95% CI: 0.64-0.99). No association was observed between sleep duration and PBF in both sexes.

CONCLUSIONS

Sleep duration was associated with increased odds of general and visceral obesity, and this association differed between men and women. No association was observed between sleep duration and PBF among either males or females.

Rotating night shift work, sleep duration and elevated gamma-glutamyl transpeptidase among steelworkers: cross-sectional analyses from a Chinese occupational cohort

OBJECTIVES

This study aimed to evaluate the separate and combined effects of rotating night shift work and lifestyle factors with elevated gamma-glutamyl transpeptidase (GGT) among steelworkers.

DESIGN, SETTING AND PARTICIPANTS

This cross-sectional study used the baseline information from a Chinese occupational cohort. The in-service workers of the production department of Tangsteel Company who participated in the occupational health examination in Tangshan from February to June 2017 were selected as the research objects.

MAIN OUTCOME MEASURES

The separate and combined effects of rotating night shift work and lifestyle factors with elevated GGT among steelworkers.

RESULTS

The information of 7031 subjects from the production department of Tangsteel Company was analysed. Results showed that the current shift workers and the workers with the duration of night shifts>19 years, the cumulative number of night shifts>1774 nights, the average frequency of night shifts≤7 nights/month and the average frequency of night shifts>7 nights/month had elevated odds of elevated GGT, compared with those who never worked night shifts, and ORs, (95% CIs) were 1.39, (1.10 to 1.75), 1.46, (1.15 to 1.86), 1.46, (1.15 to 1.85), 1.34, (1.04 to 1.73) and 1.37, (1.09 to 1.74) after adjustment for potential confounders. The independent effect of shorter sleep duration (<7 hours/day) on elevated GGT was not statistically significant. Among workers who had shorter sleep duration, the association between rotating night shift work and elevated GGT was statistically significant, but no associations were found among workers with the sleep duration of ≥7 hours/day. In addition, other lifestyle factors affected the association between rotating night shift work and elevated GGT.

CONCLUSIONS

Rotating night shift work is associated with elevated GGT among steelworkers. In particular, the effect of rotating night shift work on elevated GGT was affected by sleep duration and other lifestyle factors.

Sleep duration and mortality in patients with diabetes: Results from the 2007-2015 Korea national health and nutrition examination survey

AIM

- To evaluate the association between sleep duration and mortality in adults with type 2 diabetes.

METHODS

- This study was a longitudinal analysis of all-cause mortality according to sleep duration based on the 2007-2015 Korea National Health and Nutrition Examination Survey (KNHANES) linked to the Cause of Death data (ver. 1.1). Adult participants with type 2 diabetes were included in the analysis. According to self-reported sleep duration, participants were divided into five groups (≤ 5 [short sleeper], 6, 7, 8, and ≥ 9 h/day [long sleeper]). All missing values were replaced using multiple imputation. We used Cox proportional hazards models to evaluate the relationship between sleep duration and mortality using age as the time scale.

RESULTS

- Among the final 51,603 participants who were linked to death certificate data, 5,930 (11.5%) had type 2 diabetes. During a median follow-up of 6.5 years, 735 (12.4%) deaths occurred. In multivariable analysis, a J-shaped association between sleep duration and all-cause mortality was observed (P for quadratic trend = 0.003). In particular, long sleep duration was significantly associated with an increased risk of all-cause mortality (adjusted hazard ratio, 1.65; 95% confidence interval, 1.29-2.11. In addition, modifying effects on the relationship between sleep duration and mortality were identified for chronic kidney disease and cancer (P for interaction = 0.003 and 0.002, respectively).

CONCLUSION

- A J-shaped relationship was identified between sleep duration and all-cause mortality in Korean adults with type 2 diabetes. In particular, a long sleep duration was significantly associated with an increased risk of all-cause mortality.

Overweight and Obesity are Potential Risk Factors for Disrupted Nocturnal Sleep in Iranian Adults: A Cross-Sectional Study

Objectives: Obesity is a risk factor for several chronic conditions, including sleep disorders. We aimed to analyze the relationship between BMI, body fat percentage (FAT%), hip and waist circumference, and weight on the duration of nocturnal sleep. Methods: This study was part of the MASHAD cohort study. In all participants BMI and FAT% were measured. BMI was used to categorize individuals as obese, overweight, and normal subjects. FAT% was used to categorize individuals into tertile: tertile 1 (low) < 27.5, tertile 2 (medium) 27.5-41, and tertile 3 (high) > 41. The level of nightly sleep duration was categorized into three groups: <6, 6-8 (reference group), and >8 h. Results: There was a significant inverse association between body weight and duration of sleep (p < 0.05). Obese and overweight participants had 1.152 OR (CI:1.083-1.225) and 1.126 OR (CI:1.063-1.194) for a short duration of nocturnal sleep, respectively, relative to those with a normal BMI. Conclusion: BMI was an independent determinant of nocturnal sleep duration; obesity and overweight may have negative consequences on sleep duration. Weight control should be considered as a factor in adjusting sleep quality.

Disrupted circadian oscillations in type 2 diabetes are linked to altered rhythmic mitochondrial metabolism in skeletal muscle

Circadian rhythms are generated by an autoregulatory feedback loop of transcriptional activators and repressors. Circadian rhythm disruption contributes to type 2 diabetes (T2D) pathogenesis. We elucidated whether altered circadian rhythmicity of clock genes is associated with metabolic dysfunction in T2D. Transcriptional cycling of core-clock genes BMAL1, CLOCK, and PER3 was altered in skeletal muscle from individuals with T2D, and this was coupled with reduced number and amplitude of cycling genes and disturbed circadian oxygen consumption. Inner mitochondria–associated genes were enriched for rhythmic peaks in normal glucose tolerance, but not T2D, and positively correlated with insulin sensitivity. Chromatin immunoprecipitation sequencing identified CLOCK and BMAL1 binding to inner-mitochondrial genes associated with insulin sensitivity, implicating regulation by the core clock. Inner-mitochondria disruption altered core-clock gene expression and free-radical production, phenomena that were restored by resveratrol treatment. We identify bidirectional communication between mitochondrial function and rhythmic gene expression, processes that are disturbed in diabetes.

Sleep Duration, Sleep Quality, and the Development of Nonalcoholic Fatty Liver Disease: A Cohort Study

INTRODUCTION

The longitudinal relationship between sleep duration, sleep quality, and the risk of nonalcoholic fatty liver disease (NAFLD) is unknown. We aimed to examine the association between sleep duration, sleep quality, and NAFLD development.

METHODS

Using the Pittsburgh Sleep Quality Index, sleep duration and quality were evaluated for 143,306 NAFLD-free Korean adults with a mean age of 36.6 years, who were followed for an average of 4.0 years. Hepatic steatosis (HS) was assessed using ultrasonography and liver fibrosis by the fibrosis-4 index (FIB-4) or the NAFLD fibrosis score. Flexible parametric proportional hazard models were used to determine the hazard ratios (HRs) and 95% confidence intervals.

RESULTS

There were 27,817 subjects with incident HS, of whom 1,471 had incident HS plus intermediate/high FIB-4. Multivariable-adjusted HRs (95% confidence intervals) for incident HS comparing sleep durations of ≤5, 6, 8, and ≥ 9 hours with 7 hours were 1.19 (1.14-1.23), 1.07 (1.04-1.10), 0.98 (0.94-1.02), and 0.95 (0.87-1.03), respectively. The corresponding HRs for incident HS plus intermediate/high FIB-4 were 1.30 (1.11-1.54), 1.14 (1.01-1.29), 1.11 (0.93-1.33), and 1.08 (0.71-1.63). The association between sleep duration and HS plus intermediate/high FIB-4 was inverse in individuals with good sleep quality but tended to be U-shaped in those with poor sleep quality. The results were similar if FIB-4 was replaced by the NAFLD fibrosis score.

DISCUSSION

In young adults, short sleep duration was independently associated with an increased risk of incident NAFLD with or without intermediate/high fibrosis score, suggesting a role for inadequate sleep quantity in NAFLD risk and severity.

Sleep duration and risk of hyperlipidemia: a systematic review and meta-analysis of prospective studies

PURPOSE

Current studies indicate that the association between sleep duration and risk of hyperlipidemia is uncertain. This systematic review aimed to evaluate relevant prospective studies and make a definite conclusion.

METHODS

Three databases were searched for prospective studies on the relationship between sleep duration and hyperlipidemia risk from their inception to October 2020.

RESULTS

We identified twelve studies involving 114,439 participants. Follow-up for incident hyperlipidemia ranged from 200 days to 10 years. Neither long (RR:1.00, 95%CI:0.90-1.11, P > 0.05) nor short (RR:0.99, 95%CI:0.94-1.05, P > 0.05) sleep duration had a significant association with increased hyperlipidemia risk in adults. However, long sleep duration was decidedly associated with low HDL-C (RR:0.19, 95%CI: - 0.03-0.40, P < 0.05) and high triglycerides (RR: - 0.20, 95%CI: - 0.43-0.03, P < 0.05) in children and adolescents.

CONCLUSION

Long sleep duration has strong associations with risks of low HDL-C and high triglycerides in children and adolescents. The mechanisms underlying this association deserves to be explored in future studies.

Development and initial validation of the nonalcoholic fatty liver disease self-management questionnaire

The prevalence of nonalcoholic fatty liver disease (NAFLD) is increasing, and self-management is essential to improve health outcomes in this population. Despite the importance of self-management, there is no instrument to assess it in patients with NAFLD. The purpose of this study was to develop and validate an initial version of a self-management questionnaire for patients with NAFLD. This was a methodological and psychometric study conducted between April and November 2019. The NAFLD self-management questionnaire was developed after a theoretical and literature review and focus group interviews in three phases: (1) item generation, (2) item evaluation, and (3) psychometric evaluation. Participants (N = 155) were recruited from a hospital in Seoul, South Korea. Items were generated based on clinical NAFLD guidelines and the individual and family self-management theory. Construct validity was assessed using exploratory factor analysis. Six-factors were extracted from 22 items: lifestyle management, medical treatment compliance, management of medication and dietary supplements, alcohol consumption management, sleep management, and family support. These factors accounted for 67.4% of the total variance; each factor had an eigenvalue greater than 1, and Cronbach's alpha for the scale was 0.87. The NAFLD self-management questionnaire showed acceptable initial validity and reliability. The instrument can prove useful in the formulation of tailored interventions based on individual patients' care needs. Furthermore, it may be used as an indicator of health outcomes in this population.

The association of nighttime sleep duration and quality with chronic kidney disease in middle-aged and older Chinese: a cohort study

OBJECTIVE

This cohort study aimed to assess the associations between sleep duration and quality with the risk of incident chronic kidney disease (CKD) in middle-aged and older Chinese.

METHODS

We used the 2011 and 2015 surveys of the China Health and Retirement Longitudinal Study (CHARLS). Nighttime sleep duration was categorized into five groups: ≤4, (4-6], (6-8], (8-10], and >10 h/night. Sleep quality was assessed by restless days in the past week (<1, 1-2, 3-4, and 5-7 days/week). Multivariate logistic regression was used to assess the association between sleep duration and quality with incident CKD.

RESULTS

A total of 11,339 participants free of CKD at baseline were included in this study. After four years follow-up, the incidence of CKD was 7.8%. There was a "U-shaped" association between sleep duration and risk of CKD. Compared to 6-8 h of nighttime sleep duration, those who slept ≤4 h/night (RR: 1.639, 95% CI: 1.287-2.087) or >10 h/night (RR: 2.342, 95% CI: 1.007-5.451) had increased risk of developing CKD after adjustment for confounders. Participants with 5-7 restless days per week had significantly increased risk of CKD (adjusted RR: 1.686, 95% CI: 1.352-2.102), compared to those who rarely or never had a restless sleep.

CONCLUSIONS

Extreme nighttime sleep duration and poor sleep quality were associated with increased risk of CKD in middle-aged and older Chinese. Obtaining an optimal nighttime sleep duration and better sleep quality might reduce the risk of CKD.

Culturally-consistent diet among individuals of Mexican descent at the US-Mexico border is associated with sleep duration and snoring

BACKGROUND

Existing studies show that consuming food consistent with one's culture reduces cardiometabolic risk. However, few studies have assessed whether these dietary choices influence sleep health. Accordingly, this study assessed how Mexican food consumption by individuals of Mexican descent residing at the US-Mexico border, was associated with various measures of sleep, after accounting for acculturation.

METHODS

Data were provided by 100 adults between the ages of 18-60, in the city of Nogales, AZ. Questionnaires were provided in either Spanish or English. Acculturation was assessed with the Acculturation Scale for Mexican-Americans (ARSMA-II), with an additional question, asking how often "my family cooks Mexican foods." Frequency of cooking Mexican food was coded as either "yes" or "no." Sleep was assessed, using validated measures that include the Insomnia Severity Index (ISI), the Epworth Sleepiness Scale (ESS), the Pittsburgh Sleep Quality Index (PSQI), and sleep duration with the item "how many hours of actual sleep did you get at night?" Regression models estimated the associations between sleep health variables as outcomes and consumption of Mexican food as the independent variable. Covariates included age, sex, and acculturation scores. Parental education level was also included, as an indicator of childhood socioeconomic status and since food culture likely involves parents.

RESULT

We found that among individuals who identified as Mexican-Americans who consumed culturally-consistent foods, was associated with, on average, 1.41 more hours of sleep (95% CI 0.19, 2.62; p = 0.024) and were less likely to report snoring (OR: 0.25; 95% CI 0.07, 0.93; p = 0.039). Consuming Mexican food was not associated with sleep quality, insomnia severity or sleepiness.

CONCLUSION

Individuals of Mexican descent residing at the US-Mexico border who regularly consumed Mexican food, reported more sleep and less snoring. Mexican acculturation has been shown previously to improve sleep health. This is likely due to consumption of a culturally- consistent diet. Future studies should examine the role of acculturation in sleep health, dietary choices, and subsequent cardiometabolic risk.

Association between health behaviours and cardiometabolic dysregulation: a population-based survey among healthy adults in Hong Kong

OBJECTIVE

To explore the association between cardiometabolic dysregulation, an integral component of allostatic load, and health risk behaviours (HRBs) of the Hong Kong healthy adult population.

DESIGN

Secondary analysis of cross-sectional anonymous data.

SETTING

Data on sociodemographics, self-reported health status, HRBs and biomarkers were extracted from the Hong Kong Population Health Survey 2014/2015.

PARTICIPANTS

One thousand five hundred and fifty-one participants aged 18-64 years without self-reported diagnoses of hypertension, diabetes mellitus, hyperlipidaemia, cardiovascular disease, cognitive impairment or cancer.

PRIMARY OUTCOME MEASURES

Cardiometabolic dysregulation index (CMDI), ranging from 0 to 6, was calculated by counting the number of biomarkers including systolic blood pressure, diastolic blood pressure, waist to hip ratio, glycated haemoglobin, total cholesterol to high-density lipoprotein cholesterol ratio, and triglycerides that were above the respective normal level suggested by international guidelines and literature. HRBs including smoking, dietary habits and sleeping hours were collected by self-report questionnaire. Alcohol consumption was assessed by the 10-item Alcohol Use Disorders Identification Test, while physical activity level was measured using the Global Physical Activity Questionnaire. A composite HRB score, ranging from 0 to 5, was calculated as the cumulative number of HRBs. The effect of HRB on CMDI was evaluated by negative binomial regression with adjustment for socioeconomic status, health awareness and comorbidities of the participants.

RESULTS

The mean CMDI of the studied population was 1.6; 29.5% had a CMDI of 0, whereas 1.5% had a CMDI of 6. Significant difference was observed in mean CMDI between gender and different age groups. Sleeping less than 6 hours (incidence rate ratio (IRR)=1.26, p<0.001), smoking (IRR=1.15, p=0.027), insufficient physical activity (IRR=1.12, p=0.007) and higher composite HRB score (IRR=1.12, 95% CI 1.06 to 1.18) were significantly associated with higher CMDI.

CONCLUSION

Smoking, physical inactivity and inadequate sleep-an essential yet often overlooked health behaviour-were associated with higher CMDI in the Hong Kong healthy adult population.

Sleep duration, vegetable consumption and all-cause mortality among older adults in China: a 6-year prospective study

BACKGROUND

Sleep duration and vegetable consumption are associated with mortality at old age (termed as sleep-mortality linkage and vegetable-mortality linkage, respectively). Yet, little is known about the interplay of sleep duration and vegetable consumption on mortality.

METHODS

A dataset of nationwide longitudinal survey with 13,441 participants aged 65 years or older recruited in 2008 and followed up till 2014 was used. Sleep duration was classified into five groups (≤5, 6, 7-8, 9, and ≥ 10 h/day). Vegetable consumption was classified as either high frequency (eating vegetables almost daily) or low frequency. We used parametric Weibull hazard regression models to estimate associations of sleep duration and frequency of vegetable consumption with mortality, adjusting for demographics, socioeconomic factors, family/social support, health practice, and health conditions.

RESULTS

Over the six-year study period, when only demographics were present, participants sleeping ≤5, 6, 9, and ≥ 10 h/day had relative hazard (RH) of mortality 1.18 (p < 0.001), 1.14(p < 0.01), 1.06 (p > 0.1), and 1.30 (p < 0.001), respectively, compared to those sleeping 7-8 h/day. The HRs were attenuated to 1.08 (p < 0.05), 1.08 (p < 0.05), 1.09 (p < 0.1), 1.18(p < 0.001), respectively, when all other covariates were additionally adjusted for. High frequency of eating vegetables was associated with 22% lower risk of mortality (RH= 0.78, p < 0.001) compared to low frequency in the demographic model, and with 9% lower risk (RH = 0.91, p < 0.05) in the full model. Subpopulation and interaction analyses show that the sleeping-mortality linkage was stronger in female, urban, oldest-old (aged ≥80), and illiterate participants compared to their respective male, rural, young-old, and literate counterparts. High frequency of vegetable intakes could offset the higher mortality risk in participants with short-sleeping duration, but low frequency of eating vegetables could exacerbate mortality risk for participants with either short or long sleep duration; and except for few cases, these findings held in subpopulations.

CONCLUSIONS

Too short and too long sleep durations were associated with higher mortality risk, and infrequent vegetable consumption could exacerbate the risk, although frequent vegetable intake could offset the risk for short sleep duration. The relationship between these two lifestyles and mortality was complex and varied among subpopulations.

Daytime Napping and Nighttime Sleep Duration with Incident Diabetes Mellitus: A Cohort Study in Chinese Older Adults

Background: We aimed to examine the longitudinal associations between daytime napping and nighttime sleep duration with the risk of diabetes mellitus (DM) among Chinese elderly using data from the China Health and Retirement Longitudinal Study (CHARLS). Methods: A cohort study was conducted among 2620 participants aged 60 years or above. Information on daytime napping and nighttime sleep duration was self-reported during the 2011 baseline survey. DM status during the 2015 follow-up survey was confirmed according to the American Diabetes Association criteria. Results: Individuals with long daytime napping (>1 h/day) had increased risk of developing DM than non-nappers (adjusted RR = 1.52, 95%CI: 1.10, 2.10). In addition, we observed a U-shaped association between nighttime sleep duration and incident DM risk. We further found that nappers with <4 h of nighttime sleep, and those with >1 h of daytime napping and >6 h nighttime sleep had approximately two-fold elevated risk of DM, compared to non-nappers with 6–8 h of nighttime sleep. Conclusion: Long daytime napping and extreme nighttime sleep duration were associated with increased DM risk among Chinese elderly. There was a joint effect of long daytime napping and nighttime sleep duration on the risk of DM.

Associations of midpoint of sleep and night sleep duration with type 2 diabetes mellitus in Chinese rural population: the Henan rural cohort study

Background

The study aimed to investigate the independent and combined effects of midpoint of sleep and night sleep duration on type 2 diabetes mellitus (T2DM) in areas with limited resources.

Methods

A total of 37,276 participants (14,456 men and 22,820 women) were derived from the Henan Rural Cohort Study. Sleep information was assessed based on the Pittsburgh Sleep Quality Index. Logistic regression models and restricted cubic splines were used to estimate the relationship of the midpoint of sleep and night sleep duration with T2DM.

Results

Of the 37,276 included participants, 3580 subjects suffered from T2DM. The mean midpoint of sleep among the Early, Intermediate and Late groups were 1:05 AM ±23 min, 1:56 AM ±14 min, and 2:57 AM ±34 min, respectively. Compared to the Intermediate group, adjusted odds ratios (ORs) and 95% confidence interval (CI) of T2DM were 1.13 (1.04–1.22) and 1.14 (1.03–1.26) in the Early group and the Late group. Adjusted OR (95% CI) for T2DM compared with the reference (7- h) was 1.28 (1.08–1.51) for longer (≥ 10 h) night sleep duration. The combination of late midpoint of sleep and night sleep duration (≥ 9 h) increased 38% (95% CI 10–74%) prevalence of T2DM. These associations were more obvious in women than men.

Conclusions

Late and early midpoint of sleep and long night sleep duration were all associated with higher prevalence of T2DM. Meanwhile, midpoint of sleep and night sleep duration might have combined effects on the prevalence of T2DM, which provided potential health implications for T2DM prevention, especially in rural women.

Trial registration

The Henan Rural Cohort Study has been registered at Chinese Clinical Trial Register (Registration number: ChiCTR-OOC-15006699). Date of registration: 2015-07-06.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10833-6.

Impact of Sleep Duration on Mortality and Quality of Life in Chronic Kidney Disease: Results from the 2007-2015 KNHANES

INTRODUCTION

In the general population, short and long sleep durations have been associated with adverse health outcomes. However, this association remains unclear in patients with chronic kidney disease (CKD). We examined the relationship of sleep duration to mortality and health-related quality of life (HRQOL) in individuals with CKD.

METHODS

A total of 1,783 adults with CKD who participated in the 2007-2015 Korea National Health and Nutrition Examination Survey were analyzed. CKD was defined as an estimated glomerular filtration rate of <60 mL/min per 1.73 m2. Participants were categorized into 3 groups according to self-reported sleep duration: <6 h (short sleepers), 6-8 h, and >8 h (long sleepers). The outcome variables were all-cause mortality and HRQOL. HRQOL was assessed using the European Quality of Life-5 Dimensions (EQ-5D) index.

RESULTS

During a median of 6.4 years, 481 (27%) deaths occurred. In unadjusted Cox regression analysis, long sleepers with CKD had an increased risk of death (hazard ratio [HR], 1.62; 95% confidence interval [CI]: 1.26-2.09). This significant association remained after adjusting for age, sex, and BMI (HR, 1.36; 95% CI: 1.05-1.75); however, it was lost after adjusting for CKD stage, social and lifestyle factors, and presence of comorbidities (HR, 1.15; 95% CI: 0.89-1.49). Compared with 6- to 8-h sleepers with CKD, long sleepers with CKD had significantly worse HRQOL in multivariable linear regression models. The adjusted means of the EQ-5D index were 0.80 (95% CI: 0.77-0.82) for short sleepers, 0.81 (95% CI: 0.80-0.82) for 6- to 8-h sleepers, and 0.76 (95% CI: 0.73-0.79) for long sleepers (p = 0.01).

DISCUSSION/CONCLUSION

Long sleep duration is associated with poor HRQOL in Korean adults with CKD. The weak association between long sleep duration and mortality was attenuated after multivariable adjustment in this study.

Maternal sleep duration and neonatal birth weight: the Japan Environment and Children's Study

BACKGROUND

The adequate maternal sleep duration required for favorable obstetric outcomes is unknown. We evaluated the association between maternal sleep duration and low birth weight infants, small for gestational age infants, and macrosomia.

METHODS

Participants enrolled in the Japan Environment and Children's Study, a nationwide birth cohort study, with singleton pregnancies after 22 weeks, who gave birth between 2011 and 2014 were enrolled and categorized into five groups according to maternal sleep duration during pregnancy: < 6.0 h, 6.0-7.9 h, 8.0-8.9 h, 9.0-9.9 h, and 10.0-12.0 h. We evaluated the association between maternal sleep duration and the incidence of low birth weight infants (< 2500 g), very low birth weight infants (< 1500 g), small for gestational age infants, and macrosomia (> 4000 g), with women with maternal sleep duration of 6.0-7.9 h as the reference, using a multiple logistic regression model.

RESULTS

In total, 82,171 participants were analyzed. The adjusted odds ratios (95% confidence intervals) for low birth weight infants in women with maternal sleep duration of 9.0-9.9 h and 10.0-12.0 h and for small for gestational age infants in women with maternal sleep duration of 9.0-9.9 h were 0.90 (0.83-0.99), 0.86 (0.76-0.99), and 0.91 (0.82-0.99), respectively, before adjusting for excessive gestational weight gain. No significant association was observed between maternal sleep duration and these outcomes after adjusting for excessive gestational weight gain. Among women with appropriate gestational weight gain, the adjusted odds ratios (95% confidence intervals) for low birth weight infants and for small for gestational age infants with sleep duration of 9.0-9.9 h were 0.88 (0.80-0.97) and 0.87 (0.78-0.97), respectively.

CONCLUSIONS

Maternal sleep duration of 9.0-9.9 h was significantly associated with the decreased incidence of low birth weight infants and small for gestational age infants in pregnant women with appropriate gestational weight gain, compared with that of 6.0-7.9 h. Care providers should provide proper counseling regarding the association between maternal sleep duration and neonatal birth weight and suggest comprehensive maternal lifestyle modifications to prevent low birth weight and small for gestational age infants.

The Role of Sleep Curtailment on Leptin Levels in Obesity and Diabetes Mellitus

Emerging evidence has identified sleep as a significant, but modifiable, risk factor for metabolic syndrome, diabetes, and obesity. Leptin, an adipocyte-derived peptide and a regulator of food intake and energy expenditure, has been shown to be associated with a short sleep duration in the pathophysiology of obesity and consequently type 2 diabetes. This review focuses on the current evidence indicating the effects of a short sleep duration on the regulation of leptin concentration in association with obesity and diabetes mellitus. In summary, the evidence suggests that sleep deprivation, by affecting leptin regulation, may lead to obesity and consequently development of type 2 diabetes through increased appetite and food intake. However, findings on the role of leptin in diabetes due to sleep deprivation are contradictory, and further studies with larger sample sizes are needed to confirm previous findings.

Distinct Relevance of Nightly Sleep Duration to Metabolic, Anthropometric, and Lifestyle Factors in Patients with Type 2 Diabetes

Objective Although a number of studies have shown that both short and long sleep durations were associated with the risk of metabolic disorders related to obesity, the underlying mechanism is still not fully understood. In this study, we analyzed the association of sleep duration with metabolic, anthropometric, and lifestyle factors in patients with type 2 diabetes. Methods The subjects were 279 patients with type 2 diabetes 63 (52-70) years old (median and interquartile range) with a body mass index of 25.0 (22.2-28.3) kg/m² and HbA1c levels of 8.7% (7.6-10.3%). Patients with advanced complications were excluded from the study. Diets were evaluated by registered dietitians using a software program. Body composition was assessed by the multifrequency bioelectrical impedance method. Results The mean self-reported nightly sleep duration was 6.4 hours with no marked gender difference. Sleep duration was inversely correlated with the HbA1c levels, total energy intake, and intakes of carbohydrate, protein, and fat. The body fat ratio and skeletal muscle mass were correlated positively and negatively, respectively, with sleep duration. When the subjects were divided into three groups based on sleep duration, the intakes of total energy, carbohydrates, and fat tended to be high in those with <5.5 hours of sleep, and the percentage of patients who had habitual physical activities was lower in those with >7 hours of sleep. Conclusion The observation that sleep duration is distinctly associated with excessive eating and a sedentary lifestyle may provide a basis for effective lifestyle management of patients with type 2 diabetes.

Association between sleep duration and asthma in different weight statuses (CHNS 2009-2015)

PURPOSE

Inadequate sleep duration affects asthma and weight. The associations among sleep duration, asthma, and different weight statuses in the Chinese population need to be further determined.

METHODS

The study included 32,776 Chinese adults from the China Health and Nutrition Survey during 2009-2015. Self-reported sleep duration was classified into three groups: ≤ 6 h (short), 7 to 8 h (optimal), and ≥ 9 h (long). Age, sex, smoking, drinking alcohol, and residence location were adjusted as potential confounding factors in a generalized estimating equations model.

RESULTS

The prevalence of asthma in the Chinese population was approximately 1.17% (383/32,776). Asthmatics were associated with shorter sleep duration and higher indices of central obesity (mean waist circumference, waist to height ratio, and conicity index) than the population without asthma. After adjusting for potential confounding factors, odds ratios (ORs) indicated positive associations between sleep duration and asthma (short vs optimal, adjusted OR = 1.74, 95%CI 1.33, 2.26; and long vs optimal, adjusted OR = 1.51, 95%CI 1.18, 1.93). When stratified by weight status, the participants with central obesity showed highest prevalence of asthma among the three sleep duration groups. With the adjustment of confounding factors, underweight and obesity grouped by waist to height ratio and conicity index remained associated with higher risk of asthma among short and long sleepers than in optimal sleepers.

CONCLUSIONS

Short and long sleepers with central obesity and underweight status were associated with significantly higher prevalence of asthma than optimal sleepers in Chinese adults.

Associations Between Self-Reported Sleep Duration and Mortality in Employed Individuals: Systematic Review and Meta-Analysis

OBJECTIVE

Sleeping less or more than the 7-8 h has been associated with mortality in the general population, which encompasses diversity in employment status, age and community settings. Since sleep patterns of employed individuals may differ to those of their unemployed counterparts, the nature of their sleep-mortality relationship may vary. We therefore investigated the association between self-reported sleep duration and all-cause mortality (ACM) or cardiovascular disease mortality (CVDM) in employed individuals.

DATA SOURCES

Based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses, searches between January 1990 and May 2020 were conducted in PubMed, Web of Science and Scopus. Inclusion/exclusion criteria: Included were prospective cohort studies of 18-64-year-old disease-free employed persons with sleep duration measured at baseline, and cause of death recorded prospectively as the outcome. Gray literature, case-control or intervention design studies were excluded.

DATA EXTRACTION

Characteristics of the studies, participants, and study outcomes were extracted. The quality and risk of bias were assessed using the Newcastle-Ottawa Scale.

DATA SYNTHESIS

The pooled relative risks (RR) with 95% confidence intervals (CI) were obtained with a random-effects model and results presented as forest plots. Heterogeneity and sensitivity analysis were assessed.

RESULTS

Shorter sleep duration (≤6 h) was associated with a higher risk for (ACM) (RR: 1.16, 95% CI: 1.11 -1.22) and CVDM (RR: 1.26, 95% CI: 1.12 -1.41) compared to 7-8 h of sleep, with no significant heterogeneity. The association between longer sleep (≥8 h) and ACM (RR: 1.18, 95% CI:1.12 -1.23, P < 0.001) needs to be interpreted cautiously owing to high heterogeneity (I² = 86.0%, P < 0.001).

CONCLUSION

Interventions and education programs targeting sleep health in the workplace may be warranted, based on our findings that employed individuals who report shorter sleep appear to have a higher risk for ACM and CVDM.

Associations of short sleep duration with appetite-regulating hormones and adipokines: A systematic review and meta-analysis

In the current study, a systematic review and meta-analysis were conducted to summarize and assess whether short sleep duration is associated with appetite-regulating hormones and adipokine levels. Reference databases were searched for studies related to sleep and appetite-regulating hormones and adipokines. Qualitative and quantitative syntheses were conducted to evaluate the relationship between sleep duration and the level of appetite-regulating hormones and adipokines, including leptin, ghrelin, adiponectin, resistin, and orexin. Twenty-one of 3536 studies, covering a total of 2250 participants, met the inclusion criteria. Leptin, ghrelin, and adiponectin were included in the meta-analysis. Ghrelin levels were higher in the short sleep group (standard mean difference [SMD] = 0.14, 95% CI [0.03, 0.25], p = 0.01). Significant differences between the short sleep group and recommended sleep group were also noted in leptin level experimental subgroup studies (SMD = 0.19, 95% CI [0.03, 0.35], p = 0.02) and ghrelin level cross-sectional subgroup studies (SMD = 0.14, 95% CI [0.02, 0.27], p = 0.03). A rise in leptin and ghrelin levels were also observed in sleep deprivation groups (SMD = 0.24, 95% CI [0.10, 0.39], p = 0.001 and SMD = 0.18, 95% CI [0.04, 0.33], p = 0.01, respectively). In conclusion, short sleep duration is associated with an increased ghrelin level, while sleep deprivation had a significant effect on the levels of both leptin and ghrelin.

Insufficient nocturnal sleep was associated with a higher risk of fibrosis in patients with diabetes with metabolic associated fatty liver disease

BACKGROUND

Metabolic associated fatty liver disease (MAFLD) refers to metabolic dysfunction associated with fatty liver disease, and liver fibrosis stage is closely connected with liver-related and all-cause mortality. This study aimed to explore the association of sleep duration with liver fibrosis in the diabetic subgroup of the MAFLD population.

METHODS

This retrospective study analyzed 342 patients with MAFLD. Anthropometric measurements, clinical and biochemical markers, and lifestyle parameters were collected. Fibrosis was defined as fibrosis-4 ⩾1.3. Propensity score matching (PSM) was performed to match cases. Student's t-test and chi-square tests were applied for group comparisons, and binary regression models were used to explore the independent risk factors of liver fibrosis.

RESULTS

Among the 342 subjects, 87 (25.4%) were diagnosed with fibrosis and 255 (74.6%) without. Baseline characteristic comparisons showed differences in age and diabetes duration between the two groups, and adjustment was made by PSM. Ultimately, the fibrosis group and nonfibrosis group each had 87 patients. The fibrosis group had shorter duration of nocturnal sleep (6.77 ± 1.59 h) than the nonfibrosis group (7.77 ± 1.92 h, p < 0.001). More patients in the fibrosis group stayed up late at night (32.2% versus 14.9%, p < 0.01). Visceral adipose tissue (VAT) areas were larger in the fibrosis group than in the nonfibrosis group (p < 0.001). Glycemic profile, lipid profile, gamma-glutamyl transferase level, and serum uric acid level were not significantly different between the two groups. In the multivariate regression analysis, nocturnal sleep and VAT areas were independently associated with liver fibrosis, with odds ratios of 0.694 [95% confidence interval (CI) 0.551-0.875, p < 0.01] for nocturnal sleep and 1.031 (95% CI 1.014-1.048, p < 0.001) for VAT areas.

CONCLUSION

Insufficient nocturnal sleep was independently related to a higher risk of fibrosis. Sleep modification might be beneficial in promoting the health of patients with MAFLD.

Night sleep duration and risk of each lipid profile abnormality in a Chinese population: a prospective cohort study

Background

To explore the associations between sleep duration and abnormalities in serum lipid levels in a Chinese population.

Methods

A prospective study was conducted with 34,260 participants from the general Chinese population. Sleep duration was categorized as ≤5, 6, 7, 8 or ≥ 9 h. Each lipid profile abnormality was defined according to the Chinese Guidelines for the Prevention and Treatment of Dyslipidemia in Adults (2016). The Cox proportional hazards model was used to assess the association between sleep duration and dyslipidemia.

Results

Compared with a 7 h sleep duration, long sleep duration (≥9 h) was significantly associated with low high-density lipoprotein cholesterol (HDL-C) levels (hazard ratio (HR): 1.24; 95% CI: 1.12–1.38). In subgroup analyses, the positive association between long sleep duration and low HDL-C level in men and in the different age groups was more pronounced than the association in women. No significant interactions were observed in the association between sleep duration and each abnormal serum lipid level by sex/age in the study population (P-interaction> 0.05).

Conclusions

These findings suggest that long sleep duration is associated with low HDL-C level among the Kailuan community population.

Sleep characteristics and HbA1c in patients with type 2 diabetes on glucose-lowering medication

INTRODUCTION

To examine the association of sleep duration, insomnia, and obstructive sleep apnea (OSA) with hemoglobin A1c (HbA1c) in a cohort of patients with type 2 diabetes (T2D) on glucose-lowering medications.

RESEARCH DESIGN AND METHODS

13 346 patients with T2D were included in the present analysis (mean age: 60.2 years; 56.6% were on antidiabetic drug monotherapy; 43.4% received at least two glucose-lowering medications). Sleep duration (short: ≤6 hours/day; normal: 7-8 hours/day; long: ≥9 hours/day) and frequency of insomnia symptoms were self-reported. The risk of OSA was considered high if at least two of the following conditions were fulfilled: regular snoring, frequent daytime sleepiness, and either obesity (≥30 kg/m²) or hypertension (systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg). Associations between sleep variables and HbA1c were investigated by analysis of covariance or linear regression (adjusted for, eg, participants' age, sex, ethnic background, and systolic blood pressure).

RESULTS

Long sleep duration and a high risk for OSA were independently associated with higher HbA1c values (long vs normal sleep duration: +0.10% (95% CI 0.03 to 0.18); high vs low risk for OSA: +0.07% (95% CI 0.02 to 0.11), both p=0.004). No robust association was found of short sleep duration and frequent insomnia symptoms with HbA1c. Finally, a positive dose-response association between the number of sleep problems per subject (range: 0-3) and HbA1c was observed (β=0.04% (0.02 to 0.06), p=0.002). However, all significant associations were small.

CONCLUSION

Screening for and treatment of sleep problems may help lower HbA1c levels in patients with T2D on glucose-lowering medications.

Sleep Disorders in Individuals With High Risk for Diabetes in Indian Population

Background:

Sleep restores physiology and neurochemical components of our body and is essential for physical and mental health. Sleep disorders (SDs) are associated with insulin resistance and metabolic disorders. The association between SDs and diabetes needs to be understood in the Indian population.

Purpose:

The purpose was to investigate the association between SD and diabetes in the Indian population.

Methods:

As a part of nationwide Niyantrita Madhumeha Bharata Abhiyaan-2017 (NMB-2017), a cross-sectional study was conducted and data was collected from seven zones of India, after screening through the Indian Diabetes Risk Score (IDRS). The sleep quality was assessed on a scale of 1 to 4 (very good = 1, very bad = 4). The time taken to fall asleep (sleep latency) was assessed on a scale of 0 to 5 (“0” = nil and “5” = >1.5 h). Stress was assessed by the perceived stress scale.

Results:

Bad sleep quality was positively (odds ratio 1.055, CI [1.001, 1.113], and P < .01) associated with self-reported known diabetes. Increased time taken to fall in sleep (sleep latency) was associated significantly with IDRS high risk (odds ratio 1.085, CI [1.008, 1.168], and P = .01), with an average sleep latency /time takes to fall in sleep (maximum range 5 [>1.5 h], mode 2 [10 to 30 min]) minutes. Moderate stress was significantly associated with bad sleep quality (odds ratio 1.659).

Conclusion:

A positive association of bad sleep quality and stress with diabetes, and an increased sleep latency in the IDRS high-risk population point to the role of modifiable risk factors. Behavioral modification and stress reduction by using yoga may be beneficial in the better management of diabetes.

Behavioral Circadian Timing System Disruptors and Incident Type 2 Diabetes in a Nonshift Working Multiethnic Population

OBJECTIVE

This study aimed to describe distributions of behavioral circadian disruptors in a free-living setting among a nonshift working multiethnic population, estimate the associated risk of type 2 diabetes (T2D), and determine whether disruptors account for ethnic differences in T2D.

METHODS

Participants from six ethnic groups were included (Amsterdam, the Netherlands; n = 1,347-3,077 per group). Multinomial logistic regression was used to estimate ethnic differences in disruptors, such as skipping breakfast, eating erratically, and sleep duration. Associations between disruptors and incident T2D and the interaction by ethnicity were studied by Cox regression.

RESULTS

Ethnic minority populations skipped breakfast more often, timed meals differently, had longer periods of fasting, ate more erratically, and had more short/long sleep durations than the Dutch. Night snacking from 4 am to 6 am (HR: 5.82; 95% CI: 1.42-23.91) and both short (HR: 1.48; 95% CI: 1.03-2.12) and long sleep (HR: 3.09; 95% CI: 1.54-6.22), but no other disruptors, were associated with T2D. The higher T2D risk among ethnic minority populations compared with Dutch did not decrease after adjustment for last snack or length of sleep.

CONCLUSIONS

Although prevalence of circadian disruptors was higher among ethnic minority populations and some disruptors were associated with T2D, disruptors did not account for ethnic differences in T2D risk.

A Protocol for Comparing Dry and Wet EEG Electrodes During Sleep

Background

Sleep is commonly assessed by recording the electroencephalogram (EEG) of the sleeping brain. As sleep assessments in a lab environment are cumbersome for both the participant and researcher, it would be highly desirable to record sleep EEG with a user-friendly and mobile device. Dry electrodes that are reusable, low-cost, and easy to apply would be an essential component of such a device. In this study, we developed a testing protocol to investigate the performance of novel flat-type dry electrodes for sleep EEG recordings in free-living conditions.

Methods

Overnight sleep EEG, electrooculogram and electromyogram of four young and healthy participants were recorded at home. Two identical ambulatory recording devices, one using novel flat-type dry electrodes, the other using self-adhesive pre-gelled electrodes, simultaneously recorded sleep EEG. Between both electrode types, we then compared the signal quality, the incidence of artifacts, the sensitivity, specificity and inter-scoring reliability (Cohen’s kappa) of sleep staging, as well as the agreement of important characteristics of sleep-specific EEG microstructure features, such as slow waves (0.5–4 Hz) and sleep spindles (10–16 Hz).

Results

Our testing protocol comprehensively compared the two electrode types on a macro- and microstructure level of sleep. The dry and pre-gelled electrodes both had comparable signal quality and sleep staging was feasible with both electrodes. Also, slow-wave and spindle characteristics were similar. However, sweat artifacts were more prevalent in the flat-type dry electrodes.

Conclusion

With a reliable testing protocol, the performance of dry electrodes can be compared to reference technologies and objectively assessed also in free-living conditions.

Self-reported sleep duration is associated with time in work physical activity but not transportation or leisure physical activity among Hispanic/Latino adults in the U.S.: results from the Hispanic Community Health Study/Study of Latinos

OBJECTIVES

The objective of this study is to test the hypothesis that short sleep duration is associated with fewer minutes of transportation, work, and leisure physical activity (PA).

DESIGN

This is a cross-sectional study conducted from 2008 to 2011.

SETTING

The study setting included four sites across the U.S. (Bronx, NY; Chicago, IL; Miami, FL; San Diego, CA).

PARTICIPANTS

A total of 14,653 Hispanic/Latino adults aged 18-74 years were enrolled as participants for the study.

MEASUREMENTS

Respondents reported sleep duration and transportation (including walking and cycling), work (including volunteering, paid work, and household chores), and leisure (including sports) PA domains and sociodemographic characteristics, other sleep characteristics, cardiometabolic health, health behaviors, and depressive symptoms.

RESULTS

In analyses weighted to reflect the Hispanic/Latino population of the four cities sampled, 61% had sleep duration 7-9 hours, 19% each had sleep duration < 7 hours and > 9 hours. Those sleeping < 7 hours spent 106 minutes/day in work-related PA, compared with those who spent fewer than 40 minutes/day in transportation-related or leisure-related PA. Sleep duration < 7 hours was associated with 26 minutes more in work-related PA (95% confidence interval [CI]: 16.7, 36.0), compared with sleep duration of 7-9 hours, adjusting for age and sex. Results were similar in employed respondents only, adjusting for occupation class and shift work frequency. Sleep duration was not associated with transportation-related or leisure-related PA.

CONCLUSIONS

Short sleep duration is associated with more work-related PA, both in the overall sample and among those employed. Individuals with higher work-related PA may face multiple demands and stressors that negatively influence sleep duration.

Poor Sleep Hygiene is Associated with Decreased Discrimination and Inattention on Continuous Performance Task in Doctor of Physical Therapy Students: A Cross-sectional Study

Introduction

Reduced sleep quality impairs learning, memory formation, attention, and executive function ability. Poor sleep quality or sleep hygiene has been shown to impair academic performance of undergraduate and medical students. The purpose of this study was to examine the association between sleep quality, sleep hygiene, and cognitive performance in Doctor of Physical Therapy (DPT) students.

Methods

Fifty DPT students at the University of Kansas Medical Center completed the Pittsburgh Sleep Quality Index (PSQI) and the Sleep Hygiene Index (SHI). Cognitive performance was assessed using the Continuous Performance Test (CPT) which is a test of sustained attention and the Trail-Making Task (TMT) to assess executive functioning. An actigraph was worn for one week to objectively characterize sleep outcomes. Spearman's correlations were performed to assess the association between self-report sleep quality, sleep hygiene, and outcomes on the cognitive tasks. Post-hoc Mann-Whitney and Kruskal-Wallis tests were conducted to examine group differences between sleep outcomes and cognitive performance for demographic variable categories.

Results

Twenty-three students (46%) reported poor sleep quality, and 27 participants (54%) had objectively-reported poor sleep quality. There was a significant positive correlation between SHI and Detectability (r_s= 0.297, p= 0.036) and Omissions (r_s=.343, p=0.015). There were group differences between sex and number of pets on the CPT outcomes, and there was a significant group difference between the number of drinks/week categories on the SHI.

Discussion and Conclusions

About half of the participants were identified as having poor sleep quality. Poorer sleep hygiene was associated with poorer discrimination and inattention, which could potentially impact the students' academic and clinical performance as well as their health and wellbeing. Also, certain demographic variables may modulate the results.

Sleep Duration Patterns in Early to Middle Adulthood and Subsequent Risk of Type 2 Diabetes in Women

OBJECTIVE

To identify sleep duration trajectories from early to middle adulthood and their associations with incident type 2 diabetes.

RESEARCH DESIGN AND METHODS

Using a group-based modeling approach, we identified sleep duration trajectories based on sleep duration in ages 20-25, 26-35, 36-45, and 46+ years, which were retrospectively assessed in 2009 among 60,068 women from the Nurses' Health Study II (median age 54.9 years) who were free of diabetes, cardiovascular disease, and cancer. We investigated the prospective associations between sleep duration trajectories and diabetes risk (2009-2017) using multivariable Cox proportional hazards models.

RESULTS

We documented 1,797 incident diabetes cases over a median follow-up of 7.8 years (442,437 person-years). Six sleep duration trajectories were identified: persistent 5-, 6-, 7-, or 8-h sleep duration and increased or decreased sleep duration. After multivariable adjustment for diabetes risk factors, compared with the persistent 7-h sleep duration group, the hazard ratio was 1.43 (95% CI 1.10, 1.84) for the 5-h group, 1.17 (1.04, 1.33) for the 6-h group, 0.96 (0.84, 1.10) for the 8-h group, 1.33 (1.09, 1.61) for the increased sleep duration group, and 1.32 (1.10, 1.59) for the decreased sleep duration group. Additional adjustment for time-updated comorbidities and BMI attenuated these associations, although a significantly higher risk remained in the decreased sleep duration group (1.24 [1.03, 1.50]).

CONCLUSIONS

Persistent short sleep duration or changes in sleep duration from early to middle adulthood were associated with higher risk of type 2 diabetes in later life. These associations were weaker after obesity and metabolic comorbidities were accounted for.

The Association Between Sleep Duration, Asthma-Related Episodes/Attacks and Emergency Department Visits

BACKGROUND

Inadequate sleep duration potentially increases the risk of allergic asthma; yet, the effect of different sleep duration on asthma-related episodes/attacks and emergency department (ED) visits has remained unclear. The purpose of this study is to evaluate the association between sleep duration, asthma-related episodes/attacks and ED visits.

METHODS

This study included 1526 asthma participants from the Behavioral Risk Factor Surveillance System Questionnaire during 2013-2017. Self-reported sleep duration was classified into three groups: ≤6 h (short), 7 h to 8 h (optimal) and ≥9 h (long). Generalized additive model with binomial or Poisson regression was used to complete all statistical analyses.

RESULTS

During a 12-month period, 857 participants reported acute episodes/attacks of asthma, and 279 participants reported asthma-related ED visits. Asthmatics with ED visits harbored significantly lower mean sleep duration (6.50 h vs 7.01 h, adjusted OR=0.93, 95% CI: 0.88-0.98) than those without episodes/attacks. After adjusting the potential confounding factors, the participants with long sleep duration were associated with lower risk of asthma-related episodes/attacks (adjusted OR=0.59, 95% CI: 0.41-0.86) than those with short sleep duration. The prevalence (adjusted OR=0.67, 95% CI: 0.47-0.94) and frequency (adjusted OR=0.83, 95% CI: 0.69-0.9996) of asthma-related ED visits among short sleepers were significantly higher than that among optimal sleepers. The differences of asthma-related episodes/attacks and ED visits between long and optimal sleepers were statistically insignificant.

CONCLUSION

Our study demonstrated that asthmatics with short sleep duration were associated with highest prevalence of asthma-related episodes/attacks and ED visits among the three sleep duration groups.

Associations between self-reported sleep duration and cardiometabolic risk factors in young African-origin adults from the five-country modeling the epidemiologic transition study (METS)

OBJECTIVES

To investigate associations between self-reported sleep duration and cardiometabolic (CM) risk factors in African-origin adults residing in five countries spanning the epidemiologic transition.

DESIGN

Cross-sectional.

SETTING AND PARTICIPANTS

Ghanaian (n = 491), South African (n = 503), Jamaican (n = 508), Seychellois (n = 501) and American (n = 480) men and women.

MEASUREMENTS

Self-reported sleep duration was obtained using questionnaires. Sex- and site-stratified logistic regression analyses investigated relationships between sleep duration, individual CM risk factors and a binary CM risk variable (presence of ≥3 CM risk factors), adjusting for age, physical activity and education.

RESULTS

Sleep duration distributions varied by cohort: 44.5%, 41.4%, 35.9%, 16.8% and 2.5% of American, Jamaican, Seychellois, Ghanaian and South African men reported <7 h sleep per night respectively (p < 0.001). Similarly, 42.6%, 28.6%, 25.2%, 12.8% and 1.5% of American, Jamaican, Seychellois, Ghanaian and South African women reported <7 h sleep respectively (p < 0.001). American men reporting ≤6 h sleep were more likely to be in the elevated CM risk group (OR: 2.52, 95%CI: 1.02, 6.22, p = 0.045) and to have a high waist circumference (OR: 2.44, 95%CI: 1.07, 5.57, p = 0.034) compared to those reporting 8 h sleep. Jamaican women reporting ≤6 h sleep (OR: 2.53, 95%CI: 1.19, 5.36, p = 0.016) and American women reporting 7 h sleep (OR: 2.71, 95%CI: 1.17, 6.26, p = 0.002) were more likely to be obese than those reporting 8 h sleep.

CONCLUSIONS

Associations between short sleep and CM risk factors were only evident in the American men and women and Jamaican women. Future interventions to address CM risk and sleep health may need to be country-specific when targeting high-risk populations.

Relationship between Sleep Duration, Sun Exposure, and Serum 25-Hydroxyvitamin D Status: A Cross-sectional Study

Normal-range sleep duration is an important factor for general health and metabolism, and insufficient or excessive sleep is associated with chronic metabolic disease. Among the many factors that affect sleep duration, sun exposure plays an important role in maintaining regular circadian rhythm and is also involved in the production and activation of 25-hydroxyvitamin D [25(OH)D], which regulates various functions in the body. However, 25(OH)D is available through food and various nutritional supplements without sun exposure, so it is important to find out the complex relationship among sun exposure, vitamin D status, and sleep duration. The relationship between sun exposure, vitamin D status, and sleep duration was analyzed in the nationwide survey and examination of 25,534 study populations, after adjusting for demographic characteristics, physical characteristics, lifestyle status, and socio-demographic variables. Vitamin D status alone did not show the relationship with sleep duration, although there were statistical relationships in the various factors including sun exposure with sleep duration. There was a statistical difference in 25(OH)D according to sleep duration, only in low sun exposure group. Subjects with low sun exposure and excessive sleep duration comparatively lower 25(OH)D than those with normal-range sleep, even after adjustment for potentially confounding factors. Individuals with limited exposure to sunlight should maintain adequate vitamin D status to have an appropriate sleep duration for health.

Sleep and neurocognitive decline in the Hispanic Community Health Study/Study of Latinos

INTRODUCTION

To determine if sleep-disordered breathing (SDB), daytime sleepiness, insomnia, and sleep duration predict seven-year neurocognitive decline in US Hispanics/Latinos (N = 5247).

METHODS

The exposures were baseline SDB, daytime sleepiness, insomnia, and sleep duration. The outcomes were change in episodic learning and memory (B-SEVLT-Sum and SEVLT-Recall), language (word fluency [WF]), processing speed (Digit Symbol Substitution), and a cognitive impairment screener (Six-item Screener [SIS]).

RESULTS

Mean age was 63 ± 8 years, with 55% of the population being female with 7.0% Central American, 24.5% Cuban, 9.3% Dominican, 35.9% Mexican, 14.4% Puerto Rican, and 5.1% South American background. Long sleep (>9 hours), but not short sleep (<6 hours), was associated with decline (standard deviation units) in episodic learning and memory (β_SEVLT-Sum ⁼ -0.22 [se = 0.06]; P < .001; β_SEVLT-Recall = -0.13 [se = 0.06]; P < .05), WF (Pwf = -0.20 [se 5 0.06]; P < .01), and SIS (β_SIS = -0.16 [se = 0.06]; P < .01), but not processing speed, after adjusting for covariates. SDB, sleepiness, and insomnia were not associated with neurocognitive decline.

CONCLUSION

Long sleep duration predicted seven-year cognitive decline.

A Novel Risk Score for Type 2 Diabetes Containing Sleep Duration: A 7-Year Prospective Cohort Study among Chinese Participants

BACKGROUND

Sleep duration is associated with type 2 diabetes (T2D). However, few T2D risk scores include sleep duration. We aimed to develop T2D scores containing sleep duration and to estimate the additive value of sleep duration.

METHODS

We used data from 43,404 adults without T2D in the Beijing Health Management Cohort study. The participants were surveyed approximately every 2 years from 2007/2008 to 2014/2015. Sleep duration was calculated from the self-reported usual time of going to bed and waking up at baseline. Logistic regression was employed to construct the risk scores. Integrated discrimination improvement (IDI) and net reclassification improvement (NRI) were used to estimate the additional value of sleep duration.

RESULTS

After a median follow-up of 6.8 years, we recorded 2623 (6.04%) new cases of T2D. Shorter (both 6-8 h/night and <6 h/night) sleep durations were associated with an increased risk of T2D (odds ratio (OR) = 1.43, 95% confidence interval (CI) = 1.30-1.59; OR = 1.98, 95%CI = 1.63-2.41, respectively) compared with a sleep duration of >8 h/night in the adjusted model. Seven variables, including age, education, waist-hip ratio, body mass index, parental history of diabetes, fasting plasma glucose, and sleep duration, were selected to form the comprehensive score; the C-index was 0.74 (95% CI: 0.71-0.76) for the test set. The IDI and NRI values for sleep duration were 0.017 (95% CI: 0.012-0.022) and 0.619 (95% CI: 0.518-0.695), respectively, suggesting good improvement in the predictive ability of the comprehensive nomogram. The decision curves showed that women and individuals older than 50 had more net benefit.

CONCLUSIONS

The performance of T2D risk scores developed in the study could be improved by containing the shorter estimated sleep duration, particularly in women and individuals older than 50.

Association between sleep duration and executive function differs between diabetic and non-diabetic middle-aged and older adults

Executive function is defined as a set of cognitive skills that are necessary to plan, monitor, and execute a sequence of goal-directed complex actions. Executive function is influenced by a variety of factors, including habitual sleep duration and diabetes. In the present study, we investigated in 18,769 Swedish adults (mean age: 61 y) the association between executive function, diabetes, and self-reported sleep duration. We observed a significant interaction between diabetes and sleep duration for the Trail Making Test (TMT) ratio (P < 0.01). This ratio is a measure of executive function where higher values indicate worse performance. Among diabetic participants (n = 1,523), long (defined as ≥9 h per day) vs. normal sleep duration (defined as 7-8 hours per day) was associated with a higher TMT ratio (P < 0.05). Similar significant results were observed in diabetic individuals without pharmacological treatment for diabetes (n = 1,062). Among non-diabetic participants (n = 17,246), no association between long sleep duration and the TMT ratio was observed (P > 0.05). Instead, short (defined as <7 h per day) vs. normal sleep duration was linked to a higher TMT ratio (P < 0.05). These findings suggest that the association between sleep duration and executive function differs between diabetic and non-diabetic middle-aged and older adults. Based on the cross-sectional design of the study, no firm conclusions can be drawn on the causality of the relations.

Working hours and nonalcoholic fatty liver disease according to sleep duration

There is no study on the relationship between working hours and nonalcoholic fatty liver disease (NAFLD). The objective of the present study was to determine the relationship between working hours and NAFLD by sleep duration using a large set of abdominal ultrasonography examination data. Data from 194,625 patients who underwent health examinations from 2015 to 2017 were analyzed. Chi-square tests, linear-by-linear association and ANOVA were performed to compare general characteristics according to working hours. Multivariate logistic regression analysis was performed to determine the relationship between working hours and NAFLD by sleep duration. There was no significant relationship between working hours and NAFLD prevalence in the group of short sleep duration of ≤5 hours or the group of long sleep duration of ≥7 hours. The risk of NAFLD in the >52 working hour group was significantly higher (aOR, 1.09; 95% CI, 1.04-1.14) than that in the 40- to 52-hour working hour group after adjusting for confounding factors in the 5- to 6-hour sleep duration group. There was no significant difference between ≤40 working hours and 40 ~ 52 working hours in the 5 ~ 6 hours sleep duration group (aOR, 1.02; 95% CI, 0.97-1.06). In general, working hours were significantly related to NAFLD. There was a difference in the relationship between working hours and NAFLD according to sleep duration.