Beneficial impact of sleep extension on fasting insulin sensitivity in adults with habitual sleep restriction

The Role of Gut Microbiome in Sleep Quality and Health: Dietary Strategies for Microbiota Support

Dietary components, including dietary fiber, unsaturated fatty acids, and polyphenols, along with meal timing and spacing, significantly affect the microbiota's capacity to produce various metabolites essential for quality sleep and overall health. This review explores the role of gut microbiota in regulating sleep through various metabolites such as short-chain fatty acids, tryptophan, serotonin, melatonin, and gamma-aminobutyric acid. A balanced diet rich in plant-based foods enhances the production of these sleep-regulating metabolites, potentially benefiting overall health. This review aims to investigate how dietary habits affect gut microbiota composition, the metabolites it produces, and the subsequent impact on sleep quality and related health conditions.

Insomnia, Short Sleep, and Their Treatments: Review of Their Associations with Weight

PURPOSE OF REVIEW

Insomnia and short sleep have been linked with weight gain and obesity. However, these findings have not been consistent across studies. We review recent evidence for the association between insomnia, short sleep, and weight gain, as well as the relationship between behavioral and pharmacological treatments for sleep and weight.

RECENT FINDINGS

The relationship between insomnia and obesity is mixed, with stronger associations between insomnia with short sleep and obesity than other presentations of insomnia. Short sleep is associated with weight gain. Z-drugs and benzodiazapines do not appear to impact weight, but many antidepressants and antipsychotics that are used for insomnia treatment do cause weight gain. The relationships between insomnia and short sleep with weight gain and obesity are inconsistent. More prospective trials are needed to identify mediators and moderators of this relationship to better develop and deliver effective interventions for both sleep and weight problems.

[Association between insomnia and type 2 diabetes: A two-sample Mendelian rando-mization study]

OBJECTIVE

To explore the robust relationship between insomnia and type 2 diabetes mellitus by two-sample Mendelian randomization analysis to overcome confounding factors and reverse causality in observational studies.

METHODS

We identified strong, independent single nucleotide polymorphisms (SNPs) of insomnia from the most up to date genome wide association studies (GWAS) within European ancestors and applied them as instrumental variable to GWAS of type 2 diabetes mellitus. After excluding SNPs that were significantly associated with smoking, physical activity, alcohol consumption, educational attainment, obesity, or type 2 diabetes mellitus, we assessed the impact of insomnia on type 2 diabetes mellitus using inverse variance weighting (IVW) method. Weighted median and MR-Egger regression analysis were also conducted to test the robustness of the association. We calculated the F statistic of the selected SNPs to test the applicability of instrumental variable and F statistic over than ten indicated that there was little possibility of bias of weak instrumental variables. We further examined the existence of pleiotropy by testing whether the intercept term in MR-Egger regression was significantly different from zero. In addition, the leave-one-out method was used for sensitivity analysis to verify the stability and reliability of the results.

RESULTS

We selected 248 SNPs independently associated with insomnia at the genome-wide level (P<5×10-8) as a preliminary candidate set of instrumental variables. After clumping based on the reference panel from 1000 Genome Project and removing the potential pleiotropic SNPs, a total of 167 SNPs associated with insomnia were included as final instrumental variables. The F statistic of this study was 39. 74, which was in line with the relevance assumption of Mendelian randomization. IVW method showed insomnia was associated with higher risk of type 2 diabetes mellitus that po-pulation with insomnia were 1. 14 times more likely to develop type 2 diabetes mellitus than those without insomnia (95% CI: 1.09-1.21, P<0.001). The weighted median estimator (WME) method and MR-Egger regression showed similar causal effect of insomnia on type 2 diabetes mellitus. And MR-Egger regression also showed that the effect was less likely to be triggered by pleiotropy. Sensitivity analyses produced directionally similar estimates.

CONCLUSION

Insomnia is a risk factor of type 2 diabetes mellitus, which has positively effects on type 2 diabetes mellitus. Our study provides further rationale for indivi-duals at risk for diabetes to keep healthy lifestyle.

Sleep extension and cardiometabolic health: what it is, possible mechanisms and real-world applications

Short sleep duration is associated with heightened cardiometabolic disease risk and has reached epidemic proportions among children, adolescents and adults. Potential mechanisms underlying this association are complex and multifaceted, including disturbances in circadian timing, food intake and appetitive hormones, brain regions linked to control of hedonic eating, physical activity, an altered microbiome and impaired insulin sensitivity. Sleep extension, or increasing total sleep duration, is an emerging and ecologically relevant intervention with significant potential to advance our understanding of the mechanisms underlying the association between short sleep duration and the risk of cardiometabolic disease. If effective, sleep extension interventions have potential to improve cardiometabolic health across the lifespan. Existing data show that sleep extension is feasible and might have potential cardiometabolic health benefits, although there are limitations that the field must overcome. Notably, most existing studies are short term (2-8 weeks), use different sleep extension strategies, analyse a wide array of cardiometabolic health outcomes in different populations and, frequently, lack adequate statistical power, thus limiting robust scientific conclusions. Overcoming these limitations will require fully powered, randomized studies conducted in people with habitual short sleep duration and existing cardiometabolic risk factors. Additionally, randomized controlled trials comparing different sleep extension strategies are essential to determine the most effective interventions. Ongoing and future research should focus on elucidating the potential cardiometabolic health benefits of sleep extension. Such studies have high potential to generate crucial knowledge with potential to improve health and quality of life for those struggling with short sleep duration.

Feasibility, Acceptability, and Preliminary Effectiveness of a Sleep Intervention in Adults at Risk for Metabolic Syndrome With Short Sleep Duration

BACKGROUND

The prevalence of short sleep duration is rising and is linked to chronic comorbidities, such as metabolic syndrome (MetS). Sleep extension interventions in adults with MetS comorbidities and short sleep duration are limited and vary widely in terms of approach and duration.

OBJECTIVES

This pilot study aimed to test the feasibility and acceptability of a personalized 12-week systematic sleep time extension intervention on post-intervention sleep outcomes in middle-aged adults at risk for MetS with actigraphy-estimated short sleep duration.

METHODS

A single-arm, 12-week, 12-session systematic sleep time extension intervention was delivered weekly via videoconferencing. Feasibility and acceptability were assessed using retention rates and mean sleep diary completions. Sleep was estimated for 14 consecutive days prior to and immediately following the 12-week intervention using wrist actigraphy. Daytime sleepiness was assessed using the Epworth Sleepiness Scale. Paired sample t -tests modeled changes in study outcomes.

RESULTS

Study participants ( N = 41) had a mean age of 52 years and were mostly female and White; 86% attended >80% of sessions, and mean sleep diary completion was 6.7 diaries/week. Significant improvements in sleep from pre- to post-intervention included increased total sleep time, earlier sleep onsets, more regular sleep onsets, a higher sleep regularity index, and reduced daytime sleepiness. Extending sleep, as well as improving sleep timing and regularity in middle-aged adults with actigraphy-estimated short sleep duration and at risk for MetS, is feasible and acceptable.

DISCUSSION

Behavioral sleep characteristics may be modifiable and present a novel behavioral paradigm for mitigating MetS risk. This pilot study provides a proof of concept for the feasibility, acceptability, and preliminary effectiveness of a systematic sleep time extension for middle-aged adults at risk for MetS with actigraphy-estimated short sleep duration.

Chronic Insufficient Sleep in Women Impairs Insulin Sensitivity Independent of Adiposity Changes: Results of a Randomized Trial

OBJECTIVE

Insufficient sleep is associated with type 2 diabetes, yet the causal impact of chronic insufficient sleep on glucose metabolism in women is unknown. We investigated whether prolonged mild sleep restriction (SR), resembling real-world short sleep, impairs glucose metabolism in women.

RESEARCH DESIGN AND METHODS

Women (aged 20-75 years) without cardiometabolic diseases and with actigraphy-confirmed habitual total sleep time (TST) of 7-9 h/night were recruited to participate in this randomized, crossover study with two 6-week phases: maintenance of adequate sleep (AS) and 1.5 h/night SR. Outcomes included plasma glucose and insulin levels, HOMA of insulin resistance (HOMA-IR) values based on fasting blood samples, as well as total area under the curve for glucose and insulin, the Matsuda index, and the disposition index from an oral glucose tolerance test.

RESULTS

Our sample included 38 women (n = 11 postmenopausal women). Values are reported with ±SEM. Linear models adjusted for baseline outcome values demonstrated that TST was reduced by 1.34 ± 0.04 h/night with SR versus AS (P < 0.0001). Fasting insulin (β = 6.8 ± 2.8 pmol/L; P = 0.016) and HOMA-IR (β = 0.30 ± 0.12; P = 0.016) values were increased with SR versus AS, with effects on HOMA-IR more pronounced in postmenopausal women compared with premenopausal women (β = 0.45 ± 0.25 vs. β = 0.27 ± 0.13, respectively; P for interaction = 0.042). Change in adiposity did not mediate the effects of SR on glucose metabolism or change results in the full sample when included as a covariate.

CONCLUSIONS

Curtailing sleep duration to 6.2 h/night, reflecting the median sleep duration of U.S. adults with short sleep, for 6 weeks impairs insulin sensitivity, independent of adiposity. Findings highlight insufficient sleep as a modifiable risk factor for insulin resistance in women to be targeted in diabetes prevention efforts.

Association between sleep variability and time in range of glucose levels in patients with type 1 diabetes: Cross-sectional study

OBJECTIVE

Sleep and circadian disturbances emerge as novel factors influencing glycemic control in type 1 diabetes (T1D). We aimed to explore the associations among sleep, behavioral circadian parameters, self-care, and glycemic parameters in T1D.

METHODS

Seventy-six non-shift-working adult T1D patients participated. Blinded 7-day continuous glucose monitoring (CGM) and hemoglobin A1C (A1C) were collected. Percentages of time-in-range (glucose levels 70-180 mg/dL) and glycemic variability (measured by the coefficient of variation [%CV]) were calculated from CGM. Sleep (duration and efficiency) was recorded using 7-day actigraphy. Variability (standard deviation) of midsleep time was used to represent sleep variability. Nonparametric behavioral circadian variables were derived from actigraphy activity recordings. Self-care was measured by diabetes self-management questionnaire-revised. Multiple regression analyses were performed to identify independent predictors of glycemic parameters.

RESULTS

Median (interquartile range) age was 34.0 (27.2, 43.1) years, 48 (63.2%) were female, and median (interquartile range) A1C was 6.8% (6.2, 7.4). Sleep duration, efficiency, and nonparametric behavioral circadian variables were not associated with glycemic parameters. After adjusting for age, sex, insulin delivery mode/CGM use, and ethnicity, each hour increase in sleep variability was associated with 9.64% less time-in-range (B = -9.64, 95% confidence interval [-16.29, -2.99], p ≤ .001). A higher diabetes self-management questionnaire score was an independent predictor of lower A1C (B = -0.18, 95% confidence interval [-0.32, -0.04]).

CONCLUSION

Greater sleep timing variability is independently associated with less time spent in the desirable glucose range in this T1D cohort. Reducing sleep timing variability could potentially lead to improved metabolic control and should be explored in future research.

DATA AVAILABILITY STATEMENT

Data are available upon a reasonable request to the corresponding author.

Alignment Between 24-h Light-Dark and Activity-Rest Rhythms Is Associated With Diabetes and Glucose Metabolism in a Nationally Representative Sample of American Adults

OBJECTIVE

The alignment between environmental stimuli (e.g., dark, light) and behavior cycles (e.g., rest, activity) is an essential feature of the circadian timing system, a key contributor to metabolic health. However, no previous studies have investigated light-activity alignment in relation to glycemic control in human populations.

RESEARCH DESIGN AND METHODS

The analysis included ∼7,000 adults (aged 20-80 years) from the National Health and Nutrition Examination Survey (NHANES) (2011-2014) with actigraphy-measured, multiday, 24-h activity and light data. We used phasor analysis to derive phasor magnitude and phasor angle, which measures coupling strength and phase difference between the activity-rest and light-dark cycles, respectively. We used multinomial logistic regression and multiple linear regression to study phasor magnitude and phasor angle in relation to diabetes (primary outcome) and multiple secondary biomarkers of glycemic control.

RESULTS

Lower alignment strength (i.e., a shorter phasor magnitude) and more delayed activity relative to the light cycle (i.e., a larger phasor angle) were both associated with diabetes. Specifically, compared with individuals in the quintiles indicating the most proper alignment (Q5 for phasor magnitude and Q1 for phasor angle), those in the quintiles with the most impaired alignment had a >70% increase in the odds of diabetes for phasor magnitude (odds ratio 1.76 [95% CI 1.39, 2.24]) and for phasor angle (1.73 [1.34, 2.25]). Similar associations were observed for biomarkers for glucose metabolism. The results were generally consistent across diverse sociodemographic and obesity groups.

CONCLUSIONS

The alignment pattern between 24-h activity-rest and light-dark cycles may be a critical factor in metabolic health.

Objective sleep and cardiometabolic biomarkers: results from the community of mine study

Study Objectives

Examining multiple dimensions of sleep health may better capture associations between sleep and health risks, including cardiometabolic disease (CMD). Hispanics have elevated risk for inadequate sleep and CMD biomarkers. Few studies have explored whether associations between sleep and CMD differ by Hispanic ethnicity.

Methods

Leveraging data from the Community of Mine (CoM) study, a cross-sectional investigation of 602 ethnically diverse participants, we derived accelerometer-measured sleep duration and efficiency, and self-reported sleep quality. Accelerometer-measured sleep exposures were analyzed both as continuous and categorical variables. Multivariate and quantile regression models were used to assess associations between sleep and CMD biomarkers (insulin resistance, systolic blood pressure, and low-density-lipoprotein cholesterol), controlling for age, sex, ethnicity, education, smoking status, and body mass index. We examined the potential effect modification of Hispanic ethnicity.

Results

We observed mixed results based on CMD biomarkers and sleep exposure. Increased sleep duration was significantly related to low-density lipoprotein cholesterol in adjusted models (estimate = 0.06; 95% CI: 0.02, 0.11). Poor sleep efficiency was associated with greater insulin resistance in the adjusted quantile (estimate = 0.20; 95% CI: 0.04, 0.36) model at the 90th percentile. Self-reported sleep quality was not associated with CMD outcomes. There was no evidence of effect modification by Hispanic ethnicity.

Conclusions

In this cohort, sleep health measures were found to have mixed and at times opposing effects on CMD outcomes. These effects did not demonstrate an interaction with Hispanic ethnicity.

Stress and human health in diabetes: A report from the 19th Chicago Biomedical Consortium symposium

Stress and diabetes coexist in a vicious cycle. Different types of stress lead to diabetes, while diabetes itself is a major life stressor. This was the focus of the Chicago Biomedical Consortium's 19th annual symposium, "Stress and Human Health: Diabetes," in November 2022. There, researchers primarily from the Chicago area met to explore how different sources of stress - from the cells to the community - impact diabetes outcomes. Presenters discussed the consequences of stress arising from mutant proteins, obesity, sleep disturbances, environmental pollutants, COVID-19, and racial and socioeconomic disparities. This symposium showcased the latest diabetes research and highlighted promising new treatment approaches for mitigating stress in diabetes.

Study protocol for a longitudinal observational study of disparities in sleep and cognition in older adults: the DISCO study

INTRODUCTION

Cognitive dysfunction, a leading cause of mortality and morbidity in the USA and globally, has been shown to disproportionately affect the socioeconomically disadvantaged and those who identify as black or Hispanic/Latinx. Poor sleep is strongly associated with the development of vascular and metabolic diseases, which correlate with cognitive dysfunction. Therefore, sleep may contribute to observed disparities in cognitive disorders. The Epidemiologic Study of Disparities in Sleep and Cognition in Older Adults (DISCO) is a longitudinal, observational cohort study that focuses on gathering data to better understand racial/ethnic sleep disparities and illuminate the relationship among sleep, race and ethnicity and changes in cognitive function. This investigation may help inform targeted interventions to minimise disparities in cognitive health among ageing adults.

METHODS AND ANALYSIS

The DISCO study will examine up to 495 individuals aged 55 and older at two time points over 24 months. An equal number of black, white and Hispanic/Latinx individuals will be recruited using methods aimed for adults traditionally under-represented in research. Study procedures at each time point will include cognitive tests, gait speed measurement, wrist actigraphy, a type 2 home polysomnography and a clinical examination. Participants will also complete self-identified assessments and questionnaires on cognitive ability, sleep, medication use, quality of life, sociodemographic characteristics, diet, substance use, and psychological and social health.

ETHICS AND DISSEMINATION

This study was approved by the Northwestern University Feinberg School of Medicine Institutional Review Board. Deidentified datasets will be shared via the BioLINCC repository following the completion of the project. Biospecimen samples from the study that are not being analysed can be made available to qualified investigators on review and approval by study investigators. Requests that do not lead to participant burden or that conflict with the primary aims of the study will be reviewed by the study investigators.

The Effect of Cognitive Behavioral Therapy for Insomnia (CBT-I) on Cardiometabolic Health Biomarkers: A Systematic Review of Randomized Controlled Trials

OBJECTIVES

To assess the effectiveness of Cognitive Behavioral Therapy for Insomnia (CBT-I) on cardiometabolic health biomarkers.

METHOD

Cochrane CENTRAL, Embase, Medline, and PsycINFO were searched, and records were screened by two independent reviewers. Inclusion criteria were adult population, delivery of CBT-I, randomized controlled trial design, ≥1 cardiometabolic health outcome, and peer-review. Hedge's g effect sizes were calculated, and the quality of the evidence was appraised using the Cochrane Risk of Bias 2 tool.

RESULTS

After screening 1649 records, 15 studies were included (total N = 2067). Inflammatory markers (CRP, IL-6, TNF-α), blood pressure (SBP, DBP), and glycemic regulation (HbA1c) were most frequently reported (in ≥3 studies each). HbA1c and CRP were reduced in the CBT-I group compared to the control group (in 3 studies each). Effects varied or were null for IL-6, TNF-α, SBP, and DBP. Six studies were judged as low, four as moderate, and five as high risk of bias.

CONCLUSION

CBT-I was most consistently associated with improved HbA1c and CRP, which are relatively temporally stable, suggesting influences on enduring habits rather than short-term behavior changes. High risk of bias limits the interpretation of findings. Methodologically adequate studies are needed to better understand cardiometabolic effects of CBT-I.

Sleep Technology Intervention to Target Cardiometabolic Health (STITCH): a randomized controlled study of a behavioral sleep extension intervention compared to an education control to improve sleep duration, blood pressure, and cardiometabolic health among adults with elevated blood pressure/hypertension

BACKGROUND

Short sleep duration, defined as < 7 h sleep on weeknights, affects 40% of the US adult population, contributing to the increased risk for cardiometabolic diseases, decreased safety, and poorer mental health. Despite the prevalence of short sleep duration, few studies have tested interventions to extend sleep duration. The objective of this study is to test the effects of a behavioral sleep extension intervention on sleep duration, blood pressure, and other measures of cardiometabolic health among adults with elevated blood pressure or hypertension.

METHODS

This is a single-blind, randomized controlled trial to determine the impact of a behavioral sleep extension intervention on sleep duration and cardiometabolic health among individuals with short sleep duration (< 7 h per night) and elevated blood pressure or hypertension (SBP 120-150 mmHg or DBP 80-90 mmHg). After completing the screening, participants will be randomly assigned to either a sleep coaching (intervention) or health education (control) group. The participants will have weekly contact for either coaching or education for 8 weeks (intervention period) followed by monthly coaching or education for the next 2 months (maintenance period). Participants will complete assessment visits, actigraphy, and 24-h ambulatory blood pressure recording at baseline/screening, 8 weeks, and 6 and 12 months. The primary outcome is sleep duration at 8 weeks, and the secondary outcome is blood pressure at 8 weeks.

DISCUSSION

The results of this study will determine the effects of behavioral sleep extension on sleep and cardiometabolic health among adults with short sleep duration and elevated BP/hypertension. The results will inform the feasibility and efficacy of behavioral sleep extension and provide information needed for future multi-site effectiveness studies.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04766424. Registered on 21 February 2021.

Sleep Deficiency and Cardiometabolic Disease

Epidemiologic studies have demonstrated that short sleep duration is associated with an increased risk of cardio-metabolic health outcomes including cardiovascular disease mortality, coronary heart disease, type 2 diabetes mellitus, hypertension, and metabolic syndrome. Experimental sleep restriction studies have sought to explain these findings. This review describes the main evidence of these associations and possible mechanisms explaining them. Whether sleep extension reverses these now widely acknowledged adverse health effects and the feasibility of implementing such strategies on a public health level is discussed.

Association between weekend catch-up sleep and hyperuricemia with insufficient sleep in postmenopausal Korean women: a nationwide cross-sectional study

OBJECTIVE

Hyperuricemia is associated with metabolic and cardiovascular diseases and mortality. Efforts to lower the risk of hyperuricemia in various ways are needed as the prevalence of these diseases increases in postmenopausal women. Studies have shown that one of these methods is associated with adequate sleep duration, which is related to a low risk of hyperuricemia. Considering that it is difficult for people to get enough sleep in modern society, this study hypothesized that weekend catch-up sleep could be an alternative. To our knowledge, no past study has investigated the relation between weekend catch-up sleep and hyperuricemia in postmenopausal women. Hence, the aim of this research was to estimate the relation between weekend catch-up sleep and hyperuricemia with insufficient sleep in postmenopausal women during weekday or workday.

METHODS

This study included 1,877 participants extracted from the Korea National Health and Nutrition Examination Survey VII. The study population was divided into weekend catch-up sleep and non-weekend catch-up sleep groups. Odds ratios with 95% confidence intervals were derived using multiple logistic regression analysis.

RESULTS

Weekend catch-up sleep had a significantly lower prevalence of hyperuricemia after adjusting for confounders (odds ratio, 0.758 [95% confidence interval, 0.576-0.997]). In a subgroup analysis, weekend catch-up sleep of 1 to 2 hours was significantly correlated with a lower prevalence of hyperuricemia after adjusting for confounders (odds ratio: 0.522 [95% confidence interval, 0.323-0.845]).

CONCLUSIONS

Weekend catch-up sleep had a decreased prevalence of hyperuricemia in postmenopausal women with sleep deprivation.

The impact of fear of hypoglycaemia on sleep in adolescents with type 1 diabetes

AIMS

Fear of hypoglycaemia (FOH) can contribute to impaired sleep for adults with type 1 diabetes (T1D) and parents of children with T1D, although it is unknown how FOH may affect sleep for adolescents with T1D. This study examines the relationship between adolescent FOH and sleep and assessed the influences of continuous glucose monitor (CGM) and insulin pump use.

METHODS

Adolescents ages 14-18 years with T1D completed questionnaires evaluating FOH (Child Hypoglycemia Fear Survey) and sleep (Pittsburgh Sleep Quality Index, PSQI). Analyses included linear and logistic regression, t-tests and Fisher's exact tests.

RESULTS

Participants included 95 adolescents (52 female) with a median (IQR) age of 16.5 (15.3-17.7) years and a T1D duration of 5.7 (2.5-9.6) years. Analyses showed increased FOH-Worry subscale scores were associated with reduced sleep duration (β = -0.03, p = 0.042, adjusting for BMI z-score, race and ethnicity) and increased sleep disturbances (OR = 1.1, p = 0.038, adjusting for race and ethnicity). Frequent CGM users had longer sleep duration (average 7.5 h) compared with infrequent or non-CGM users (average = 6.8 h; p = 0.029), and pump users had overall improved sleep health as determined by PSQI score (p = 0.019). Technology use did not have significant interactions in the relationships between FOH and sleep duration or sleep disturbances.

CONCLUSIONS

Worrying about hypoglycaemia was associated with impaired sleep for adolescents with T1D. Diabetes technology users have some sleep improvements, but CGM and pump use do little to alter the relationship between FOH and sleep outcomes.

Sleep and dreaming in the light of reactive and predictive homeostasis

Dreams are often viewed as fascinating but irrelevant mental epihenomena of the sleeping mind with questionable functional relevance. Despite long hours of oneiric activity, and high individual differences in dream recall, dreams are lost into oblivion. Here, we conceptualize dreaming and dream amnesia as inherent aspects of the reactive and predictive homeostatic functions of sleep. Mental activity during sleep conforms to the interplay of restorative processes and future anticipation, and particularly during the second half of the night, it unfolds as a special form of non-constrained, self-referent, and future-oriented cognitive process. Awakening facilitates constrained, goal-directed prospection that competes for shared neural resources with dream production and dream recall, and contributes to dream amnesia. We present the neurophysiological aspects of reactive and predictive homeostasis during sleep, highlighting the putative role of cortisol in predictive homeostasis and forgetting dreams. The theoretical and methodological aspects of our proposal are discussed in relation to the study of dreaming, dream recall, and sleep-related cognitive processes.

Association between triglyceride glucose index and sleep disorders: results from the NHANES 2005-2008

BACKGROUND

To determine the association between sleep disorders and Triglyceride glucose index.

METHODS

A cross-sectional analysis of the 2005 to 2008 National Health and Nutrition Examination Survey (NHANES) was performed. The 2005 to 2008 NHANES national household survey for adults ≥ 20 years was examined for the sleep disorders.TyG index: ln [triglyceride (mg/ dL) × fasting blood glucose (mg/dL)/2].Multivariable logistic and linear regression models were used to explore the association between the TyG index and sleep disorders.

RESULTS

A total of 4,029 patients were included. Higher TyG index is significantly associated with elevated sleep disorders in U.S. adults. TyG was moderately correlated with HOMA-IR (Spearman r = 0.51). TyG was associated with higher odds of sleep disorders(adjusted OR [aOR],1.896; 95% CI, 1.260 2.854), Sleep apnea (aOR, 1.559; 95% CI, 0.660 3.683), Insomnia(aOR, 1.914;95% CI, 0.531 6.896), and Restless legs (aOR, 7.759; 95% CI,1.446 41.634).

CONCLUSIONS

In this study, our result shown that population with higher TyG index are significantly more likely to have sleep disorders in U.S. adults.

How Are You Sleeping? Why Nutrition Professionals Should Ask Their Patients About Sleep Habits

Current literature has identified relationships among sleep, nutrition, and diet-related chronic diseases; however, knowledge about how sleep influences diet-related diseases is lacking in dietetics practice. This narrative review briefly explains sleep physiology and outlines the relationships between sleep duration and quality and common nutrition-related diseases, including obesity, diabetes, cardiovascular disease, obstructive sleep apnea, and cancer. Additionally, the review discusses how sleep influences wound healing and pregnancy outcomes and why hospitalized patients are likely to experience sleep problems. Plausible mechanisms explaining the relationships between sleep and disease are presented. Finally, commonly used sleep assessment tools and interventions are reviewed. Given the importance of sleep to health, dietitians should not only be aware of the role sleep plays in disease development and prevention but also assess sleep when feasible and refer patients and clients who are at high risk for sleep problems to a sleep clinic or community program that can address sleep issues.Teaching points:Sleep duration and quality influence risk and outcomes of common nutrition-related diseases.Sleep health evaluation is a missing piece in dietetic practice.There are easy-to-use, validated tools that dietitians can use to screen for sleep problems in order to refer patients and clients to sleep experts.

Objective sleep characteristics and continuous glucose monitoring profiles of type 2 diabetes patients in real-life settings

AIM

To investigate the association between objective sleep parameters and glycaemic variability determined by continous glucose monitoring (CGM) among patients with type 2 diabetes, given the significant role of sleep in glycaemic control.

METHODS

In this study, CGM was carried out in 28 patients with T2D (aged 62.3 ± 4.8 years, 57% women). Sleep characteristics were assessed by actigraphy within the CGM period. CGM-derived outcomes included glucose level, and percentages of time in range (TIR) and time above range (TAR) during the monitoring period. Associations between intraindividual night-to-night variations in sleep characteristics and overall CGM outcomes were analysed using linear regression. Associations between sleep characteristics during each night and time-matched CGM outcomes were analysed using linear mixed models.

RESULTS

A total of 249 person-days of CGM, coupled with 221 nights of sleep characteristics, were documented. Greater standard deviation (SD) of objective sleep duration (minutes) between measurement nights was associated with higher glucose level (coefficient 0.018 mmol/L [95% confidence interval {CI} 0.004, 0.033], P = 0.017), smaller proportion of TIR (% in observation period; coefficient -0.20% [95% CI -0.36, -0.03], P = 0.023), and greater proportion of TAR (coefficient 0.22% [95% CI 0.06, 0.39], P = 0.011). Later sleep midpoint (minutes from midnight) was associated with greater SD of glucose during the same sleep period (coefficient 0.002 minutes [95% CI 0.0001, 0.003], P = 0.037), longer nocturnal sleep duration was associated with smaller coefficient of variation of glucose level in the upcoming day (-0.015% [95% CI -0.03, -0.001], P = 0.041).

CONCLUSION

Objectively determined sleep duration and sleep midpoint, as well as their daily variability, are associated with CGM-derived glucose profiles in T2D patients.

Sleep Health as a Determinant of Disparities in Stroke Risk and Health Outcome

Sleep is essential to human survival and overall vascular health. Sleep health encompasses the objective and subjective qualities associated with one's daily pattern of sleep and wakefulness and has become a growing clinical and public health concern. Impaired sleep duration and quality can increase stroke risk and mediate the relationship between the physical aspects of an individual's environment and disparities in stroke incidence. Here, we review observational studies evaluating the association between sleep health and cerebrovascular disease. We assess the influence on sleep of the physical environment, including the ambient environment with noise levels and the built environment. We also describe the influences on sleep health and stroke risk of social determinants of health, including the chronic stressor of racial discrimination. Finally, we discuss how changes in historical neighborhood characteristics or societal policies can influence the social factors affecting sleep health and stroke risk among socioeconomically disadvantaged groups or ethnic and racial minorities. Given the regional and racial or ethnic differences in stroke risk across the United States, an understanding of novel vascular risk factors, such as the multifaceted role of sleep health, will be critical to develop effective public policies to improve population health.

Association between sleep duration and quality with rapid kidney function decline and development of chronic kidney diseases in adults with normal kidney function: The China health and retirement longitudinal study

Research have shown that sleep is associated with renal function. However, the potential effects of sleep duration or quality on kidney function in middle-aged and older Chinese adults with normal kidney function has rarely been studied. Our study aimed to investigate the association of sleep and kidney function in middle-aged and older Chinese adults. Four thousand and eighty six participants with an eGFR ≥60 ml/min/1.73 m² at baseline were enrolled between 2011 and 2015 from the China Health and Retirement Longitudinal Study. Survey questionnaire data were collected from conducted interviews in the 2011. The eGFR was estimated from serum creatinine and/or cystatin C using the Chronic Kidney Disease Epidemiology Collaboration equations (CKD-EPI). The primary outcome was defined as rapid kidney function decline. Secondary outcome was defined as rapid kidney function decline with clinical eGFR of <60 ml/min/1.73 m² at the exit visit. The associations between sleep duration, sleep quality and renal function decline or chronic kidney disease (CKD) were assessed based with logistic regression model. Our results showed that 244 (6.0%) participants developed rapid decline in kidney function, while 102 (2.5%) developed CKD. In addition, participants who had 3-7 days of poor sleep quality per week had higher risks of CKD development (OR 1.86, 95% CI 1.24-2.80). However, compared with those who had 6-8 h of night-time sleep, no significantly higher risks of rapid decline in kidney function was found among those who had <6 h or >8 h of night time sleep after adjustments for demographic, clinical, or psychosocial covariates. Furthermore, daytime nap did not present significant risk in both rapid eGFR decline or CKD development. In conclusion, sleep quality was significantly associated with the development of CKD in middle-aged and older Chinese adults with normal kidney function.

Connecting insufficient sleep and insomnia with metabolic dysfunction

The global epidemic of obesity and type 2 diabetes parallels the rampant state of sleep deprivation in our society. Epidemiological studies consistently show an association between insufficient sleep and metabolic dysfunction. Mechanistically, sleep and circadian rhythm exert considerable influences on hormones involved in appetite regulation and energy metabolism. As such, data from experimental sleep deprivation in humans demonstrate that insufficient sleep induces a positive energy balance with resultant weight gain, due to increased energy intake that far exceeds the additional energy expenditure of nocturnal wakefulness, and adversely impacts glucose metabolism. Conversely, animal models have found that sleep loss-induced energy expenditure exceeds caloric intake resulting in net weight loss. However, animal models have significant limitations, which may diminish the clinical relevance of their metabolic findings. Clinically, insomnia disorder and insomnia symptoms are associated with adverse glucose outcomes, though it remains challenging to isolate the effects of insomnia on metabolic outcomes independent of comorbidities and insufficient sleep durations. Furthermore, both pharmacological and behavioral interventions for insomnia may have direct metabolic effects. The goal of this review is to establish an updated framework for the causal links between insufficient sleep and insomnia and risks for type 2 diabetes and obesity.

Functional hypogonadism among patients with obesity, diabetes, and metabolic syndrome

Testosterone deficiency, defined as low total testosterone combined with physical, cognitive, and sexual signs and/or symptoms, is a common finding in adult men. Functional hypogonadism (FH) is defined as borderline low testosterone (T) secondary to aging and/or comorbid conditions such as diabetes, obesity, and/or metabolic syndrome. The relationship between FH and metabolic disorders is multifactorial and bidirectional, and associated with a disruption of the hypothalamic-pituitary-gonadal axis. Resolution of FH requires the correct diagnosis and treatment of the underlying condition(s) with lifestyle modifications considered first-line therapy. Normalization of T levels through dietary modifications such as caloric restriction and restructuring of macronutrients have recently been explored. Exercise and sleep quality have been associated with T levels, and patients should be encouraged to practice resistance training and sleep seven to nine hours per night. Supplementation with vitamin D and Trigonella foenum-graecum may also be considered when optimizing T levels. Ultimately, treatment of FH requires a multidisciplinary approach and personalized patient care.

Sleep Modulates Alcohol Toxicity in Drosophila

Alcohol abuse is a significant public health problem. While considerable research has shown that alcohol use affects sleep, little is known about the role of sleep deprivation in alcohol toxicity. We investigated sleep as a factor modulating alcohol toxicity using Drosophila melanogaster, a model for studies of sleep, alcohol, and aging. Following 24 h of sleep deprivation using a paradigm that similarly affects males and females and induces rebound sleep, flies were given binge-like alcohol exposures. Sleep deprivation increased mortality, with no sex-dependent differences. Sleep deprivation also abolished functional tolerance measured at 24 h after the initial alcohol exposure, although there was no effect on alcohol absorbance or clearance. We investigated the effect of chronic sleep deprivation using mutants with decreased sleep, insomniac and insulin-like peptide 2, finding increased alcohol mortality. Furthermore, we investigated whether pharmacologically inducing sleep prior to alcohol exposure using the GABA_A-receptor agonist 4,5,6,7-tetrahydroisoxazolo(5,4-c)pyridin-3-ol (THIP) mitigated the effects of alcohol toxicity on middle-aged flies, flies with environmentally disrupted circadian clocks, and flies with short sleep. Pharmacologically increasing sleep prior to alcohol exposure decreased alcohol-induced mortality. Thus, sleep prior to binge-like alcohol exposure affects alcohol-induced mortality, even in vulnerable groups such as aging flies and those with circadian dysfunction.

Healthy Sleep Every Day Keeps the Doctor Away

When one considers the big picture of their health, sufficient sleep may often go overlooked as a keystone element in this picture. Insufficient sleep in either quality or duration is a growing problem for our modern society. It is essential to look at what this means for our health because insufficient sleep increases our risks of innumerable lifechanging diseases. Beyond increasing the risk of developing these diseases, it also makes the symptoms and pathogenesis of many diseases worse. Additionally, consistent quality sleep can not only improve our physical health but has also been shown to improve mental health and overall quality of life. Substandard sleep health could be a root cause for numerous issues individuals may be facing in their lives. It is essential that physicians take the time to learn about how to educate their patients on sleep health and try to work with them on an individual level to help motivate lifestyle changes. Facilitating access to sleep education for their patients is one way in which physicians can help provide patients with the tools to improve their sleep health. Throughout this paper, we will review the mechanisms behind the relationship between insufficient sleep health and chronic disease and what the science says about how inadequate sleep health negatively impacts the overall health and the quality of our lives. We will also explain the lifechanging effects of sufficient sleep and how we can help patients get there.

Short sleep duration and risk of gestational diabetes

ObjectiveSleep disturbances and short sleep duration are common in pregnancy and might contribute to the development of hyperglycemia. Therefore, we evaluated the association of sleep disturbances and gestational diabetes (GDM) in a cohort of women.MethodsWe collected data of 386 women consecutively screened for GDM in 2019 by 75 gr OGTT, according with IDPSG criteria. Pittsburgh Sleep Quality Index (PSQI) questionnaire was used to assess self-reported poor sleep quality (PSQI score >5) and short nocturnal sleep duration (<6 h).ResultsOf 386 women, 148 (38.3%) had poor sleep quality and 87 (22.5%) short sleep duration. GDM prevalence was 26.9%. There was no difference in GDM prevalence between women with poor or good sleep quality (26% vs. 28%; n.s.), while GDM was more frequent in women with short sleep duration (35.6% vs. 24.4%; p = 0.038). On univariate logistic regression analysis, short sleep duration (OR 1.71; 95%CI: 1.03-2.86; p = 0.039), previous GDM (OR 3.52; 95%CI: 1.83-6.76; p < 0.0001), family history of diabetes (OR 1.96; 95%CI: 1.21-3.91; p = 0.007), pre-pregnancy overweight (OR 1.85; 95%CI: 1.06-3.23; p = 0.031) or obesity (OR 2.56; 95%CI: 1.40-4.70; p = 0.002) were associated to GDM. However, after adjustment for confounders, short sleep duration did not persist as an independent risk factor for GDM (OR: 1.55; 95%CI: 0.91-2.65; ns).ConclusionsSleep disturbances are relative common among pregnant women. Although GDM seems more common among women with short sleep duration, this sleep disturbance does not seem to be an independent risk factor for GDM in women at high risk.

Sleep duration irregularity is associated with elevated blood pressure in young adults

Sleep irregularity (i.e., highly variable sleep patterns) is an emerging risk factor for cardiometabolic disease. Though irregular sleep patterns are common among young adults, the cardiometabolic health (CMH) repercussions of sleep irregularity in this population are unclear. We examined associations between sleep duration and irregularity with measures of CMH in 44 (24 M/20 F, 23 ± 5y, BMI 26 ± 4 kg/m², blood pressure (BP): 125/71 ± 14/9 mmHg) young adults. Participants wore actigraphy monitors for seven-days and sleep duration irregularity was operationalized as the standard deviation of nightly sleep duration (sleep SD). CMH variables of interest included brachial and aortic BP, arterial stiffness (cf-PWV), augmentation index (AIx75), and fasting blood glucose and lipids. Associations between sleep duration and sleep SD with CMH variables were assessed via correlations adjusted for sex and BMI. Sleep duration generally was not associated with CMH indices. However, sleep SD was associated with brachial systolic (r = 0.433, p = .027) and diastolic BP (r = 0.415, p = .035). Similarly, sleep duration SD was associated with aortic systolic BP (r = 0.447, p = .022). Our findings show that sleep irregularity, but not duration, is associated with higher brachial and central BP in young adults.Abbreviations: AIx75: augmentation index at a heart rate of 75 beats per minute; BP: blood pressure; CMH: cardiometabolic health; cf-PWV: carotid-femoral pulse wave velocity; DXA: dual x-ray absorptiometry; mg/dl: milligrams per deciliter; PWA: pulse wave analysis; PWV: pulse wave velocity; sleep duration SD: standard deviation of nightly sleep duration.

Inflammation, Oxidative Stress, and Antioxidant Micronutrients as Mediators of the Relationship Between Sleep, Insulin Sensitivity, and Glycosylated Hemoglobin

Background

Sleep deprivation and poor sleep quality contribute to increases in oxidative stress, antioxidant imbalance, and a pro-inflammatory state which may predispose to a higher risk of diabetes. Our objective was to estimate the contributions of C-reactive protein (CRP), gamma glutamyl transferase (GGT), and micronutrient antioxidants (bilirubin, carotenoids, uric acid, vitamins A, C-E?) to the relationships between sleep-fasting insulin concentration and -glycosylated hemoglobin (HbA1c).

Methods

Data from the 2005/06 US National Health and Nutritional Examination Survey were used (N = 1,946; 20 y+). Sleep quality and quantity was assessed by the Sleep Disorders Questionnaire, and fasting blood was collected to quantify CRP, GGT, antioxidant micronutrients, insulin concentration, and HbA1c. The bootstrap method was used to estimate the amount of mediation or contribution of these mediators to the sleep-insulin concentration and -HbA1c relationships, which were quantified as large (≥0.25) or moderate (≥0.09).

Results

The sleep duration-fasting insulin relationship was mediated by GGT, carotenoids, uric acid, and vitamins C and D, whereas CRP and bilirubin were non-significant mediators of a moderate effect size. Similarly, the sleep quality-fasting insulin relationship was mediated by CRP, bilirubin and vitamin C, whereas GGT, carotenoids, uric acid, and vitamin D were non-significant large-to-moderate mediators. To a lesser degree, these micronutrients mediated for the relationship between sleep-HbA1c levels.

Conclusion

Several factors related to inflammation, oxidative stress, and antioxidant status were found to lie on the pathway of the sleep-insulin and -glycemic control relationships. Sleep hygiene, reduced systemic inflammation/oxidative stress, and optimal antioxidants intake are potentially beneficial targets for managing diabetes risk.

Effects of Sleep-Extend on glucose metabolism in women with a history of gestational diabetes: a pilot randomized trial

Objectives

Women with a history of gestational diabetes (GDM) are at 7-fold increase in the risk of developing diabetes. Insufficient sleep has also been shown to increase diabetes risk. This study aimed to explore the feasibility of a sleep extension in women with a history of GDM and short sleep, and effects on glucose metabolism.

Methods

Women age 18–45 years with a history of GDM and actigraphy confirmed short sleep duration (<7 h/night) on weekdays were randomized at a ratio of 1 control (heathy living information) to 2 cases (6 weeks of “Sleep-Extend” intervention: use of a Fitbit, weekly digital content, and weekly coaching to increase sleep duration). An oral glucose tolerance test (OGTT), 7-day actigraphy recording, and questionnaires were obtained at baseline and 6 weeks. Mean differences between baseline and end-of-intervention parameters were compared using independent samples t-tests.

Results

Mean (SD) sleep duration increased within the Sleep-Extend group (n=9, +26.9 (42.5) min) but decreased within the controls (n=5, − 9.1 (20.4) min), a mean difference (MD) of 35.9 min (95% confidence interval (CI) − 8.6, 80.5). Fasting glucose increased, but less in Sleep-Extend vs. control groups (1.6 (9.4) vs 10.4 (8.2) mg/dL, MD − 8.8 mg/dL (95% CI − 19.8, 2.1), while 2-h glucose levels after an OGTT did not differ. Compared to controls, Sleep-Extend had decreased fatigue score (MD − 10.6, 95%CI − 20.7, − 0.6), and increased self-report physical activity (MD 5036 MET- minutes/week, 95%CI 343, 9729. Fitbit compliance and satisfaction in Sleep-Extend group was high.

Conclusion

Sleep extension is feasible in women with a history of GDM, with benefits in fatigue and physical activity, and possibly glucose metabolism. These data support a larger study exploring benefits of sleep extension on glucose metabolism in these high-risk women.

Trial registration

ClinicalTrials.gov, NCT03638102 (8/20/2018)

Sleep Deficiency and Cardiometabolic Disease

Epidemiologic studies have demonstrated that short sleep duration is associated with an increased risk of cardio-metabolic health outcomes including cardiovascular disease mortality, coronary heart disease, type 2 diabetes mellitus, hypertension, and metabolic syndrome. Experimental sleep restriction studies have sought to explain these findings. This review describes the main evidence of these associations and possible mechanisms explaining them. Whether sleep extension reverses these now widely acknowledged adverse health effects and the feasibility of implementing such strategies on a public health level is discussed.

Time-restricted Eating for the Prevention and Management of Metabolic Diseases

Time-restricted feeding (TRF, animal-based studies) and time-restricted eating (TRE, humans) are an emerging behavioral intervention approach based on the understanding of the role of circadian rhythms in physiology and metabolism. In this approach, all calorie intake is restricted within a consistent interval of less than 12 hours without overtly attempting to reduce calories. This article will summarize the origin of TRF/TRE starting with concept of circadian rhythms and the role of chronic circadian rhythm disruption in increasing the risk for chronic metabolic diseases. Circadian rhythms are usually perceived as the sleep-wake cycle and dependent rhythms arising from the central nervous system. However, the recent discovery of circadian rhythms in peripheral organs and the plasticity of these rhythms in response to changes in nutrition availability raised the possibility that adopting a consistent daily short window of feeding can sustain robust circadian rhythm. Preclinical animal studies have demonstrated proof of concept and identified potential mechanisms driving TRF-related benefits. Pilot human intervention studies have reported promising results in reducing the risk for obesity, diabetes, and cardiovascular diseases. Epidemiological studies have indicated that maintaining a consistent long overnight fast, which is similar to TRE, can significantly reduce risks for chronic diseases. Despite these early successes, more clinical and mechanistic studies are needed to implement TRE alone or as adjuvant lifestyle intervention for the prevention and management of chronic metabolic diseases.

Integrative Identification of Genetic Loci Jointly Influencing Diabetes-Related Traits and Sleep Traits of Insomnia, Sleep Duration, and Chronotypes

Accumulating evidence suggests a relationship between type 2 diabetes mellitus and sleep problems. A comprehensive study is needed to decipher whether shared polygenic risk variants exist between diabetic traits and sleep traits. Methods: We integrated summary statistics from different genome-wide association studies and investigated overlap in single-nucleotide polymorphisms (SNPs) associated with diabetes-related traits (type 2 diabetes, fasting glucose, fasting insulin, and glycated hemoglobin) and sleep traits (insomnia symptoms, sleep duration, and chronotype) using a conditional/conjunctional false discovery rate approach. Pleiotropic genes were further evaluated for differential expression analysis, and we assessed their expression pattern effects on type 2 diabetes by Mendelian randomization (MR) analysis. Results: We observed extensive polygenic pleiotropy between diabetic traits and sleep traits. Fifty-eight independent genetic loci jointly influenced the risk of type 2 diabetes and the sleep traits of insomnia, sleep duration, and chronotype. The strongest shared locus between type 2 diabetes and sleep straits was FTO (lead SNP rs8047587). Type 2 diabetes (z score, 16.19; P = 6.29 × 10⁻⁵⁹) and two sleep traits, sleep duration (z score, −6.66; P = 2.66 × 10⁻¹¹) and chronotype (z score, 7.42; P = 1.19 × 10⁻¹³), were shared. Two of the pleiotropic genes, ENSA and PMPCA, were validated to be differentially expressed in type 2 diabetes, and PMPCA showed a slight protective effect on type 2 diabetes in MR analysis. Conclusions: Our study provided evidence for the polygenic overlap between diabetic traits and sleep traits, of which the expression of PMPCA may play a crucial role and provide support of the hazardous effect of being an “evening” person on diabetes risk.

A Time to Rest, a Time to Dine: Sleep, Time-Restricted Eating, and Cardiometabolic Health

Cardiovascular disease (CVD) poses a serious health and economic burden worldwide. Modifiable lifestyle factors are a focus of research into reducing the burden of CVD, with diet as one of the most investigated factors. Specifically, the timing and regularity of food intake is an emerging research area, with approaches such as time-restricted eating (TRE) receiving much attention. TRE involves shortening the time available to eat across the day and is associated with improved CVD outcomes compared with longer eating windows. However, studies that have examined TRE have not considered the impact of sleep on CVD outcomes despite recent evidence showing that sleep duration can influence the timing and amount of food eaten. In this article, we argue that as TRE and sleep influence each other, and influence the same cardiometabolic parameters, experiencing inadequate sleep may attenuate any positive impact TRE has on CVD. We examine the relationship between TRE and CVD, with sleep as a potential mediator in this relationship, and propose a research agenda to investigate this relationship. This will provide necessary evidence to inform future interventions aimed at reducing the burden of CVD.

Sleep Duration and Hypertension: Epidemiological Evidence and Underlying Mechanisms

While the contribution of several physiological systems to arterial blood pressure regulation has been studied extensively, the role of normal and disrupted sleep as a modifiable determinant of blood pressure control, and in the pathophysiology of hypertension, has only recently emerged. Several sleep disorders, including sleep apnea and insomnia, are thought to contribute to the development of hypertension, although less attention is paid to the relationship between sleep duration and blood pressure independent of sleep disorders per se. Accordingly, this review focuses principally on the physiology of sleep and the consequences of abnormal sleep duration both experimentally and at the population level. Clinical implications for patients with insomnia who may or may not have abbreviated sleep duration are explored. As a corollary, we further review studies of the effects of sleep extension on blood pressure regulation. We also discuss epidemiological evidence suggesting that long sleep may also be associated with hypertension and describe the parabolic relationship between total sleep time and blood pressure. We conclude by highlighting gaps in the literature regarding the potential role of gut microbial health in the cross-communication of lifestyle patterns (exercise, diet, and sleep) with blood pressure regulation. Additionally, we discuss populations at increased risk of short sleep, and specifically the need to understand mechanisms and therapeutic opportunities in women, pregnancy, the elderly, and in African Americans.

The links between sleep duration, obesity and type 2 diabetes mellitus

Global rates of obesity and type 2 diabetes mellitus (T2DM) are increasing globally concomitant with a rising prevalence of sleep deprivation and sleep disorders. Understanding the links between sleep, obesity and T2DM might offer an opportunity to develop better prevention and treatment strategies for these epidemics. Experimental studies have shown that sleep restriction is associated with changes in energy homeostasis, insulin resistance and β-cell function. Epidemiological cohort studies established short sleep duration as a risk factor for developing obesity and T2DM. In addition, small studies suggested that short sleep duration was associated with less weight loss following lifestyle interventions or bariatric surgery. In this article, we review the epidemiological evidence linking sleep duration to obesity and T2DM and plausible mechanisms. In addition, we review the impact of changes in sleep duration on obesity and T2DM.

Behavioral interventions to extend sleep duration: A systematic review and meta-analysis

The goal of this study was to examine the effects of behavioral sleep extension interventions on sleep duration outcomes in children and adults ≥ age 12. We conducted a systematic literature review, article extraction and meta-analysis. Our search yielded 42 studies from 14 countries. The majority of studies (n = 19) enrolled adults, 10 studies enrolled college students, 13 enrolled children (high school or middle school aged). Results from the meta-analysis demonstrated behavioral sleep extension resulted in a significantly higher sleep duration as compared to control group or baseline, with pooled standardized mean difference (SMD) that was similar for both two-arm 0.80 (95 % CI 0.28 to 1.31; p < 0.01; I2 = 99.2%) and one-arm studies 0.75 (95% CI 0.39 to 1.11; p < 0.01; I2 = 86%), and there was significant heterogeneity among both study types. Subgroup analyses revealed that studies with direct interventions on sleep duration (i.e., specified the sleep schedule) had larger effects compared to indirect methods (coaching, educational approaches) and a greater number of curriculum components was associated with smaller effects. Results of this review demonstrate that sleep extension studies are effective at extending sleep in a variety of populations but improving the description of intervention methods and use of more rigorous study designs will improve the quality and reproducibility of this area of research.

Gut microbiota alterations in response to sleep length among African-origin adults

Sleep disorders are increasingly being characterized in modern society as contributing to a host of serious medical problems, including obesity and metabolic syndrome. Changes to the microbial community in the human gut have been reportedly associated with many of these cardiometabolic outcomes. In this study, we investigated the impact of sleep length on the gut microbiota in a large cohort of 655 participants of African descent, aged 25-45, from Ghana, South Africa (SA), Jamaica, and the United States (US). The sleep duration was self-reported via a questionnaire. Participants were classified into 3 sleep groups: short (<7hrs), normal (7-<9hrs), and long (≥9hrs). Forty-seven percent of US participants were classified as short sleepers and 88% of SA participants as long sleepers. Gut microbial composition analysis (16S rRNA gene sequencing) revealed that bacterial alpha diversity negatively correlated with sleep length (p<0.05). Furthermore, sleep length significantly contributed to the inter-individual beta diversity dissimilarity in gut microbial composition (p<0.01). Participants with both short and long-sleep durations exhibited significantly higher abundances of several taxonomic features, compared to normal sleep duration participants. The predicted relative proportion of two genes involved in the butyrate synthesis via lysine pathway were enriched in short sleep duration participants. Finally, co-occurrence relationships revealed by network analysis showed unique interactions among the short, normal and long duration sleepers. These results suggest that sleep length in humans may alter gut microbiota by driving population shifts of the whole microbiota and also specific changes in Exact Sequence Variants abundance, which may have implications for chronic inflammation associated diseases. The current findings suggest a possible relationship between disrupted sleep patterns and the composition of the gut microbiota. Prospective investigations in larger and more prolonged sleep researches and causally experimental studies are needed to confirm these findings, investigate the underlying mechanism and determine whether improving microbial homeostasis may buffer against sleep-related health decline in humans.

Sleep extension and metabolic health in male overweight/obese short sleepers: A randomised controlled trial

While limited evidence suggests that longer sleep durations can improve metabolic health in habitual short sleepers, there is no consensus on how sustained sleep extension can be achieved. A total of 18 men (mean [SD] age 41 [ 9] years), who were overweight/obese (mean [SD] body mass index 30 [3] kg/m² ) and short sleepers at increased risk of type 2 diabetes were randomised to a 6-week sleep-extension programme based on cognitive behavioural principles (n = 10) or a control (n = 8) group. The primary outcome was 6-week change in actigraphic total sleep time (TST). Fasting plasma insulin, insulin resistance (Homeostatic Model Assessment for Insulin Resistance [HOMA-IR]), blood pressure, appetite-related hormones from a mixed-meal tolerance test, and continuous glucose levels were also measured. Baseline to 6-week change in TST was greater in the sleep-extension group, at 79 (95% confidence interval [CI] 68.90, 88.05) versus 6 (95% CI -4.43, 16.99) min. Change in the sleep-extension and control groups respectively also showed: lower fasting insulin (-11.03 [95% CI -22.70, 0.65] versus 7.07 [95% CI -4.60, 18.74] pmol/L); lower systolic (-11.09 [95% CI -17.49, -4.69] versus 0.76 [95% CI -5.64, 7.15] mmHg) and diastolic blood pressure (-12.16 [95% CI -17.74, -6.59] versus 1.38 [95% CI -4.19, 6.96] mmHg); lower mean amplitude of glucose excursions (0.34 [95% CI -0.57, -0.12] versus 0.05 [95% CI -0.20, 0.30] mmol/L); lower fasting peptide YY levels (-18.25 [95%CI -41.90, 5.41] versus 21.88 [95% CI -1.78, 45.53] pg/ml), and improved HOMA-IR (-0.51 [95% CI -0.98, -0.03] versus 0.28 [95% CI -0.20, 0.76]). Our protocol increased TST and improved markers of metabolic health in male overweight/obese short sleepers.

Feasibility of sleep extension and its effect on cardiometabolic parameters in free-living settings: a systematic review and meta-analysis of experimental studies

AIMS

Inadequate sleep is a global health issue and has been associated with an increased risk for cardiovascular diseases. As a part of sleep hygiene, intentional lengthening of night-time sleep duration (i.e. sleep extension) might be a behavioural intervention to improve cardiometabolic health. To examine the feasibility of sleep extension and its effects on cardiometabolic parameters in free-living settings.

METHODS AND RESULTS

This review was registered in PROSPERO (CRD42019146174). Five databases were searched. Only experimental studies conducted in adults without a diagnosis of sleep disorder were included. The pooled mean difference was calculated by the inverse variance method. Narrative summaries were also used. Thirteen studies from 11 trials were included. The intervention ranged from 3 days to 6 weeks. Sleep extension increased total sleep time by 51 min [95% confidence interval (CI) 39-63]. Overall, sleep extension did not result in significant changes in blood pressure. However, sub-group analysis revealed that when 24 h mean blood pressure was obtained among those with pre-hypertension or Stage 1 hypertension, sleep extension reduced systolic (weighted mean difference = -7.8 mm/Hg; 95% CI -10.6 to -4.9), and diastolic blood pressure (weighted mean difference = -4.2 mm/Hg; 95% CI -6.7 to -1.8). The pooled effects on fasting glucose and insulin resistance were not significant. The effect of sleep extension on other parameters (e.g. heart rate) was not consistent.

CONCLUSION

Sleep extension is feasible and could increase sleep in free-living settings. Sleep extension shows promise for reducing 24 h mean blood pressure among those with pre-hypertension or hypertension. More large-scale studies are needed to examine its long-term effects.

The feasibility of at-home sleep extension in adolescents and young adults: A meta-analysis and systematic review

Insufficient sleep duration is detrimental to health and performance and is alarmingly common in adolescents and young adults. The aim of this pre-registered meta-analysis was to determine the feasibility of at-home sleep extension as a means to improve sleep duration and daytime sleepiness, and maintain or improve sleep quality and efficiency, in adolescents and young adults. Peer-reviewed journal articles and dissertations were screened to identify studies with at least five consecutive days of at-home sleep extension, pre- and post-extension measurement of sleep duration, and participants 13-30 years of age. Out of 2254 studies assessed for eligibility, 17 met review inclusion criteria - seven in adolescents and ten in young adults. At-home extension of sleep opportunity reliably increased sleep duration and sleep quality, and decreased daytime sleepiness when compared to unmanipulated sleep opportunity. These results indicate that at-home sleep extension is feasible in adolescents and young adults. However, the degree of improvement in sleep duration, sleep quality, and daytime sleepiness varied by study population and sleep extension method, which will have downstream consequences for the effectiveness of sleep extension as an experimental manipulation and intervention to improve health and performance during adolescence and young adulthood.

A Model of Adolescent Sleep Health and Risk for Type 2 Diabetes

PURPOSE OF REVIEW

This paper presents a review of the current literature in support of a model explaining the relationships between sleep health and risk for type 2 diabetes in adolescents.

RECENT FINDINGS

Short sleep duration is associated with risk of developing obesity in youth. Sleep restriction increases energy expenditure, but also increases hunger, appetite, and food intake, causing positive energy balance, impacting appetite-regulating hormones, and leading to increased eating late at night. Insufficient sleep may lead to reduced physical activity and greater sedentary behaviors. In addition, short sleep duration is associated with reduced insulin sensitivity. The cumulative negative consequences of insufficient sleep increase risk for type 2 diabetes. Applications to clinical care, public policy, and future research are discussed. Insufficient sleep in adolescence increases risk for type 2 diabetes directly through impact on insulin sensitivity and indirectly through increased dietary intake, sedentary activity, and weight gain.

Daytime Workers with Longer Daily Rest Periods Have Smaller Sleep Debt and Social Jetlag: A Cross-Sectional Web Survey

Objectives: The work interval duration between the end of one workday and the start of the following workday is referred to as the daily rest period (DRP). The present study examined whether DRP - a proxy for sleep opportunity between work shifts - is associated with indicators of sleep debt and social jetlag among daytime workers. Methods: We used a web-based survey to gather data on demographics, average DRP in the previous month, time in bed (TIB), bedtime, wake-up time, and sleep timing on workdays and non-workdays. The Japanese daytime workers (n = 3,914) were divided into seven DRP groups (hours) as follows: <11, 11, 12, 13, 14, 15, and ≥16. Results: The two-way analyses of covariance (DRP group x day) for TIB, mid-sleep as sleep timing, bedtime, and wake-up time showed significant interactions (all p < .001). Specifically, TIB was significantly shorter, and mid-sleep and wake-up time were significantly earlier on workdays than on non-workdays, across all DRP groups (all p < .001). Additionally, the different values for TIB (sleep debt), sleep timing (social jetlag), bedtime, and wake-up time were calculated by subtracting workdays from non-workdays. The trend analysis showed that workers with longer DRP (sleep opportunity) had smaller differences in TIB, sleep timing, and wake-up time between workdays and non-workdays (all p < .001). Conclusions: Overall, daytime workers reported significant sleep debt and misalignment between work and free sleep-wake periods. However, workers with shorter DRPs (less sleep opportunity between shifts) reported significantly greater amounts of sleep debt and social jetlag than did workers with longer DRPs.

Sleep interventions and glucose metabolism: systematic review and meta-analysis

OBJECTIVE

Sleep disturbances (insufficient or poor sleep quality) have been linked to abnormal glucose metabolism. This systematic review and meta-analysis aimed to explore the effects of behavioral and pharmacological sleep interventions on glucose metabolism.

METHODS

Medline and Embase were used for systematic search. Studies reporting behavioral or pharmacological interventions in population with sleep disturbances, with measured outcomes of glucose metabolism and sleep parameters were selected.

RESULTS

Twenty two studies were eligible for review (eight were conducted in people with type 2 diabetes). Studies were grouped into three types of intervention: sleep extension (n = 6), sleep education or cognitive behavioral therapy for insomnia (CBT-I, n = 6) and pharmacological interventions (n = 10). CBT-I and sleep education resulted in significantly improved self-reported sleep quality (Pittsburgh Sleep Quality Index, mean difference, MD, -1.31, 95% confidence interval (CI) -1.83, -0.80), non-significant reduction in hemoglobin A1c level (MD -0.35%, 95% CI -0.84, 0.13), and non-significant reduction in fasting glucose levels (MD -4.76 mg/dL, 95% CI -14.19, 4.67). Other studies were not eligible for meta-analysis due to heterogeneity of interventions or outcomes. Sleep extension was able to increase sleep duration by varying degrees in short sleepers, and five of six studies demonstrated relationships between the intervention and measures of insulin resistance. A majority of pharmacological intervention studies showed improved sleep but the effects on glucose metabolism were mixed.

CONCLUSIONS

Available sleep interventions were effective in improving sleep but the effects on glucose metabolism were inconclusive. Larger randomized studies with consistent outcome measurements are needed to demonstrate this potential causal relationship.

Sleep Extension: A Potential Target for Obesity Treatment

PURPOSE OF REVIEW

Sleep and obesity share a bidirectional relationship, and weight loss has been shown to enhance sleep. Aiming to extend sleep on its own or as part of a lifestyle intervention may attenuate health consequences of short sleep. This review highlights several sleep extension approaches, discusses feasibility of each, and summarizes findings relevant to obesity.

RECENT FINDINGS

Sleep extension in response to experimental sleep restriction demonstrates partial rescue of cardiometabolic dysfunction in some but not all studies. Adequate sleep on a nightly basis may be necessary for optimal health. While initial sleep extension interventions in habitually short sleepers have been met with obstacles, preliminary findings suggest that sleep extension or sleep hygiene interventions may improve glycemic control, decrease blood pressure, and enhance weight loss. Sleep extension has the potential to attenuate obesity risk and cardiometabolic dysfunction. There is tremendous opportunity for future research that establishes a minimum threshold for sleep extension effectiveness and addresses logistical barriers identified in seminal studies.

The Frequency of Poor Sleep Quality in Patients With Diabetes Mellitus and Its Association With Glycemic Control

Background and objective

Emerging evidence suggests that sleep problems are more common among individuals with diabetes mellitus (DM) than in the general population; these sleep issues are associated with poor glycemic control and they negatively affect the overall prognosis of the disease by increasing cardiometabolic risk. Our study aimed to determine the frequency of poor sleep quality and its association with glycemic control among Pakistani adult patients with DM.

Methods

This prospective cross-sectional study was conducted at the outpatient department (OPD) of The Indus Hospital (TIH), Karachi, and included 329 participants. To be eligible, participants had to be 14 years or older, should have been visiting the OPD at TIH for six months or more to seek treatment for DM, and had to give informed consent. Participants were assessed for poor sleep quality using the Pittsburgh Sleep Quality Index (PSQI) score and glycemic control using HbA1C levels ascertained through electronic health record review, with higher HbA1C levels reflecting poorer glycemic control.

Results

Two-thirds of the participants were females (n=212; 64.4%), and approximately 90% of the participants were married (n=292; 88.8%); 57% (n=188) of the participants were found to have poor sleep quality (PSQI of >5) and 233 (70.82%) had poor glycemic control (HbA1C of >7). Interestingly, no significant difference was observed in the PSQI scores between participants with controlled diabetes and those with uncontrolled diabetes.

Conclusion

Based on our findings, there is a high prevalence of sleep disturbance among Pakistani adults with DM, and we believe this necessitates the fostering of sleep-promoting interventional research in the country, as it might be highly rewarding and would positively affect the overall prognosis for diabetes by improving cardiometabolic risks. However, our results did not indicate any significant association between sleep quality and glycemic control. Further research should be conducted to explore the association between sleep disturbance and DM in Pakistani adults, by employing objective measures of sleep quality and involving a larger sample of individuals with DM to determine if these results hold true.