Associations between sleep duration and sleep debt with insulin sensitivity and insulin secretion in the EGIR-RISC Study

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 Duration and Stroke in Different Status of Metabolic Syndrome: A Cross-Sectional Study in Shanghai Adult Residents

Purpose

This study aimed to investigate the relationship between sleep duration (SD) and stroke, and examine the effects of SD on stroke with or without metabolic syndrome (Mets) and its components among the adult residents in Shanghai, China.

Participants and Methods

A total of 20,245 participants (51.72% male, mean age 44.66 years) were included from Shanghai Chronic Disease and Risk Factors Surveillance (SCDRFS) in 2017. The weighted logistic regressions were performed to examine the associations between SD and stroke in different status of Mets and its components.

Results

The mean SD was 7.51±0.03 h/d. After adjusting for all the potential factors, SD<6 h/d (OR=1.73, 95% CI: 1.35-2.20) or ≥10 h/d (OR=1.66, 95% CI: 1.08-2.57) was significantly positively associated with stoke in the total participants; moreover, in the non-Mets group, only SD<6 h/d (OR=1.77, 95% CI: 1.19, 2.64) significantly increased the risk of stroke; while, in the Mets group, SD<6 h/d (OR=1.80, 95% CI:1.17-2.76) and ≥10 h/d (OR=1.97, 95% CI: 1.00-3.88) both had a positive significantly association with stoke. In addition, the effects of SD<6 h/d on stroke were more pronounced among those with high WC (OR=2.24, 95% CI: 1.40-3.58) and high TG (OR=2.60, 95% CI: 1.86-3.62), and the effects of SD≥10 h/d on stroke were more evident among those with high TG (OR=2.28, 95% CI: 1.02-5.08) and high FBG (OR=2.58, 95% CI: 1.30-5.10).

Conclusion

Both short and long SD were significantly positively associated with stroke in the total participants, and the associations were stronger in the Mets group; conversely, in the non-Mets group, only short SD was significantly positively associated with stroke, and no significant association was observed between long SD and stroke. Therefore, more precise sleep measures may be needed to prevent stroke according to the different status of Mets.

Poor sleep pattern is associated with metabolic disorder during transition from adolescence to adulthood

OBJECTIVE

The purpose of this study was to investigate whether sleep pattern is associated with metabolic disorders among young adults.

METHODS

We measured sleep patterns using multiple sleep behaviors in an ongoing prospective cohort among college students (n = 1,151). At baseline, 729 college students provided fasting blood samples and human body morphological measurements for quantification of metabolic parameters. Then, 340 participants continued to take metabolic parameters measurements at a 2-year follow-up. Sleep patterns were defined by chronotype, sleep duration, insomnia, snoring, and daytime sleepiness. Metabolic scores were derived for four metabolic parameters including body mass index (BMI), waist circumference (WC), fasting blood sugar (FBG), and insulin. Multivariate linear regression model was applied to analyze the association between sleep pattern types and metabolic parameters and metabolic scores.

RESULTS

In the baseline survey, we found that a total of 41 (4.1%) participants had poor sleep patterns. Then, metabolic scores were significantly higher among college students with poor sleep patterns, compared with those who with healthy sleep patterns at baseline (1.00 ± 0.96 vs. 0.78 ± 0.72, p < 0.05) and 2-year follow-up (0.34 ± 0.65 vs. 1.50 ± 1.64, p < 0.05). After covariates were adjusted, poor sleep pattern (β = 0.22, 95% CI: 0.06~2.53, p = 0.001) was associated with elevated metabolic scores at the 2-year follow-up.

CONCLUSIONS

The elevated metabolic burden observed in college students with poor sleep patterns highlights the need to identify and address sleep problems in order to minimize the long-term impact on disease vulnerability.

A J-shaped Relationship between Sleep Duration and the Risk of Insulin Resistance in a General Japanese Population

Objective Data on the role of sleep in the risk of insulin resistance (IR) are lacking. We therefore examined the association between sleep duration and IR in a general Japanese population. Methods Data of 1,344 individuals 34 to 89 years old from the Tanushimaru Study were analysed. IR was calculated using the fasting plasma glucose level×fasting insulin level/405, i.e. the homeostasis model assessment of IR (HOMA-IR). IR was defined as a HOMA-IR ≥1.73 based on the diagnostic criteria used in Japan. Information regarding sleep duration was collected via questionnaire. Results The frequencies of IR and metabolic syndrome (MetS) were 36.7% and 26.9%, respectively. A J-shaped relationship between sleep duration and IR was observed, and the same relationship was also shown between sleep duration and MetS; however, the relationship with MetS disappeared after adjusting for age, sex, and other confounding factors. Conclusion A J-shaped relationship was observed between sleep duration and the risks of IR in a general Japanese population.

Causal association between sleep traits and the risk of coronary artery disease in patients with diabetes

Background and aims

The association between sleep traits and coronary artery disease (CAD) in patients with diabetes has been reported in previous observational studies. However, whether these potential relationships are causal remains unclear. We aim to assess the causal relationship between sleep traits and CAD in diabetic.

Methods

Genetic instrumental variables associated with five sleep-related traits (insomnia, sleep duration, ease of getting up, morningness and snoring) were extracted from corresponding genome-wide association studies (GWAS). The associations of genetic variants with CAD were based on 15,666 individuals with diabetes (3,968 CAD cases and 11,696 controls). The primary analysis was derived using the inverse variance weighting method. Further sensitivity analysis was conducted to confirm the robustness and consistency of the main results.

Results

Genetic liability to insomnia was significantly related to the increased risk of CAD in individuals with diabetes [odds ratio (OR): 1.163; 95% CI: 1.072-1.254; p = 0.001]. Suggestive evidence was found for the borderline associations between both sleep duration (OR: 0.629; 95% CI: 0.380-1.042, p = 0.072) and snoring (OR: 1.010, 95% CI: 1.000-1.020, p = 0.050) with CAD risk. However, no consistent evidence was found for the association between ease of getting up and morningness with the risk of CAD in diabetic. Similar results can be verified in most sensitivity analyses.

Conclusions

We provide consistent evidence for the causal effect of insomnia on the increased risk of CAD in individuals with diabetes. The management of sleep health should be emphasized to prevent CAD in diabetic patients.

Evaluation of Sleep Habits and Disturbances Among US Adults, 2017-2020

IMPORTANCE

Unhealthy sleep behaviors and sleep disturbances are associated with higher risk of multiple diseases and mortality. The current profiles of sleep habits and disturbances, particularly the differences between workdays and free days, are unknown in the contemporary US.

OBJECTIVE

To comprehensively evaluate sleep habits on workdays and free days and the prevalence of sleep disturbances among US adults.

DESIGN, SETTING, AND PARTICIPANTS

This study is a cross-sectional analysis of US nationally representative data from the National Health and Nutrition Examination Survey (2017-2020) among adults aged 20 years or older. Data analysis was performed from February to May 2022.

MAIN OUTCOMES AND MEASURES

The main outcomes were means and/or distributions of sleep habits, including sleep duration and sleep-wake timing on workdays and free days, sleep debt (ie, the difference between sleep duration on free days and mean weekly sleep duration), and social jet lag (ie, the difference between the midpoint between sleep and wake time on workdays and free days). Prevalence of trouble sleeping (ie, participants told a doctor or other health professional that they have trouble sleeping) and daytime sleepiness (ie, self-reported feeling of being overly sleepy during the day ≥5 times per month) were also determined.

RESULTS

A total of 9004 individuals (mean [SE] age, 48.3 [0.53] years; 4635 women [51.9%]; 3158 non-Hispanic White [62.8%]) were included in the current study. The mean sleep duration was 7.59 hours (95% CI, 7.54 to 7.64 hours) on workdays and 8.24 hours (95% CI, 8.17 to 8.31 hours) on free days (difference, 0.65 hour). The mean sleep and wake times were at 11:02 pm (95% CI, 10:57 pm to 11:17 pm) and 6:41 am (95% CI, 6:36 am to 6:45 am), respectively, on workdays and 11:25 pm (95% CI, 11:21 pm to 11:35 pm) and 7:41 am (95% CI, 7:37 am to 7:46 am), respectively, on free days (differences, 0.23 hour for sleep time and 1.00 hour for wake time). On workdays, 23.1% (95% CI, 21.3% to 24.9%) of adults slept less than 7 hours and 25.4% (95% CI, 24.1% to 26.6%) went to sleep at midnight or later; the corresponding percentages changed to 12.9% (95% CI, 11.6% to 14.1%) and 40.9% (95% CI, 38.4% to 43.5%), respectively, on free days. Furthermore, the mean sleep debt was 0.73 hours (95% CI, 0.68 to 0.77 hours), and mean social jet lag was 1.10 hours (95% CI, 1.05 to 1.15 hours); 30.5% (95% CI, 26.8% to 33.3%) of adults experienced 1 hour or more of sleep debt, and 46.5% (95% CI, 42.6% to 50.3%) experienced 1 hour or more of social jet lag. The prevalence of trouble sleeping was 29.8% (95% CI, 28.2% to 31.5%), and that of daytime sleepiness was 27.2% (95% CI, 25.0% to 29.5%).

CONCLUSIONS AND RELEVANCE

In 2017 to 2020, US adults showed variability in sleep habits between workdays and free days, with longer sleep duration and later sleep-wake phases on free days, and high percentages of US adults experienced long-term sleep deprivation, chronic social jet lag, and frequent sleep disturbances. These findings provide evidence to further investigate potential approaches to optimize overall US sleep health.

Association between sleep duration and incidence of type 2 diabetes in China: the REACTION study

Backgrounds:

Inadequate sleep duration is associated with a higher risk of type 2 diabetes and the relationship is nonlinear. We aim to assess the curve relationship between night sleep duration and the incidence of type 2 diabetes in China.

Methods:

A cohort of 11,539 participants from the REACTION study without diabetes at baseline (2011) were followed until 2014 for the development of type 2 diabetes. The average number of hours of sleep per night was grouped. Incidence rates and odds ratios (ORs) were calculated for the development of diabetes in each sleep duration category.

Results:

Compared to people who sleep for 7 to 8 h/night, people with longer sleep duration (≥9 h/night) had a greater risk of type 2 diabetes (OR: 1.27; 95% CI: 1.01–1.61), while shorter sleep (<6 h/night) had no significant difference in risk of type 2 diabetes. When the dataset was stratified based on selected covariates, the association between type 2 diabetes and long sleep duration became more evident among individuals <65 years of age, male, body mass index <24 kg/m² or with hypertension or hyperlipidemia, no interaction effects were observed. Furthermore, compared to people persistently sleeping 7 to 9 h/night, those who persistently slept ≥9 h/night had a higher risk of type 2 diabetes. The optimal sleep duration was 6.3 to 7.5 h/night.

Conclusions:

Short or long sleep duration was associated with a higher risk of type 2 diabetes. Persistently long sleep duration increased the risk.

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.

Association of sleep duration with risk of type 2 diabetes mellitus in a rural Chinese population: a nested case-control study

PURPOSE

To investigate the association of sleep duration with type 2 diabetes mellitus (T2DM) in a rural Chinese population.

METHODS

A 1:1 matched nested case-control study was performed based on a cohort that had been established in rural communities in Henan Province, China. T2DM patients and healthy controls (550 pairs) were included in this study.

RESULTS

Abnormal sleep duration significantly increased the risk of T2DM with an approximate U-shaped association (sleep duration ≤ 6 h, OR = 1.742, 95% CI = 1.007-3.011, P = 0.047; sleep duration 8-9 h, OR = 1.462, 95% CI = 1.038-2.060, P = 0.030) compared with participants with a night sleep duration of 7-8 h, after adjusting for multiple confounders. When stratified by gender, only women were sensitive to shorter sleep duration (OR = 2.483, 95% CI = 1.149-5.366, P = 0.021). Abnormal sleep duration (too short or too long) had adverse effects on homeostasis model assessment (HOMA) and blood metabolites, and the effect was more noticeable in people with longer sleep durations.

CONCLUSION

In a rural Chinese population, both too short and too long sleep duration increased the risk of T2DM. Especially women with less sleep duration have a higher risk of T2DM. Abnormal sleep also affects the HOMA index and metabolites; the relationship between HOMA-IR, total cholesterol, and LDL-Cholesterol with sleep duration was U-shaped, while fasting plasma glucose, body mass index, waist circumference, and triglyceride levels increased significantly only with longer sleep duration.

Sleep duration and type 2 diabetes risk: A prospective study in a population-based Mexican American cohort

STUDY OBJECTIVES

The primary aim of the study was to estimate the effect of sleep duration on prospective type 2 diabetes (T2D) risk across demographic characteristics and follow-up periods, and test body mass index (BMI) as a mediator and moderator.

METHODS

Data included adults (M_age = 39.0 ± 12.7 years) born in the United States or Mexico recruited from 2001 to 2012 in a Mexican American cohort study conducted in Houston, TX (n = 15,779). Participants completed self-reported questionnaires at baseline related to health, health behaviors (sleep duration, physical activity, smoking, drinking), and sociocultural factors and were followed up annually.

RESULTS

Cox proportional hazard models estimated hazard ratios (HR) for the effect of sleep duration on T2D diagnosis at follow-up. Of the participants, 10.3% were diagnosed with T2D. Self-reported ≤5 hours of sleep, compared to 7-8 hours, at baseline predicted greater risk for T2D (HR = 1.32, P = .001), yet was no longer significant after adjusting for sociodemographic characteristics and BMI. Notably, those with BMI <25 kg/m² reporting ≤5 hours of sleep were at significant risk for T2D at 3 (HR = 4.13, P = .024) and 5-year follow-up (HR = 3.73, P = .008) compared to 7-8 hours. Obesity status accounted for 31.6% and 27.3% of the variance in the association between ≤5 and 6 hours of sleep and increased T2D risk, respectively.

CONCLUSIONS

Results highlighted the mediating and moderating role of BMI, and its effect on T2D risk at earlier follow-up among those without obesity. T2D prevention and control for Mexican American adults should consider the role of chronic sleep loss.

Association of apnea-hypopnea index during rapid eye movement sleep with insulin resistance in patients with suspected obstructive sleep apnea: a cross-sectional study

Background

Obstructive sleep apnea (OSA) is associated with insulin resistance. However, the association between special stages of OSA [rapid eye movement (REM) sleep] and insulin resistance is not clear. This study was designed to assess the association of the frequency of respiratory events during REM sleep with insulin resistance in adults with suspected OSA.

Methods

In this cross-sectional study, 4,062 adult participants with suspected OSA who underwent polysomnography in our sleep center between 2009 and 2016 were screened. Polysomnographic variables, biochemical indicators, and physical measurements were collected. Logistic regression analyses were conducted to determine the odds ratios (ORs) and 95% confidence intervals (95% CIs) for insulin resistance as assessed by the presence of hyperinsulinemia, the homeostasis model assessment of insulin resistance (HOMA-IR) index, the fasting insulin resistance index (FIRI), and Bennett’s insulin sensitivity index (ISI).

Results

The final analyses included 2,899 adults with suspected OSA. Multivariate adjustments, including the apnea-hypopnea index (AHI) during non-REM sleep (AHI_NREM), were performed. The AHI during REM sleep (AHI_REM) was found to be independently associated with insulin resistance across increasing AHI_REM quartiles. For hyperinsulinemia the ORs (95% CIs) followed the order of 1.340 (1.022, 1.757), 1.210 (0.882, 1.660), and 1.632 (1.103, 2.416). For abnormal HOMA-IR, ORs (95% CIs) were 1.287 (0.998, 1.661), 1.263 (0.933, 1.711), and 1.556 (1.056, 2.293). For abnormal FIRI, ORs (95% CIs) were 1.386 (1.048, 1.835), 1.317 (0.954, 1.818), and 1.888 (1.269, 2.807). For abnormal Bennett’s ISI, ORs (95% CIs) were 1.297 (1.003, 1.678), 1.287 (0.949, 1.747), and 1.663 (1.127, 2.452). All linear trends were statistically significant (P<0.01). Additionally, the results showed that REM sleep duration was independently associated with hyperinsulinemia (OR =0.777, 95% CI: 0.615–0.982; P<0.05).

Conclusions

AHI_REM was independently associated with hyperinsulinemia and an abnormal HOMA-IR, FIRI, and Bennett’s ISI in adults with suspected OSA. Additionally, REM sleep duration was independently associated with hyperinsulinemia.

Mechanisms of Insulin Resistance at the Crossroad of Obesity with Associated Metabolic Abnormalities and Cognitive Dysfunction

Obesity mediates most of its direct medical sequelae through the development of insulin resistance (IR). The cellular effects of insulin occur through two main postreceptor pathways that are the phosphatidylinositol 3-kinase (PI3-K) and the mitogen-activated protein kinase (MAP-K) pathways. Obesity-related IR implicates the PI3-K pathway that confers the metabolic effects of insulin. Numerous and complex pathogenic pathways link obesity with the development of IR, including chronic inflammation, mitochondrial dysfunction (with the associated production of reactive oxygen species and endoplasmic reticulum stress), gut microbiota dysbiosis and adipose extracellular matrix remodelling. IR itself plays a key role in the development of metabolic dysfunction, including hypertension, dyslipidaemia and dysglycaemia. Furthermore, IR promotes weight gain related to secondary hyperinsulinaemia, with a resulting vicious cycle of worsening IR and its metabolic sequelae. Ultimately, IR underlies obesity-related conditions such as type 2 diabetes mellitus (T2D) and polycystic ovary syndrome (PCOS). IR also underlies many obesity-related malignancies, through the effects of compensatory hyperinsulinaemia on the relatively intact MAP-K insulin pathway, which controls cellular growth processes and mitoses. Furthermore, the emergent data over recent decades support an important role of obesity- and T2D-related central IR in the development of cognitive dysfunction, including effects on hippocampal synaptic plasticity. Importantly, IR is largely reversible through the optimisation of lifestyle factors that include regular engagement in physical activity with the avoidance of sedentariness, improved diet including increased fibre intake and sleep sufficiency. IR lies at the key crossroad between obesity and both metabolic and cognitive dysfunction. Given the importance of IR in the pathogenesis of many 21st century chronic diseases and its eminent reversibility, it is important that we all embrace and facilitate optimised lifestyles to improve the future health and wellbeing of the populace.

Interaction between obstructive sleep apnea and short sleep duration on insulin resistance: a large-scale study : OSA, short sleep duration and insulin resistance

Objectives

Both short sleep duration and obstructive sleep apnea (OSA) seem to be associated with insulin resistance. We aimed to explore whether short sleep duration modifies the relationship between OSA and insulin resistance.

Methods

Participants were consecutively enrolled from our sleep center during the period from 2007 to 2017. The index of homeostasis model assessment insulin resistance (HOMA-IR) was calculated from insulin and glucose. Sleep duration was determined by standard polysomnography. The associations between sleep duration and insulin resistance were estimated by logistic regression analyses.

Results

A total of 5447 participants (4507 OSA and 940 primary snorers) were included in the study. OSA was independently correlated with insulin resistance after adjusting for all potential confounders (OR, 1.319; 95% CI, 1.088–1.599), but not short sleep duration. In stratified analysis by sleep duration, compared with primary snorers, in the OSA group only extremely short sleep duration (< 5 h) was significantly associated with insulin resistance after adjusting for all covariates (OR, 2.229; 95% CI, 1.283–3.874). Rapid eye movement predominant OSA was significantly associated with insulin resistance (OR = 1.355, 95% CI: 1.019–1.802) after adjustment for confounding factors including age, sex and body mass index.

Conclusions

OSA, but not short sleep duration, was independently associated with insulin resistance. It is worth noting that OSA combined with extremely short sleep duration showed a greater detrimental effect than OSA itself with regard to insulin resistance.

Associations of sleep quality, sleep apnea and autonomic function with insulin secretion and sensitivity: HSCAA study

RATIONALE AND PURPOSE

Although sleep disorders are shown to be involved in occurrence of diabetes, impacts of several quantitative parameters related to sleep on insulin secretion and sensitivity is yet to be elucidated. We cross-sectionally examined relationships among quantitative sleep quality, sleep apnea, and autonomic function with insulin secretion and sensitivity in 399 patients without previous diagnosed diabetes who underwent 75-g oral glucose tolerance test (75gOGTT).

METHOD

Poor sleep quality (PSQ) was defined as an activity index ≥50 by actigraphy. Sleep apnea was measured by apnomonitor, while standard deviation of all normal-to-normal R-R intervals (SDNN) was measured by active tracer. Parameters of insulin secretion and sensitivity were measured by 75gOGTT.

RESULTS

Patients with PSQ exhibited significantly lower insulinogenic index (r = 0.155, p < 0.01), a parameter of insulin secretion, with the association independent of other clinical factors including apnea and SDNN (β = -0.156, p < 0.01). In contrast, presence of sleep apnea (r = -0.143, p < 0.05) and the lower SDNN (r = -0.150, p < 0.01) were significantly and inversely associated with BIGTT-S, an insulin sensitivity parameter, with the association of SDNN with BIGTT-S remaining significant even after adjustments for PSQ and sleep apnea (β = -0.111, p < 0.05).

CONCLUSION

Poor sleep quality is an independent predictor of pancreatic β-cell function, which could be involved in occurrence of type 2 diabetes.

Energy, Nutrient and Food Intakes of Male Shift Workers Vary According to the Schedule Type but Not the Number of Nights Worked

Shift work is associated with increased risk of chronic diseases due to circadian rhythm disruptions and behavioral changes such as in eating habits. Impact of type of shifts and number of night shifts on energy, nutrient and food intake is as yet unknown. Our goal was to analyze shift workers’ dietary intake, eating behavior and eating structure, with respect to frequency of nights worked in a given week and seven schedule types. Eating habits and dietary intakes of 65 male shift workers were analyzed in three steps based on 365 24-h food records: (1) according to the number of nights, (2) in a pooled analysis according to schedule type, and (3) in search of an interaction of the schedule and the timing of intake. Mean nutrient and food group intake during the study period did not depend on the number of nights worked. Amount and distribution of energy intake as well as quality of food, in terms of nutrient and food groups, differed depending on the type of schedule, split night shifts and recovery day (day after night shift) being the most impacted. Shift workers’ qualitative and quantitative dietary intakes varied between different schedules, indicating the need for tailored preventive interventions.

The Association between Habitual Sleep Duration and Sleep Quality with Glycemic Traits: Assessment by Cross-Sectional and Mendelian Randomization Analyses

Evidence on whether habitual sleep duration and sleep quality are associated with increased insulin resistance is inconsistent. Here, we investigated the associations between different measures of habitual sleep with glycemic traits through cross-sectional and Mendelian randomization (MR) analyses. We assessed the associations of sleep duration and sleep quality with glycemic traits using multivariable linear regression models adjusted for potential confounders in 4672 middle-aged (45–65 years; 48% men) nondiabetic participants of the Netherlands Epidemiology of Obesity (NEO) study. Genetic variants for total, short, and long sleep duration were used as instrumental variables in MR analyses using summary-level data of glycemic traits in nondiabetic individuals (MAGIC; n = 58,074). In cross-sectional analyses, shortest sleepers (median 5.0 h of sleep per night) had 14.5% (95% confidence interval (CI): 2.0; 28.6%) higher fasting insulin level and 16.3% (95% CI: 2.7; 31.7%) higher HOMA-β. Bad sleep quality was associated with higher insulin resistance (e.g., 14.3% (95% CI: 4.7; 24.9%) higher HOMA-IR). All these associations disappeared after adjustment for BMI and the risk of sleep apnea. MR analyses did not indicate a causal association between total, short or long sleep duration and glycemic traits. Therefore, our used measures of habitual sleep duration and sleep quality are unlikely to directly associate with insulin resistance.