Relationships among sleep timing, sleep duration and glycemic control in Type 2 diabetes in Thailand

Attention to Innate Circadian Rhythm and the Impact of Its Disruption on Diabetes

Novel strategies are required to reduce the risk of developing diabetes and/or clinical outcomes and complications of diabetes. In this regard, the role of the circadian system may be a potential candidate for the prevention of diabetes. We reviewed evidence from animal, clinical, and epidemiological studies linking the circadian system to various aspects of the pathophysiology and clinical outcomes of diabetes. The circadian clock governs genetic, metabolic, hormonal, and behavioral signals in anticipation of cyclic 24-hour events through interactions between a "central clock" in the suprachiasmatic nucleus and "peripheral clocks" in the whole body. Currently, circadian rhythmicity in humans can be subjectively or objectively assessed by measuring melatonin and glucocorticoid levels, core body temperature, peripheral blood, oral mucosa, hair follicles, rest-activity cycles, sleep diaries, and circadian chronotypes. In this review, we summarized various circadian misalignments, such as altered light-dark, sleep-wake, rest-activity, fasting-feeding, shift work, evening chronotype, and social jetlag, as well as mutations in clock genes that could contribute to the development of diabetes and poor glycemic status in patients with diabetes. Targeting critical components of the circadian system could deliver potential candidates for the treatment and prevention of type 2 diabetes mellitus in the future.

Association of BMAL1 clock gene polymorphisms with fasting glucose in children

BACKGROUND

The brain and muscle Arnt-like protein-1 (BMAL1) gene is an important circadian clock gene and previous studies have found that certain polymorphisms are associated with type 2 diabetes in adults. However, it remains unknown if such polymorphisms can affect fasting glucose in children and if other factors modify the associations.

METHODS

A school-based cross-sectional study with 947 Chinese children was conducted. A multivariable linear regression model was used to analyze the association between BMAL1 gene polymorphisms and fasting glucose level.

RESULTS

After adjusting for age, sex, body mass index (BMI), physical activity, and unhealthy diet, GG genotype carriers of BMAL1 rs3789327 had higher fasting glucose than AA/GA genotype carriers (b = 0.101, SE = 0.050, P = 0.045). Adjusting for the same confounders, rs3816358 was shown to be significantly associated with fasting glucose (b = 0.060, SE = 0.028, P = 0.032). Furthermore, a significant interaction between rs3789327 and nutritional status on fasting glucose was identified (P_interaction = 0.009); rs3789327 was associated with fasting glucose in the overweight/obese subgroup (b = 0.353, SE = 0.126, P = 0.006), but not in non-overweight/non-obese children.

CONCLUSIONS

BMAL1 polymorphisms were significantly associated with the fasting glucose level in children. Additionally, the observed interaction between nutritional status and BMAL1 supports promoting an optimal BMI in children genetically predisposed to higher glucose level.

IMPACT

Polymorphisms in the essential circadian clock gene BMAL1 were associated with fasting blood glucose levels in children. Additionally, there was a significant interaction between nutritional status and BMAL1 affecting fasting glucose levels. BMAL1 rs3789327 was associated with fasting glucose only in overweight/obese children. This finding could bring novel insights into mechanisms by which nutritional status influences fasting glucose in children.

Associations between sleep variability and cardiometabolic health: A systematic review

This review explored the associations between sleep variability and cardiometabolic health. It was performed following PRISMA guidelines. We identified 63 studies. Forty-one studies examined the association between sleep variability and body composition, with 29 examined body mass index (BMI). Thirteen studies used social jet lag (SJL), n = 30,519, with nine reporting a null association. Eight studies used variability in sleep duration (n = 33,029), with five reporting a correlation with BMI. Fourteen studies (n = 133,403) focused on overweight/obesity; significant associations with sleep variability were found in 11 (n = 120,168). Sleep variability was associated with weight gain (seven studies; n = 79,522). Twenty-three studies examined glucose outcomes. The association with hemoglobin A1c (16 studies, n = 11,755) differed depending on populations, while associations with diabetes or glucose were mixed, and none were seen with insulin resistance (five studies; n = 6416). Sixteen studies examined cardiovascular-related outcomes, with inconsistent results. Overall significant associations were found in five studies focusing on metabolic syndrome (n = 7413). In summary, sleep variability was likely associated with obesity, weight gain, and metabolic syndrome. It might be associated with hemoglobin A1c in people with type 1 diabetes. The associations with other outcomes were mixed. This review highlighted the possible association between sleep variability and cardiometabolic health.

Effect of exercises according to the circadian rhythm in type 2 diabetes: Parallel-group, single-blind, crossover study

BACKGROUND AND AIM

To evaluate the effectiveness of structured exercise appropriate the circadian rhythm in terms of blood sample test (BST), functionality and quality of life (QoL) in individuals with type 2 diabetes.

METHODS AND RESULTS

This was a parallel-group, single-blind, crossover study. Thirty individuals with type 2 diabetes aged 35-65 years were enrolled in the study and allocated into 2 groups as the Morning Chronotype (MC) Group (n = 15) and the Evening Chronotype (EC) Group (n = 15) using Morningness-Eveningness Questionnaire which was used to determine the chronotypes. Participants were evaluated in terms of BST, functionality and QoL at the beginning of the study (T0), at 6 (T1), 12 (T2), and 18 (T3) weeks after the study started. A structured exercise program for 3 days a week over 6 weeks was applied in accordance with the chronotypes (T1-T2) and cross-controlled for the chronotypes (T2-T3). Significant differences were found in favor of the exercise given at the appropriate time for the chronotype in all parameters in both groups within groups (T0-T1-T2-T3) (p < 0.05). In the time∗group interactions, exercise in accordance with the appropriate chronotype in both groups provided the highest statistical improvement in all parameters (p < 0.05).

CONCLUSION

It was concluded that structured exercise performed at the appropriate time for chronotype improves HbA_1c, fasting blood glucose, HDL-LDL cholesterol, triglyceride, total cholesterol, functionality and quality of life in type 2 diabetes. This variation in blood values was observed to reflect the quantitative effects of exercise administered according to the circadian rhythm in individuals with type 2 diabetes.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT04427488). The protocol of the study was registered at ClinicalTrials.gov (NCT04427488).

The Effects of Objective Push-type Sleep Feedback on Habitual Sleep Behavior and Momentary Symptoms in Daily Life: Mobile Health Intervention Trial using a Healthcare IoT System (Preprint)

Background

Sleep is beneficial for physical and mental health. Several mobile and wearable sleep-tracking devices have been developed, and personalized sleep feedback is the most common functionality among these devices. To date, no study has implemented an objective push-type feedback message and investigated the characteristics of habitual sleep behavior and diurnal symptoms when receiving sleep feedback.

Objective

We conducted a mobile health intervention trial to examine whether sending objective push-type sleep feedback changes the self-reported mood, physical symptoms, and sleep behavior of Japanese office workers.

Methods

In total, 31 office workers (mean age 42.3, SD 7.9 years; male-to-female ratio 21:10) participated in a 2-arm intervention trial from November 30 to December 19, 2020. The participants were instructed to indicate their momentary mood and physical symptoms (depressive mood, anxiety, stress, sleepiness, fatigue, and neck and shoulder stiffness) 5 times a day using a smartphone app. In addition, daily work performance was rated once a day after work. They were randomly assigned to either a feedback or control group, wherein they did or did not receive messages about their sleep status on the app every morning, respectively. All participants wore activity monitors on their nondominant wrists, through which objective sleep data were registered on the web on a server. On the basis of the estimated sleep data on the server, personalized sleep feedback messages were generated and sent to the participants in the feedback group using the app. These processes were fully automated.

Results

Using hierarchical statistical models, we examined the differences in the statistical properties of sleep variables (sleep duration and midpoint of sleep) and daily work performance over the trial period. Group differences in the diurnal slopes for mood and physical symptoms were examined using a linear mixed effect model. We found a significant group difference among within-individual residuals at the midpoint of sleep (expected a posteriori for the difference: −15, 95% credible interval −26 to −4 min), suggesting more stable sleep timing in the feedback group. However, there were no significant group differences in daily work performance. We also found significant group differences in the diurnal slopes for sleepiness (P<.001), fatigue (P=.002), and neck and shoulder stiffness (P<.001), which was largely due to better scores in the feedback group at wake-up time relative to those in the control group.

Conclusions

This is the first mobile health study to demonstrate that objective push-type sleep feedback improves sleep timing of and physical symptoms in healthy office workers. Future research should incorporate specific behavioral instructions intended to improve sleep habits and examine the effectiveness of these instructions.

The cross talk between chronotype, depression symptomatology, and glycaemic control among sudanese patients with diabetes mellitus: A case-control study

Aim of the Study:

There is an increasing awareness about chronotype and depression among patients with diabetes mellitus as commonly ignored serious association. We aimed to investigate the same among patients with type 2 diabetes mellitus and their relation to glycaemic control.

Subjects' and Methods:

This case-control study conducted at two diabetes centers in Omdurman, Sudan during the period from April 2019 to September 2019. Ninety-two patient with type 2 diabetes and 94 controls signed a written informed consent then interviewed using a structured questionnaire based on the morningness–eveningness scale and the 12-item general health questionnaire; A blood sample was taken for the glycated haemoglobin to assess glycaemic control. The Statistical Package for Social Silences was used for Data analysis.

Results:

They were 92 patients with diabetes (58.7% women) and 94 healthy control subjects (52.1% women); matched for ages (57.03 ± 8.59 for diabetic patients and 58.46 ± 10.58 years for control subjects) and sex. Morning chronotype was reported in 95.3% vs. 47.5% and intermediate chronotype was evident in 52.4% vs. 4.3% in controls and patients respectively, P < 0.05. Depression symptomatology was found in 76.1% of patients with diabetes vs. 40.4% of control subjects, P < 0.05. No association was shown between depression symptomatology, chronotype, age, sex, and HbA1c, P > 0.05.

Conclusion:

Sudanese patients with diabetes were more likely intermediate, less morning chronotype, and more depressed compared to their counterparts. No association was found between depression symptomatology and other patient's characters. Larger studies investigating the risk behind depression, chrono-nutrition, and social jetlag among patients with diabetes are needed.

Accelerometer-derived sleep onset timing and cardiovascular disease incidence: a UK Biobank cohort study

Aims

Growing evidence suggests that poor sleep health is associated with cardiovascular risk. However, research in this area often relies upon recollection dependent questionnaires or diaries. Accelerometers provide an alternative tool for measuring sleep parameters objectively. This study examines the association between wrist-worn accelerometer-derived sleep onset timing and cardiovascular disease (CVD).

Methods and results

We derived sleep onset and waking up time from accelerometer data collected from 103 712 UK Biobank participants over a period of 7 days. From this, we examined the association between sleep onset timing and CVD incidence using a series of Cox proportional hazards models. A total of 3172 cases of CVD were reported during a mean follow-up period of 5.7 (±0.49) years. An age- and sex-controlled base analysis found that sleep onset time of 10:00 p.m.-10:59 p.m. was associated with the lowest CVD incidence. An additional model, controlling for sleep duration, sleep irregularity, and established CVD risk factors, did not attenuate this association, producing hazard ratios of 1.24 (95% confidence interval, 1.10-1.39; P < 0.005), 1.12 (1.01-1.25; P = 0.04), and 1.25 (1.02-1.52; P = 0.03) for sleep onset <10:00 p.m., 11:00 p.m.-11:59 p.m., and ≥12:00 a.m., respectively, compared to 10:00 p.m.-10:59 p.m. Importantly, sensitivity analyses revealed this association with increased CVD risk was stronger in females, with only sleep onset <10:00 p.m. significant for males.

Conclusions

Our findings suggest the possibility of a relationship between sleep onset timing and risk of developing CVD, particularly for women. We also demonstrate the potential utility of collecting information about sleep parameters via accelerometry-capable wearable devices, which may serve as novel cardiovascular risk indicators.

Sleep Timing May Predict Congestive Heart Failure: A Community-Based Cohort Study

Background

Previous studies have suggested that sleep timing is associated with cardiovascular risk factors. However, there is no evidence on the relationship between sleep timing and congestive heart failure (CHF). We aimed to examine this relationship in this study.

Methods and Results

We recruited 4765 participants (2207 men; mean age, 63.6±11.0 years) from the SHHS (Sleep Heart Health Study) database in this multicenter prospective cohort study. Follow‐up was conducted until the first CHF diagnosis between baseline and the final censoring date. Sleep timing (bedtimes and wake‐up times on weekdays and weekends) was based on a self‐reported questionnaire. Cox proportional hazard models were constructed to investigate the association between sleep timing and CHF. During the mean follow‐up period of 11 years, 519 cases of CHF (10.9%) were reported. The multivariable Cox proportional hazards models revealed that participants with weekday bedtimes >12:00 am (hazard ratio [HR], 1.56; 95% CI, 1.15–2.11; P=0.004) and from 11:01 pm to 12:00 am (HR, 1.25; 95% CI, 1.00–1.56; P=0.047) had an increased risk of CHF compared with those with bedtimes from 10:01 pm to 11:00 pm. After stratified analysis, the association was intensified in participants with a self‐reported sleep duration of 6 to 8 hours. Furthermore, wake‐up times >8:00 am on weekdays (HR, 1.53; 95% CI, 1.07–2.17; P=0.018) were associated with a higher risk of incident CHF than wake‐up times ≤6:00 am.

Conclusions

Delayed bedtimes (>11:00 pm) and wake‐up times (>8:00 am) on weekdays were associated with an increased risk of CHF.

Later bedtime is associated with angina pectoris in middle-aged and older adults: results from the Sleep Heart Health Study

OBJECTIVES

Sleep timing is related to several risk factors for angina pectoris (AP), such as obesity and diabetes. This study was designed to evaluate the relationship between sleep timing and AP, specifically whether later bedtime was associated with AP in middle-aged and older adults.

METHODS

This community-based study was based on the Sleep Heart Health Study cohort and included 4710 participants (45.9% men, aged 63.3 ± 11.0 years). Lifestyle and epidemiological information were obtained from baseline records. Self-reported sleep measures provided information on bedtime and wake-up time of weekdays and weekends. Individuals were divided into three categories according to bedtime (≤22:00, 22:01-23:00, and >23:00). Odds ratios (OR) and 95% confidence intervals (CIs) of AP for bedtimes were estimated with multivariate logistic regression analysis.

RESULTS

The prevalence of AP was 44.2% and the distribution of weekday bedtimes ≤22:00, 22:01-23:00_, and >23:00 were 36.6%, 47.5% and 46.0%, respectively. After adjusting for potential confounders, weekday bedtimes >23:00 (OR 1.34; 95% CI 1.13-1.60; P = 0.001) and 22:01-23:00 (OR 1.54; 95% CI 1.29-1.82; P < 0.001) were significantly associated with an increased risk of AP compared with the reference group (≤22:00). In addition, weekend bedtimes >23:00 (OR 1.44; 95% CI 1.20-1.73; P < 0.001) and 22:01-23:00 (OR 1.70; 95% CI 1.40-2.05; P < 0.001) increased the risk of AP.

CONCLUSIONS

Later bedtimes on both weekdays and weekends were significantly associated with an increased prevalence of AP. Early bedtimes may help people decrease the risk of AP.

Association of Evening Chronotype with Poor Control of Type 2 Diabetes: Roles of Sleep Duration and Insomnia Level

BACKGROUND

Evening chronotype is usually associated with insomnia and short sleep duration.

OBJECTIVES

To investigate the independent association of chronotype with diabetes control.

METHODS

In this cross-sectional study, 140 patients with type 2 diabetes were studied. The insomnia score was examined by a 7-item questionnaire. Also, chronotype was assessed by a 19-item questionnaire, and using the questionnaire, the patients were divided into three groups of morning, intermediate, and evening. This questionnaire has been developed for evaluating the preference for performing mental and physical activities at a special time of day. The Multivariate hierarchical analysis was applied for investigating the independent association of chronotype and glycated hemoglobin (HbA1c).

RESULTS

The fasting blood glucose and HbA1c levels were significantly different across all the three chronotype groups such that it had the highest value in the evening group and the lowest value in the morning group (FBS = 164.5 ± 34.1 mg/dL and HbA1c = 8.7% ± 1.7, in the evening group, and FBS = 132.7 ± 23.1 mg/dL and HbA1c = 6.9% ± 0.4 in the morning group, P < 0.001). The morning group had longer sleep duration and less insomnia than other groups. Results of the hierarchical regression analysis showed that the chronotype explained 28.4% of the variance of HbA1c. Results of the final model demonstrated that the chronotype had a relationship with HbA1c, independent of body mass index (BMI), time of going to bed, and insomnia score.

CONCLUSIONS

Evening chronotype is associated with poorer control of diabetes, independent of BMI and sleep variables.

The relationship between sleep onset time and cardiometabolic biomarkers in Chinese communities: a cross-sectional study

Background

Late sleep onset time (SOT) is a common social phenomenon in modern society, and it was associated with a higher risk of obesity. However, the literature gap exists about the SOT and cardiometabolic biomarkers which closely associated with obesity. The present study aimed to explore the association of SOT with cardiometabolic biomarkers in Chinese communities.

Methods

A cross-sectional study enrolled a total of 2418 participants was conducted in Ningxia province of China. The cardiometabolic biomarkers included triglyceride, total cholesterol, high-density lipoprotein, low-density lipoprotein and fasting plasma glucose were measured quantitatively using the standard method. The SOT and sleep duration were acquired by a self-report questionnaire. The multiple mixed-effect linear regression model was employed to examine the association.

Results

Binary analysis found an inverse association of SOT with high-density lipoprotein (β = − 0.05, 95%CI: − 0.06, − 0.03), with 1 h delayed in SOT the high-density lipoprotein decreased 0.05 mmol/L. After controlling for demographic variables, health-related behaviors, and physical health covariates, late SOT was associated with a higher level of triglyceride (β = 0.12, 95%CI: 0.06, 0.18), a higher level of low-density lipoprotein (β = 0.06, 95% CI: 0.02, 0.09), and a lower level of high-density lipoprotein (β = − 0.05, 95% CI: − 0.06, − 0.03). when stratified by sleep duration (less than eight hours vs. eight and longer hours), a positive association between SOT and LDL (β = 0.08, 95% CI: 0.04, 0.12) was found among participants with sleep duration eight hours and longer.

Conclusion

Late sleep onset time with the negative effect on the cardiometabolic biomarkers, and individuals with late SOT coupled with longer sleep duration may take risk of a higher level of low-density lipoprotein which in turn lead to increase the risk of cardiovascular disease.

Sleep and HbA1c in Patients With Type 2 Diabetes: Which Sleep Characteristics Matter Most?

OBJECTIVE

Poor sleep has been identified as a risk factor for poor glycemic control in individuals with type 2 diabetes (T2D). As optimal sleep can be characterized in several ways, we evaluated which sleep characteristics are most strongly associated with glycated hemoglobin A_1c (HbA_1c).

RESEARCH DESIGN AND METHODS

A total of 172 patients with T2D completed 7-day wrist-actigraphy and sleep questionnaires. Linear regression was used to evaluate associations between sleep measures (total sleep duration, variability in sleep duration, midsleep time, variability in midsleep time, sleep efficiency, subjective sleep quality, and subjective insomnia symptoms) and HbA_1c, individually and in concert.

RESULTS

Variability in sleep duration was individually most strongly associated with HbA_1c (β = 0.239; P = 0.002; R ² = 4.9%), followed by total sleep duration (U-shaped: β = 1.161/β² = 1.044; P = 0.017/0.032; R ² = 4.3%), subjective sleep quality (β = 0.191; P = 0.012; R ² = 3.6%), variability in midsleep time (β = 0.184; P = 0.016; R ² = 3.4%), and sleep efficiency (β = -0.150; R ² = 2.3%). Midsleep time and subjective insomnia symptoms were not associated with HbA_1c. In combination, variability in sleep duration, total sleep duration, and subjective sleep quality were significantly associated with HbA_1c, together explaining 10.3% of the variance in HbA_1c. Analyses adjusted for covariates provided similar results, although the strength of associations was generally decreased and showing total sleep duration and subjective sleep quality to be most strongly associated with HbA_1c, together explaining 6.0% of the variance in HbA_1c.

CONCLUSIONS

Sleep in general may be a modifiable factor of importance for patients with T2D. The prevention of sleep curtailment may serve as a primary focus in the sleep-centered management of T2D.

Association Between Late Bedtime and Diabetes Mellitus: A Large Community-Based Study

STUDY OBJECTIVES

The aim of this study was to investigate the association of bedtime with the prevalence of diabetes mellitus (DM) based on a large community-based population.

METHODS

In total, 5,420 participants (2,574 males and 2,846 females; aged 63.5 ± 11.0 years) from the Sleep Heart Health Study database were selected in this study. Sleep habit was recorded based on a questionnaire administered to patients upon recruitment. Bedtime was categorized as 11:00 pm and before, 11:00 pm to 12:00 am, and 12:00 am and later in the current study. Multivariate logistic regression was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) to determine the relationship between bedtime and the prevalence of DM.

RESULTS

The distribution of weekday bedtime at 11:00 pm and before, 11:00 pm to 12:00 am, 12:00 am and later was observed in 3,316 participants (61.2%), 991 participants (18.3%), and 1,113 participants (20.5%), respectively. Meanwhile, individuals with weekday bedtime of 12:00 am and later had a higher prevalence of DM than those with bedtime at 11:00 pm to 12:00 am, and 11:00 pm and before (10.6% versus 5.7% versus 6.6%, respectively; P < .001). In the adjusted multivariate logistic regression model, bedtime at 12:00 am and later on a weekday was significantly associated DM prevalence (OR 1.446, 95% CI 1.107-1.888, P = .007). No significant association was found between weekend bedtime and DM.

CONCLUSION

Late bedtime at 12:00 am and later on a weekday may be a risk factor for the prevalence of DM. Stable sleep timing leads to lower risk of DM deserves future exploration.

Effect of Educational Strategies on the Sleep Quality of People with Diabetes: Randomized Clinical Trial

Objective: To evaluate the effect of educational strategies on sleep quality and its relation to diabetes-related distress and glycemic control in people with type 2 diabetes mellitus (DM2). Materials and methods: Randomized clinical trial involving two groups. Group 1 (G1, n = 45) received verbal guidance and leaflets on sleep hygiene strategies and group 2 (G2, n = 46) received usual health care guidelines on self-care with the feet. Sleep was assessed by the Pittsburgh Sleep Quality Inventory and diabetes-related distress by the Diabetes Distress Scale. Linear mixed-effects models and linear regression model were used for the statistical analysis. Results: At the end of the follow-up, sleep quality improvement (p = 0.02) was verified in G1. Low diabetes-related distress score (p = 0.03), being male (p = 0.02), belonging to G1 (p = 0.002), and age (p = 0.04) contributed to better sleep quality. Conclusion: Educational guidelines on sleep hygiene in patients with DM2 were effective in improving sleep quality, measured by the PSQI instrument and emotional stress related to diabetes as assessed by the Diabetes Distress Scale.

Daylight Saving Time and Artificial Time Zones - A Battle Between Biological and Social Times

Many regions and countries are reconsidering their use of Daylight Saving Time (DST) but their approaches differ. Some, like Japan, that have not used DST over the past decades are thinking about introducing this twice-a-year change in clock time, while others want to abolish the switch between DST and Standard Time, but don’t agree which to use: California has proposed keeping perennial DST (i.e., all year round), and the EU debates between perennial Standard Time and perennial DST. Related to the discussion about DST is the discussion to which time zone a country, state or region should belong: the state of Massachusetts in the United States is considering switching to Atlantic Standard Time, i.e., moving the timing of its social clock (local time) 1 h further east (which is equivalent to perennial DST), and Spain is considering leaving the Central European Time to join Greenwich Mean Time (GMT), i.e., moving its social timing 1 h further west. A wave of DST discussions seems to periodically sweep across the world. Although DST has always been a political issue, we need to discuss the biology associated with these decisions because the circadian clock plays a crucial role in how the outcome of these discussions potentially impacts our health and performance. Here, we give the necessary background to understand how the circadian clock, the social clock, the sun clock, time zones, and DST interact. We address numerous fallacies that are propagated by lay people, politicians, and scientists, and we make suggestions of how problems associated with DST and time-zones can be solved based on circadian biology.

Eveningness Is Associated With Greater Depressive Symptoms in Type 2 Diabetes Patients: A Study in Two Different Ethnic Cohorts

BACKGROUND

Eveningness is associated with greater depressive symptoms in the general population. Depression and type 2 diabetes (T2D) commonly coexist. We aimed to explore the association between morningness-eveningness and depressive symptoms in T2D patients in the United States and in Thailand.

PARTICIPANTS

T2D patients (n = 182) from an endocrinology clinic in Chicago, Illinois, and six hospitals in Thailand (n = 251) were enrolled.

METHODS

Diabetes history was collected. Depressive symptoms were assessed by the Center for Epidemiologic Studies Depression scale (CES-D). The Chicago cohort completed the Morningness-Eveningness Questionnaire (MEQ) and the Thai cohort completed the Composite Scale of Morningness (CSM). Sleep quality was assessed using the Pittsburg Sleep Quality Index (PSQI).

RESULTS

The mean (SD) CES-D score was 13.7 (9.1) in Chicago and 11.9 (6.4) in Thailand. In Chicago participants, after adjusting for age, sex, ethnicity, hemoglobin A1c, insulin use, and PSQI score, greater eveningness (lower MEQ scores) was associated with higher CESD scores (B = -0.117, p = 0.048). In Thai participants, after adjusting for age, sex, and PSQI score, eveningness (lower CSM score) was associated with higher CES-D score (B = -0.147, p = 0.016). In both cohorts, however, eveningness was not independently associated with the likelihood of being in the at-risk range for clinical depression (CES-D ≥ 16).

CONCLUSIONS

Eveningness is independently associated with greater depressive symptoms in T2D in two different ethnic cohorts. The results support the association between individual differences in circadian rhythms and psychological functioning in T2D.

Chronotype: Implications for Epidemiologic Studies on Chrono-Nutrition and Cardiometabolic Health

Chrono-nutrition is an emerging research field in nutritional epidemiology that encompasses 3 dimensions of eating behavior: timing, frequency, and regularity. To date, few studies have investigated how an individual's circadian typology, i.e., one's chronotype, affects the association between chrono-nutrition and cardiometabolic health. This review sets the directions for future research by providing a narrative overview of recent epidemiologic research on chronotype, its determinants, and its association with dietary intake and cardiometabolic health. Limited research was found on the association between chronotype and dietary intake in infants, children, and older adults. Moreover, most of the evidence in adolescents and adults was restricted to cross-sectional surveys with few longitudinal cohorts simultaneously collecting data on chronotype and dietary intake. There was a gap in the research concerning the association between chronotype and the 3 dimensions of chrono-nutrition. Whether chronotype modifies the association between diet and cardiometabolic health outcomes remains to be elucidated. In conclusion, further research is required to understand the interplay between chronotype, chrono-nutrition, and cardiometabolic health outcomes.

Real-World Data in Support of Short Sleep Duration with Poor Glycemic Control, in People with Type 2 Diabetes Mellitus

AIMS

Sleep duration (SD) has been associated with metabolic outcomes. Is there an independent association between short/long SD and glycemic control (GC) in type 2 diabetes mellitus (T2DM) outpatients, compared to intermediate SD? Employing up-to-date definitions of SD, we comprehensively considered, simultaneously, all known confounding/mediating factors that recently emerged in the literature: age, gender, diet, physical activity, obesity, night pain, nocturnal diuresis, sleep quality, chronotype, sleep apnea, depressive symptoms, alcohol, caffeine, tobacco, number of endocrinologist appointments, T2DM family history, and sleep medication.

METHODS

A cross-sectional study of 140 consecutive T2DM outpatients, ages 40-65, glycohemoglobin (HbA _1c ) goal ≤ 7. We searched for variables (including HbA_1c) significantly associated with short (<6 hours) or long (>8 hours) SD, in comparison to intermediate SD (6-8 hours).

RESULTS

Higher HbA_1c levels increased the chance of belonging to the group that sleeps <6 hours (p ≤ 0.001). Better sleep quality, nocturnal diuresis, and morningness increased the chance of belonging to the group that sleeps >8 hours (p < 0.05).

CONCLUSIONS

There is an independent association between short SD and elevated HbA_1c, in real-world T2DM outpatients. Future interventional studies could evaluate weather consistent, long-term sleep extension, from <6 hours to 7-9 hours per 24 hours, improves GC in T2DM outpatients.

The relationship between sleep disturbance and glycaemic control in adults with type 2 diabetes: An integrative review

AIMS AND OBJECTIVES

To explore and synthesise current research to assess the state of science about the relationship between sleep disturbance and glycaemic control in adults with type 2 diabetes.

BACKGROUND

Sleep disturbance is suggested a risk factor for type 2 diabetes. Diabetes alone is a leading cause of death, but when coupled with sleep disturbance poses additional health risks. However, little is known about the relationship between sleep disturbance and glycaemic control in people with overt diabetes.

DESIGN

An integrative review.

METHODS

Whittemore and Knafl's methodology guided this integrative review. Original studies published before October 2016 were identified through systematic searches of seven databases using terms: diabet*; sleep or insomnia; glycem* or glucose or A1C or HbA1c or sugar; and their combinations. The matrix and narrative synthesis were employed to organise and synthesise the findings, respectively. The Crowe Critical Appraisal Tool was used to evaluate the study quality.

RESULTS

A total of 26 studies were identified; 17 of which reported significant relationships between sleep measures and glycaemic control. In 13 studies, sleep duration was associated with glycaemic control in both linear (n = 2) and nonlinear (n = 3) relationships; however, eight studies reported no significant relationships. Sleep quality was significantly related to glycaemic control in 14 of 22 studies. Nine studies found no relationship between any measure of sleep and glycaemic control.

CONCLUSIONS

There is strong evidence supporting the relationship between sleep quality and glycaemic control but further examination of the relationship between sleep duration and glycaemic control is warranted. Sleep disturbance, particularly impaired sleep quality, could potentially influence glycaemic control in adults with type 2 diabetes.

RELEVANCE TO CLINICAL PRACTICE

Nurses who treat patients with diabetes should include assessment of sleep, education for healthy sleep, and referral for treatment of sleep disturbance in order to maximise the potential for achieving good glycaemic control.

Diabetes-related distress and its associated factors among patients with type 2 diabetes mellitus in China

Diabetes-related distress is one of the psychological disorders affecting patients with diabetes, yet there are few studies about diabetes-related distress in Chinese patients. To assess the level of psychological distress and examine its associated factors, we conducted a cross-sectional analysis of patients with type 2 diabetes mellitus from a Chinese tertiary hospital. The Diabetes Distress Scale (DDS) and the General Self-Efficacy Scale (GSES) were administered. There were 210 (57.85%) patients with little or no diabetes-related distress, 84 (23.14%) with moderate diabetes-related distress and 69 (19.01%) with high diabetes-related distress. Stepwise multiple linear regression showed that sleep time was significantly related to the DDS total score and the subscale scores of emotional burden (EB) (β=-0.190, -0.379), respectively. GSES was associated with the DDS total score (β=-0.128) and the EB score (β=-0.153). Oral medication plus insulin was significantly related to regimen-related distress (RD) (β=0.137), physician-related distress (PD) (β=0.152) and interpersonal distress (ID) (β=0.103). Physical activity (β=-0.185) and making meal plan with health care professionals(HCP) (β=-0.169) were associated with RD. The prevalence of diabetes-related distress among patients with type 2 diabetes mellitus was high in China. DDS and EB were associated with poorer sleep time and lower self-efficacy. Interventions to improve sleep are needed. Qualitative and longitudinal studies are required to understand why type 2 diabetic patients are not getting enough sleep.

Night-shift work is associated with poorer glycaemic control in patients with type 2 diabetes

The circadian system plays a role in regulating metabolism. Night-shift work, a form of circadian misalignment, is associated with increased type 2 diabetes risk. This study aimed to determine if night-shift workers with type 2 diabetes experience poorer glycaemic control than non-shift workers. Patients with type 2 diabetes (104 unemployed, 85 day workers and 60 night-shift workers) participated. Sleep duration, sleep quality, morningness-eveningness preference, depressive symptoms and dietary intake were assessed using standardized questionnaires. Haemoglobin A1c levels were measured. Night-shift workers had significantly higher haemoglobin A1c levels compared with others, while there were no differences between day workers and unemployed participants (median 7.86% versus 7.24% versus 7.09%, respectively). Additionally, night-shift workers were younger, had a higher body mass index, and consumed more daily calories than others. Among night-shift workers, there were no significant differences in haemoglobin A1c levels between those performing rotating versus non-rotating shifts (P = 0.856), or those with clockwise versus counterclockwise shift rotation (P = 0.833). After adjusting for age, body mass index, insulin use, sleep duration, morningness-eveningness preference and percentage of daily intake from carbohydrates, night-shift work, compared with day work, was associated with significantly higher haemoglobin A1c (B = 0.059, P = 0.044), while there were no differences between unemployed participants and day workers (B = 0.016, P = 0.572). In summary, night-shift work is associated with poorer glycaemic control in patients with type 2 diabetes.

Effect of Sleep and Salivary Glucose on Gingivitis in Children

It has been shown that inadequate sleep has deleterious effects on health by suppressing immunity and promoting inflammation. The aim of this study was to investigate the effect of sleep and salivary glucose levels on the development of gingivitis in a prospective longitudinal study of Kuwaiti children. Data were collected from 10-y-old children ( N = 6,316) in 2012 and again in 2014. Children were approximately equally distributed from 138 elementary schools representing the 6 governorates of Kuwait. Calibrated examiners conducted oral examination, self-reported sleep evaluation interviews, anthropomorphic measurements, and unstimulated whole saliva sample collection. Salivary glucose levels were measured by a florescent glucose oxidase method; values of salivary glucose ≥1.13 mg/dL were defined as high glucose levels. A multilevel random intercept and slope analysis was conducted to determine the relationship between sleep duration and gingivitis on 3 levels: within schools, among children, and over time. The outcome was the progression of the extent of gingival inflammation in children over time. The main independent variables were the number of daily sleep hours and salivary glucose levels. Other explanatory variables and confounders assessed were governorate, dental caries and restorations, and obesity by waist circumference (adjusted for snacking and sex). Gingivitis increased over time in children who had shorter sleep duration ( P < 0.05). Salivary glucose levels >1.13 mg/dL predicted gingivitis ( P < 0.05). Children who had more decayed or filled teeth had more gingivitis ( P < 0.05). No significant association was found between gingivitis and obesity. The level of gingivitis was different among the 6 governorates of Kuwait. Additionally, there was a strong clustering effect of the observations within schools and among children across time. Longitudinal analysis of 6,316 Kuwaiti children revealed that shorter sleep duration and higher salivary glucose levels were both associated with increased gingival inflammation.