Search

Purpose: Few data are available on sleep characteristics of elite track-and-field athletes. Our study aimed to assess (1) differences in sleep between sexes and among different track-and-field disciplines, (2) the effect of individualized sleep-hygiene strategies on athletes' sleep parameters, and (3) daytime nap characteristics in track-and-field athletes. Methods: Sleep characteristics of 16 elite Olympic-level track-and-field athletes (male: n = 8; female: n = 8) were assessed during the preseason period, at baseline (T0), and during the in-season period, after the adoption of individualized sleep-hygiene strategies (T1). Sleep parameters were objectively monitored by actigraphy for a minimum of 10 days, for each athlete, at both T0 and T1. A total of 702 nights were analyzed (T0 = 425; T1 = 277). Results: Female athletes displayed better sleep efficiency (88.69 [87.69–89.68] vs 91.72 [90.99–92.45]; P =.003, effect size [ES]: 0.44), lower sleep latency (18.99 [15.97–22.00] vs 6.99 [5.65–8.32]; P <.001, ES: 0.65), higher total sleep time (07:03 [06:56–07:11] vs 07:18 [07:10–07:26]; P =.030, ES: 0.26), earlier bedtime (00:24 [00:16–00:32] vs 00:13 [00:04–00:22]; P =.027, ES: 0.18), and lower nap frequency (P <.001) than male athletes. Long-distance runners had earlier bedtime (00:10 [00:03–00:38] vs 00:36 [00:26–00:46]; P <.001, ES: 0.41) and wake-up time (07:41 [07:36–07:46] vs 08:18 [08:07–08:30]; P <.001, ES: 0.61), higher nap frequency, but lower sleep efficiency (88.79 [87.80–89.77] vs 91.67 [90.95–92.38]; P =.013, ES: 0.44), and longer sleep latency (18.89 [15.94–21.84] vs 6.69 [5.33–8.06]; P <.001, ES: 0.67) than athletes of short-term disciplines. Furthermore, sleep-hygiene strategies had a positive impact on athletes' total sleep time (429.2 [423.5–434.8] vs 451.4 [444.2–458.6]; P <.001, ES: 0.37) and sleep latency (14.33 [12.34–16.32] vs 10.67 [8.66–12.68]; P =.017, ES: 0.19). Conclusions: Sleep quality and quantity were suboptimal at baseline in Olympic-level track-and-field athletes. Large differences were observed in sleep characteristics between sexes and among different track-and-field disciplines. Given the positive effect of individualized sleep-hygiene strategies on athlete's sleep, coaches should implement sleep education sessions in the daily routine of top-level athletes. [ABSTRACT FROM AUTHOR]

Chronotype refers to individual differences in the circadian phase that affect a person’s biological and psychological functioning. One of the most useful tools for measuring chronotype in children aged 4 – 11 years is the Children’s Chronotype Questionnaire (CCTQ). Therefore, due to the importance of measuring chronotype in children and also the lack of a standard scale in Iran, this study aimed to examine the reliability and validity of the Persian version of this questionnaire for children. The participants of this cross-sectional study were 272 Iranian children aged five to eleven years with their parents, selected by convenience sampling method. To collect data, all participants completed the CCTQ and the Children’s Sleep Habits Questionnaire (CSHQ), which were examined by the researchers for their construct and concurrent validity. Over a period of three weeks, 50 mothers participated in a test of the test-retest reliability of the CCTQ. During this time, their sleep patterns were monitored using a sleep diary to test for reliability. The Cronbach’s alpha of the CCTQ-M/E was 0.71. Test-retest reliability using the Spearman correlation coefficient between two observations with an interval of three weeks was 0.83. The MSFsc index was significantly correlated with M/E, CT, and most of the parent-reported sleep/wake parameters. In addition, the three indicators of the CCTQ were significantly associated with most of the sleep/wake parameters of the sleep diary and the components of the CSHQ. The Persian version of the CCTQ has desirable psychometric properties for the assessment of chronotype in five- to eleven-year-old children. [ABSTRACT FROM AUTHOR]

Models of shift work and health suggest that individual differences in circadian rhythm characteristics may moderate the relationship between night shift work and injury, but this argument has not been directly tested. In this study, we tested the efficacy of two circadian rhythm characteristics—vigour and flexibility—as moderators of the path between shift work and injury. In addition, we aimed to replicate the association between vigour, flexibility, and alertness by time of day, and the measurement properties of the Circadian Type Inventory. We recruited 401 healthcare workers from Australia and Great Britain. After controlling for confounding variables, the results showed that vigour moderated the association between shift work and injury. Participants with values of vigour at the mean (β = 0.5120, p < 0.0013, 95% CI = [0.2018, 0.8223) and one standard deviation below the mean (β = 0.9048, p < 0.0001, 95% CI = [0.4648, 1.3447] reported significantly more injuries. No moderation was found for flexibility. Significant differences in alertness by time of day were observed in participants with higher levels of vigour compared to lower levels of vigour. No differences in alertness were observed for the flexibility scale. These results indicate that vigour may be a robust indicator of shift work tolerance. We replicated the posited two-factor structure of the Circadian Type Inventory, found the scales to have good reliability, and established for the first time, criterion-related validity for the vigour scale. [ABSTRACT FROM AUTHOR]

Temporal patterns of eating and diet composition are influenced by factors including circadian preference (chronotype) and work schedule, yet their combined influence is unknown. We investigated relationships between chronotype, temporal eating patterns (duration of eating window (DEW), time of first (FEO) and last (LEO) eating occasions), and diet composition on workdays (WD) and work-free days (FD). Non-shift workers (n = 39) completed the Chrononutrition Questionnaire (CNQ) (age: 38.8 ± 17.2 years, BMI: 24.8 ± 4.78 kg/m2, 82% female) that captures chronotype and temporal eating patterns, and returned work diaries (work schedule) and 7-day food diaries (diet composition) after 2 weeks. Twenty-nine participants provided dietary data for at least two work and work-free days. Later chronotype was associated with later FEO on FD (rs = 0.45, p = 0.004), later LEO on FD (rs = 0.60, p < 0.001) and WD (rs = 0.61, p < 0.001), and longer DEW on WD (rs = 0.37, p = 0.024). Relationships between chronotype and diet composition were small. Later FEO was associated with higher % energy from fat (rs = 0.39, p = 0.043) and lower fibre intake (rs = −0.69, p < 0.001) on WD. Later chronotypes had shorter and later eating windows on FD than WD. Our findings suggest that relationships between chronotype, temporal eating patterns, and diet composition differ by day type. Further investigation may inform dietary strategies that are day-specific. [ABSTRACT FROM AUTHOR]

Plasma glucose spikes affect cardiac autonomic modulation resulting in a decrease of heart rate variability (HRV). We hypothesize that a later chronotype or a higher morning plasma melatonin level is associated with larger decreases of HRV following an early high glycaemic index (GI) breakfast. In persons with an early (n = 21) or a late (n = 15) chronotype who consumed a high GI breakfast at 7 a.m. glucose data were continuously monitored. Time domain HRV parameters were calculated from blood volume pulses derived by wireless wrist worn multisensor. HRV changes (values after minus values before breakfast) were associated with chronotype by multivariable linear regression adjusted for age, sex and baseline levels. Morning plasma melatonin levels were determined from samples drawn on the run-in day. Time domain parameters indicate a higher HRV before high GI breakfast in both chronotypes. A later chronotype tended to be associated with smaller decreases of mean interbeat intervals (p = 0.08) only; no associations were seen with morning melatonin levels. This exploratory analysis in a small sample provides a first indication that in young healthy adults later chronotype might be associated with reduced ANS activation following a high GI breakfast. Future studies should elucidate whether this indicates parasympathetic or sympathetic inhibition. [ABSTRACT FROM AUTHOR]

Actigraphy provides a unique method for objectively measuring sleep activity patterns, but confusion remains about how to use actigraphy data to determine chronotype. To determine the most suitable parameter, this study made a systematic comparison of actigraphy-derived parameters: the average midpoint of sleep of all record days (aMS-acti), cosine parameter (Bathyphase), and non-parametric parameter (L5-mid) in terms of the consistency with subjective chronotype parameters, test–retest reliability, and external validity. More importantly, we proposed multiple Munich Chronotype Questionnaire (MCTQ)-based actigraphy parameters: considering the difference between weekday (MSW-acti) with weekends (MSF-acti) and the sleep debt (MSFsc-acti). The study collected 5 days of actigraphy and scale data from 1,055 young adults, 138 of whom participated in the retest 2 years later. The results showed that, in terms of consistency with subjective chronotype, aMS-acti generally performed better than other actigraphy parameters. In addition, aMS-acti had the highest test–retest reliability and was more closely related to the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), and Self-Rating Depression Scale (SDS). The results suggest that the simplest parameter (aMS-acti) is superior to traditional cosine and non-parametric parameters and MCTQ-derived parameters for short-term assessment of chronotype. [ABSTRACT FROM AUTHOR]

Background: Benign prostatic hyperplasia (BPH) is a common chronic condition in elderly men. Observational studies have identified several comorbidities associated with BPH. However, these studies are limited by various confounding factors and do not clearly explain the association between BPH and its comorbidities. We investigated the association between BPH and comorbidities using the Global Burden of Disease (GBD) database combined with Mendelian randomization (MR) methods. Methods: Through an extensive PubMed search, we identified 22 diseases associated with BPH and selected 9 significant comorbidities from the GBD database for a detailed correlation analysis. We also considered socio-economic and environmental influences on BPH. Utilizing the GWAS database, we gathered data on BPH and 20 comorbidities, employing the Linkage Disequilibrium Score Regression (LDSC) method to unearth genetic connections. Causality was determined through both univariable and multivariable bidirectional MR analyses, supplemented by Steiger directionality tests to confirm causation. The study's integrity was fortified by employing various MR models and conducting rigorous sensitivity analyses. The synthesis of GBD data with LDSC and MR findings offered a nuanced understanding of the BPH-comorbidity nexus. Additionally, we explored the genetic basis and the role of mediating factors between BPH and comorbidities through phenome-wide association studies (PheWAS), colocalization analysis, and mediation MR. Results: Correlation analysis of GBD data found associations of prostate cancer, chronic kidney disease and depression with BPH. LDSC results indicated that prostatitis and bladder cancer are related to BPH. Two associations were replicated in bidirectional univariable MR, linking BPH with a higher risk of prostatitis and prostate cancer. conducted sensitivity analyses to confirm the robustness of the results and all Steiger directionality tests were correct. Multiple multivariable MR models validated these results. PheWAS analysis showed that outliers in MR do not significantly impact MR results. Through colocalization analysis, three shared loci between BPH and both prostatitis and prostate cancer were identified. Mediation analysis found that, after adjusting for BPH, fruit consumption was associated with a lower risk of prostatitis, and morning person and chronotype were associated with a lower risk of prostate cancer. Conclusions: This study uncovered associations between BPH and various comorbidities, emphasizing the causal relationships between BPH, prostatitis, and prostate cancer. Our research provides a new perspective in understanding the comorbid associations of BPH. [ABSTRACT FROM AUTHOR]

Anxiety is being increasingly linked to circadian rhythms, including chronotype, in addition to its intricate links with sleep quality. Emotional competence is thought to be a strong predictor of wellbeing and mental health. This study aimed to examine whether a combination of chronotype, sleep quality, and intrapersonal emotional competence can predict anxiety in emerging adults (aged 18–29), who have the greatest prevalence of adult anxiety. One hundred and seventeen participants completed self-report measures of chronotype, sleep quality, emotional competence, and anxiety. A multiple linear regression, with anxiety as the criterion variable, showed that while all predictors were significant, sleep quality was the strongest predictor of anxiety. A later chronotype, poorer sleep quality and lower intrapersonal emotional competence were related to higher anxiety. Thus, integrating intrapersonal emotional competence and chronotype considerations into interventions may address the interplay between sleep quality and anxiety in emerging adults more effectively. [ABSTRACT FROM AUTHOR]

Sleep quality, chronotype, and mood may be closely interconnected processes. Typically, such constructs are measured independently, leaving out important information regarding their intrinsic relationships. The Sleep, Circadian Rhythms, and Mood (SCRAM) questionnaire is a promising tool for measuring sleep, chronotype, understood as diurnal preference, and depressive symptomatology, and the interrelationships between them. Anxiety has also been linked to sleep quality, chronotype, and depression, but there is currently no scale that measures these constructs together. This study aims to validate a revised version of the SCRAM questionnaire (rSCRAM), incorporating items to measure anxious mood. 486 Italian participants were involved in two studies. In Study 1, principal component analysis (PCA) identified representative anxiety elements from validated questionnaires. In Study 2, after adding the anxiety elements, exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) established a 4-factor, 16-item model. The rSCRAM demonstrated excellent psychometric properties: high internal consistency (α = 0.72–0.90) and a strong test-retest reliability of the scales over 2 weeks (r = 0.73–0.82), a high correlation for convergent validity, and low correlations for divergent validity. The rSCRAM questionnaire measures the constructs for which it was created and revised. Including the anxiety scale enhances its utility in assessing mental health constructs within a single instrument. [ABSTRACT FROM AUTHOR]

Observational studies have shown that individual sleep traits habits are potential risk factors for major depression. However, it is not known whether there is a causal relationship between individual sleep traits habits such as continuous sleep duration, short sleep duration, short sleep duration, insomnia, nap during the day, snoring, and major depression. In this study, Mendelian randomization (MR) was used to predict major depressive disorder (MDD) in individuals sleep traits habits. Data were obtained from the genome-wide association study (GWAS). Nine MR analysis methods were used: Inverse Variance Weighted (IVW) [fixed effects/multiplicative random effects], simple mode, simple mode, weighted mode, simple median, weighted median, penalised weighted median, and MR-Egger, MR Egger (bootstrap). IVW was used as the main analysis method for the MR analysis of two samples, and the other methods were used as supplements. The results obtained through the IVW method supported a causal relationship between sleep duration and decreased risk of MDD (odds ratio, OR ivw : 0.998; 95 % CI: 0.996–0.999, P<0.001). Two-Sample MR, results showed that short sleep duration has a causal effect on the increased risk of MDD (odds ratio, OR ivw : 1.179; 95 % CI: 1.108–1.255, P<0.001). However, there were no sufficient evidence supported that long sleep duration has a causal effect on the decreased risk of MDD (odds ratio, OR ivw : 0.991; 95 % CI: 0.924–1.062, P = 0.793). A significant causal relationship between insomnia and increased risk of MDD was observed (OR: 1.233; 95 % CI: 1.214–1.253, P<0.001). Interestingly, our study also found that daytime napping has a causal effect on the increased risk of MDD (odds ratio, OR ivw : 1.519; 95 % CI: 1.376–1.678, P<0.001). The present results did not show a significant causal relationship between snoring and the risk of MDD (OR ivw : 1.000; 95 % CI: 0.998–1.002, P = 0.906). Obstructive sleep apnea (odds ratio, OR ivw : 1.021; 95 % CI: 0.972–1.072, P = 0.407) and morning person (odds ratio, OR ivw : 1.021; 95 % CI: 0.972–1.072, P = 0.407) have no causal effect on the increased risk of MDD. The study could not ascertain whether there were genetic differences among different ethnicities, nations, and regions, as it only included participants of European ancestry. In summary, our research provides genetic evidence for the relationship between individual sleep traits (short sleep duration, insomnia, daytime napping) and the increased risk of MDD. Interventions targeting lifestyle factors may reduce the risk of MDD. • This study explored the causality between lifestyle and major depressive disorder by Mendelian Randomization analysis. • This research provides genetic evidence supporting that sleep traits increase major depressive disorder risk. • The research primarily included European ancestry. The conclusions may not apply to other ethnic and regional groups. [ABSTRACT FROM AUTHOR]

While links between certain chronotypes and poorer health outcomes have been well established in previous studies, few studies have examined the relationship between chronotype and cellular aging. Using data from the California Teachers Study (CTS), the present study evaluates the relationship between cellular aging and chronobiology through an analysis of leukocyte telomere length (LTL) and chronotype among 817 predominantly postmenopausal women with no history of cancer and occupations not associated with night-shift work. Unconditional logistic regression models were run to estimate odds ratios (ORs) for each chronotype category, adjusted for age, ethnicity, and smoking status. Analyses were then stratified by potential modifiers to assess whether results varied among specific subgroups within the sample. Women who reported being current evening types and evening types from teen years to now were significantly less likely to have short LTL compared to women who reported being current morning types or morning types from teen years to now (OR = 0.72; 95% CI = 0.53-0.98; OR = 0.57; 95% CI = 0.39-0.84). Our results suggest that women with no history of cancer who identify as evening chronotypes may undergo decreased cellular aging compared to women in the same population who identify as morning types. Further studies on populations of postmenopausal women are warranted. [ABSTRACT FROM AUTHOR]

Sleep is crucial for children’s health and eating habits. The decline in family meals has raised concerns about its impact on children. Previous research indicated associations between family meals and psychological health and dietary habits, but their relationship with sleep behavior is less understood. This study examined the association between family meals (breakfast and dinner), sleep patterns, and quality of life among Japanese preschoolers and elementary school students (1st to 3rd grade). The cross-sectional study involved 6,177 children aged 3–8 years in Japan. Mothers completed an online survey on family meal habits, sleep patterns, and the KINDL-R questionnaire to assess quality of life. Results showed that family meals were associated with sleep behaviors and KINDL scores. Multiple regression analysis indicated that family breakfast was associated with earlier bedtime and wake-up time, shorter weekend sleep duration, reduced social jet lag, and a morning chronotype, as detected by the Munich ChronoType Questionnaire. Family dinners were linked to later sleep and wake-up times and an evening chronotype. Family breakfast and dinner were associated with higher KINDL scores, with dinner having a stronger positive impact. These findings underscore the significance of family meals in associating sleep patterns and quality of life among Japanese children. [ABSTRACT FROM AUTHOR]

Background: The association between chronotype and leisure-time physical activity (LTPA) remains unclear. We investigated the difference in regular LTPA and for a sufficient duration between those with evening-type (ET) and morning-type chronotypes (MT). Methods: We conducted a cross-sectional analysis using the data of the Aichi Workers' Cohort Study. It included 3,221 men (mean [standard deviation] age: 45.0 [11.6] years) and 1,294 women (39.8 [11.2] years). Chronotypes were determined with the reduced version of the Morningness-Eveningness Questionnaire. We calculated the metabolic equivalents (METs) consumed per week based on the four types of LTPA: strolling, brisk walking, light- and moderate-intensity PA, and vigorous-intensity PA. Regular LTPA and for a sufficient duration was defined as doing once or more per week and for 30 min or longer per session, respectively. Logistic regression analysis was conducted separately by sex to calculate odds ratios of ET for regular LTPA and for a sufficient duration, adjusted for age and other factors, for each type of LTPA. Results: ET men consumed fewer total METs per week than MT men (p <.001), although this pattern is not found in women. Compared to MT men, ET men were less likely to be engaged in regular LTPA in all types of LTPA (prevalence and adjusted odds ratio [95% confidence interval]: strolling: 39.1% vs. 28.7%, 0.685 [0.524–0.895]; brisk walking: 23.9% vs. 14.4%, 0.639 [0.454–0.899]; light- and moderate-intensity PA: 15.4% vs. 8.4%, 0.613 [0.404–0.929]; vigorous-intensity PA: 21.4% vs. 16.8%, 0.715 [0.518–0.989]). They were less likely to spend a sufficient duration in brisk walking (25.9% vs. 16.5%, 0.635 [0.461–0.875]), light- and moderate-intensity PA (37.1% vs. 26.8%, 0.684 [0.521–0.899]), and vigorous-intensity PA (35.3% vs. 35.8%, 0.741 [0.568–0.968]). Compared with MT women, ET women were less likely to be engaged in strolling (30.5% vs. 22.2%, 0.629 [0.398–0.995]), and less likely to spend a sufficient duration in light- and moderate-intensity PA (27.3% vs. 15.3%, 0.561 [0.335–0.937]). Conclusions: ET was inversely associated with LTPA in men and partly in women. [ABSTRACT FROM AUTHOR]

\nHIGHLIGHTSThis study examined the impact of nutrition education on chronotype, sleep quality, and dietary quality among university students. Participants included 317 students with nutrition education and 280 without. Data were collected through questionnaires assessing demographic characteristics, chronotype (using the Morning-Evening Questionnaire), sleep quality (via the Pittsburgh Sleep Quality Index), and dietary habits. Anthropometric measurements and 24-hour food recalls were also recorded. Dietary quality was evaluated using the Healthy Eating Index (HEI)-2020, while dietary fat and carbohydrate quality were assessed with the Fat Quality Index (FQI) and Carbohydrate Quality Index (CQI), respectively. Results indicated that students who received nutrition education had significantly lower body weight, height, and waist circumference compared to those without. Of the students, 8.9% had a morning, 7% had an evening and the rest had an intermediate chronotype. HEI-2020, CQI, and FQI scores were significantly higher in the nutrition education group. Although no significant relationship was found between nutrition education and chronotype, improved dietary and sleep quality were observed in the group with education. This suggested that enhancing nutritional knowledge can positively impact health by improving dietary quality and sleep. Dietary quality, carbohydrate quality and fat quality were found to be higher in the group with nutrition education.No relationship was found between chronotype and nutrition education.A positive relationship was found between nutrition education and sleep quality.As sleep quality decreased, tendency to evening type increased.Dietary quality, carbohydrate quality and fat quality were found to be higher in the group with nutrition education.No relationship was found between chronotype and nutrition education.A positive relationship was found between nutrition education and sleep quality.As sleep quality decreased, tendency to evening type increased. [ABSTRACT FROM AUTHOR]

Background: Myopia is a growing healthcare concern worldwide. Increasing evidence suggests that sleep and circadian rhythms may be associated with myopia. Furthermore, the risk factors of myopia have not been studied in the Estonian population to date. This study aimed to evaluate chronotype, lifestyle factors, and parental myopia in relation to myopia in Estonian secondary school students. Methods: Grade 10 students from three secondary schools in Tallinn, each with distinct focuses: one science-oriented, one arts-oriented, and one sports-oriented, were invited to participate. They underwent a comprehensive ocular examination, including cycloplegic autorefraction and ocular biometry. Chronotype was evaluated with the Morningness − Eveningness Questionnaire. Participants reported parental myopia and replied to a set of questions, separately for schooldays and free days, to indicate the amount of time they spent outdoors, doing near work and intermediate distance activities. Myopia was defined as cycloplegic SER ≤ − 0.50 D. Logistic regression analysis was performed to assess the association of the studied factors with myopia. Results: A total of 123 students (57% female) participated in the study, with a mean age of 16.71 years (standard deviation 0.41). In a multivariable regression model, having two myopic parents was associated with higher odds of myopia (OR 3.78, 95% CI 1.15 − 12.42). We found no association between myopia and chronotype. Notably, time spent outdoors and doing near work or intermediate distance work did not affect the likelihood of having myopia. We observed that students attending the sports-oriented school had lower odds of myopia than those attending the science-oriented school (OR 0.12, 95% CI 0.03–0.51). Conclusion: Chronotype was not associated with myopia in our study sample. Consistent with previous reports, we identified parental myopia as a myopia risk factor. Interestingly, there was no association between myopia and time spent outdoors or near work. However, the odds of myopia varied depending on the school attended by the participants, which may reflect the educational load or lifestyle of participants in earlier childhood. [ABSTRACT FROM AUTHOR]

Introduction: Multiple individual sleep health dimensions (satisfaction, regularity, and duration) are associated with diabetes symptoms, precursors to micro-and macrovascular complications, among young adults with type 1 diabetes mellitus (T1DM). Nearly half of young adults with T1DM develop vascular complications; however, modifiable contributors of diabetes symptoms, including sleep health, have been understudied. Methods: This cross-sectional quantitative descriptive study involved the completion of multiple validated self-report questionnaires and the collection of raw continuous glucose monitor and diary data over a 14-day period. The sleep health composite score was calculated by summing the number of dimensions with "good" sleep health. Chronotype was estimated with the 19-item Morningness-Eveningness Questionnaire. Multiple linear regression analyses were conducted to evaluate the associations between the independent variables (sleep health composite and chronotype) and diabetes symptom burden. Covariates, including age, race, sex at birth, T1D duration, continuous subcutaneous insulin infusion use, and hemoglobin A1C (HbA1C), were considered to determine their contribution to these relationships. Results: One hundred nineteen young adults with T1DM who were aged 18 to 26 years were included in this study from 2 cohorts. Higher sleep health composite scores were associated with a lower overall diabetes symptom burden, even after adjusting for covariates in the linear regression models. Initially, a later chronotype was linked to a higher diabetes symptom burden, but this association became insignificant after accounting for HbA1C levels. Conclusion: Improving multiple dimensions of sleep health may alleviate the diabetes symptom burden among young adults with T1DM. [ABSTRACT FROM AUTHOR]

Background: Here, we (a) examined the trajectories of night‐time sleep duration, bedtime and midpoint of night‐time sleep (MPS) from infancy to adolescence, and (b) explored perinatal risk factors for persistent poor sleep health. Methods: This study used data from 12,962 participants in the Avon Longitudinal Study of Parents and Children (ALSPAC). Parent or self‐reported night‐time sleep duration, bedtime and wake‐up time were collected from questionnaires at 6, 18 and 30 months, and at 3.5, 4–5, 5–6, 6–7, 9, 11 and 15–16 years. Child's sex, birth weight, gestational age, health and temperament, together with mother's family adversity index (FAI), age at birth, prenatal socioeconomic status and postnatal anxiety and depression, were included as risk factors for persistent poor sleep health. Latent class growth analyses were applied first to detect trajectories of night‐time sleep duration, bedtime and MPS, and we then applied logistic regressions for the longitudinal associations between risk factors and persistent poor sleep health domains. Results: We obtained four trajectories for each of the three sleep domains. In particular, we identified a trajectory characterized by persistent shorter sleep, a trajectory of persistent later bedtime and a trajectory of persistent later MPS. Two risk factors were associated with the three poor sleep health domains: higher FAI with increased risk of persistent shorter sleep (OR = 1.20, 95% CI = 1.11–1.30, p <.001), persistent later bedtime (OR = 1.28, 95% CI = 1.19–1.39, p <.001) and persistent later MPS (OR = 1.30, 95% CI = 1.22–1.38, p <.001); and higher maternal socioeconomic status with reduced risk of persistent shorter sleep (OR = 0.99, 95% CI = 0.98–1.00, p =.048), persistent later bedtime (OR = 0.98, 95% CI = 0.97–0.99, p <.001) and persistent later MPS (OR = 0.99, 95% CI = 0.98–0.99, p <.001). Conclusions: We detected trajectories of persistent poor sleep health (i.e. shorter sleep duration, later bedtime and later MPS) from infancy to adolescence, and specific perinatal risk factors linked to persistent poor sleep health domains. [ABSTRACT FROM AUTHOR]

During adolescence major shifts in sleep and circadian systems occur with a notable circadian phase delay. Yet, the circadian influence on pain during early adolescence is largely unknown. Using 2 years of data from the Adolescent Brain Cognitive Development study, we investigated the impact of chronotype on pain incidence, moderate-to-severe pain, and multiregion pain 1 year later in U.S. adolescents. Based on the Munich ChronoType Questionnaire, chronotype was calculated as the midpoint between sleep onset and offset on free days, corrected for sleep debt over the week. Adolescents reported pain presence over the past month, and if present, rated pain intensity (0-10 numerical rating scale; ≥ 4 defined as moderate-to-severe pain) and body site locations (Collaborative Health Outcomes Information Registry Body Map; ≥2 regions defined as multiregion pain). Three-level random intercept logistic regression models were specified for each pain outcome, adjusting for baseline sociodemographic and developmental characteristics. Among 5991 initially pain-free adolescents (mean age 12.0 years, SD 0.7), the mean chronotype was 3:59 am (SD 97 minutes), and the 1-year incidence of pain, moderate-to-severe pain, and multiregional pain was 24.4%, 15.2%, and 13.5%, respectively. Each hour later chronotype at baseline was associated with higher odds of developing any pain (odds ratio [OR] = 1.06, 95% confidence interval [CI] = 1.01, 1.11), moderate-to-severe pain (OR = 1.10, 95% CI = 1.05-1.17), and multiregion pain (OR = 1.08, 95% CI = 1.02-1.14) during 1-year follow-up. In this diverse U.S. adolescent sample, later chronotype predicted higher incidence of new-onset pain. [ABSTRACT FROM AUTHOR]

Purpose: Presenting a chain mediation model to investigate whether mobile phone dependence results in a reduction in health-related quality of life (HRQoL) among Chinese college students, through the mediating effect of chronotype and sleep quality. Design and Setting: A cross-sectional survey was conducted on students from a Chinese university using a validated structured questionnaire. Sample: 2014 freshmen. Measures: The study measured the students' level of mobile phone dependence using the Self-rating Questionnaire for Adolescent Problematic Mobile Phone Use. Chronotype and sleep quality were measured by the Chinese version of the Morningness-Eveningness Questionnaire (MEQ) and the Pittsburgh Sleep Quality Index (PSQI), respectively. HRQoL was evaluated using the five-level EuroQol five-dimensional questionnaire (EQ-5D-5L), including a descriptive system and a visual analog scale (VAS). Analysis: Descriptive statistical analysis, correlation analysis, and mediation analysis. Results: Mobile phone dependence had a significant negative effect on HRQoL as indicated by both the EQ-5D-5L index score and EQ-VAS score (P <.001 for both). Additionally, it was found to significantly predict chronotype (MEQ score) (β = −.546, P <.001) and sleep quality (PSQI score) (β =.163, P <.001). Chronotype negatively predict sleep quality (β = −.058, P <.001), and sleep quality was a significant negative predictor of HRQoL (EQ-5D-5L index score, β = −.008, P <.001; EQ-VAS score, β = −1.576, P <.001). Conclusion: Mobile phone dependence negatively impacts students' HRQoL through chronotype and sleep quality, and there is a chain mediating effect. Students should consider making lifestyle changes to improve their HRQoL and promote health. [ABSTRACT FROM AUTHOR]

The human body's physiological and behavioral activities are largely regulated by circadian rhythms. Chronotype predispose individuals to health problems. This paper emphasizes the importance of integrating chronotype assessments into studies on circadian rhythm and health. Precise risk assessments could result from this approach, especially in Asia and northern latitudes. [ABSTRACT FROM AUTHOR]

Summary Objective Methods Results Conclusion This study aimed to assess associations between chronotype and obesity‐related indicators in a sample of Spanish adolescents.This cross‐sectional study used data from The Eating Healthy and Daily Life Activities (EHDLA) Study, which included a representative sample of adolescents from Spain. A total of 820 adolescents (54.7% girls) aged 12–17 years were included in the analyses. The adolescents' chronotype was determined using the Morningness/Eveningness Scale in Children. Obesity‐related indicators included body mass index, waist circumference, waist‐to‐height ratio, triceps and medial calf skinfolds, sum of skinfolds, and body fat percentage. Generalized linear models were used to examine the relationship between the Morningness‐Eveningness score and chronotype status and the above‐mentioned obesity‐related indicators in adolescents. All analyses were adjusted for sex, age, socioeconomic status, sleep duration, physical activity, sedentary behaviour, adherence to the Mediterranean diet, and energy intake.The morningness chronotype was associated with higher abdominal obesity (odds ratio [OR] = 1.67, 95% confidence interval (CI) 1.12 to 2.50; p = 0.001), waist‐to‐height ratio (unstandardized beta coefficient [B] = 0.01, 95% CI 0.01 to 0.05; p = 0.029) and skinfold calves (B = 1.04 95% CI 0.24 to 1.94; p = 0.011), compared with the intermediate chronotype.Adolescents with a morningness chronotype may be more prone to abdominal obesity than their counterparts with an intermediate chronotype. Effective intervention‐related approaches can be applied to those with a morningness chronotype. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the relationship between chronotype, video game addiction, and sleep quality in school-age children using structural equation modeling. It was performed using structural equation modeling, with 545 secondary school students in northern Turkey meeting the inclusion criteria. Data were collected through face-to-face interviews utilizing the Personal Information Form, the Morningness Eveningness Scale for Children (MESC), the Video Game Addiction Scale for Children (VASC), and the Sleep Quality Scale. The findings revealed that the average video game addiction score of children was 55.22, which was associated with poor sleep quality and efficiency. Additionally, chronotype was found to mediate the relationship between video game addiction and both sleep quality (β = 0.024; p < 0.001) and sleep efficiency (β = −0.068; p < 0.001). The model was found to be close to acceptable levels for the variables according to the fit indices. [ABSTRACT FROM AUTHOR]

Summary Burgeoning interest in marathons necessitates an understanding of performance determinants. Research has highlighted the importance of diet, training and sleep, yet relations of circadian preference and sleep inertia with marathon performance remain largely unexplored. Because marathons generally start early‐to‐mid morning, these characteristics may have relevant impact. This study investigates relationships of circadian preference, sleep inertia and their interaction with marathon completion time. Consenting participants in a 2016 large mass‐participation city marathon completed self‐report questionnaires capturing circadian preference and sleep inertia, along with demographics and other characteristics. Circadian preference and sleep inertia were described across subgroups. Analyses examined the associations and interactions of circadian preference and sleep inertia with marathon completion times, with adjusted analyses accounting for age, sex and sleep health. Participants were marathon finishers (n = 936; 64.5% male; 66.3% young‐adults), with a majority reporting morningness tendencies (60.8%). Results supported a linear association between increasing eveningness preference with slower marathon times (p = 0.003; padjusted = 0.002), while some support was provided for a linear relationship between greater sleep inertia and slower marathon times (p = 0.04; padjusted = 0.07). A significant interaction was observed (p = 0.02; padjusted = 0.01), with the directionality suggesting that the circadian preference relationship weakened when sleep inertia severity increased, and vice‐versa. Our results suggest deleterious associations of increasing eveningness preference and greater sleep inertia with marathon completion time. These features may aid identifying marathoners who could be at a disadvantage, while also serving as modifiable targets for personalized training regimens preceding competition. [ABSTRACT FROM AUTHOR]

Introduction Material and Methods Results Conclusions Circadian rhythm disruption has been associated with the risk of polycystic ovary syndrome (PCOS), as the evening chronotype (EC) shares several traits with PCOS, including metabolic disorders, cardiovascular diseases, and psychiatric disorders. It has been suggested that the biological clock could be targeted with new, preventive, and therapeutic strategies for PCOS in women with biorhythm disorders. We evaluated inner circadian rhythmicity in middle‐aged women with PCOS in a population‐based setting, focusing on whether women with PCOS and an EC have a specific subtype in relation to their clinical characteristics.The data derived from the Northern Finland Birth Cohort, a population‐based longitudinal birth cohort of 12 058 individuals born in 1966. We compared the circadian phenotype between 314 women with PCOS (according to the Rotterdam criteria) and 1248 women without PCOS at age 46 years using the validated Finnish shortened 6‐item Morningness‐Eveningness Questionnaire (sMEQ) and the single‐item self‐assessed morningness‐eveningness question.PCOS was not associated with the EC by the sMEQ (p = 0.495) or self‐assessment (p = 0.303). The self‐assessed morningness‐eveningness values differed from the sMEQ chronotype distribution (p < 0.001), nevertheless, the most frequent chronotype was the intermediate chronotype (IC) determined by both chronotyping methods (sMEQ PCOS 47.7% vs. 45.2% non‐PCOS; self‐assessment PCOS 66.5% vs. 68.4% non‐PCOS). The hyperandrogenic PCOS phenotypes A–C did not differ from the non‐hyperandrogenic phenotype D as for the chronotype (p = 0.271). The EC was associated in both groups with depressive and anxiety symptoms (PCOS p = 0.012, non‐PCOS p < 0.001) and the use of sleep medication (PCOS p = 0.017, non‐PCOS p < 0.001).The EC was not over‐represented in middle‐aged women with PCOS or in the hyperandrogenic PCOS phenotypes A–C in our study. This does not support the need for chronotyping in the comprehensive assessment of women with PCOS. However, as chronotypes tend to change with aging, cross‐sectional studies in different age groups are warranted to draw conclusions on the role of chronotypes in PCOS and the associated metabolic risks. [ABSTRACT FROM AUTHOR]

Introduction: Light is a key factor in moderating human alertness, both subjective and objective. However, the methodology applies in research on the effects of exposure to light of different wavelengths and intensities on objective and subjective alertness varies greatly and evidence on objective alertness in particular is still inconclusive. Thus, the present, highly standardized within-subject laboratory study on N = 44 healthy males explored how LED light of different intensities (dim vs. bright light) and wavelengths (red vs. blue) affected objective (reaction time/RT) as well as subjective (sleepiness) alertness in the morning after wake-up. Methods: Participants spent two separate nights in the laboratory and were exposed to either one of the two light intensities or colors for 60 min after wake-up. Additionally, they indicated their sleepiness on the Karolinska Sleepiness Scale and participated in an auditory RT task before and after light intervention. It was hypothesized that both bright and blue light would lead to greater subjective and objective alertness when compared to dim and red light, respectively. Results: Results indicated that average RTs were longer for participants in the bright light condition (p = 0.004, f2 = 0.07) and that RTs decreased post-light exposure irrespective of light being dim or bright (p = 0.026, f2 = 0.07). However, dim versus bright light and RT did not interact (p = 0.758, f2 = 0.07). Chronotype was a significant covariate in the interaction of dim versus bright light and subjective sleepiness (p = 0.008, f2 = 0.22). There was no difference in RTs when comparing exposure to red or blue light (p = 0.488, f2 = 0.01). Findings on subjective sleepiness and light of different wavelengths revealed that sleepiness was reduced after light exposure (p = 0.007, f2 = 0.06), although the wavelength of light did not appear to play a role in this effect (p = 0.817, f2 = 0.06). Conclusion: Hence, neither of the hypotheses could be confirmed. However, they indicated that evening types might benefit from exposure to bright light regarding sleepiness, but not morning types. [ABSTRACT FROM AUTHOR]

ObjectivesMethodResultsConclusionsA preference for eveningness – one’s perception of being most alert later in the day – is associated with negative developmental outcomes in adolescence. Sleep onset consistency is protective against such outcomes. Toward a more nuanced understanding of relations between sleep-wake processes and adolescent development, we examined weeknight sleep onset consistency as a moderator of relations between eveningness and multiple indicators of development.A sample of 272 high-school students (Mage = 17 years, SD = 9.12 months; n = 133 identified as female; 41% non-Hispanic Black/African-American, 59% non-Hispanic White/European-American) participated in a week of at-home sleep actigraphy assessment in 2017–2018. Adolescents reported their morningness – eveningness, internalizing symptoms (depression, anxiety), positive affect (optimism and subjective happiness), and physical health, and mothers reported on youths’ behavior problems. Relations were examined between morningness – eveningness and each indicator of development; sleep onset consistency was examined as a moderator of these associations.On average, adolescents with a preference for eveningness had higher levels of externalizing behaviors and internalizing symptoms and lower levels of positive affect and physical health compared to peers with a preference for morningness (Bs = –0.27*–0.12***). Each association was moderated by weeknight sleep onset consistency. Across all indicators of development, evening-preferring youth with more consistent weeknight sleep onset had 0.49–0.72 SD better outcomes on average than evening-preferring youth with less consistent weeknight sleep onset.Falling asleep at roughly the same time each night can protect adolescent night owls from behavior problems and internalizing symptoms and can promote their positive affect and physical health. [ABSTRACT FROM AUTHOR]

Eveningness has been associated with both disturbed sleep and depression. It is unclear, however, if deprived sleep explains evening types' vulnerability to depression. The role of pre‐sleep rumination in these associations also remains understudied. The present study assessed the relationship between eveningness and sleep quality, as well as the possible mediating effect of pre‐sleep rumination and the moderating effect of a history of depression, under naturalistic conditions. Eighty‐eight Dutch‐speaking participants (87.5% females, 21.4 ± 3.7 years) were selected on the basis of their non‐intermediate chronotype using the Morningness Eveningness Questionnaire (evening types (n = 53); morning types (n = 35)). Depression status was assessed through a diagnostic interview (healthy (n = 61); remitted depressed (n = 27)). Participants' sleep characteristics were monitored via actigraphy and sleep diaries for seven consecutive days and nights. Pre‐sleep rumination was measured via a self‐report questionnaire. Evening types had longer subjective and actigraphic sleep onset latency than morning types. Pre‐sleep rumination did not mediate the former associations but predicted longer subjective sleep onset latency. Furthermore, the relationship between chronotype and subjective sleep onset latency was moderated by depression history. Remitted depressed evening types reported longer sleep onset latency than healthy evening and morning types, possibly posing the former at a higher risk for depressive relapse. Overall, the current findings address the need to further investigate the physiological signature of circadian rhythms and sleep latency. This could serve as a foundation for the development of prevention and early intervention programs, tailored for mood and sleep disorders. [ABSTRACT FROM AUTHOR]

Chronotype is the temporal behavior of an organism. Social jetlag, fear of missing out (FoMO), and phubbing have received increasing attention recently and are closely related to sleep quality. This study aimed to explore the relationship between chronotype and these factors and their effects on sleep quality among medical students. The FoMO scale, phubbing behavior assessment scale, morning-evening questionnaire, Pittsburgh sleep quality index, social jetlag questionnaire, and online sociodemographic data form were filled out by 537 students participating in the study. The average age of participants was 21.34 ± 1.38 years; 43.2% were male, and 56.8% were female. The majority (66.7%) had an intermediate chronotype, 20.9% an evening type, and 12.5% a morning type. Evening chronotypes exhibited the highest levels of social jetlag, daily internet/phone use, and the poorest sleep quality and daily functioning. Women reported significantly higher levels of FoMO (p < 0.001), phubbing (p = 0.020), and daytime dysfunction (p = 0.005). Multiple regression analysis showed poor sleep quality was associated with high FoMO, high phubbing, high levels of social jetlag, and evening chronotype. Additionally, daytime dysfunction was associated with female gender, poor sleep quality, high FoMO, and high levels of phubbing (p < 0.001, F = 16.128, R2 = 0.221). These results suggest that individuals with an evening type may be susceptible to social interaction, social media use, and sleep patterns, which may negatively affect sleep quality. It has also been determined that females may be at greater risk for FoMO and phubbing. Evaluation of individuals' chronotypes will be an essential step in treating behavioral addictions such as social media, screen, and smartphone addiction. [ABSTRACT FROM AUTHOR]

The Morningness-Eveningness-Stability-Scale-improved (MESSi) assesses three components of circadian functioning: Morning Affect (time to fully awaken), Eveningness (orientation/preference for evening activity), and Distinctness (amplitude of diurnal variations in functioning). Following the original German version, translations of the MESSi (including Spanish, Turkish, and Chinese) have been validated, but validity evidence for the English-language version has been lacking. The current study tested the factor structure, internal consistency, and predicted correlations of the English-language MESSi. A sample of 600 adults from an online recruitment platform (aged 18–78, mean = 41.31, SD = 13.149) completed an online survey including the MESSi, reduced Morningness-Eveningness Questionnaire (rMEQ), Sleep Inertia Questionnaire (SIQ), and measures of personality and depressive symptoms. Exploratory factor analysis exactly reproduced the three-component structure of Morning Affect (MA), Eveningness, and Distinctness, with all items loading strongly on their respective component. Confirmatory factor analysis of this structure showed acceptable fit. The three subscales showed good internal consistency and replicated previously reported correlations with depressive symptoms, sleep inertia, sleep quality, and personality. Further factor analysis combining the items of the MESSi, rMEQ, and SIQ replicated a previously found seven-factor structure: Cognitive, Emotional, and Physiological sleep inertia (SI), Responses to SI (including one MA item); Duration of SI (one SIQ item, 3/5 MA items); Morningness-Eveningness (MESSi Eveningness items, plus 3/5 rMEQ items); Distinctness (5/5 MESSi items). In conclusion, the English-language MESSi shows sound psychometric properties, but Morning Affect may be more suitably characterised as a measure of sleep inertia duration, rather than morningness preference. [ABSTRACT FROM AUTHOR]

Immune dysregulation has been observed in individuals with sleep disturbance, with HLA molecules play a crucial role in the immune response. This study aimed to investigate the associations between HLA alleles and sleep behaviours, considering several environmental factors. Data were sourced from the UK Biobank. Logistic regression analyses were performed to explore the associations between 359 HLA alleles and 4 sleep behaviours, including chronotype (n = 204,636), insomnia (n = 227,553), snoring (n = 214,350) and daytime dozing (n = 227,197). Furthermore, gene‐environmental interaction studies (GEIS) were conducted to evaluate the interactions of HLA alleles with environmental factors on sleep behaviours. This study analysed a total sample and subgroups stratified by sex to elucidate the impact of HLA alleles on sleep behaviours. Our findings revealed several associations between specific HLA alleles and sleep behaviours. Notably, HLA‐A*23:01 was associated with evening chronotype in the total sample (OR = 0.918, 95%CI: 0.872–0.965), while HLA‐A*32:01 was associated with evening chronotype in males (OR = 1.089, 95%CI: 1.037–1.144). Furthermore, GEIS identified multiple sets of interactions associated with sleep behaviours. For example, the interaction of HLA‐DPA1*01:04 with alcohol consumption was associated with daytime dozing in the total sample (OR = 1.993, 95%CI: 1.351–2.941), while the interaction of HLA‐DQB1*05:04 with ever suffered mental distress preventing usual activities was associated with insomnia in males (OR = 0.409, 95%CI: 0.254–0.658). Our findings highlight the involvement of HLA in sleep regulation and underscore the potential interactions between HLA alleles and environmental factors in modulating susceptibility to sleep behaviours. [ABSTRACT FROM AUTHOR]

Background: There is considerable evidence supporting the elevated risk of mental health problems in individuals with evening chronotype relative to those with morning or intermediate chronotypes. Recent data, however, suggest that this risk may be explained, at least partially, by poor sleep quality. Methods: This study aimed to further clarify the roles of chronotype and sleep quality in mental health outcomes (depression, anxiety, stress) in young individuals (18–40 years) living in the UK (n = 185) or Germany (n = 209). Results: Consistent with our recent observations in a comparable North Indian sample, we found that poor quality of sleep had significantly positive associations with adverse mental health outcomes both in the UK and Germany-based samples. Significant associations between evening chronotype and poor mental health were also evident, but these associations were fully mediated by poor quality of sleep in both samples. Conclusions: These observations suggest that efforts to identify sleep disruption in a timely manner and promotion of good sleep may prevent mental health problems, especially in individuals with evening chronotype and other known risks for mental disorders. [ABSTRACT FROM AUTHOR]

Background: The causal connection between morning diurnal preference and psychiatric disorders remains enigmatic. Using bidirectional two-sample Mendelian randomization (MR), we aim to explore the potential causal associations between morning diurnal preference and seven prominent psychiatric disorders. Methods: MR is a genetic epidemiological method that leverages genetic variants as instrumental variables to infer causal associations between exposures and outcomes. We obtained morning diurnal preference data from genome-wide association study (GWAS) datasets and identified 252,287 individuals as morning people. Psychiatric disorder data were sourced from the FinnGen consortium R9 dataset. Our primary analysis used the inverse-variance weighted (IVW) approach to evaluate the overall causal effect by combining the estimates from each genetic variant. Addition analyses, including weighted median, MR-Egger regression, weighted mode, and simple mode techniques were conducted to ensure robustness. Results: Being a morning person is related to reduced odds of multiple psychiatric disorders, including depression or dysthymia (OR: 0.93, 95% CI: 0.88, 0.999), anxiety disorders (OR: 0.90, 95% CI: 0.84, 0.96), self-harming behaviors (OR: 0.87, 95% CI: 0.76, 0.99), substance-use disorders (OR: 0.81, 95% CI: 0.71, 0.93), alcohol dependence (OR: 0.82, 95% CI: 0.73, 0.92), alcohol use disorders (OR: 0.85, 95% CI: 0.76, 0.94), acute alcohol intoxication (OR: 0.86, 95% CI: 0.76, 0.96), schizophrenia (OR: 0.77, 95% CI: 0.65, 0.92), and schizophrenia or delusion (OR: 0.80, 95% CI: 0.70, 0.92). Alcohol dependence (OR: 0.97, 95% CI: 0.94, 0.999) and alcohol use disorders (OR: 0.96, 95% CI: 0.94, 0.99) were also related to a lower morning diurnal preference. Conclusions: Our study provides evidence that being a morning person is a protective factor for various psychiatric disorders from a genetic perspective. The results provide insights for potential targeted interventions to improve mental wellbeing. [ABSTRACT FROM AUTHOR]

Chronotypes play a crucial role in regulating sleep–wake cycles and overall health. The aim of this study was to investigate chronotype, sleep quality, polymorphisms of clock genes and the level of leptin in serum. We used standardized questionnaires to assess chronotype and sleep quality. Genetic analysis was performed to determine the selected clock gene polymorphism. Serum leptin level was measured by the Elisa method. The results showed that serum leptin concentration was elevated in women, as well as in men who had a high waist-to-hip ratio (WHR) and body mass index (BMI). The evidence indicated that younger students (<22 years old) were most likely to experience poor sleep quality. Nevertheless, our multivariate analysis revealed that young age and a morning-oriented chronotype were associated with better sleep quality. We noted that clock gene polymorphisms were present in 28.6% of the participants. Moreover, polymorphisms of PER1 c.2247C>T (rs2735611) and PER2 c.-12C>G (rs2304672) genes were associated with serum leptin level and chronotype, respectively. These findings provide insights into the relationships between chronotype, sleep quality, clock gene polymorphisms and obesity risk in biomedical students. Understanding these factors can contribute to better sleep management and potential interventions to improve health outcomes in humans. [ABSTRACT FROM AUTHOR]

This study was designed to examine the mediator role of resilience in the relationship between chronotype and mental toughness in adolescents. The descriptive correlational study was completed with 342 high school students from one school in Türkiye (mean age 17.25±1.11 years). Data were collected with the Morningness–Eveningness Scale for Children, Child and Youth Resilience Measure, and Mental Toughness Scale for Adolescents. Hierarchical regression analyses with PROCESS Model 4 were used to evaluate the mediator effect. It was observed that the morning chronotype tendency increased resilience (p < 0.001) mental toughness (p < 0.001). Higher resilience led to increased mental toughness. When the mediation effect was examined, resilience was a full mediator in the relationship between chronotype characteristics and mental toughness (β=0.396; p = 0.000). According to these results, a morning chronotype tendency in adolescents increases their resilience and, therefore, mental toughness. These results suggest that effective methods for enhancing mental toughness in adolescents should be multifaceted. Additionally, it highlights the importance of identifying and regulating chronotype tendencies among adolescents, while also emphasizing the need to increase resilience in this demographic. [ABSTRACT FROM AUTHOR]

Summary Circadian disruption, arising from conflict between internal circadian time and behavioural sleep–wake and fasting–feeding rhythms, may contribute to the prevalence of type 2 diabetes mellitus and disease severity. Previous studies have demonstrated a link between irregular breakfast eating and poorer metabolic health. We aimed to further explore the relationships between breakfast habits, circadian misalignment (social jetlag), and metabolic parameters in a cohort of adult participants with type 2 diabetes mellitus. A total of 330 adult participants with type 2 diabetes mellitus attending for routine clinical review completed structured questionnaires to assess habitual sleep timing, chronotype, and social jetlag. Statistical analysis was via inferential groupwise approaches and path analysis to establish interdependencies of effects of social jetlag, chronotype, and breakfast eating regularity on HbA1c. 22.7% of the participants reported eating breakfast five times or fewer a week, and were categorised as irregular breakfast eaters. Compared with those who ate breakfast six or seven times a week, irregular breakfast eaters had significantly higher HbA1c and diastolic blood pressure, were younger and had greater social jetlag. In the path analysis, irregular breakfast eating exerted a direct effect on HbA1c, whilst social jetlag exerted only an indirect effect on HbA1c through breakfast eating regularity. Chronotype did not exert any effect on HbA1c, but did exert an indirect effect on breakfast eating regularity via social jetlag. Our results showed that adult participants with type 2 diabetes mellitus, who ate breakfast irregularly had poorer metabolic health and greater social jetlag. The relationship between social jetlag and glycaemic control appears to be mediated through breakfast eating habits. [ABSTRACT FROM AUTHOR]

Background: Temporomandibular joint disorders (TMDs) are common in young adults, and the link between chronotype profile and TMDs is unclear. Objective: This study examined TMD prevalence and chronotype distribution and explored the relationship between chronotype and TMDs in young adults. Materials and Methods: A total of 663 students from Sichuan University completed questionnaires. Chronotype profiles were assessed using the Morningness‐Eveningness Questionnaire, and TMDs were screened using the Fonseca Memory Index. To validate the findings, 68 TMD patients and 136 controls were enrolled. Results: The prevalence of TMDs was 69.7%, with significant differences among chronotype profiles. The intermediate profile was the most common chronotype. Eveningness profile was associated with higher TMDs prevalence and severity. Muscle pain and side movement difficulty scores were higher in eveningness and intermediate profiles. Female gender (OR 2.345; 95% CI 1.668–3.297) was a TMD risk factor, while morningness profile (OR 0.537; 95% CI 0.297–0.970) was protective. Validation with TMD patients and controls supported these findings, showing higher eveningness profile prevalence in the TMD groups. Conclusions: TMDs have a high prevalence in college students, chronotype profiles shown to be associated with TMDs. Morningness is the protection factor in TMDs and PT, eveningness is a risk factor for IT. [ABSTRACT FROM AUTHOR]

Circadian clock properties vary between individuals and relate to variation in entrained timing in captivity. How this variation translates into behavioural differences in natural settings, however, is poorly understood. Here, we tested in great tits whether variation in the free‐running period length (tau) under constant dim light (LL) was linked to the phase angle of the entrained rhythm ("chronotype") in captivity and in the wild, as recently indicated in our study species. We also assessed links between tau and the timing of first activity onset and offset under LL relative to the last experienced light–dark (LD) cycle. We kept 66 great tits, caught in two winters, in LL for 14 days and subsequently released them with a radio transmitter back to the wild, where their activity and body temperature rhythms were tracked for 1 to 22 days. For a subset of birds, chronotype was also recorded in the lab before release. Neither wild nor lab chronotypes were related to tau. We also found no correlation between lab and wild chronotypes. However, the first onset in LL had a positive relationship with tau, but only in males. Our results demonstrate that links between tau and phase of entrainment, postulated on theoretical grounds, may not consistently hold under natural conditions, possibly due to strong masking. This calls for more holistic research on how the many components of the circadian system interact with the environment to shape timing in the wild. Wild birds showed chronotypes in the field that were unlinked to their circadian period length tau measured in captivity. In males only, the first onset of activity after exposure to constant dim light did correlate with tau. Our study emphasises the need to investigate clocks in the real world, including a need to better understand masking. [ABSTRACT FROM AUTHOR]

The aim of this study is to examine the psychometric properties of the Turkish adaptation of the Morningness/Eveningness Scale (M/E Scale-Parent Report Form) family evaluation form for preschool children. The study sample consisted of 276 parents with children aged 4–6 years. The study calculated Cronbach's alpha internal consistency coefficient and corrected item-total correlations of the scale. It also determined the scale's distinctiveness, stability analyses, and convergent validity. The Turkish version of the M/E Scale (Parent Report Form), consisting of 10 items, is unidimensional. The Cronbach's alpha internal consistency coefficient of the scale was 0.80 and the corrected item-total correlation values varied between 0.51 and 0.76. There was a positive correlation at the level of 0.75 between the applications of the scale with two-week intervals and at the level of 0.63 between the single-item chronotype scale within the scope of convergent validity and the M/E Scale (Parent Report Form). This study determined a low correlation between the child's chronotype and the father's chronotype, and a moderate correlation with the mother's chronotype. The Turkish M/E Scale (Parent Report Form) was found to be valid and reliable. This scale is a short and easy-to-use measurement tool for determining the chronotypes of 4–6-year-old children. [ABSTRACT FROM AUTHOR]

Available data shows associations between chronotype, circadian rhythms, sleep quality and fibromyalgia (FM) presentation. However, no studies have explored links between the chronobiological variables and effectiveness of pharmacotherapy. We aimed to assess the chronotypes, circadian rhythms, sleep-wake cycle and sleep quality in FM and their links to treatment response to serotonin and noradrenalin reuptake inhibitors (SNRI). 60 FM patients: 30 responsive to SNRI (FM T[+]), 30 non-responsive to SNRI (FM T[-]) and 30 healthy controls participated. Subjects were assessed by physician and with questionnaire tools: Composite Scale of Morningness, Biological Rhythms Interview of Assessment in Neuropsychiatry, Sleep-Wake Pattern Assessment Questionnaire, Pittsburgh Sleep Quality Index and Fibromyalgia Impact Questionnaire. ANOVA analysis and simple logistic regressions were used to examine the relationships between chronological variables and response to SNRI. FM T[-] vs. FM T[+] presented lower morning affect (11.50[95%CI 9.96-13.04] vs. 14.00[95%CI 12.42-15.57];p=0.04), anytime wakeability (2.27[95%CI 1.4-3.13] vs. 4.03[95%CI 2.99-5.08];p=0.013) worse overall (11.40[95%CI 9.92-12.88] vs. 7.97[95%CI 6.75-9.19];p=0.002) and subjective (1.70[95%CI 1.30-2.01] vs. 1.17[95%CI 0.94-1.39];p=0.008) sleep quality, higher circadian rhythm disruptions (55.47[95%CI 52.32-58.62] vs. 44.97[95%CI 41.31-48.62];p<0.001), sleep disturbances (1.63[95%CI 1.38-1.68] vs. 1.30[95%CI 1.1-1.5];p=0.04), sleeping-medication use (1.80[95%CI 1.27-2.32] vs. 0.70[95%CI 0.28-1.12];p=0.003). Levels of morningness (AIC=82.91,OR=0.93,p=0.05), morning affect (AIC=81.901,OR=0.86,p=0.03) diurnal dysrhythmia (AIC=69.566,OR=1.14,p<0.001), anytime wakeability (AIC=80.307,OR=0.76,p=0.015), overall sleep quality (AIC=74.665, OR=1.31,p=0.002) subjective sleep quality (AIC=79.353, OR=2.832,p=0.01) and disturbances (AIC=82.669,OR=2.54,p=0.043), sleep medication use (AIC=77.017, OR=1.9,p=0.003) and daytime disfunction (AIC=82.908, OR=1.971,p=0.049) were predictors of non-response to SNRI. Chronobiological variables vary between FM T[+] and FM T[-] and are predictors of non-response to SNRI. [ABSTRACT FROM AUTHOR]

Sleep paralysis (SP) is a REM-related parasomnia, characterized by the inability to perform voluntary movements. It is a relatively widespread phenomenon in the general population and, although usually not dangerous, it is experienced with intense fear. The current study aims to evaluate the lifetime prevalence and characteristics of SP in the Italian student population. The study was conducted online, through an online battery of questionnaires. We used the Unusual Sleep Experience Questionnaire to investigate the prevalence of the disorder and the typical characteristics, metacognitive beliefs on the episodes, and previous distress factors. We also collected information about anxiety and depression symptomatology, sleep quality, and circadian preferences. Four hundred and thirty-two participants (333 F, 22.8 ± 2.57 y) took part in the study and 37.5 % of them reported having experienced at least one SP episode in their lifetime. On a physiological level, the most common features were the inability to speak followed by a tingling sensation and the inability to open the eyes, consistent with REM muscle atonia. Cognitive features during episodes include the perception of a presence in the room, followed by the fear of dying. Participants who reported SP had higher anxiety and worse sleep quality, and were more associated with evening chronotypes compared to non-SP responders. Our results show that SP is generally widespread in Italian students, in line with the prevalence reported in previous studies. Further studies could investigate the effects of suggested therapies to decrease the number of episodes of the disorder, especially in those who experience it recurrently. • Sleep paralysis (SP) seems to be a widespread phenomenon in Italian students. • The most common features of SP were the inability to speak and a tingling sensation. • Another common feature of SP was the perception of a presence in the room. • SP participants had higher anxiety and worse sleep quality than non-SP participants. [ABSTRACT FROM AUTHOR]

Planning-based interventions are often used to help individuals form habits. Existing literature suggests a one-size-fits all approach to habit formation, but planning interventions may be optimized if tailored to individual differences and/or behavioral complexity. We test the hypothesis that planning to do a relatively complex behaviour (exercise) at a time that matches an individuals' diurnal preference will facilitate behavioral engagement; whereas for a simpler behaviour (calcium supplementation), the optimal time-of-day for a new behavior will occur in the morning. Young, women volunteers (N = 317) were randomly assigned to take calcium supplements or to exercise for 4 weeks and to control (no planning) or to one of three planning interventions (morning plan; evening plan; unassigned-time plan). Participants reported diurnal preference at baseline and habit strength and behavioral frequency weekly. Fitbit Zips and Medication Event Monitoring System Caps (MEMS) were used to objectively assess behavioral engagement. Multilevel modelling found that calcium-supplementation was greatest for morning-types in the morning-cue condition, whereas exercise was greatest for morning-types with morning cues and evening-types with evening cues. Habit-formation strategies may depend on diurnal preference and behavioral complexity. Future research can evaluate the role of other individual differences. [ABSTRACT FROM AUTHOR]

People can identify as morning types or evening types. Research has shown that evening types are generally less happy and have a lower sense of well‐being. While there is limited research in consumer psychology on chronotypes, one question may be asked: Would they gain from the experiential advantage (where people elicit greater happiness from experiential vs. material purchases) and become happier? We find that evening types, in fact, elicit lower levels of happiness from their experiential purchases compared to morning types and, in effect, feel happier from their material purchases. Furthermore, this is because of the greater subjective distance they feel from their experiential purchases. This research contributes to our understanding of long‐term happiness in a significant section of society—evening types and also calls on researchers to explore the topic of evening chronotype happiness and well‐being in greater depth from a marketing perspective. [ABSTRACT FROM AUTHOR]

Summary The efficacy of digital brief behavioural treatment for insomnia using a smartphone application in conjunction with light therapy was investigated in university students who had insomnia symptoms with late chronotypes. In this two‐arm parallel randomized–controlled trial, participants with insomnia symptoms and late chronotypes were recruited between October and November 2023. The duration of the intervention program was 4 weeks. The smartphone application provides digital brief behavioural treatment for insomnia, including programs for advanced phases. The intervention group used blue‐light‐emitting diode glasses in the morning after waking up for 2–4 weeks. The primary outcome was a change in the Insomnia Severity Index during the study period. The Insomnia Severity Index was obtained weekly using a web questionnaire. Of the 28 students, 14 each were assigned to the intervention and control groups. The mean Insomnia Severity Index scores at baseline were 12.2 and 12.5; after 4 weeks, they declined to 7.2 and 10.6 in the intervention and control groups, respectively. Primary analysis using a linear mixed model showed a significant improvement in the temporal trends of the Insomnia Severity Index in the intervention group (p < 0.001). The scores on the Morningness–Eveningness Questionnaire (p = 0.008) and RU‐SATED (p = 0.005) significantly improved in the intervention group relative to the control group following the intervention. This study demonstrated the effectiveness of the digital brief behavioural treatment for insomnia with light therapy in participants with both insomnia symptoms and late chronotypes. [ABSTRACT FROM AUTHOR]

Objective Methods Results Conclusion Evaluation of the biomarkers and their relations with sleep in attention deficit hyperactivity disorder (ADHD) is important for understanding the impairments in cognitive functioning. In this study, we aimed to investigate the brain‐derived neurotrophic factor (BDNF) and sialic acid (Sia) levels, and their possible relations with chronotypes in ADHD.The study included 100 drug‐naive children with ADHD and 74 healthy children as controls. Conners' Parent Rating Scale‐Revised (CPRS‐R) scores were used for the severity assessment. Morningness Eveningness Questionnaire (MEQ) was used to determine the chronotypes of participants. ELISA kits were used for the assessment of BDNF and Sia plasma levels.Levels of BDNF and Sia were found to be statistically significantly higher in the ADHD group compared to healthy children (p < 0.001, p < 0.001, respectively). BDNF and Sia levels were found to be higher in the ADHD group with eveningness chronotype (p = 0.045, p = 0.038). The binary logistic regression model was statistically significant (p = 0.033), higher BDNF and Sia levels were assessed as predictive factors for the diagnosis of ADHD. Also, eveningness chronotype was found as a predictive factor of BDNF and Sia levels in ADHD.The results indicate that BDNF and Sia levels, which are related to cognitive functions and sleep, increase with the age of ADHD. Eveningness chronotype, connected with the severity of ADHD, is related to BDNF and Sia levels. There is a need for further studies to confirm these results. [ABSTRACT FROM AUTHOR]

Background: Circadian rhythms are crucial for physiological functioning, and they vary among people. There are three distinct chronotypes: morning, evening, and neither type. Morning types experience their highest level of activation during the early part of the day and tend to be more conscientious and focused on achieving their goals. Evening types, on the other hand, reach their peak performance during the latter portion of the day and exhibit a higher level of intelligence. University class schedules may occasionally clash with evening-type individuals' circadian preferences, potentially impacting their academic performance in comparison to their morning-type peers. Therefore, this study was done to investigate if morningness-eveningness can affect college students' academic performance as sleeping late or sleep deprivation can lead to disease in the young population. Materials and methods: A sample of 100 collegiate students aged 18–30 years were recruited via convenience sampling from Jamia Hamdard, Delhi, and informed consent was obtained from the subjects. The morningness-eveningness questionnaire (MEQ) was used to assess students' chronotype, and the mean of the last three academic years percentage was used to assess the academic performance of the students. Results: The total academic performance score was better in the morning category (75.53 ± 7.28) as compared to the evening (66.42 ± 10.08) and intermediate (73.72 ± 6.46) categories. There was a low degree of positive correlation between total academic performance and TMEQ (total morning-evening questionnaire) score (ρ = 0.204). Conclusion: The academic performance of morning chronotype students was better than that of evening chronotype students. [ABSTRACT FROM AUTHOR]

Objectives: Eating disorders (EDs) have emerged as a growing public health concern. However, the role of sleep in this context remains underexplored. The aim of this cross-sectional study was to determine the associations between sleep parameters and chronotype with ED risk in a sample of university students in Spain. Methods: ED risk was assessed via the Sick, Control, One stone, Fat, Food Questionnaire, and sleep quality was assessed via the Pittsburgh Sleep Quality Index. Other sleep parameters and chronotypes were self-reported. Sociodemographic, body composition, lifestyle, and depressive symptom data were collected. Logistic and linear regression models adjusted for the main confounders were used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) of the study associations. Results: A total of 403 students (70.2% female) aged 18 to 30 years participated in the study. Those reporting poor sleep quality (OR = 1.85, 95% CI 1.08–3.17, p = 0.025) and ≤6 h of night-time sleep duration (OR = 4.14, 95% CI 2.00–8.57, p < 0.01) were more likely to be at risk of EDs in the adjusted analyses. The association between night-time sleep duration and the risk of ED did not remain significant when we adjusted for sleep quality. In addition, an evening chronotype was associated with an increased risk of EDs (OR = 1.68, 95% CI 1.07–2.66, p = 0.039) only before adjustment for confounders. Conclusions: Among university students, poorer sleep quality was cross-sectionally associated with EDs. Future prospective studies are needed to examine whether promoting sleep quality may serve as an effective strategy for preventing the risk of EDs. [ABSTRACT FROM AUTHOR]

This systematic review aims to identify the sleep parameters of Olympic athletes and the instruments used to assess and monitor the sleep of these athletes. The search was conducted until February 2023 and was performed in PubMed, Web of Science, and Scopus databases. This systematic review has included studies that investigated at least one of the following sleep parameters: total sleep time (TST), sleep onset latency (SOL), sleep efficiency (SE), awakenings after sleep onset (WASO), quality of sleep, daytime sleepiness, and chronotype; the participants were Olympic athletes. The search returned a total of 280 studies. After screening based on exclusion and inclusion criteria, 11 studies were included. The main results demonstrate that Olympic athletes have TST of 06:10 h, SE of 84%, SOL of 28 min, and WASO of 49 min. The most predominant chronotype is indifferent; over half of the athletes have poor sleep quality and complaints. Furthermore, actigraphy was the most used method to assess sleep. It is concluded that Olympic athletes have TST, SE, and WASO poor than the recommended values. In addition, sleep complaints and poor sleep quality were also observed. Among the objective sleep assessment methods, actigraphy was the method most frequently used in this population. [ABSTRACT FROM AUTHOR]

Summary One of the most striking changes in the regulation of sleep–wake behaviour during adolescence is circadian phase delay. Light exposure synchronises circadian rhythms, impacting sleep regulation, however, the influence of real‐life light exposure on sleep variations remains less clear. We aimed to describe the sleep and light exposure patterns of high school students with comparable schedules and socio‐economic backgrounds, and to evaluate whether there was any association between them, considering chronotype. We analysed five school days and two free days of actigraphy records, from 35 adolescents (24 female, mean age: 16.23 ± 0.60). The sample was described using the Sleep Regularity Index (SRI), chronotype (actigraphy MSFsc), and self‐reported diurnal preference (Morning/Evening Scale). Regression models were constructed to assess the impact of light exposure (daytime and nighttime) on subsequent sleep episodes; and to confirm whether the associations could be an indirect consequence of chronotype. Despite following similar routines, the SRI varied considerably (48.25 to 88.28). There was compatibility between the actigraphy proxy for chronotype and the self‐reported diurnal preference, extracted using the circadian rhythm scale for adolescents. Less light exposure during the day was associated with later sleep onset and shorter sleep duration. An increase of 100 lux in average daytime light exposure advance of 8.08 minutes in sleep onset and 7.16 min in sleep offset. When the regressions were controlled for chronotype, these associations persisted. These findings facilitate discussions regarding the behavioural aspect of the impact of real‐life light exposure on sleep and its potential as a target for interventions aiming to enhance adolescents’ sleep quality. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effect of cognitive insight on anxiety in communitydwelling schizophrenia patients and to construct a chain mediating model to determine the underlying mechanisms of the relationship between cognitive insight and anxiety through family cohesion and chronotype. Methods: The Beck Cognitive Insight Scale, the Chinese version of the Family Adaptability and Cohesion Scale, the Morningness-Eveningness Scale, and the Generalized Anxiety Disorder Scale were used to assess cognitive insight, family cohesion, chronotype, and anxiety in a sample of 785 individuals with schizophrenia living in the community. Spearman correlation analysis, multiple linear regression and Bootstrap methods were employed to analyze the four variables. Results: Residential region, current employment status, and family economic status impacted anxiety among community-dwelling schizophrenia patients. All variables were associated with each other, but self-certainty was not significantly associated with anxiety. Cognitive insight and self-reflection had direct effects on anxiety, as well as indirect effects on anxiety through the partial mediating effect of chronotype, the suppressing effect of family cohesion, and the chain mediating effect of family cohesion and chronotype. Conclusions: Family cohesion and chronotype can mediate the relationship between cognitive insight and anxiety. Improving family functioning, promoting emotional relationships within families, and correcting non-circadian sleep patterns can reduce anxiety in community-dwelling schizophrenia patients, with important implications for improving adverse mental health outcomes. [ABSTRACT FROM AUTHOR]

Background: Although healthy sleep patterns have been linked to a lower risk of cardiovascular disease in earlier research, it is unclear how beneficial they are for venous thromboembolism (VTE). Aim: This research aimed to examine the correlation between sleep patterns, genetic susceptibility, and VTE. Methods: In the UK Biobank cohort, healthy sleep behaviors were defined as early chronotype, 7–8 hours of sleep each day, no snoring, infrequent insomnia, and infrequent daytime sleepiness. Each of the five criteria was given 1 point, creating a healthy sleep score ranging from 0 to 5. Cox proportional hazards regression models were utilized to examine the associations between genetic susceptibility, healthy sleep score and VTE. Results: The UK Biobank study included 384,758 participants aged 56.6 ± 8.0 years. After a median of 11.9 years of follow-up, 8,885 (2.3%) participants were diagnosed with VTE. A healthy sleep score inversely affected VTE risk. For participants with a score of 5, the hazard ratio of VTE was 0.813 (95% confidence interval: 0.758–0.873, P<0.001) compared to those with a score ≤2. Early chronotype, sleeping 7–8 hours each day, infrequent insomnia, and infrequent daytime sleepiness were significantly associated with a 7.9%, 8.3%, 5.1%, and 20.7% lower risk of VTE, respectively. In addition, the correlation between sleep pattern and the incidence of VTE was consistent, regardless of genetic susceptibility (P for interaction = 0.366). Conclusions: Our secondary analysis of a large-scale prospectively gathered registry revealed that individuals with a healthy sleep pattern are significantly correlated with lower risk of developing VTE, irrespective of genetic susceptibility. [ABSTRACT FROM AUTHOR]