Morningness-Eveningness Questionnaire Research Articles

In terms of chronotype, and academic achievement: Can an evening education program be an alternative?

This research aims to analyze the biological rhythm and academic achievement in university students studying in daytime and evening education programs. This is a descriptive research. Its sample group consists of 777 nursing students. "The form for inspection by variables", "Morningness-Eveningness questionnaire", "Biological Rhythms Interview of Assessment Scale" and "Perceived Achievement Assessment Scale", were used in data collection. 71% of the students receiving daytime education were of moderate type in terms of morningness-eveningness and they had a biological rhythm scale score of 49.30±7.27. Their achievement score was 2.51±0.47 and they assessed themselves as having moderate achievement. 69% of the students receiving evening education were of moderate type in terms of morningness-eveningness and they had a rhythm scale score of 50.26±7.68. Their academic achievement score was 2.42±0.47 and they assessed themselves as having moderate achievement. It was observed that most of the students had intermediate-type and irregular biological rhythms. Daytime education students have higher academic achievement scores than evening education students; perceived academic achievement was average in both groups. The academic success, sleep, and eating habits of evening education students are negatively affected, so education should be done during the daytime.

Consistency of chronotype measurements is affected by sleep quality, gender, longitude, and latitude

ABSTRACT Chronotype has received increasing research attention. However, there remains some confusion about the influence of gender, age, sleep quality, insomnia severity, longitude, and latitude on the consistency of the chronotype measured by the different tools. Chronotype measurement indicators were collected from 421 participants. The midpoint of sleep for actigraphy (MSF_A), sleep diary (MSF_D), and Munich Chronotype Questionnaire (MCTQ) (MSFsc) on free days and the Morningness-Eveningness Questionnaire (rMEQ) scores were used to measure the chronotype. In addition, demographic information, Pittsburgh Sleep Quality Index (PSQI), and Insomnia Severity Index (ISI) were also collected. A significant correlation was identified between the questionnaires (MSF_D, MSFsc, rMEQ) and actigraphy (MSF_A) as measures of chronotype. MSF_A was associated with sleep latency and sleep disturbance in the PSQI subdimensions. The correlation between MS_D and sleep disturbance was significant. Both rMEQ and MSFsc were significantly correlated with PSQI (total scores and daytime dysfunction) and ISI. The consistency of all chronotype measurements for the questionnaires and actigraphy was influenced by gender. Among them, MSF_D is also affected by age, while only the latitude and sleep disturbance effect was found in the MSFsc. The influence of age, gender, sleep quality, and latitude should be emphasized when measuring the chronotype using self-reported methods.

Chronotype, Daytime Sleepiness, and Related Factors Effects on Skipping Classroom among Medical Students in Tabuk

Background: Lecture attendance is very critical in medical practice. Good sleep hygiene is crucial for academic performance. Therefore, this research aimed to assess the relationship between daytime sleepiness and the chronotype, and skipping the classroom.
 Methods: A cross-sectional study was conducted among medical Students in Tabuk from April 2022 to July 2022. Three hundred and thirty-four medical students were randomly selected. A standardized questionnaire based on the daytime sleepiness scale, morningness–eveningness questionnaire, and risk for skipping classrooms was used. The students detailed their sleeping habits for two weeks and then responded to the questionnaire distributed directly by the researchers who attended to solve any difficulties.
 Results: Out of the 334 students,74.7% skipped the classroom last month. The most common reason for absence was the lecturer directly reading from the slide show (72.8%), followed by late lectures (67.8%), lecturers’ presentation skills (65.6%), and lack of interest (57.9%). Daytime sleepiness was evident in 40.1% of the students and was associated with skipping lectures (Wald, 3.86, P-value, 0.049, and 95% CI, 0.19–0.91). The majority were intermediate chronotypes (66.4%), followed by evening chronotypes (24.2%) with no association with skipping classrooms.
 Conclusion: Skipping lectures is common among medical students in Tabuk City, Saudi Arabia; the causes were lecture timing, daytime sleepiness, and lecturers’ presentation skills. Most students were an intermediate chronotype that was not associated with classroom absence. Further larger multi-center studies are needed.

Effect of Circadian Preferences and Personality Traits on Academic Achievement in Active Students

Objective: During the past decades, several studies have explored individuals’ differences and their impact on scholarly achievement. The effect of circadian preference and personality on academic performance has been studied in different countries. However, studies have yet to analyze these variables in the Moroccan context (North West Africa) and test whether academic performance relates to circadian types and personality traits. This study aimed to investigate the relationship between those variables in young active students.Methods: This study included 167 Moroccan active students (age=16.34 years; SD=1.2). The personality trait was measured with Big Five Questionnaire for Children (BFQ-C). We also assessed the circadian typology by using Morningness–Eveningness Questionnaire (MEQ). School grades were used to calculate academic success (grade point average [GPA]). We investigated the relationships between all the parameters.Results: This study indicates a significant difference in Big Five factors between athlete groups of chronotype. GPA is significantly related positively to MEQ score and openness but negatively to neuroticism. However, no correlation was observed with the other significant five factors.Conclusion: Professionals must consider circadian preferences and personality traits when looking to facilitate students’ scholarly achievement.

Chronotype, Aerobic Performance, and Sleep Quality of Young Athletes Before and During Ramadan Observance

Background and Objective Intermittent fasting has become a popular topic in recent years, with many people turning to this dietary approach to improve their health and manage their weight. It has also been studied for its potential impact on various aspects of health, including sleep and physical performance. This study aimed to investigate the impacts of intermittent fasting during Ramadan and chronotype on sleep quality and aerobic performance in young athletes.Methods This study is a prospective cohort design with repeated measurements, including 117 amateur athletes (16.86 ± 1.07 years) from Morocco. The aerobic performance was measured with the 20-m shuttle-run test. We also assessed sleep quality with the Pittsburgh Sleep Quality Index. The chronotype was assessed by the Morningness-Eveningness Questionnaire. We examined the difference in means before and during Ramadan; then, we analyzed the correlation between all variables.Results The current study showed that while aerobic performance and sleep quality declined during Ramadan, those with good sleep quality performed better in all periods. It also showed that chronotype is correlated with the aerobic performance before but not during Ramadan. However, the chronotype is associated with the sleep quality before and during Ramadan.Conclusions During Ramadan, athletes must build coping strategies to improve their sleep quality and maintain optimal physical performance.

Promotion of Para Athlete Well-being (PROPEL II): A Cross-sectional Study of Sleep in Para Athletes Across Two Nations.

Limited research exists on the sleep profiles of South African Para athletes. The aims of this study are to describe sleep quality, day-time sleepiness, and chronotype of South African Para athletes and to compare the relationship between sleep-related outcomes and demographic factors to athletes from a higher-resource country. A descriptive, cross-sectional survey was conducted. Sleep-related characteristics were assessed with the Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale and Morningness-Eveningness Questionnaire. Multiple regression models were run with and without country as independent variable. One hundred twenty-four South African athletes and 52 Israeli athletes were included. Thirty percent of South African athletes presented with excessive daytime sleepiness, 35% slept 6 hrs or less per night, and 52% reported poor sleep quality. Thirty-three percent of Israeli athletes reported excessive daytime sleepiness, 29% slept 6 hrs or less, and 56% reported poor sleep quality. Chronotype was the only variable that differed significantly between countries (overrepresentation of morning types in South African athletes, and intermediate types in Israeli athletes). Intermediate chronotypes had significantly greater odds of excessive daytime sleepiness ( P = 0.007) and poor sleep quality ( P = 0.002) than morning types, irrespective of country. The high prevalence of poor sleep among both South African and Israeli Para athletes warrants further investigation.

616-P: Glucose Metabolism—Does Chronotype Matter?

Glucose and insulin follow circadian-mediated metabolic profiles. Accumulating evidence has demonstrated significant associations between circadian disruption-related lifestyles and an increased risk of type 2 diabetes typical of Evening-types (E-types), more active in the last part of the day, compared to Morning-types (M-types). However, few studies have examined the contribution of chronotype to abnormalities of glucose profile considering both lifestyle factors and body composition. We conducted a cross-sectional study on 575 adults (71% females, 48.5±12.8 years, BMI 29.3±6.0 kg/m2) with no endocrine diseases and no consumption of medications affecting endocrine function. Chronotype was assessed through the reduced Morningness-Eveningness Questionnaire (rMEQ), glycemia, insulinemia and HbA1c plasma levels HOMA-IR were estimated. Anthropometric parameters were collected and abdominal fat distribution was measured by ultrasonography. Smoking and physical activity habits were collected by a medical history and adherence to Mediterranean diet was assessed by MEDAS questionnaire. Logistic regression models were used to investigate the association between glycemia, insulinemia and chronotype. Sex, age, BMI, total body fat, visceral and subcutaneous fat, physical activity, smoking habits and MEDAS were included in all models. Insulin levels were significantly higher in the E-Types compared to M-Types. We did not find a significant interaction between chronotype, glycemia and HbA1c, however insulin and HOMA-IR decreased with increasing rMEQ score and morningness, indicating that E-Types have +5,6 and +1,4 points of insulinemia and HOMA-IR, respectively, compared to M-Types (β=−0.28 [−0.5; −0.1], p=0.003; β=−0.07 [−0,12; −0,02], p=0.005). Chronotype is independently associated with abnormalities in insulin profile, pointing to the importance of understanding the mechanisms underlying the impact of circadian disruption on glucose metabolism, which may contribute to improved glycemic control. Disclosure R.De amicis: None. A.Battezzati: None. A.Foppiani: None. A.Leone: None. L.Galasso: None. A.Montaruli: None. E.Roveda: None. L.Castelli: None. F.Esposito: None. S.Bertoli: None. Funding Italian National Recovery and Resilience Plan Mission 4 Component 2 Investment 1.3 - Call for Proposals (341) of 15 March 2022 of Italian Ministry of University and Research funded by the European Union - NextGenerationEU (PE00000003) Concession Decree (1550) of 11 October 2022 adopted by the Italian Ministry of University and Research (CUP D93C22000890001)

The Effects of Napping on Wakefulness and Endurance Performance in Athletes: A Randomized Crossover Study.

Background: Athletes often experience poor sleep quality due to stress, altitude exposure, travel across different time zones, and pre-competition nervousness. Coaches use daytime naps to counteract the negative effects of fragmented nighttime sleep. Napping before competitions has also been used to enhance performance in athletes without sleep problems, with mixed results in previous studies, particularly for endurance performance. Thus, we investigated the effects of napping after partial sleep deprivation (PSD) on endurance performance and wakefulness in athletes. Methods: We recruited 12 healthy and trained participants (seven female and five male) for a randomized crossover study design. The participants underwent two test sessions: a five-hour night of sleep without a nap (noNap) and a five-hour night of sleep with a 30-min nap opportunity (Nap30). Participants recorded their sleep-wake rhythm one week before and during the study using the Consensus Sleep Diary-Core and the Morningness-Eveningness Questionnaire to examine their circadian rhythm type. We quantified PSD and the nap with pupillography (pupil unrest index, PUI), a subjective level of sleepiness questionnaire (Karolinska Sleepiness Scale, KSS), and polysomnography. After each night, participants performed a maximal cycling ergometry test to determine time to exhaustion (TTE) and maximal oxygen uptake (VO 2max). Results: Participants had an average sleep duration of 7.2 ± 0.7 h and were identified as moderately morning types (n = 5), neither type (n = 5), and moderately evening types (n = 2). There was a significant difference in both sleepiness parameters between the two conditions, with the PUI (p = 0.015) and KSS (p ≤ 0.01) significantly decreased at 5 h and nap compared with only 5 h of sleep. The PUI (p ≤ 0.01) and KSS (p ≤ 0.01) decreased significantly from before to after the nap. However, there was no significant difference in physical exercise test results between the conditions for TTE (p = 0.367) or VO 2max (p = 0.308). Conclusions: Our results suggest that napping after light PSD does not significantly influence endurance performance. We conclude that aerobic performance is a multidimensional construct, and napping after PSD may not enhance it. However, napping is an effective method to increase wakefulness and vigilance, which can be beneficial for sports competitions.

A randomized controlled trial of a behavioral intervention for decreasing bedtime procrastination using a wait-list control group in a non-clinical sample of young adults

Study objectivesBedtime Procrastination (BP) is defined as the behavior of going to bed later than intended, without external reasons. This study is a randomized controlled trial aiming to establish efficacy of a behavioral intervention to decrease BP in a non-clinical sample. MethodThis was an open-label trial that was conducted in sixty participants (mean age 21.33 ± 2.35 years, 86.7% females) without insomnia or psychopathology who endorsed frequent BP. They were randomized to either the treatment group (n = 32) or wait-list control group (n = 28). Participants completed the Bedtime Procrastination Scale (BPS), the Epworth Sleepiness Scale (ESS), the Insomnia Severity Index (ISI), Center for Epidemiologic Studies Depression Scale (CES-D), Morningness-Eveningness Questionnaire (MEQ), and a weekly sleep diary. Functional analysis was conducted to investigate the function of BP. Linear mixed models were used for analyses. ResultThe treatment group showed significant improvement on the BPS (35.56% decrease, d = 2.19, bedtime procrastination duration based on the sleep diary (−46.29 min, d = 1.22), and sleep efficiency (5.70% increase, d = 1.25) compared to the wait-list control group following the intervention. There were also significant reductions in time spent from bedtime to lights out, and wake time to time out of bed, in addition to improvements in ISI and ESS scores in the treatment group compared to the control group. Functional analysis results indicated emotional regulation (31.3%), compensation (26.5%), and social interaction and belongingness (18.1%) as the most frequent functions of bedtime procrastination. ConclusionThis study shows promising results for a behavioral intervention targeting BP and sleep. In addition, this study demonstrated various functions of BP as a sleep-interfering behavior. We expect that these findings could be used in future studies and clinical settings to decrease BP.

Relationship between chronotype and mental behavioural health among adolescents: a cross-sectional study based on the social ecological system

BackgroundHealth risk behaviors (HRBs) is a kind of phenomenon behavior that often occurs in adolescence, and also often appears in clusters. Previous studies suggested an association between social ecological risk factors (SERFs) and HRBs. This study explored 1) whether chronotype moderates the risk of HRBs associated with SERFs and 2) whether mental health is a mediator in this relationship.MethodsAdolescents were recruited from 39 junior or senior schools (three cities, 13 schools per city) using a multistage cluster sampling method conducted between October, 2020 and June, 2021. The Social Ecological System, Morningness–Eveningness Questionnaire, Brief Instrument on Psychological Health Youths, and Youth Risk Behavior Surveillance questionnaires were used to measure the SERFs, chronotype, mental health and HRBs. Latent category analysis was used to explore the clustering mode of HRBs. The primary exposure was SERFs, and the primary outcome was HRBs; chronotype was a moderator, and mental health was a mediator. The multivariable logistic regression model was used to determine the relationship between SERFs and chronotype and mental behavioral health status. Mediation moderate analysis using the PROCESS method was used to explore the relationship between these variables. Sensitivity analysis was conducted to evaluate the robustness of the model.ResultsIn total, 17,800 individuals were initially enrolled. After excluding 947 individuals with invalid questionnaires, 16,853 participants were finally included in the analysis. The mean age of participants was 15.33 ± 1.08 years. After adjusting for covariates, multivariable logistic regression found that high levels of SERFs (odds ratio [OR] = 10.10, 95% confidence interval [CI]: 8.88–11.43, P < 0.01), intermediate chronotype (OR = 5.24, 95% CI: 4.57–6.01, P < 0.01), and eveningness (OR = 1.83, 95% CI: 1.64–2.05, P < 0.01) were associated with higher HRBs frequency. This study also assessed the interaction between chronotype, SERFs and HRBs (OR = 27.84, 95% CI: 22.03–35.19, P < 0.01) and mental health (OR = 18.46, 95% CI: 13.16–25.88, P < 0.01). The moderated mediation analyses examined the relationship between chronotype, SERFs, mental health and HRBs.ConclusionsSERFs may be important variables in measuring the effect of the adolescent psychosocial environment on HRBs; this effect is mediated by mental health and moderated by chronotype.

0690 People without any sleep complaints achieve results that exceed the cut-off thresholds in standardized sleep assessment

Abstract Introduction With increasing prevalence of sleep problems in the general population, a question arises on whether standardized clinical sleep assessment shows results exceeding the cut-off thresholds in healthy subjects who do not report any sleep complaint. The aim of this ongoing study is to assess a sample of healthy subjects who report good sleep quality, for each gender in age groups 18-30, 31-40, 41-50, 51-60, 61-75 years old. Methods Up to now 70 healthy subjects have taken part in the project (38 females, 32 males, mean age 39.5 ±12.5, median 37 years). Assessment of sleep, and mental health related symptoms was performed using actigraphy, sleep diaries and clinical ratings scales: the Insomnia Severity Index (ISI), Epworth Sleepiness Scale(ESS), Morningness Eveningness Questionnaire(MEQ), Ford Insomnia Response to Stress Test (FIRST), International Physical Activity Questionnaire (IPAQ), STOP-Bang Questionnaire, Sheehan Disability Scale (SDS), Quick Inventory of Depressive Symptoms (QIDS-16SR), Generalized Anxiety Disorders Scale (GAD7), World Health Organization Quality of Life Scale (WHOQOL-BREF). Results In ISI scale 20 subjects (28,6%) reported mild and 2 subject (2,8%) moderate insomnia symptoms. In ESS 7 subjects (10.0%) were found to have mild, 5 (7,1%) moderate and 3 (4,3%) severe excessive daytime sleepiness. Anxiety symptoms reported 15 (21,4%) subjects and depressive symptoms 18 (22,9%) subjects. Moderate for risk for sleep apnea was found in 9 (12,8%) and high in one (1,4%) subject. In sleep diaries sleep latency above 30 minutes was found in 4 (5,6%) subjects, WASO above 30 minutes in 7 (10.0%) subjects, total sleep time below 6,5 hours in 22 (31,4%) subjects. Average time in bed was 474 ±55 minutes and average sleep efficiency 86,8 ±7,5%. ISI correlated with FIRST (r=0.496, p&amp;lt; 0.001), GAD-7 (r=0.445, p&amp;lt; 0,001), QIDS-SR16 (r=0,483, p&amp;lt; 0.001), sleep latency (r=0,313, p&amp;lt; 0,05), WASO (r=0,270, p&amp;lt; 0,05). ESS corelated with FIRST (r=0.316, p&amp;lt; 0,01), GAD-7 (r=0,275, p&amp;lt; 0,05). Conclusion Substantial proportion of subjects from the general population who did not initially report any sleep complaints obtained results exceeding suggested threshold in standard clinical scale and sleep parameters below normal valse in sleep diaries. Poor sleep indices are most related to scales measuring stress, anxiety and depressive symptoms. Support (if any)

0826 Chronotype, unhealthy lifestyle, and diabetes risk in middle-aged US women: A prospective cohort study in Nurses’ Health Study II

Abstract Introduction Chronotype refers to one’s inclination to earlier or later sleeping times. Late chronotype has been linked to increased diabetes risk, which may be mediated through adherence to unhealthy lifestyle. This study aimed to evaluate the interplay among chronotype, lifestyle factors, and diabetes risk. Methods In 2009, 63,594 diabetes-free women (mean age=54 yrs) from the Nurses’ Health Study II self-reported their chronotype using a validated question from the Morningness-Eveningness Questionnaire and were prospectively followed for incident type 2 diabetes (T2DM) until June 2017. Unhealthy lifestyle was defined by having &amp;lt; 4 of the following 6 healthy lifestyle factors: high diet quality (AHEI≥49), physical activity (≥3.5 MET-hours/week), moderate alcohol intake (≥5 and &amp;lt; 15 g/day), normal body mass index (≥18.5 and &amp;lt; 25 kg/m2), non-current smoking, and 7-9 hours of sleep. T2DM was self-reported and confirmed using a validated supplementary questionnaire. We used modified Poisson regression models to estimate the cross-sectional associations between chronotype and unhealthy lifestyle. Cox proportional hazards models were used to estimate the adjusted hazard ratios (aHR) for incident diabetes risk according to chronotype and assess the proportion of the association explained by lifestyle factors (mediation analyses). Results Participants reporting a “definitely-evening” type were 55% (95% CI: 1.51-1.60) more likely to have an unhealthy lifestyle compared with participants reporting a “definitely-morning” type. We documented 1,921 T2DM cases over 468,555 person-years of follow-up. With increasing eveningness, the risk of T2DM became significantly higher (Ptrend&amp;lt; 0.0001). Compared with the “definitely-morning” type, the aHR (95% CI) for T2DM was 1.10 (0.97-1.24) for “more-morning”, 1.01 (0.81-1.27) for “intermediate”, 1.26 (1.11-1.42) for “more-evening”, and 1.65 (1.44-1.90) for “definitely-evening” chronotypes, after adjusting for sociodemographic factors, shift-work, depression and family history of diabetes. Additional adjustment of unhealthy lifestyle explained 56.8% (95% CI: 39.4%-72.6%) of the association [aHR (95% CI) for “definitely-evening” versus “definitely-morning”: 1.27 (1.10-1.46)]. Conclusion Women with a late chronotype are more likely to engage in unhealthy lifestyle behaviors. Late chronotype is prospectively associated with increased diabetes risk, which is partly explained by unhealthy lifestyle behaviors. Our results suggest that lifestyle interventions may potentially reduce the adverse impact of late chronotype on diabetes risk. Support (if any) R01HL155395, K01HL143034, U01CA176726

0185 Circadian Rhythm of Rock Climbing Specific Finger Strength

Abstract Introduction Circadian rhythm influences various aspects of athletic performance; however, the sport specific effects in rock climbing are not well studied. This study aimed to evaluate circadian changes in finger strength in rock climbers. This may have important implications for timing of training and challenging climbing goals. Methods Participants completed two rounds of finger strength testing on the same day (morning 7-9 am and evening 5-7 pm) consisting of maximal pulls on a polyurethane training block (18 mm flat edge) anchored to a dynamometer (TindeqTM). Participants were cued to keep 4 fingers on without using the thumb and given two attempts on each hand with the highest load recorded each session. Demographic data, climbing experience level, sleep quality (Promis Sleep short form.), and chronotype (Morningness-Eveningness questionnaire) were recorded for secondary outcome analysis. Standard descriptive statistics and paired t-tests were performed to compare the morning and afternoon findings. Results 10 participants completed finger strength testing. There was a significant increase in mean maximum finger strength from morning (M = 35.2 kg, SD = 14.8) to afternoon (M = 40.1 kg, SD = 16.1), t(9) = 4.1, p = .003, with a large effect size (Cohen’s d = 1.3). The mean increase was 5.0 kg with 95% confidence interval of 2.2 kg to 7.7 kg. The morning to afternoon increase in maximal strength remained significant when subdivided by sex (males n = 6, p = .04, 95% CI [0.4kg, 10.0] kg, and females n = 4, p = 0.48, 95% CI [0.1, 9.1] kg). This study lacked sufficient power to detect differences related to other secondary measures. Conclusion Maximum finger strength in rock climbers was greater in the afternoon compared to morning suggesting a circadian rhythm influence. Rock climbers needing peak finger strength may benefit from timing hard climbs in the afternoon rather than early morning. Further study is needed to determine if this finding is seen in larger groups or impacted by sleep quality and chronotype. Support (if any) Training space was supported by Triangle Rock Club, Durham NC.

0647 Rest-activity pattern in Major depressive disorder - a case control study

Abstract Introduction Disruption of rest-activity pattern are important behavioral manifestations in patients with major depressive disorder (MDD). Actigraphy provides accessible and objective measurement on physical activity, sleep, and circadian rhythm, but it was not widely used in studying patients with MDD, especially among Asian population. Methods Rest-activity pattern was recorded by Actiwatch Spectrum Plus/PRO for 7 continuous days. Physical activity and sleep estimation was processed by Philips Actiware software 6. Circadian rhythm characteristics were generated by using the “cosinor” and “nparACT” packages in R to perform the cosinor and nonparametric analysis respectively. Results A total of 70 MDD subjects, and 59 age- and sex-comparable controls were included in the actigraphy data analysis. The mean age of MDD subjects was 51.24 ± 10.39 years, and 71.4% of MDD subjects were female. Of these MDD subjects, 54.3% were unremitted for their depressive illness. For sleep and circadian features, MDD subjects had higher Insomnia Severity Index (ISI score, MDD: 10.29 ± 5.70; controls: 6.05 ± 5.20, P &amp;lt; 0.001) and lower reduced Morningness-Eveningness questionnaire (rMEQ score, MDD: 13.19 ± 4.62; controls: 16.07 ± 3.28, P &amp;lt; 0.001) than controls. The percentage of mobility measured by actigraphy was significantly lower in MDD patients than controls (MDD: 58.58%; controls: 62.27%, P &amp;lt; 0.001), albeit the difference only occurred during rest period. MDD subjects had later acrophase (P = 0.024), M10 midpoint (P = 0.040) and a trend of delayed sleep midpoint (P = 0.076) and longer sleep duration (P = 0.067) than controls. When the comparison was performed among three groups, unremitted MDD subjects showed a higher intra-individual variability of sleep midpoint than remitted MDD group (P = 0.021) and higher intra-individual variability for sleep duration than controls (P = 0.016). Conclusion MDD subjects had increased insomnia and eveningness than controls, which was supported by the acitgraphy data at which MDD had a tendency of longer major rest interval and delayed circadian phase. Unremitted MDD subjects showed a higher intra-individual variability of sleep midpoint and sleep duration. These actigraphy parameters may be useful markers for phenotyping and monitoring of MDD. Support (if any)

0021 Bimodality prevalence in a sample of undergraduate students in Sao Paulo city

Abstract Introduction The concept of bimodality comprises a fourth circadian phenotype, the bimodal, whose identification is made by a re-scoring of the Morningness-Eveningness Questionnaire and was first described by Martynhak and colleagues in 2010. Bimodal subjects are originally classified as “intermediate” because they answer the questions sometimes as a morning person and, some others, as an evening one. The present work aimed to describe the prevalence of the bimodal chronotype in a sample of undergraduate students in Sao Paulo city. Methods A web-based cross-sectional study conducted between September 2018 and March 2021, with a convenience sampling method, composed by 615 undergraduate students (82% females, mean age: 23.4±6.5 years) from two higher education institutions at Sao Paulo city. Results Forty-four students (7%) had positive bimodality indexes and bimodal individuals comprised 19 students (74% female; 26% male), 3% of the total sample. Conclusion We met our initial goal and found a bimodality prevalence of 3%. The description of bimodality prevalence in a sample of college students is interesting because they may be a maladaptive population from a sleep and rhythmicity point of view, which may be interesting for the design of academic public policies more consistent with the circadian preferences of students. Support (if any) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), Associação Fundo de Incentivo à Pesquisa (AFIP).

0093 Chronotypic characteristics of sleep, mental health, and daily life of Japanese university of health sciences students

Abstract Introduction Students’ lifestyles change after entering the university negatively impacting effective sleep regulation, daytime alertness, motivation to learn, and mental health. An evening chronotype has been increasingly associated with negative impacts upon performance and well-being. Greater understanding of chronotype differences in sleep-related, mental health, and daily life characteristics is needed to develop a sleep health promoting intervention. Methods Cross-sectional descriptive design among health sciences students (nursing, occupational therapy and physical therapy) in a Japanese university. The Japanese version of the Morningness-Eveningness Questionnaire (MEQ-J) was used to create morning (M), intermediate (I), and evening (E) chronotype groups. One-way analysis of variance was used to investigate differences among chronotype groups by sleep, mental health, and daily life characteristics. We assessed insomnia severity (ISI-J), sleep quality (PSQI-J), sleep hygiene (SHPS-J), daytime sleepiness and dysfunctional sleep beliefs; depression (JCES-D) and anxiety; and time use in club, commuting, sleep, and work, as well as engagement in meaningful day-to-day activities (EMAS-J), significant group differences were explored post-hoc. Results Of 369 students there were 21% classified as M chronotype, 63% as I, and 16 % as E; an approximate 1:3:1 ratio. Sleep quality was progressively better as chronotype advanced from E, to I, to M (PSQI-J: d range 0.41-1.07); along with sleep problems being less likely (ISI-J: d range 0.45-1.16). Sleep hygiene practices were most effective for the M chronotype, followed by I then E (SHPS-J: d range 0.49-1.14). No group differences were found in daytime sleepiness or dysfunctional sleep beliefs. Depression symptoms were greater in the E chronotype compared to I and M (JCES-D: d range 0.52-0.84). M chronotypes reported the longest commuting times (d range 0.45-0.55). No differences were found in sleep duration or time spent in other activity types. Lastly, M chronotypes reported engaging in more meaningful activities compared to E (EMAS-J: d = 0.47). Conclusion Sleep health lifestyle intervention should target chronotype preference to be less evening-like, thereby promoting sleep quality and mental health. Intervention could tailor sleep hygiene beliefs and skills to address sleep timing, pre-sleep arousal and environment regulation according to individuals’ daily life characteristics and chronotype differences. Support (if any)

External validity of the reduced Morningness-Eveningness Questionnaire for Children and Adolescents: an actigraphic study.

The aim of this study was to examine the external validity of the reduced Morningness-Eveningness Questionnaires for Children and Adolescents, using circadian motor activity, assessed through actigraphy, as an external criterion. Overall, 458 participants (269 females), with a mean (standard deviation) age of 15.75 (1.16) years, took part in this study. Each adolescent was requested to wear the actigraph Micro Motionlogger Watch actigraph (Ambulatory Monitoring, Inc., Ardlsey, NY, USA) around the non-dominant wrist for 1 week. At the end of the actigraphic recording, participants completed the reduced Morningness-Eveningness Questionnaires for Children and Adolescents. We extracted the motor activity counts, minute-by-minute over the 24 h, to depict the 24-h motor activity pattern, and we adopted the statistical framework of functional linear modelling to examine its changes according to chronotype. According to the reduced Morningness-Eveningness Questionnaires for Children and Adolescents cut-off scores, 13.97% of participants (n = 64) belonged to the evening-types category, 9.39% (n = 43) to morning-types, while the remaining (76.64%, n = 351) to the intermediate-types category. Evening types moved significantly more than the intermediate and morning types from around 10:00 p.m. to 2:00 a.m., while the opposite pattern of results was observed around 4:00 a.m. The results highlighted a significant difference in the 24-h motor activity pattern between chronotypes, in line with the expectations based on their well-known behaviour. Therefore, this study shows that the external validity of the reduced Morningness-Eveningness Questionnaire for Children and Adolescents, established by considering motor activity (recorded through actigraphy) as an external criterion, is satisfactory.

The Relationship between Nomophobia, Insomnia, Chronotype, Phone in Proximity, Screen Time, and Sleep Duration in Adults: A Mobile Phone App-Assisted Cross-Sectional Study.

Earlier studies that have investigated the association between nomophobia and insomnia revealed that a strong relationship exists between both variables. This study aimed to explore possible associations between these variables and their impact on physical and mental health outcomes using a cross-sectional study design and mobile phone apps to collect data. Using a survey approach, data were collected from 444 participants (52% female, mean age 34 ± 12) using the Nomophobia Questionnaire (NMP-Q), the Insomnia Severity Index (ISI), the Morningness-Eveningness Questionnaire (MEQ) and three Android mobile phone apps. The Plees Tracker, screen time, and pedometer apps aided in collecting data on sleep duration, time spent on screen per day, and how close the phone was to the person. A statistically significant association was noted between nomophobia and insomnia, nomophobia and the eveningness chronotype, and nomophobia and screen time. The eveningness chronotype was also associated with an increased screen time use. The results show that NMP-Q, ISI, and screen time increase according to the chronotype. No statistically significant differences were noted in daily steps or sleep duration according to chronotype. The findings suggest that interventions targeting nomophobia may be beneficial in addressing insomnia among adults, particularly those with an evening chronotype. Future studies should consider exploring the causal relationship between them.

Chronotype as a predictor of weight loss and body composition improvements in women with overweight or obesity undergoing a very low-calorie ketogenic diet (VLCKD)

Recent studies reported that chronotype play a role in the development of metabolic comorbidities and in determining dietary habits in obesity. However, little is known if chronotype could predict the efficacy of nutritional approaches for obesity. The aim of this study was to investigate whether chronotype categories can have a role in determining the efficacy of very low-calorie ketogenic diet (VLCKD) in terms of weight loss and changes of body composition in women with overweight or obesity. In this retrospective study we analyzed data from 248 women (BMI 36.03±5.20kg/m2, aged 38.76±14.05 years) clinically referred for weight loss and who completed a VLCKD program. In all women, we assessed anthropometric parameters (weight, height, and waist circumference), body composition and phase angle (through bioimpedance analysis, Akern BIA 101) at the baseline and after 31 days of active phase of VLCKD. Chronotype score was assessed using Morningness-Eveningness questionnaire (MEQ) at baseline. After 31 days of active phase of VLCKD all enrolled women experienced significant weight loss (p<0.001) and reduction of BMI (p<0.001), waist circumference (p<0.001), fat mass (kg and %) (p<0.001), and free fat mass (kg) (p<0.001). Women with evening chronotype experienced significantly less weight loss (p<0.001) and reduced fat mass (kg and %) (p<0.001), increased fat free mass (kg and %) (p<0.001) and phase angle (p<0.001) than women with morning chronotype. In addition, chronotype score correlated negatively with percentage changes in weight (p<0.001), BMI (p<0.001), waist circumference (p<0.001) and fat mass (p<0.001) and positively with fat free mass (p<0.001) and phase angle (p<0.001) from baseline to the 31st day of active phase of VLCKD. Using a linear regression model, chronotype score (p<0.001) was the main predictors of weight loss achieved with VLCKD. Evening chronotype is associated with a lower efficacy in terms of weight loss and improvements of body composition after VLCKD in obesity.

Changes associate with chronotype, sleep pattern and depression levels among school students during pandemic COVID-19 lockdown and post lockdown online classes

Aim: To determine chronotype, daytime sleepiness, sleep quality, and depression level among school students during lockdown and post-lockdown online classes, and how it differed from their offline classes. Methodology: The study was conducted in three phases. The first phase was conducted during April and July 2019, second phase was conducted between 25th April to 23rd May 2020, and the third phase was conducted during July during August 2021. Hundred school students (46 male and 54 female) of age group 14-20 years participated. Morningness-Eveningness Questionnaire (MEQ) was used to measure their chronotype, while daytime sleepiness was assessed by Epworth Sleepiness Scale (ESS). Pittsburgh’s Sleep Quality Index (PSQI) was used to assess the sleep quality. Zung Self-Rating Depression Scale (SDS) was used to determine the depression level. Results: Results showed an increase in the evening type and a decrease in the morning and neither type persons during lockdown and online classes. In addition, higher depression levels, more daytime sleepiness, and poor sleep quality were observed during lockdown and online classes, irrespective of gender. Altogether, study suggests that lockdown and social isolation during post lockdown had a poor mental effect, increased daytime sleepiness, and poor sleep quality in school students. Interpretation: These findings would help in planing policies on the interventions on sleep, circadian rhythms, and stress management to maintain a healthy sleep-wake cycle and daily routine during social isolation. Key words: Daytime sleepiness, Depression, Epworth Sleepiness Scale, Morningness-Eveningness Questionnaire, Pittsburgh’s Sleep Quality Index