Distribution Of Chronotypes Research Articles

Chronotypes in middle-aged women with polycystic ovary syndrome: A population-based study.

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.

Exploring the associations between chronotype, meal frequency, and physical activity: A population-based study in adults

ABSTRACT Chronotype is an established concept designed to capture the internal clock’s phase in real-life conditions. It is vital in many aspects of daily life and can interfere considerably with numerous factors in a given population. Recognizing nonmodifiable and modifiable factors is crucial for identifying covariates of interest when studying the link between chronotype and health status. To date, chronotype and its related factors have not been extensively investigated. The present study aimed to explore the association of chronotypes with meal frequency, physical activity, and demographic factors among the Saudi population. This cross-sectional web-based questionnaire involved 1369 adults (aged 18 years and above) from the general public in Saudi Arabia and was conducted between March and May 2019. Chronotype was assessed using the reduced version of the original Horne and Ostberg morningness-eveningness questionnaire (MEQ). Meal frequencies and demographics data (age, gender, marital status, place of residence, educational level, employment status, income) were obtained. Physical activity level was also obtained using the international physical activity questionnaire. The MEQ scores group individuals into three categories: morning-type, neither-type, and evening-type. The neither-type individuals represented 41.6% (95% confidence interval [CI], 37.5% − 45.6%) of the study population, followed by the morning-type (34.1%; 95% [CI], 29.8% − 38.4%), then the evening-type (24.3%, 95% [CI], 19.6% − 28.9%). Chronotype was significantly associated with age, marital status, employment status and monthly income (All p < 0.05). Significant associations between chronotype with meal frequencies (number of meals per day, breakfast frequency, lunch frequency, and dinner frequency) and physical activity were also observed (All p < 0.05). This study highlights that meal frequencies and physical activity levels are associated with chronotype distribution. Furthermore, demographics, including age, marital status, employment status, and income, were associated with chronotype distribution.

Assessment of Chronotype Distribution Among University Students and Its Association With Lifestyle Characteristics and Academic Performance.

Chronotype is associated with the timing of peak physical and mental performance and activity levels. University students may experience changes in their chronotype, influencing their daytime activity and academic performance. This study aims to assess the distribution of chronotypes among a sample of university students from southern Saudi Arabia, examining its association with demographic, academic, and lifestyle factors. A cross-sectional study was conducted atJazan University, located in the southwestern region of Saudi Arabia, between FebruaryandMarch 2023. Data collection was carried out using a structured questionnaire comprising three main components: demographic and academic data of participants, lifestyle characteristics, and an assessment of chronotype using the reduced version of the Horne andÖstbergmorningness-eveningnessquestionnaire. Associations between chronotype and demographic/lifestyle characteristics were analyzed using Pearson'schi-squared test or Fisher'sexact test. The study included 507 students. The mean age of theparticipants was 22 years (standard deviation: 2.07), with over half being male 277 (54.6%). The chronotype assessment indicated that 139 (27.4%) of students were morning types, 112 (22.1%) evening types, and 256 (50.5%) were neither type. Statistically significant variations in chronotypes were found in relation to the year of study, perceived influence of sleep habits on academic performance, meal frequency, consumption of fast food and certain caffeinated beverages, and smoking or Khat chewing habits (P<0.05). The findings suggest that an unhealthy lifestyle and the use of certain stimulants can influence chronotypes. Students with an evening chronotype should be a focus for university health services, allowing early identification and counseling to mitigate the negative impact of a disturbed chronotype on academic performance and reduce the risk of study-related stress.

Assessing sleep in primary brain tumor patients using smart wearables and patient-reported data: Feasibility and interim analysis of an observational study.

Sleep-wake disturbances are common and disabling in primary brain tumor (PBT) patients but studies exploring longitudinal data are limited. This study investigates the feasibility and relationship between longitudinal patient-reported outcomes (PROs) and physiologic data collected via smart wearables. Fifty-four PBT patients ≥ 18 years wore Fitbit smart-wearable devices for 4 weeks, which captured physiologic sleep measures (eg, total sleep time, wake after sleep onset [WASO]). They completed PROs (sleep hygiene index, PROMIS sleep-related impairment [SRI] and Sleep Disturbance [SD], Morningness-Eveningness Questionnaire [MEQ]) at baseline and 4 weeks. Smart wearable use feasibility (enrollment/attrition, data missingness), clinical characteristics, test consistency, PROs severity, and relationships between PROs and physiologic sleep measures were assessed. The majority (72%) wore their Fitbit for the entire study duration with 89% missing < 3 days, no participant withdrawals, and 100% PRO completion. PROMIS SRI/SD and MEQ were all consistent/reliable (Cronbach's alpha 0.74-0.92). Chronotype breakdown showed 39% morning, 56% intermediate, and only 6% evening types. Moderate-severe SD and SRI were reported in 13% and 17% at baseline, and with significant improvement in SD at 4 weeks (P = .014). Fitbit-recorded measures showed a correlation at week 4 between WASO and SD (r = 0.35, P = .009) but not with SRI (r = 0.24, P = .08). Collecting sleep data with Fitbits is feasible, PROs are consistent/reliable, > 10% of participants had SD and SRI that improved with smart wearable use, and SD was associated with WASO. The skewed chronotype distribution, risk and impact of sleep fragmentation mechanisms warrant further investigation. NCT04 669 574.

CHRONOTYPE AND DAILY FUNCTIONING OF PATIENTS WITH DIFFERENT MOTOR SUBTYPES OF PARKINSON DISEASE

Introduction. Sleep and circadian rhythm disturbances can occur at any stage of Parkinson disease (PD) and significantly affect quality of life. Chronotypes of patients with PD are associated with different phenotypes, in particular with the motor subtype. Thus, we hypothesized that patients with different motor subtypes of PD may have differences in the distribution of chronotypes and patterns of daily activity. Methods and materials. We conducted clinical research on the basis of the Centre for Parkinson Disease and Neurodegenerative Diseases of the Department of Neurological Diseases of Poltava State Medical University. PD was verified according to the recommendations of the International Movement Disorders and Parkinson's Disease Society. The motor subtype of PD was determined by the Stebbin method, which is based on the calculation of the Stebbins coefficient by the sum of the Unified PD Rating Scale scores. The examined patients were divided into 3 groups according to the motor subtype of PD: group 1 (n = 38) - patients with PD subtype with the predominance of postural instability and gait disorders (PIGD); group 2 (n = 26) - patients with PD subtype with the predominance of tremor and mixed subtype; control group (n = 30) - conditionally healthy individuals without CNS lesions. Circadian patterns were analyzed using the Munich Chronotype Questionnaire (MCTQ). Results. It was found that in PD patients sleep onset and time of getting out of bed was later (p&lt;0.001 and p=0.042, respectively), sleep latency was longer (p&lt;0.001), sleep duration was shorter (p=0.001), the mid-sleep corresponded to a later time (p&lt;0.001). Patients with the PIGD subtype had a later time of getting out of bed (p=0.038), longer sleep inertia (p&lt;0.001), shorter sleep duration (p&lt;0.001), and later mid-sleep time (p=0.028). We have shown the tendency of patients with PD, mostly in the PIGD subtype, to later chronotypes (p&lt;0.001). Light exposure indirectly moderately correlated with mid-sleep in all study groups. It was found that both the motor subtype (p&lt;0.001) and the level of light exposure during the day (p&lt;0.001) statistically significantly affect the mid-sleep. Conclusion. Thus, we have found that patients with PD differ from age-matched controls without neurodegenerative diseases by chronotype and circadian pattern of functioning. The motor subtype of the disease is associated with circadian differences, namely, the PIGD subtype is associated with shorter sleep duration, a predisposition to a later chronotype, and longer sleep inertia.

Personalising circadian hygiene educational initiatives aimed at university students-"He who has ears to hear, let him hear".

The aim of the present study was to characterise "early drop-outs" (n = 3185) out of a group of university students (n = 7766) engaged in an ongoing circadian education initiative, to evaluate its efficacy and direct its developments. The initiative is aimed at improving sleep timing/quality through one of two sets of circadian hygiene advice covering the timing of sleep, meals, exercise and light exposure, and it has already been shown to have a positive effect on sleep timing. This second, interim analysis confirmed the high prevalence of disturbed night sleep and social jetlag amongst students at Padova University. Three-thousand, one-hundred and eighty-five (41.0%) students were early drop-outs. These were more commonly males (46.4 versus 37.6%; χ2 = 58, p < 0.0001), had later sleep-wake habits, more daytime sleepiness and worse night sleep quality. Chronotype distribution was also different, with a slight but significantly higher proportion of extremely evening/evening types amongst early drop-outs (χ2 = 10, p < 0.05). These results suggest that the more evening the student, the lower their likelihood of choosing/being able to follow circadian advice.

Hemodialysis-induced chronodisruption and chronotype distribution in patients with chronic kidney disease

ABSTRACT Changes in circadian rhythms have been observed in patients with chronic kidney disease (CKD), and evidence suggests that these changes can have a negative impact on health. This study aimed to investigate the existence of hemodialysis-induced chronodisruption, the chronotype distribution, and their association with sleep quality and quality of life (QoL). This was a cross-sectional study that enrolled 165 patients (mean age: 51.1 ± 12.5 y, 60.6% male) undergoing hemodialysis from three local units. The following instruments were used: the Morning-Eveningness Questionnaire (MEQ); a modified version of the Munich Chronotype Questionnaire (MCQT) to estimate hemodialysis-induced chronodisruption (HIC); the Kidney Disease QoL Short Form (KDQOL-SF); the Epworth Sleepiness Scale (ESS); the Pittsburgh Sleep Quality Index (PSQI) and the 10–Cognitive Screener (10-CS). HIC was present in 40.6% of CKD patients. Morning chronotype was prevalent in CKD patients (69%) compared to evening-type (17.1%) and significantly different from a paired sample from the general population (p < 0.001). HIC and chronotype were associated with different domains of QoL but not with sleep quality. This study suggests that there is a HIC and that morning chronotype is associated with CKD patients undergoing hemodialysis, with implications for QoL.

Impact of sleep–wake patterns and daily rhythms including training on midsleep time in adolescent basketball players during the COVID-19 pandemic

ObjectivesThe coronavirus disease (COVID-19) had a major impact on sleep and training behavior in adolescent athletes. A crucial sleep parameter is midsleep time, which illustrates the midpoint between sleep onset and offset. The aim of this investigation was to examine the impact of chronotype, age, sex, pandemic phase, weekend, and training habits on midsleep time. The sample consisted of German elite adolescent basketball athletes (N = 91, 15.75 ± 1.15 years, female = 39.46%).MethodData were collected through a 10-day subjective monitoring program during three different pandemic phases, with more severe restrictions in phase 1. In total, 1146 measurement points were analyzed. A linear mixed model approach was used for the evaluation.ResultsA negative linear association between chronotype and midsleep time was revealed. A negative effect was identified for phases 2 and 3. The weekend parameter showed a positive effect, which may illustrate the occurrence of social jetlag. The main finding of this investigation is that a morning chronotype distribution was associated with earlier midsleep timing throughout the entire survey period.ConclusionThe results acknowledge that chronotype is one of the main influencing parameters for midsleep time. The study represents a useful contribution to the research of chronotype and sleep behavior in athletes, with a focus on the major impact of the COVID-19 pandemic.

The association between chronotype profile and temporomandibular disorders among college students.

Temporomandibular joint disorders (TMDs) are common in young adults, and the link between chronotype profile and TMDs is unclear. This study examined TMD prevalence and chronotype distribution and explored the relationship between chronotype and TMDs in young adults. 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. 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. 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.

Rise and shine for eating right: the link between healthy nutrition and chronotype among young adults.

Many studies have examined the relationship between chronotype and general health. Because healthy eating is the basis of health aim of this study is to evaluate the relationship between healthy nutrition attitudes and chronotype in young adults. Methods: This cross-sectional study was conducted with 1,400 young adults (936 females and 464 males). Chronotype was assessed by the Turkish version of the Morningness-Eveningness Questionnaire (MEQ) and the Attitude Scale for Healthy Nutrition (ASHN) was applied by face-to-face interview. Furthermore, 24-h dietary recall was collected. The scores of nutrient adequacy ratio (NAR) and mean adequacy ratio (MAR) were calculated. The anthropometric measurements including body weight and height were taken. The chronotype distribution of participants according to the MEQ score and MAR score were not significantly different between females and males (p > 0.05). The percentage of participants with high healthy eating attitude was lowest in the evening chronotype and highest in the morning chronotype (49.7, 37.7 and 25.4% in morning-, intermediate-, evening-types, respectively; p = 0.000 for all groups according to the reciprocal comparisons). There was a positive correlation of the MEQ scores with the scores of ASHN (r = 0.282, p < 0.01). ASHN score was shown to be a predictor for MEQ score (β = 0.280, p = 0.000). Moreover, the score of "poor eating habits" was shown to be highest in the evening chronotype and lowest in the morning chronotype (14.9 ± 3.0 and 13.1 ± 3.0, respectively; p < 0.01). The results of this study indicate that individuals with the evening chronotype are more deficient in terms of healthy nutrition attitudes. Further studies with larger populations will potentially guide the development of health promotion strategies to prevent and treat chronic diseases based on an individual's chronotype.

Chronotype and quality of sleep in alpine skiers

ABSTRACT Alpine skiing is among the most demanding sporting activities in terms of physical effort and mental workload. The aim of the study was to compare sleep quality and chronotype distribution between 84 highly trained alpine skiers and a control sample of 84 non-athletes matched by age and sex ratio. Quality of sleep was assessed by the Pittsburgh Quality of Sleep Index (PSQI), and chronotype was assessed by the Morningness-Eveningness Questionnaire (MEQ). Additional questions assessed sleep management during training or competitions. The results showed a marked skewed chronotype distribution towards morningness in alpine skiers (52.4% morning type, 42.8% intermediate, and 4.8% evening type) in comparison to the control group. The midpoint of sleep was significantly anticipated among alpine skiers. Differently from the previous literature that showed poor sleep quality and quantity in competitive athletes, the quality and quantity of sleep in alpine skiers was within the normal range in all the PSQI subcomponents.

Morningness-eveningness Preferences among Medical Students: A Cross-sectional Study

Introduction: Morningness and eveningness is a phenomenon which looks at the differences among the individuals regarding their diurnal preferences, sleep-wake pattern of activity and alertness in evening or morning. Morning chronotypes are individuals who exhibit morning tendencies like rising early in the morning while evening chronotypes prefer to get up later in the morning and stay awake later at night time and also perform their best during late afternoon or evening. Morning chronotypes are known to exhibit better physical and mental health, greater self-esteem and academic performance. Aim: To estimate the prevalence of morningness and eveningness among medical students. Association of chronotype with academic performance was also determined. Materials and Methods: The present cross-sectional study was conducted on 110 apparently healthy medical students at Shaheed Hasan Khan Mewati Government Medical College, Nalhar, Haryana, India from October 2021 to January 2022. All the participants were sent a validated Morningness-Eveningness self-assessment Questionnaire (MEQ). Data of chronotypic preferences expressed as frequencies of participants (%) and association determined using Pearson’s Chi-square test and p-value &lt;0.05 was considered statistically significant. Results: Study revealed that 67 (61%) students belonged to the Intermediate (I) chronotype, around one-fourth {n=26 (24%)} were Morning (M) type while 17 (15%) were Evening (E) type. Morningness was more frequently reported by females as compared to males in n=8 (28%) vs. n=18 (22%) respectively. Higher scores (≥50%) were more prevalent among M types as compared E types in n=10 (38%) vs. n=3 (18%) respectively}; however, association between chronotype and academic performance could not reach significant level (p-value=0.15). Conclusion: The distribution of chronotypes in study sample provided the evidence that majority of students could be classified as intermediate type. Morningness was more frequent in females as compared to males. Further studies with large sample size are needed to explore the influence of chronotype on academic performance.

Photoperiodic stability and distribution of chronotypes in young residents of the North with different organization of activities

AIM: To assess individual subjective chronotypic properties in residents of Khanty-Mansiysk under the influence of such biotropic and social stress factors as regular daytime and aperiodically presented shift daytime and nighttime employment.&#x0D; MATERIALS AND METHODS: This study involved students (100 girls and 53 boys) of Khanty-Mansi Autonomous Okrug Yugra with a daily study load and employees of the Ambulance station (31 women and 26 men) in Khanty-Mansiysk, working in shifts. The photoperiodic chronotype stability was studied using the computer program Photoperiodic chronotype stability calculator (registration no. 2019661664) in the form of a mobile application for Android Photoperiodic stability index.&#x0D; RESULTS: The photoperiodic stability of the chronotype in women was: with regular daily employment 3.5 (1.56.0) arb. units, with shift work 1.0 (04.0) arb. units. The photoperiodic stability of the chronotype in men was: with regular daily employment 3.0 (1.04.0) arb. units, with shift work 1.5 (03.0) arb. units.&#x0D; Volunteers with a regular daytime job tended to choose to shift activities to the afternoon and refusing morning activity. In the group with shift work, the proportion of people preferring the morning type of work capacity was higher. In the group with shift and night work, there were no representatives of a definitely morning chronotype among women, and definitely an evening chronotype among men. In the summer season, male and female respondents, regardless of the production regime, showed an increase in the signs of the morning chronotype.&#x0D; CONCLUSION: The production and intersexual features of the chronotypological properties of the inhabitants of the North have been established. With the superposition of extreme climatic and geographical factors and social and production conditions, a general pattern of increased rigidity of the chronotype was recorded. Male and female respondents under different production regimes, when assessing subjective biorhythmic performance in the summer, demonstrated a shift toward the morning chronotype.

Chronotype, sleep, and sleepiness in Parkinson's disease

We aimed to determine the distribution of chronotypes in a cohort of PD patients and to evaluate the relationships between chronotype and PD characteristics, and self-reported metrics of sleep and sleepiness. Chronotype was characterized using the Horne-Ostberg Morningness-Eveningness Questionnaire (MEQ). PD participants were categorized as Evening Types (ET), Neither Types (NT), or Morning Types (MT). Sleepiness was assessed by the Epworth Sleepiness Scale. Sleep metrics included self-reported sleep times and latency. 186 participants with PD, age 65.5 ± 9.8 yrs, disease duration 6.17 ± 6.7 yrs completed the MEQ. Most participants were classified as MT (63.4%). Participants in the ET group were younger than those in the NT and MT groups (57.6 ± 6.3 vs 67.3 ± 10.2 vs 64.9 ± 9.5). The mean disease duration was not different among chronotypes. No significant relationship between chronotype and sleepiness was found. MT participants woke up and went to bed significantly earlier than NT participants. There was no significant difference between chronotypes and PD medications. Further studies should examine if PD severity and progression affect the chronotype, and whether certain chronotype differentially affects the quality of life, symptom control, and medication effectiveness in the PD population.

The interindividual variability of sleep timing and circadian phase in humans is influenced by daytime and evening light conditions

Human cognitive functioning shows circadian variations throughout the day. However, individuals largely differ in their timing during the day of when they are more capable of performing specific tasks and when they prefer to sleep. These interindividual differences in preferred temporal organization of sleep and daytime activities define the chronotype. Since a late chronotype is associated with adverse mental and physical consequences, it is of vital importance to study how lighting environments affect chronotype. Here, we use a mathematical model of the human circadian pacemaker to understand how light in the built environment changes the chronotype distribution in the population. In line with experimental findings, we show that when individuals spend their days in relatively dim light conditions, this not only results in a later phase of their biological clock but also increases interindividual differences in circadian phase angle of entrainment and preferred sleep timing. Increasing daytime illuminance results in a more narrow distribution of sleep timing and circadian phase, and this effect is more pronounced for longer photoperiods. The model results demonstrate that modern lifestyle changes the chronotype distribution towards more eveningness and more extreme differences in eveningness. Such model-based predictions can be used to design guidelines for workplace lighting that help limiting circadian phase differences, and craft new lighting strategies that support human performance, health and wellbeing.

Годовая динамика показателей дисперсионного картирования электрокардиограммы у студентов разных хронотипов

The paper examines the annual profile of fluctuating microalternations of some ECG parameters in healthy students who live in northern conditions and have different chronotypes. The main method of the research was the dispersion mapping that helped assess the energy and metabolic processes in myocardium. Among male and female students, 14,3% had the morning chronotype, 50,7% had the arrhythmic chronotype, and 35% had the evening chronotype. Previously published research results showed a similar distribution of chronotypes among the population of the north: individuals with the arrhythmic chronotype dominate in the sample, the evening chronotype is the second most common, and the morning chronotype can be found in a smaller number of people. The seasonal dynamics of dispersion mapping indicators in students was analyzed. The analyses revealed an increase in the values of the Myocardium Index in students of all chronotypes in spring, with no significant deviations to be noted. The maximum values of the Heart Rate and Rhythm indicators in the annual dynamics in all students were noted in spring, and the minimum values, in summer, with significant deviations observed. The Rhythm integral indicator pointed to the signs of tension of adaptation mechanisms in the subjects with the evening chronotype in spring. Increased ECG microalterations (Myocardium, Heart Rate, Rhythm) in male and female students in spring may indicate the influence of climatic conditions that put a greater stress on the cardiovascular system in the transitional seasons. It is manifested by a change in the electrophysiological properties of the myocardium. In the subjects with the evening chronotype, the circadian rhythms of the circulatory system were more sensitive to the hypocomfortable conditions of the north.

Does the chronotype distribution vary between different level football leagues? Insights gained from Czech elite football players

ABSTRACT Chronotype refer to individuals’ time-of-day preferences for activities, which can be classified as “morning types = (M-types)”, “evening types = (E-types)”, and “neither types (N-types)”. The primary aim of this study was to compare the chronotype distribution of Czech First League (1L) and Czech National Football League (2L) male elite football players, which was divided into two secondary aims: (i) statistically identify and compare the number (presence) of particular chronotypes in 1L, and (ii) statistically identify and compare the number (presence) of particular chronotypes in 2L. The present cross-sectional study employed a self-reported standardized questionnaire, the Composite Scale of Morningness, to study the chronotype distribution among the male elite football players. The chronotype distribution of 139 (85 from 1L with mean age ± S.D. = 25.5 ± 3.7 years and 54 from 2L age = 24.4 ± 4.5 years) players was assessed. Overall, 61 (71.8%) of the participants from 1L were mainly N-types, followed by M- and E-types. Similarly, 40 (74.1%) participants from 2L were mainly N-types, followed by M- and E-types. The statistical analysis of the 1L players showed a significantly higher presence of N-types compared to M- and E-types (χ2 (2) = 57.62, p < .05, V = .58). The same results were detected in 2L, where the N-type was identified in the majority of football players (χ2 (2) = 57.62, p < .05, V = .58). The statistical comparison of the number of presented chronotypes did not show a significant difference (F = 3.29, p > .05, V = .16) between players of the 1L and 2L. Thus, N-types are dominant among Czech elite football players, and the chronotype distribution of male elite football players from the Czech First League and the Czech National Football League does not vary.

Sleep quality among adults with attention deficit hyperactivity disorder or autism spectrum disorder: which is the role of gender and chronotype?

Both Attention Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) present increased prevalence rates of sleep difficulties, which persist into adulthood. However, it is still unclear whether in adults these disorders show specific sleep patterns and which role is played by comorbidities, circadian preferences and gender. This study aimed to describe and compare subjective measures of sleep in adults with ADHD and high-functioning ASD, in relation to the levels of anxiety and depression, chronotype and gender. In a sample of 136 adults (43 ADHD, 43 high-functioning ASD, 50 controls) subjective sleep quality was measured with the Pittsburgh Sleep Quality Index (PSQI), and clinical scales were used to assess chronotype and the levels of anxiety and depression. The three groups showed a significant difference in the distribution of chronotypes, with greater prevalence of an Evening chronotype among ASD compared to controls. The MANCOVA using PSQI subscale scores as dependent variables and MEQ-SA score and depression range as covariates showed that the three groups significantly differ in quality, latency, efficiency, and dysfunction scores with a significant differences between ASD and ADHD in efficiency and dysfunction. Compared to men, women showed higher scores on PSQI total and quality subscale across the three groups and higher duration scores only within ASD group. Our results indicate that both ADHD and ASD adults show unique sleep disturbances and suggest that ASD patients, especially women, may display more pronounced disordered sleep.

Chronotype distribution in the Chinese population

Purpose: Individual chronotypes are reported to be closely associated with mood, health status, and even disease progression. However, no reports of chronotype distribution in the Chinese population have been made available to date. Methods: We performed a chronotype survey using the classic Morningness–Eveningness Questionnaire both online and offline. The webpage-based online survey was distributed via a social network application on mobile phones. The offline survey was distributed to local primary and middle schools. A total of 9476 questionnaires were collected, of which 8395 were valid. The mean age of the participants was 30.38 ± 11.47 years, and 37.38% were male. Results: Overall, the Chinese chronotypes showed a near-normal distribution with a slight shift toward eveningness. When analyzed in different age groups, the overall Chinese population was shown to be “latest” in their early twenties. In the young population, two significant points of change in chronotype were identified at the ages of 10 and 16 years. The chronotype composition remained relatively stable during early adulthood (from 17 to 28 years of age). Conclusion: This study generated the first overview of chronotype distribution in the Chinese population and will serve as essential background data for future studies.

Pre-Race Sleep Management Strategy and Chronotype of Offshore Solo Sailors.

PurposeTo evaluate chronotype and the sleep management strategy adopted by sailors before the offshore solo sailing race “Mini Transat La Boulangère”. As secondary aim, we assessed whether adopting pre-race sleep management strategy influences performance at race.Materials and MethodsForty-two solo sailors completed questionnaires on sleep quality, sleepiness, chronotype and an ad hoc questionnaire on the pre-race sleep management strategy adopted. Arrival times, separately for each race’s leg, were provided by the race organization team.ResultsSolo sailors present mainly with a morning-type (40%) and intermediate-type (60%) chronotype, while none have an evening-type chronotype. Fifty-five percent of sailors adopted pre-race sleep management strategy. Sailors that adopted strategy have travelled more miles in offshore compared to sailors that did not adopt strategy (p<0.05). Significant differences emerged in rMEQ scores, with sailors that adopted strategy presenting lower score compared to sailors that did not adopt sleep strategy (p<0.05), as well as in chronotype distribution with morning-type sailors that are less likely to adopt pre-race sleep management strategy compared to intermediate type sailors (p<0.05). No differences emerged in final arrival times and in arrival time at leg1 and leg2. The most commonly adopted strategy (52% of sailors) consists of sleep extension, followed by the polyphasic sleep (26%), and sleep deprivation (22%) strategy. Sailors trained in polyphasic sleep have higher ESS than sailors trained in sleep deprivation (p<0.05).ConclusionMorning-type chronotype is overrepresented in this large cohort of solo sailors compared to the general population; moreover, chronotype seems to influence the adoption of sleep management strategy. A little over half of solo sailors participating in the Mini Transat trained in sleep management strategy before the race; however, neither the general adoption of pre-race sleep management strategy nor the adoption of a specific sleep strategy seems to significantly influence final arrival times.