Morning Chronotypes Research Articles

Mediterranean diet and chronotype: Data from Italian adults and systematic review of observational studies

Scientific evidence suggests a relation between dietary factors and sleep. Several studies show that higher adherence to the Mediterranean diet is associated with better sleep quality, but the relation with chronotype has been only recently explored. The aim of this study was to better understand the relation between chronotype and Mediterranean diet adherence. For this purpose, an analysis of 1936 adults (age 18–90 y) living in Italy was performed to investigate the association between chronotype (assessed with a short form of the morningness-eveningness questionnaire) and adherence to the Mediterranean diet (assessed through a 110-item food frequency questionnaire and the Medi-Lite literature-based Mediterranean adherence score). A multivariate logistic regression analysis was conducted to calculate odds ratios (OR) and 95 % confidence intervals (CIs) describing the association between chronotypes and high adherence to the Mediterranean diet (>14 points). Moreover, a systematic review of other observational studies published so far was performed. Individuals reporting having intermediate (n = 614) and evening (n = 173) chronotypes were less likely to have high adherence to the Mediterranean diet compared to morning chronotype (OR = 0.28, 95 % CI: 0.18, 0.42 and OR = 0.08, 95 % CI: 0.03, 0.27, respectively). When the analysis was conducted in subgroups of age, the results were similar in mid-age (>50 y) participants (for intermediate and evening chronotypes, OR = 0.21, 95 % CI: 0.10, 0.43 and OR = 0.92, 95 % CI: 0.01, 0.69, respectively) while the association with high adherence to the Mediterranean diet of evening compared to morning chronotype lost significance in older (>60 y) participants (for intermediate and evening chronotypes, OR = 0.27, 95 % CI: 0.09, 0.82 and OR = 0.22, 95 % CI: 0.02, 1.92, respectively). Out of 10 studies (date range of publication 2020–2022) included in the systematic review, there was a general consistence of findings showing higher adherence to the Mediterranean diet among morning chronotypes, although few studies reported null results. In conclusion, current evidence suggests that an intermediate and evening chronotype could be associated with lower adherence to a Mediterranean diet, but the association could be modified by other factors when considering older individuals.

Differences in Dietary Intake, Eating Occasion Timings and Eating Windows between Chronotypes in Adults Living with Type 2 Diabetes Mellitus.

Chronotype studies investigating dietary intake, eating occasions (EO) and eating windows (EW) are sparse in people with type 2 Diabetes mellitus (T2DM). This analysis reports data from the CODEC study. The Morningness-Eveningness questionnaire (MEQ) assessed chronotype preference. Diet diaries assessed dietary intake and temporal distribution. Regression analysis assessed whether dietary intake, EW, or EO differed by chronotype. 411 participants were included in this analysis. There were no differences in energy, macronutrient intake or EW between chronotypes. Compared to evening chronotypes, morning and intermediate chronotypes consumed 36.8 (95% CI: 11.1, 62.5) and 20.9 (95% CI: -2.1, 44.1) fewer milligrams of caffeine per day, respectively. Evening chronotypes woke up over an hour and a half later than morning (01:36 95% CI: 01:09, 02:03) and over half an hour later than intermediate chronotypes (00:45 95% CI: 00:21; 01:09. Evening chronotypes went to sleep over an hour and a half later than morning (01:48 95% CI: 01:23; 02:13) and an hour later than intermediate chronotypes (01:07 95% CI: 00:45; 01:30). Evening chronotypes' EOs and last caffeine intake occurred later but relative to their sleep timings. Future research should investigate the impact of chronotype and dietary temporal distribution on glucose control to optimise T2DM interventions.

Chronotype and Cardiometabolic Parameters in Patients with Bipolar Disorder: Preliminary Findings.

Cardiometabolic alterations are very common in bipolar disorder (BD). The aim of this study was to investigate the relationship between chronotype and cardiometabolic parameters in patients with a primary diagnosis of BD. This study is an observational clinical investigation including 170 subjects consecutively admitted to the Psychiatric Inpatient Unit of the IRCCS Ospedale Policlinico San Martino (Genoa, Italy), recruited over a period of 48 months. A psychometric tool assessing chronotype was administered and blood tests were performed. Furthermore, the atherogenic coefficient ((total cholesterol-HDL cholesterol)/HDL cholesterol), and Castelli risk index-I (total cholesterol/HDL cholesterol) and -II (LDL cholesterol/HDL cholesterol) were calculated. Patients with BD and an eveningness chronotype showed a higher body mass index, total and low-density lipotrotein cholesterol compared to patients with BD and an intermediate or morning chronotype. Furthermore, the Atherogenic Coefficient and Castelli Risk-Index I-II were found to be higher in bipolar patients with an evening chronotype. The role of chronotype in the development of obesity and cardiovascular risk is, therefore, a relationship worth being investigated, especially in the context of BD, to ameliorate the clinical and therapeutic approach, aiming at increasing the quality of life and reducing the mortality.

The role of individual organization of circadian rhythms in the formation of carbohydrate metabolism disorders

BACKGROUND: In medical literature sources, there are data on the relationship of disorders of circadian rhythms (desynchronosis) with the development of type 2 diabetes mellitus (T2DM). Desynchronosis of circadian rhythms of glycemia can be triggered both by external factors (exposure to excessive artificial lighting in the evening, violation of the diet, «sleep-wake»), and internal — from the individual organization of circadian rhythms (chronotype). In this connection, there is an interest in the most detailed study of the influence of individual characteristics of the organization of circadian rhythms on the risk of developing T2DM. AIM: To characterize the individual organization of circadian rhythms in persons without carbohydrate metabolism disorders, with prediabetes and T2DM with obesity and BMI = 30.0–34.9 kg/m2.MATERIALS AND METHODS: Тhe Horn-Ostberg questionnaires were analyzed retrospectively in individuals with visceral obesity without carbohydrate metabolism disorders (n=40), with prediabetes (n=40) and T2DM (n=40). The results of the Horn-Ostberg test were compared with anamnestic anthropometric, laboratory parameters, nutrition diaries, daily rhythms of integral physiological indicators of carbohydrate and energy metabolism.RESULTS: All study participants (n=120) were identical age 56,7 [52,2; 58,6] years, BMI 31.3 [30.7; 33.9] kg/m2, waist circumference (OW) in women 96.54 ± 1.35 cm in men 98.75 ± 2.61 cm Sex distribution: 73% women and 27% men. Persons with morning chronotype made up 24% (29 people), intermediate 63% (75 people) and evening 13% (16 people) . In the groups, the late time for the first breakfast was noted (without carbohydrate metabolism disorders 9:45h, prediabetes 9:31 and T2DM 10:00h), and 20% of the participants missed it (p<0.05). A larger amount of daily energy value was shifted to the afternoon (p<0.05). Late bedtime was observed in all groups: without carbohydrate metabolism disorders 22.50–00.29h, with prediabetes 22.30–00.29h and T2DM 22.45–00.29h with an increase in sleep duration in the prediabetes group (08.14h, 09.00h and 08.38h, respectively). In all groups, morning and evening chronotypes had correlations with the amplitude of the daily rhythm of glycemia (r=-0.7, p=0.002 and r=-0.6, p=0.035), basal body temperature (r=0.4, p=0.046 and r=-0.5, p<0.0001) and daily energy value (r=-0.6, p= 0.041 and r=-0.6, p=0.05), differing only in the strength of the relationship.CONCLUSION: Thus, people with the morning and intermediate types of the morning chronotype, who organize a daily routine and nutrition that do not correspond to the individual characteristics of this given chronotype, can, along with people of the evening chronotype, become vulnerable in the context of the development of type 2 diabetes.

Associations of social jetlag with physical activity and sedentary behaviour in children and adolescents: A systematic review and meta-analysis.

Sleep and daytime movement behaviours occur co-dependently with each other within a finite 24 h day. Sleep parameters other than sleep duration, such as social jetlag and chronotype, have been linked to health problems and unhealthy behaviours among children and adolescents. Given the increasing number of studies examining sleep timing/chronotype and weight-related behaviours, including physical activity and sedentary behaviour, in the past decade, this systematic review and meta-analysis collated and evaluated the evidence on the relationships of social jetlag and chronotype with physical activity and sedentary behaviour among children and adolescents aged 3-17 years. Seven databases were searched on 16 March 2022, and 52 studies were identified as eligible for inclusion, 47 of which were suitable for the meta-analysis. A positive association was found between social jetlag and screen media use (r = 0.14, 95% CI: 0.04-0.24; I2 = 96%; p = 0.008). The morning chronotype was associated with a higher level of physical activity and a lower level of sedentary behaviour than the evening chronotype. No relationship was found between social jetlag and physical activity. The magnitude of heterogeneity among the included studies was high. Further experimental studies are urgently required to understand how circadian preference or misalignment affects activity behaviours. Interventions to promote an active lifestyle in young populations should consider their circadian preference, especially among individuals with the evening chronotype.

Gender peculiarities of blood pressure changes in patients with arterial hypertension and different biorhythms

Background. It is known that the risk of cardiovascular diseases, especially in conditions of increased rhythm of life, psycho-emotional stress, social cataclysms, is associated with various biorhythms, therefore, the study of the influence of various factors on the course of hypertension, taking into account the patient's chronotype, remains relevant. Aim of the study was to analyze the level of blood pressure in patients with arterial hypertension with different chronotypes of the female and male genders. Materials & Methods. The study included 42 patients with diagnosed essential arterial hypertension who were receiving inpatient treatment. The inclusion criterion was patients with arterial hypertension of the 2nd degree. Measurements of Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP) (mmHg) were performed using the Korotkoff method. To study the chronotype, we used the validated questionnaire "Composite Scale of Morningness" and scales from official available sources. Results & Conclusions. Arterial hypertension was diagnosed in 33.33% of patients with the evening chronotype, 7.17% with the morning chronotype, and 59.53% with the intermediate chronotype. Taking into account gender, female patients with evening and morning chronotypes and male patients with an intermediate chronotype predominated. Patients with evening chronotype compared to patients with intermediate and morning chronotypes had significantly higher Body Mass Index (BMI) (by 62.69% and 40.33%), disease duration (by 42.68% and 6.23%) and SBP (by 8.21% and 12.21%), respectively. At the same time, BMI in patients with arterial hypertension with an evening chronotype was as close as possible to obesity. The obtained results can be used in the practical work of nurses for the prevention of arterial hypertension by adjusting the duration of sleep and wakefulness and the diet. Keywords: chronotype, gender, age, body mass index, relationships.

Association of breakfast styles such as Japanese, Western, and cereals with sleeping habits, eating habits, and lifestyle in preschool and elementary school children.

In Japan, breakfast styles are categorized into five groups; Japanese breakfast (JB; rice and miso soup), Western breakfast (WB; bread and milk), Japanese-Western breakfast (J-WB; alternative daily serving), cereal breakfast (CB), and breakfast skipping. In our recent studies, breakfast style was highly associated with the daily sleep-wake phase (chronotype), and healthy eating habits. In contrast with other breakfast style consumers, JB-consumers were positively associated with the morning chronotype and healthy eating habits such as a high consumption of a variety of protein sources, vegetables, and dietary fibers, and low consumption of sweetened juices. These previous studies included only adult participants; hence, in the current study, we investigated whether similar observations can be made in children. Preschool (aged 3-5 years) and elementary school children (6-8 years) (N = 6,104, 49.87% boys, 50.13% girls, mean body mass index 15.39 ± 0.03 kg/m2 for preschoolers and percentage of overweight -2.73 ± 0.22 for elementary school children) participated in this cross-sectional online survey on lifestyle, including eating and sleep habits, through their mother's responses. The results showed that the morning-evening type index values (chronotype indicator, smaller indicates morning type) were negatively correlated with JB intake (-0.05, p < 0.01) and positively correlated with WB (0.03, p < 0.05) and CB intake (0.06, p < 0.01), suggesting that the JB group exhibited the morning chronotype and the WB and CB groups exhibited the evening chronotype. The JB group consumed a variety of protein sources (mean ± SE; days/week) with more frequency (fish 2.95 ± 0.038 p < 0.001, soy 3.55 ± 0.043 p < 0.001, egg 3.82 ± 0.044 p < 0.001) compared with the WB group (fish 2.58 ± 0.033, soy 3.00 ± 0.038, egg 3.49 ± 0.039). On the other hand, the JB group consumed snacks (5.48 ± 0.042 p < 0.001) and sweetened juice (2.50 ± 0.050 p < 0.001) less frequently than the WB group (snacks; 5.80 ± 0.037 and sweetened juice; 2.74 ± 0.049). JB-eating children with a morning chronotype exhibited better sleep and eating habits than WB-eating children with an evening type pattern. The results suggest that JB eating habits may be associated with good eating and sleeping lifestyles, even among preschool and elementary school children.

The Associations of Chronotype and Shift Work With Rheumatoid Arthritis.

The circadian clock regulates multiple aspects of human physiology including immunity. People have a circadian preference termed chronotype. Those with an evening preference may be better suited to shift work, but also carry higher risk of adverse health. Shift work leads to misalignment of circadian rhythms and is associated with increased risk of inflammatory disease such as asthma and cancer. Here, we investigate the association between chronotype, shift work, and rheumatoid arthritis (RA). The associations between exposures of shift work and chronotype on risk of RA were studied in up to 444,210 U.K. Biobank participants. Multivariable logistic regression models were adjusted for covariates: age, sex, ethnicity, alcohol intake, smoking history, Townsend Deprivation Index (TDI), sleep duration, length of working week, and body mass index (BMI). After adjusting for covariates, individuals with a morning chronotype had lower odds of having rheumatoid arthritis (RA; odds ratio [OR]: 0.93, 95% confidence interval [CI]: 0.88-0.99) when compared to intermediate chronotypes. The association between morning chronotype and RA persisted with a more stringent RA case definition (covariate-adjusted OR: 0.89, 95% CI: 0.81-0.97). When adjusted for age, sex, ethnicity, and TDI, shift workers had higher odds of RA (OR: 1.22, 95% CI: 1.1-1.36) compared to day workers that attenuated to the null after further covariate adjustment (OR: 1.1, 95% CI: 0.98-1.22). Morning chronotypes working permanent night shifts had significantly higher odds of RA compared to day workers (OR: 1.89, 95% CI: 1.19-2.99). These data point to a role for circadian rhythms in RA pathogenesis. Further studies are required to determine the mechanisms underlying this association and understand the potential impact of shift work on chronic inflammatory disease and its mediating factors.

Using human genetics to understand the phenotypic association between chronotype and breast cancer.

Little is known regarding the shared genetic influences underlying the observed phenotypic association between chronotype and breast cancer in women. Leveraging summary statistics from the hitherto largest genome-wide association study conducted in each trait, we investigated the genetic correlation, pleiotropic loci, and causal relationship of chronotype with overall breast cancer, and with its subtypes defined by the status of oestrogen receptor. We identified a negative genomic correlation between chronotype and overall breast cancer ( = -0.06, p = 3.00 × 10-4), consistent across oestrogen receptor-positive ( = -0.05, p = 3.30 × 10-3) and oestrogen receptor-negative subtypes ( = -0.05, p = 1.11 × 10-2). Five specific genomic regions were further identified as contributing a significant local genetic correlation. Cross-trait meta-analysis identified 78 loci shared between chronotype and breast cancer, of which 23 were novel. Transcriptome-wide association study revealed 13 shared genes, targeting tissues of the nervous, cardiovascular, digestive, and exocrine/endocrine systems. Mendelian randomisation demonstrated a significantly reduced risk of overall breast cancer (odds ratio 0.89, 95% confidence interval 0.83-0.94; p = 1.30 × 10-4) for genetically predicted morning chronotype. No reverse causality was found. Our work demonstrates an intrinsic link underlying chronotype and breast cancer, which may provide clues to inform management of sleep habits to improve female health.

Evaluation of Nursing Students' Sleep Patterns, Social Jet Lag, and Quality of Life*,*.

The aim of this study is to evaluate the relationship between the chronotypes of nursing students, social jet lag, and quality of life. This study was planned and performed in a descriptive, method. Research data were collected in the 2019-2020 fall semester. The research population consisted of nursing students working at the nursing departments of state and private universities in Istanbul. The study sample included 1152 nursing students who agreed to participate in the study after obtaining informed consent. Data were collected using the "Student Information Form," "Morningness- Eveningness Scale," and "Short Form of the Turkish WHO Quality of Life Scale." Of the nursing students, 81.2% (n = 935) were women, 26.5% (n = 305) were first-year students, 86.5% (n = 997) were non-smoker, and 92.4% (n = 1065) not consumed alcohol. Most of the nursing students in this study were intermediate chronotypes (80.2%). Students' social-jet lag mean value was 1.36±0.73 hours (min:0-max:4.8). Multiple regression analysis showed that an increase in social jetlag decreases the average scores of the physical and environmental subdimension and an increase in the morning chronotype increases the average scores of the physical, mental, and social subdimension. High social jet lag reduced the quality of life and a morning chronotype improved the quality of life.

For Whom (and When) the Time Bell Tolls: Chronotypes and the Synchrony Effect

Circadian rhythms are powerful timekeepers that drive physiological and intellectual functioning throughout the day. These rhythms vary across individuals, with morning chronotypes rising and peaking early in the day and evening chronotypes showing a later rise in arousal, with peaks in the afternoon or evening. Chronotype also varies with age from childhood to adolescence to old age. As a result of these differences, the time of day at which people are best at attending, learning, solving analytical problems, making complex decisions, and even behaving ethically varies. Across studies of attention and memory and a range of allied areas, including academic achievement, judgment and decision-making, and neuropsychological assessment, optimal outcomes are found when performance times align with peaks in circadian arousal, a finding known as the synchrony effect. The benefits of performing in synchrony with one’s chronotype (and the costs of not doing so) are most robust for individuals with strong morning or evening chronotypes and for tasks that require effortful, analytical processing or the suppression of distracting information. Failure to take the synchrony effect into consideration may be a factor in issues ranging from replication difficulties to school timing to assessing intellectual disabilities and apparent cognitive decline in aging.

Expression of periferal core molecular clock genes in oral mucosa depends on the chronotype in patients with maxillofacial cellulitis

IntroductionAccurate determination of the patient's chronotype is one of the problems of personalized medicine. Recent studies have shown that determining of the expression of timing genes is a valuable method that can help gain molecular insight into a patient's intrinsic circadian timing. Odontogenic cellulitis is very common pathology. Since acute inflammatory diseases are an urgent pathology, the time of surgical intervention can correspond depend on the time of the patient's hospitalization. Materials and methodsThe level of mRNA expression of peripheral circadian clock genes clock and bmal1, per1, cry1 in buccal epithelial cells in patients with odontogenic purulent inflammatory diseases of maxillofacial area in the morning and evening was investigated. ResultsDuring analyzing the results of the mRNA expression study of the genes of the negative regulatory link of the peripheral molecular clock, per1 and cry1, in patients with Cellulitis of the maxillofacial area, a significant decrease (P = 0.0003) in the mRNA expression level of the cry1 gene by 2.61 times in the evening compared to its morning mRNA expression values. ConclusionThe obtained data indicate that in patients with odontogenic purulent inflammatory diseases of the maxillofacial area with an evening chronotype, a violation of the expression profile of the per1 gene in the cells of the buccal epithelium is noted, which is manifested by an increase in its evening expression in comparison with patients with a morning chronotype.

Breakfast Frequency and Sleep Quality in College Students: The Multiple Mediating Effects of Sleep Chronotypes and Depressive Symptoms.

Sleep disorders, which are prominent problems among college students, may be associated with skipping breakfast. Therefore, we aimed to explore the role of sleep chronotypes and depressive symptoms as mediators in the relationship between breakfast frequency and sleep quality. A cross-sectional survey enrolling random samples of 712 college students was conducted by the Questionnaire Star online platform. Statistical description and correlation analysis were performed by SPSS 25.0, and a chain mediation test was performed by model 6 in PROCESS 3.5. The result of the article demonstrated that breakfast frequency can affect sleep quality through two mediating pathways: ① sleep chronotypes, with a mediating effect of 32%; and ② depressive symptoms, with a mediating effect of 52.4%. However, the chain mediating effects of sleep chronotypes and depressive symptoms was not significant, and neither was the direct effect of breakfast frequency on sleep quality. Breakfast frequency can indirectly affect sleep quality by adjusting sleep chronotypes and depressive symptoms. Regular breakfast can increase morning and intermediate sleep chronotypes, reduce depressive symptoms, and thus improve sleep quality.

Understanding Bipolar Disorder: Risk Factors & Protective Measures

Bipolar Affective Disorder (BD) is a severe mental pathology characterized by recurrent mood episodes that usually cycle between two opposite poles: mania or hypomania and depression. It has a high level of morbidity/mortality (i.e., cardiovascular disease, cognitive impairment, altered functionality, and absenteeism from work) and associated substantial socioeconomic costs. The most dramatic outcome is death by suicide, which occurs in 5% to 15% of patients. Early detection plays a vital role in modifying the natural course of the disease. It is essential to determine the disease's risk and specific protective factors to prevent its occurrence, delay its appearance, and reduce its deterioration effects. Characteristics such as genetic profile, cognitive reserve (partially explained by educational level and premorbid intelligence), chronotype (particularly morning chronotype), personality aspects (including resilience and hyperthymic temperament), the absence of substance use and childhood maltreatment, in addition to an adequate support network, have been associated with a lower impact in the onset and course of the disease. Once present, interventions -both in the early and late stages (i.e., specific pharmacotherapy and psychotherapy, dietary factors, physical activity, and judicious use of antipsychotics)-can play a protective role against the appearance of the disease and the severity of its mood episodes.

Correlation Between Chronotypes and Depressive Symptoms Mediated by Sleep Quality Among Chinese College Students During the COVID-19 Pandemic.

The COVID-19 pandemic has adversely impacted the mental health of the population. The current study aimed to determine the prevalence of depressive symptoms and sleep disturbances among Chinese college students during the COVID-19 pandemic and investigate the correlations between chronotypes, sleep quality, and depressive symptoms. In the current study, 2526 college students responded anonymously to an online questionnaire survey from 26 May 2020 to 20 July 2020. The participants' chronotypes, sleep quality, and depressive symptoms were evaluated using the Chinese version of the Morning and Evening Questionnaire-5 (MEQ-5), Pittsburgh Sleep Quality Index (PSQI), and Patient Health Questionnaire-9 (PHQ-9). Sociodemographic information of the participants was also acquired. Statistical analyses were performed using Statistical Package for Social Sciences (SPSS) 19.0 software, with the mediating effect assessed by Hayes' PROCESS Macro. During the COVID-19 pandemic, the prevalence of depressive symptoms and sleep disturbances among Chinese college students surveyed was 54.95% and 48.18%, respectively. From absolute evening chronotype to absolute morning chronotype, the surveyed college students' chronotypes were negatively correlated with their depressive symptoms. Moreover, the mediation analysis showed that the correlation between chronotypes and depressive symptoms was fully mediated by sleep quality. Eveningness college students with poorer sleep quality were more likely to report higher levels of depressive symptoms. Our findings suggest that during the COVID-19 pandemic, delayed circadian preference (ie, eveningness) may be linked to worse depressive symptoms among Chinese college students, and call for more attention to the sleep quality of Chinese college students as sleep quality fully mediated the correlation between chronotypes and depressive symptoms among them. Reasonable adjustment in bedtime/circadian preference and improvement in sleep quality may help to reduce the prevalence and severity of depressive symptoms among Chinese college students.

Multidimensional Sleep Health Prior to SARS-CoV-2 Infection and Risk of Post–COVID-19 Condition

The association of multiple healthy sleep dimensions with post-COVID-19 condition (PCC), also known as long COVID, has not been investigated. To examine whether multidimensional sleep health before and during the COVID-19 pandemic, prior to SARS-CoV-2 infection, was associated with the risk of PCC. This prospective cohort study (2015-2021) included Nurses' Health Study II participants who reported testing positive (n = 2303) for SARS-CoV-2 infection in a substudy series of COVID-19-related surveys (n = 32 249) between April 2020 and November 2021. After exclusion for incomplete information about sleep health and nonresponse to a question about PCC, 1979 women were included in the analysis. Sleep health was measured both before (June 1, 2015, to May 31, 2017) and early (April 1 to August 31, 2020) in the COVID-19 pandemic. Prepandemic sleep score was defined according to 5 dimensions: morning chronotype (assessed in 2015), 7 to 8 hours of sleep per day, low insomnia symptoms, no snoring, and no frequent daytime dysfunction (all assessed in 2017). On the first COVID-19 substudy survey (returned between April and August 2020), average daily sleep duration and sleep quality for the past 7 days were queried. SARS-CoV-2 infection and PCC (≥4 weeks of symptoms) were self-reported during 1 year of follow-up. Comparisons were examined between June 8, 2022, and January 9, 2023, using Poisson regression models. Of the 1979 participants reporting SARS-CoV-2 infection (mean [SD] age, 64.7 [4.6] years; 1979 [100%] female; and 1924 [97.2%] White vs 55 [2.8%] other races and ethnicities), 845 (42.7%) were frontline health care workers, and 870 (44.0%) developed PCC. Compared with women who had a prepandemic sleep score of 0 or 1 (least healthy), those who scored 5 (most healthy) had a 30% lower risk of developing PCC (multivariable-adjusted relative risk, 0.70; 95% CI, 0.52-0.94; P for trend <.001). Associations did not differ by health care worker status. No or little daytime dysfunction prepandemic and good sleep quality during the pandemic were independently associated with a lower risk of PCC (relative risk, 0.83 [95% CI, 0.71-0.98] and 0.82 [95% CI, 0.69-0.99], respectively). Results were similar when PCC was defined as having 8 or more weeks of symptoms or as having ongoing symptoms at the time of PCC assessment. The findings indicate that healthy sleep measured prior to SARS-CoV-2 infection, both before and during the COVID-19 pandemic, may be protective against PCC. Future research should investigate whether interventions on sleep health may prevent PCC or improve PCC symptoms.

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)

Erenumab and Possible CGRP Effect on Chronotype in Chronic Migraine: A Real-Life Study of 12 Months Treatment.

The introduction of monoclonal antibodies (mAbs) directed against the calcitonin gene-related peptide (CGRP), or its receptor (CGRPr), revolutionized migraine management due to their high efficacy and few side effects. Data suggest that the CGRP may even be implicated in circadian rhythm, but studies about the effect of anti-CGRP treatments on sleep are still lacking. The aim of the present study was to assess the effect of erenumab (70 and 140 mg per month), a human mAb directed against CGRPr, on chronotype in chronic migraineurs; secondly, we assessed its efficacy, safety, and the effects on anxiety and depression. Sleep was evaluated using self-administrable questionnaires investigating chronotype, sleep quality, and daytime sleepiness. Migraine diaries and several self-administrable questionnaires regarding headache impact and psychological correlates were evaluated every 3 months during 12 months of treatment. Eighty-eight patients were included; most of them showed a significant reduction in headache frequency and an improvement in psychological symptoms. Moreover, an initial change in chronotype was observed at the three-month assessment from a morning chronotype to an intermediate one; a similar trend remained in the other evaluations, even if it did not reach a statistical significance. Lastly, patients who responded to the treatment showed a progressive sleep efficiency reduction. The present real-life study hypothesized the influence of erenumab on chronotype, representing a link between circadian rhythm, CGRP, and migraine.

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.

The Relationship between Sleep, Chronotype, and Dental Caries-A Narrative Review.

This article provides an overview of how sleep and circadian rhythm disturbances mutually influence the occurrence of dental caries and how it is possible to reduce the risk of circadian rhythm disturbances, sleep, and associated adverse effects. Dental caries is a global problem worldwide that contributes to sociological limitations. Numerous factors influence the occurrence of dental caries, from socioeconomic factors to cariogenic bacteria, dietary habits, and oral hygiene. However, sleep disorders and circadian rhythm disturbances represent a new approach in the fight against the increasing prevalence of dental caries worldwide. Bacteria in the oral cavity and the oral microbiome are mainly responsible for the development of caries, and saliva plays an important role in their regulation. The circadian rhythm regulates numerous physiological functions, including sleep and saliva production. Disturbances in sleep and circadian rhythms affect saliva production, which impacts the development of dental caries, as saliva is necessary for regulating and maintaining oral health, especially for controlling oral infections. A person's preference for a particular time of day depends on the circadian rhythm called chronotype. Individuals with an evening chronotype have a less healthy lifestyle that can lead to a higher caries risk than individuals with a morning chronotype. Because circadian rhythms are critical to maintaining sleep homeostasis and oral health, sleep disturbances can disrupt circadian rhythms and lead to a vicious cycle.