Morning Chronotypes Research Articles

Chronotype is differentially associated with lifetime mood and panic-agoraphobic spectrum symptoms in patients with bipolar disorder and healthy controls.

Although the association between chronotype and mood disorders has been consistently reported, conversely, attempts to measure the association between chronotype and anxiety symptoms have generated inconsistent results. We aimed at evaluating whether chronotype (assessed through subjective and objective measures) is associated with lifetime mood and panic-agoraphobic spectrum symptoms in healthy controls (HCs) and in patients with bipolar disorder (BD). Overall, 173 subjects, patients with BD in euthymic phase (n =76) and HC (n =97), were evaluated through the reduced Morningness-Eveningness Questionnaire (rMEQ), actigraphy monitoring and mood and panic-agoraphobic spectrum self-report (MOODS-SR and PAS-SR). The discrepancy between objective (actigraphic-based) versus subjective (rMEQ-based) circadian typology was estimated through the Circadian Classification Discrepancy Index (CCDI). rMEQ-based evening chronotype (ET) was associated with higher scores in MOODS-SR depressive and rhythmicity and vegetative functions domains in HC and BD.Both ET and morning chronotypes (MT) were associated with higher PAS-SR scores in BD only. Actigraphic-based MT was associated with higher MOODS-SR depressive scores in HC. Likewise, the discrepancy between actigraphic-based and rMEQ-based circadian typology was associated with depressive symptoms in HC only. Self-reported ET was consistently associated with mood symptoms, while associations with panic-agoraphobic symptoms only emerged in BD and involved both extreme chronotypes. The discrepancy between the preferred circadian typology (rMEQ-based) and the actual one (actigraphic-based) could contribute to depressive symptoms in HC. These results pave the way for interventional studies targeting circadian typology in an attempt to prevent or treat mental health disorders.

Type 2 Diabetes: Also a “Clock Matter”?

We investigated whether chronotype is associated with glycemic control, antidiabetic treatment, and risk of developing complications in patients with type 2 diabetes (T2DM). The diabetologists filled out an online questionnaire on the Google Form platform to collect the following parameters of subjects with T2DM: body mass index (BMI), fasting plasma glucose (FPG), glycosylated hemoglobin (HbA1c), diabetes history, antidiabetic treatment, diabetic complications, and chronotype categories. We enrolled 106 subjects with T2DM (M/F: 58/48; age: 63.3 ± 10.4 years; BMI: 28.8 ± 4.9 kg/m2). Thirty-five point eight% of the subjects showed a morning chronotype (MC), 47.2% an intermediate chronotype (IC), and 17% an evening chronotype (EC). EC subjects reported significantly higher HbA1c (p < 0.001) and FPG (p = 0.004) values, and higher prevalence of cardiovascular complications (CVC) (p = 0.028) and of subjects taking basal (p < 0.001) and rapid insulin (p = 0.01) compared to MC subjects. EC subjects reported significantly higher HbA1c (p < 0.001) and FPG (p = 0.015) than IC subjects. An inverse association was found between chronotype score, HbA1c (r = -0.459; p < 0.001), and FPG (r = -0.269; p = 0.05), remaining significant also after adjustment for BMI, age, and disease duration. EC is associated with higher prevalence of CVC and poorer glycemic control independently of BMI and disease duration in subjects with T2DM.

Influence of Environmental Exposure to Steel Waste on Endocrine Dysregulation and PER3 Gene Polymorphisms.

To evaluate the association between environmental exposure to the following chemical substances: cadmium (Cd), lead (Pb), nickel (Ni), manganese (Mn), benzene (BZN), and toluene (TLN), and Period Circadian Regulator 3 (PER3) gene variable number of tandem repeats (VNTR) polymorphisms, according to chronotype in a population living in a steel residue-contaminated area. This assessment comprises a study conducted from 2017 to 2019 with 159 participants who completed health, work, and Pittsburgh sleep scale questionnaires. Cd, Pb, Ni, Mn, BZN, and TLN concentrations in blood and urine were determined by Graphite Furnace Atomic Absorption Spectrometry (GFAAS) and Headspace Gas Chromatography (GC), and genotyping was carried out using Polymerase Chain Reaction (PCR). A total of 47% of the participants were afternoon chronotype, 42% were indifferent, and 11% were morning chronotype. Insomnia and excessive sleepiness were associated with the indifferent chronotype, while higher urinary manganese levels were associated with the morning chronotype (Kruskal-Wallis chi-square = 9.16; p < 0.01). In turn, the evening chronotype was associated with poorer sleep quality, higher lead levels in blood, and BZN and TLN levels in urine (χ2 = 11.20; p < 0.01) in non-occupationally exposed individuals (χ2 = 6.98; p < 0.01) as well as the highest BZN (χ2 = 9.66; p < 0.01) and TLN (χ2 = 5.71; p < 0.01) levels detected in residents from the influence zone 2 (far from the slag). Mn, Pb, benzene, and toluene contaminants may have influenced the different chronotypes found in the steel residue-exposed population.

Is Being a Lark Healthier for Patients with Type 1 Diabetes Mellitus?

Background Sleep quality and mood have been evaluated in type 1 diabetic (T1DM) patients, but chronotypes were not studied. Our objectives were to analyze chronotypes, sleep and mood variables and to describe their association with some metabolic variables in this population. Methods An observational, cross-sectional study was performed. Adults with a diagnosis of T1DM were included. We evaluated chronotypes by the Morningness-Eveningness Questionnaires, sleep quality by Pittsburgh Sleep Quality Index (PSQI), excessive daytime sleepiness by Epworth Sleepiness Scale (ESS), symptoms of depression by Patient Health Questionnaire - 9 (PHQ-9) and emotional well-being by Emotional Well Being Index (IWHO-5). A few metabolic variables were included. Results Ninety-five patients participated. The mean age was 38 years old (range 18-70). The average body mass index (BMI) was 24.4 Kg/m 2 (standard deviation [SD]: 4.6). Out of the total sample, 52.6% were males. The Intermediate chronotype was predominant: n = 56 (55%). We found poor quality of sleep in 67.4% of the sample, excessive daytime sleepiness in 14.7%, depressive symptoms in 6.3% by PHQ9 and low perception of well-being by IWHO-5 in 16.8%. Evening chronotype scored worse in sleep quality ( p = 0.05) and had lower well-being ( p = 0.03) compared with the other chronotypes. Higher MEQ values (morningness) correlated with lower height ( p = 0.043), lower values in the PSQI ( p = 0.021); and higher values in emotional well-being ( p = 0.040). Conclusions We found that the predominant chronotype in T1DM was the intermediate. Two-thirds reported poor quality of sleep and 14,7% excessive daytime sleepiness. Possible diagnosis of a depressive disorder in 6.3% and poor self-perception of emotional well-being in 16. 8% were observed. The morning chronotype had significant correlation with better sleep quality and higher scores in emotional well-being.

Associations Between Chronotype, Adherence to the Mediterranean Diet, and Attitude to Healthy Nutrition

Background. Chronotype is the attitude of a subject in determining the individual circadian preference in behavioral and biological rhythm associated with eating behaviors and health.&#x0D; Objective. The aim of this study was to evaluate the associations between chronotype, adherence to the Mediterranean diet, and attitudes to healthy nutrition in Turkish adults.&#x0D; Methods. A survey was conducted online using online platforms. A total of 1,197 volunteers between 18-65 years of age participated in our study. Participants’ adherence to the Mediterranean diet was assessed using the Mediterranean Diet Adherence Screener (MEDAS); their healthy eating attitude and chronotype were assessed using the Attitude Scale for Healthy Nutrition (ASHN) and the Morning-Evening Questionnaire (MEQ), respectively.&#x0D; Results. Most of the participants were classified as those with an intermediate chronotype. More than half of evening-type participants and nearly half of intermediate-type participants had poor Mediterranean diet adherence. In addition, the percentages of individuals with morning and evening chronotypes in the very low and moderate classification ranges were similar and lower than the percentages of those with an intermediate chronotype. Linear regression analysis revealed that participants with higher MEQ values had higher ASHN and MEDAS scores and a lower body mass index as compared to those with lower MEQ values.&#x0D; Conclusions. Chronotype was associated with Mediterranean diet adherence and healthy eating attitude. In particular, morning-type subjects showed higher adherence to the Mediterranean diet than intermediate- and evening-type subjects.

Improvement in chrono-nutrition is associated with robust weight loss outcomes: An extension of the feasibility study

ABSTRACT Previously we had demonstrated the development and feasibility of an integrated chrono-nutrition weight reduction program among non-shift workers with morning and evening chronotypes. In this current paper, we described the association between the changes in chrono-nutrition practice and weight loss outcomes upon completing the weight reduction program. A total of 91 overweight/obese non-shift workers participated in the 12-week integrated chrono-nutrition weight reduction program (Age: 39.6 ± 6.3 y; 74.7% women; BMI: 31.2 ± 4.5 kg/m2). All the assessments including anthropometry, dietary, sleep habits, physical activity, and process of change were measured during pre- and post-intervention. Participants who had lost ≥3% of their body weight were categorized as satisfactory weight loss outcome, and those who did not achieve 3% weight loss were categorized as unsatisfactory weight loss. The satisfactory weight loss had greater daily percent energy intake during earlier in the day from protein (Mean difference (MD): +3.2%, 95% CI: 1.6, 4.9, p < .001) and smaller intake from fat during later in the day (MD: −2.6%, 95% CI: −5.1, −0.1, p = .045), earlier last mealtime (MD: −49.5 min, 95% CI: −86.5, −12.6, p = .009) and midpoint of eating (MD: −27.3 min, 95% CI: −46.3, −8.2, p = .006), shorter eating window (−0.8 h, 95% CI: −1.4, −0.1, p = .031) and greater reduction in night eating syndrome score (MD: −2.4, 95% CI: −4.3, −0.5, p = .015) compared to unsatisfactory weight loss outcome. After accounting for potential confounders, the temporal pattern of energy, protein, and fat intake were associated with greater odds of achieving a satisfactory weight loss. The findings suggest a promising role of chrono-nutrition as one of the strategies in weight reduction intervention.

Exploratory Study on the Associations between Lifetime Post-Traumatic Stress Spectrum, Sleep, and Circadian Rhythm Parameters in Patients with Bipolar Disorder.

The present study aimed at exploring whether lifetime post-traumatic stress spectrum symptoms are associated with chronotype in patients with bipolar disorder (BD). Moreover, we explored whether the chronotype can moderate the potential associations between lifetime post-traumatic stress spectrum symptoms and rest-activity circadian and sleep-related parameters. A total of 74 BD patients were administered the Trauma and Loss Spectrum Self-Report (TALS-SR) lifetime version for lifetime post-traumatic stress spectrum symptoms, the Pittsburgh Sleep Quality Index (PSQI) for self-reported sleep quality, and the Reduced Morningness-Eveningness Questionnaire (rMEQ) to discriminate evening chronotypes (ETs), neither chronotype (NT), and morning chronotype (MT). Actigraphic monitoring was used to objectively evaluate sleep and circadian parameters. Patients classified as ET reported significantly higher scores in the re-experiencing domain, as well as poorer sleep quality, lower sleep efficiency, increased wake after sleep onset, and delayed mid-sleep point compared with both NT and MT (p-value ≤ 0.05). Moreover, ET presented significantly higher scores in the TALS-SR maladaptive coping domain than NT and lower relative amplitude than MT (p-value ≤ 0.05). Moreover, higher TALS-SR total symptomatic domains scores were significantly correlated with poor self-reported sleep quality. Regression analyses showed that the PSQI score maintained the association with the TALS total symptomatic domains scores after adjusting for potentially confounding factors (age and sex) and that no interaction effect was observed between the chronotype and the PSQI. Conclusions: This exploratory study suggests that patients with BD classified as ET showed significantly higher lifetime post-traumatic stress spectrum symptoms and more disrupted sleep and circadian rhythmicity with respect to other chronotypes. Moreover, poorer self-reported sleep quality was significantly associated with lifetime post-traumatic stress spectrum symptoms. Further studies are required to confirm our results and to evaluate whether targeting sleep disturbances and eveningness can mitigate post-traumatic stress symptoms in BD.

Quasi-causal associations between chronotype and post-traumatic stress disorder symptoms: A twin study

ObjectiveThe evening (“night owl”) chronotype is associated with greater severity and lifetime prevalence of post-traumatic stress disorder (PTSD) symptoms compared to morning or intermediate chronotypes. This twin study investigated the gene-environment relationships between chronotype, recent PTSD symptoms, and lifetime intrusive symptoms. MethodsWe used the reduced Horne-Östberg Morningness-Eveningness Questionnaire (rMEQ) to assess chronotype in a sample of 3777 same-sex adult twin pairs raised together (70.4% monozygotic, 29.6% dizygotic) in the community-based Washington State Twin Registry. PTSD symptoms were reported on the Impact of Events Scale (IES) and a single item for lifetime experience of intrusive symptoms after a stressful or traumatic event. ResultsGenetic influences accounted for 50% of chronotype variance, 30% of IES score variance, and 14% of lifetime intrusive symptom variance. Bivariate twin models showed a phenotypic association (bp) between evening chronotype and more severe PTSD symptoms (bp = −0.16, SE = 0.02, p < .001) that remained significant even after adjusting for shared genetic and environmental influences (bp = −0.10, SE = 0.04, p = .009), as well as age, sex, and self-reported sleep duration (bp = −0.11, SE = 0.04, p = .004). An association was found between evening chronotype and lifetime intrusive symptoms (bp = −0.11, SE = 0.03, p < .001) that was no longer significant after adjusting for shared genetic and environmental influences (bp = 0.04, SE = 0.06, p = .558). ConclusionsOur results suggest a “quasi-causal” relationship between evening chronotype and PTSD symptoms that is not purely attributable to genetic or shared environmental factors. Evening chronotype may increase vulnerability to pathologic stress responses in the setting of circadian misalignment, providing potential avenues of prevention and treatment using chronobiological strategies.

Effect of the one-day fasting on cortisol and DHEA daily rhythm regarding sex, chronotype, and age among obese adults.

Physiological and biochemical processes in the human body occur in a specific order and show rhythmic variability. Time dependence characterizes the secretion of cortisol and dehydroepiandrosterone (DHEA). One-day fasting implies alternating fasting days and eating days. The study aimed to determine how 24-h fasting affects the daily rhythm of cortisol and DHEA levels in obese people while taking into account gender and chronotype. Forty-nine obese patients (BMI 32.2-67.1 kg/m2; 25 women and 24 men) underwent a 3-week hospital-controlled calorie restriction diet to reduce body weight. During hospitalization, patients fasted for 1 day, during which only water could be consumed. Samples of whole mixed unstimulated saliva were collected at 2-3-h intervals over a 64-h period and analyzed for cortisol and DHEA by immunoassays. The individual chronotypes were assessed by the morning and evening questionnaire, according to Horne and Östberg. Three components of daily rhythm were evaluated: amplitude, acrophase, and the so-called MESOR. Cortisol rhythm showed differences in amplitude (p = 0.0127) and acrophase (p = 0.0005). The amplitude on the fasting day was 11% higher (p = 0.224) than the day after. The acrophase advanced on the day of fasting, 48 min earlier than the day before (p = 0.0064), and by 39 min to the day after fasting (p = 0.0005). In the rhythm of DHEA, differences were found in the MESOR (p = 0.0381). The MESOR on the fasting day increased. Our results obtained during 64 consecutive hours of saliva sampling suggest that one-day fasting may affect three components of cortisol and DHEA daily rhythm. Additionally, no differences were found in the daily rhythm between the morning and evening chronotypes and between females and males. Although aging did not influence daily cortisol rhythm, DHEA amplitude, MESOR, and acrophase changed with age. To the best of our knowledge, this is the first presentation of changes in DHEA rhythm during one-day fasting.

The Role of Chronotype of Patients and Cryoexrtact of Placenta in the Activity of Antioxidant Enzymes in Facial Scar

BACKGROUND: The chronotypical features of people have a significant impact on the course of reparative processes in the patient’s body. Understanding the mechanisms of influence on the course of reparative skin regeneration after planned surgical interventions within the maxillofacial tissues can contribute to improving the provision of medical care to such patients. AIM: The study was aimed to determine role of chronotype of patients and cryoexrtact of placenta in the activity of antioxidant enzymes in facial scar. METHODS: In our study, 60 patients (36 males and 24 females) of the Department of Maxillofacial Surgery of the Poltava Regional Clinical Hospital, Ukraine, aged from 18 to 68 years, who underwent inpatient treatment for planned surgical interventions of the maxillofacial area, were enrolled. At the time of the study, the patients did not have concomitant diseases, but if necessary, all patients could consult by other specialists. The practical section was carried out between September 2019 and August 2021 as follow. According to our study, 60 patients were divided depending on the type of chronotype, which was determined by the Horn-Ostberg questionnaire in Stepanova’s modification and the type of using treatment taking into account different ways of using of cryoextract of placenta. The activities of superoxide dismutase and catalase were determined on the 90th, 180th, and 360th days of observation in the forming scar tissue. We used the method of Chevari et al. to determine the activity of superoxide dismutase. Catalase activity in homogenates of scar tissue was determined according to the method of M.A. Koroliuk. RESULTS: It was noted that the enzymatic activity of catalase in the scar homogenate is characterized by a lower dynamics of changes than the activity of superoxide dismutase. Positive dynamics were noted under the conditions of use in the treatment protocol of placenta cryoextract, which was more pronounced in patients with a morning chronotype. CONCLUSIONS: The most significant changes were observed in the studied indicators of antioxidant protection in patients of the morning chronotype who underwent intrawound administration of cryoextract of the placenta in combination with electrophoresis of this remedy against the background of a standard treatment protocol, especially at earlier terms after surgical treatment.

Chronotype, Time of Day, and Performance on Intelligence Tests in the School Setting.

Research suggests the existence of an association between chronotype and intellectual performance, but the nature of this link remains unclear. Studies conducted in a laboratory setting point to the synchrony effect (better performance at a person's preferred time of day) for fluid intelligence, but not for crystallized intelligence, whereas studies that have analyzed students' grades suggest that the effect exists for both. In the present study, we aimed to verify the synchrony effect by applying direct measures of crystallized intelligence, fluid intelligence, and subjective sleepiness-alertness in a sample of high school students during their morning or afternoon class. The results revealed a synchrony effect for crystallized, but not for fluid intelligence. During morning class, students with a morning chronotype performed better than evening chronotypes on a test of crystallized intelligence, whereas during afternoon class there was no difference between chronotypes. The association resulted from decreased performance during morning class in evening chronotypes that improved during afternoon class and constant performance in morning chronotypes. These effects were independent of sleepiness-alertness levels. The results suggest that individual differences between chronotypes may be important for tasks performed during morning classes, but not during afternoon ones, and that performance across school days may depend on time of day in evening chronotypes.

Chronotype as a predictor of scholar performance in a full-time middle school.

The performance of day-to-day tasks, whether satisfactory or unsatisfactory, varies due to several environmental synchronizers, including the 24-hour light-dark cycle. For instance, human performance on physical and/or cognitive demanding activities reaches its peak during the day when the body temperature is at its circadian peak. Individual differences in the circadian peaks in temperature along with individuals' timing of sleep is referred to as chronotype. Here, we aimed to answer if (a) chronotypes affect the performance of students in a Brazilian full-time school with an early start time and if (b) there are differences in performance based on chronotype. We expected to find (a) a positive effect of the morning chronotype on the students' performance, particularly in subjects that take place in early morning; (b) while a negative effect of the evening chronotype in that same period. To address the effect of the chronotype on the students' scholar performance we build a Generalized Linear Mixed Model (GLMM). Results support the hypothesis that the students' performance is partially attributed to their chronotype. In particular, our findings shows that evening-type students are expected to have an increase of 0.038 (p ≤0.05) log counts on their performance in Portuguese classes compared to other chronotypes. Here we add evidence for the effect that individual chronotypes have on the students' performance in a Brazilian full-time middle school. Distinctive features of the studied Brazilian full-time middle school related to chronotypes are discussed.

Factors Associated with Sleep Quality Among Malaysian Undergraduate Students During the COVID-19 Pandemic

Poor sleep quality has become a public health concern due to its association with several health risks. Recent studies had shown that university students had poor sleep quality during the COVID-19 pandemic. Thus, this study aimed to determine the factors associated with sleep quality among undergraduate students in Malaysia during the COVID-19 pandemic. This cross-sectional study involved 377 undergraduates from public and private universities in Malaysia. The study ws conducted between 16 June 2021 to 31 July 2021. Respondents completed an online survey reagarding to their sociodemographic background, sleep quality, chronotype pattern, night eating syndrome, food security, physical activity, internet addiction and self-reported body weight and height. There was poor sleep quality in 62.3% of the respondents. Respondents who were Malay (AOR = 3.84, 95% CI =2.07-7.11), in the arts stream (AOR = 2.55, 95% CI = 1.20-5.42) and internet-addicted (AOR = 2.14, 95% CI = 1.22-3.77) had higher risk of poor sleep quality. Respondents who lived in a rented house (AOR = 0.38, 95% CI = 0.16-0.88), were sophomores (AOR = 0.49, 95% CI = 0.25-0.99) and were the morning chronotype (AOR = 0.35, 95% CI = 0.17-0.72) had lower risk for developing poor sleep quality. This study underscored the high prevalence of poor sleep quality among undergraduate students during the COVID-19 pandemic. The findings suggested that by preventing internet addiction and the evening chronotype can improve sleep quality.

Vitamin D and chronotype: is there any relationship in individuals with obesity?

Chronotype is the attitude to perform most of the daily activities in the morning ("morning chronotype", MC) or in the evening ("evening chronotype", EC). The latter, as well as vitamin D deficiency, has been associated with an increased risk of obesity-related complications, likely through the promotion of insulin resistance. Therefore, we aimed to investigate whether there is any relationship between vitamin D (25-OH-D) and chronotype in individuals with obesity. In this cross-sectional study, we enrolled 59 individuals (43.1 ± 13years; 17M/42F) with obesity. Anthropometric parameters, lifestyle habits, personal medical history, chronotype, insulin resistance, and 25-OH-D were assessed. Individuals with EC presented significantly higher BMI than MC (p < 0.001), greater waist (p = 0.012), and hip circumferences (p = 0.001). Individuals with EC showed significantly lower insulin sensitivity (p = 0.017) and 25-OH-D than MC. In addition, the prevalence of vitamin D deficiency and impaired fasting glucose was significantly higher in EC than in MC. 25-OH-D directly correlated with chronotype score (r = 0.351; p = 0.019) whereas inversely with BMI (r = -0.363; p = 0.016). The regression analysis showed that BMI was most tightly associated with 25-OH-D concentrations (β = -0.323, p = 0.032), followed by chronotype score (β = 0.340, p = 0.042). Using chronotype score as the dependent variable, BMI significantly predicted a lower chronotype score (β = -0.586, p < 0.001). The present study showed that 25-OH-D, as well as chronotype, correlate independently with obesity.

THE EFFECT OF PLACENTA CRYOEXTRACT ON REPARATIVE PROCESSES AFTER MAXILLOFACIAL SURGERY, DEPENDING ON THE PATIENT'S CHRONOTYPE.

Currently, there is intense interdisciplinary interest and a significant amount of literature on the prevention and treatment of postoperative scars, but international treatment recommendations and regimens have not yet caught up with current knowledge and practice in many medical institutions.&#x0D; The aim of our study was to establish how the biological rhythm can affect the reparative functions of the human body, namely wound healing and scar formation when combining the intraoperative injection of placenta cryoextract and the postoperative electrophoresis on the 90th to 180th day.&#x0D; The research was conducted in the Department of Maxillofacial Surgery on the basis of the Poltava Regional Clinical Hospital. M.V. Sklifosivskyi of the Poltava Regional Council". In total, 40 people took part in the study.&#x0D; On the 90th day of the clinical study, the average score of postoperative scars was as follows: subgroup 1a was 49.3% lower compared to subgroup 2a. A difference of 25.5% could be observed between subgroups 1a and 1b, and 18.5% between subgroups 2a and 2b. From the data of clinical studies, the best results were obtained in subgroup 1a, which indicates the maximum impact of the author's prevention method on the condition of the postoperative scar in patients with a morning chronotype. In this group, a significant decrease in P1, P2, and P7 indicators was established on the 90th day and zero values ​​on the 180th day, respectively; Indicators P3, P4, and P5 recorded the lowest values ​​on the 90th day and a uniform decrease on the 180th and 360th days.&#x0D; Thus, it can be argued that the most optimal results are in patients with the morning type of chronotype, who were injected with placenta cryoextract; the clinical difference was especially noticeable in the earlier period of the postoperative period.

CORRELATION BETWEEN PERIODONTAL HEALTH INDICES AND PECULIARITIES OF CIRCADIAN RHYTHM IN BUCCAL EPITHELIAL CELLS

There is a complex system of biological rhythms arranging the coordinationion of physiological functions and the environmental rhythms. The leading place it taken by the circadian rhythm, a 24-hour cycle that is a part of the body's internal clock. Circadian regulation of normal physiological and metabolic processes is carried out by the fluctuations in the expression of genes (clock-controlled genes (CCGs)) and the proteins they encode, which differ in each individual organ or tissue. The circadian rhythm of gene expression was detected in the basal cells of the oral epithelium, in the cells of ameloblasts and odontoblasts, cells of the dental pulp, cells of the periodontal ligament, osteoblasts and osteoclasts of the alveolar bone. However, so far little is known about the dependence of clock controlled gene expression on chronotype in buccal epithelial cells.&#x0D; The purpose of the study is to determine the expression level of the clock controlled genes Per1, Cry1, Bmal1 and Clock in the buccal epithelial cells of healthy people with different chronotype.&#x0D; Materials and methods. In order to achieve the goal we surveyed 14 people (7 men (50%) and 7 women (50%) aged from 36 to 45 years with a healthy periodontium without any somatic pathology or with compensated one. All participants signed an informed consent forms. The chronotype of the participants was determined by the Horn-Ostberg test modified by S.I. Stepanova and determined the mRNA expression of Clock, Bmal1, Per1 and Cry1 in buccal epithelium samples at 7:00 am and 7:00 pm in one day in the autumn-winter period.&#x0D; Results. The Per1 is better expressed early in the morning than in the evening, regardless of the chronotype (р1&lt;0.05). The level of Clock expression is higher in the evening in both groups (р1&lt;0.05). The difference between the indicators of the evening expression of the Clock in the two groups is statistically significant (р2&lt;0.05). Bmal1 expression is higher in the evening, regardless of chronotype (р1&lt;0.05). The Cry1 shows the same evening predominance among participants of both chronotypes, but it is not statistically significant.&#x0D; Conclusion. The study has revealed the correlation between chronotype and the evening expression of the Clock that is higher in people with the evening chronotype. Belonging to the morning or evening chronotype did not reveal any effect on the expression level of Per1, Bmal1 and Cry1.

The association between metabolic parameters and evening chronotype and social jetlag in non-shift workers: A meta-analysis.

The aim of the study was to evaluate the association between evening chronotype and social jetlag (SJL) with obesity, blood glucose and lipid levels in non-shift working adults. The databases of MEDLINE, EMBASE and Cochrane Reviews were searched for studies analyzing the metabolic parameters among groups of different chronotypes or SJL until Feb 2022. Weighted mean difference (WMD) and 95% confidence intervals (CI) were used to analyze the association between these parameters and chronotypes or SJL. A total of 27 studies were included in this meta-analysis. Compared with morning chronotype, the participants with evening chronotype had higher body mass index (BMI) (WMD= 0.44 kg/m2, 95%CI, 0.30 to 0.57 kg/m2, p<0.001), higher fasting blood glucose level (WMD= 5.83mg/dl, 95%CI, 3.27to 8.38 mg/dl, p<0.001), higher total cholesterol level (WMD= 6.63mg/dl, 95%CI, 0.69 to 12.56 mg/dl, p=0.03), and lower high density lipoprotein cholesterol (HDL-C) level (WMD= -1.80mg/dl, 95%CI, -2.30 to -1.31 mg/dl, p<0.001). Compared with the participants with small SJL, the participants with large SJL had larger waist circumference (WMD= 0.80cm, 95%CI, 0.77 to 0.83cm, p<0.001). Evening chronotype and SJL were associated with obesity and unfavorable metabolic parameters of glucose and lipid metabolism. https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022303401.

Circadian Disruption and Colorectal Cancer Incidence in Black Women.

Animal and experimental studies suggest circadian disruption increases colorectal cancer risk, but evidence in humans is limited. We examined night shift work, chronotype, and residential position within a time zone, proxies for circadian disruption, in relation to colorectal cancer risk. Participants in the Black Women's Health Study, a prospective cohort of 59,000 Black American women established in 1995, reported history of night shift work and chronotype on follow-up questionnaires. Residential position within a time zone was estimated using participant addresses at each questionnaire cycle. Number of colorectal cancer cases and follow-up duration varied by analysis depending on timing of exposure assessment, ranging from 204 over the 2005 to 2018 night shift work study period to 452 over the 1995 to 2018 residential position study period. Cox proportional hazards regression was used to estimate multivariable-adjusted HRs and 95% confidence intervals (CI). Compared with never having worked a night shift, working a night shift for ≥10 years was associated with increased colorectal cancer risk (HR = 1.64; 95% CI, 1.01-2.66). However, shorter duration was not. The HR for evening versus morning chronotype was 0.96 (95% CI, 0.73-1.27). Westward position of residence within a time zone was not associated with colorectal cancer risk (HR per 5-degree longitude increase: 0.92; 95% CI, 0.82-1.03). Our findings suggest a possible increased risk of colorectal cancer associated with long duration night shift work; however, results require confirmation in larger studies. Circadian disruption from long-term night shift work may contribute to colorectal cancer development in Black women.

Independent and joint effect of chronotype and sleep duration on self-rated health in medical students

Objective: To investigate the independent and joint effects of chronotype and sleep duration on self-rated health in medical students. Methods: A cross-sectional study was conducted in 1 526 medical students selected through proportional stratified cluster random sampling from a medical university in Zhejiang province. A questionnaire survey was conducted to collect the information about their basic demographic characteristics, chronotype, sleep duration, and other lifestyle factors such as midnight snack, sedentary behavior, physical activity, meal time, and self-rated health. The independent and joint effects of chronotype and sleep duration on self-rated health were assessed by logistic regression model after controlling for confounding variables. Results: The numbers of the students with evening chronotype, neutral chronotype, and morning chronotype were 664 (43.5%), 442 (29.0%), and 420 (27.5%), respectively. Among the medical students, 42.8% (653) had poor self-rated health. Compared with those with the morning chronotype, the adjusted ORs for those with neutral chronotype and evening chronotype were 1.69 (95%CI: 1.23-2.31) and 2.43 (95%CI: 1.81-3.26), respectively, trend test P<0.001. Compared with those with sleep duration of 8 h or above per night, the adjusted ORs for those with sleep duration of 7 and ≤6 h per night were 1.40 (95%CI: 1.07-1.84) and 2.38 (95%CI: 1.69-3.37), respectively, trend test P<0.001. In the joint effect, compared with those with the morning chronotype and sleep duration of 8 h or above per night, the adjusted OR for those with evening chronotype and sleep duration of ≤6 h per night was 6.53 (95%CI: 3.53-12.09). Conclusions: Both evening chronotype and insufficient sleep were associated with increased odds of poor self-rated health in medical students, and they had joint effects. Therefore, it is necessary to promote early to bed, early to rise and adequate sleep in medical student to maintain their health.

Cross-sectional interrelationships between chronotype, obstructive sleep apnea and blood pressure in a middle-aged community cohort.

Chronotype is linked to adverse health measures and may have important associations with obstructive sleep apnea and blood pressure, but data are limited. This study aimed to determine the separate and combined associations of chronotype with obstructive sleep apnea and blood pressure in a middle-aged community population. Adults (n= 811) from the Raine Study (female=59.2%; age mean [range]=56.6 [42.1-76.6] years) were assessed for chronotype (Morningness-Eveningness Questionnaire), blood pressure and hypertension (doctor diagnosed or systolic blood pressure ≥ 140 mmHg and/or diastolic ≥ 90 mmHg), and obstructive sleep apnea at different in-laboratory apnea-hypopnea index thresholds (5, 10, 15 events per hr). Linear and logistic regression models examined relationships between chronotype and the presence and severity of obstructive sleep apnea, blood pressure, hypertension, and blood pressure stratified by obstructive sleep apnea severity at above-mentioned apnea-hypopnea index thresholds. Covariates included age, sex, body mass index, alcohol consumption, smoking, physical activity, sleep duration, anti-hypertensive medication, insomnia, and depressive symptoms. Most participants were categorised as morning (40%) or intermediate (43%), with 17% meeting criteria for evening chronotypes. Participants with apnea-hypopnea index ≥ 15 events per hr and morning chronotype had higher systolic (9.9 mmHg, p< 0.001) and a trend for higher diastolic blood pressure (3.4 mmHg, p= 0.07) compared with those with an evening chronotype, and higher systolic blood pressure compared with those with an intermediate chronotype (4.8 mmHg, p= 0.03). Across chronotype categories, no differences in systolic or diastolic blood pressure or odds of hypertension were found at apnea-hypopnea index thresholds of ≥ 5 or ≥ 10 events per hr. Among participants with apnea-hypopnea index ≥ 15 events per hr, systolic blood pressure is higher in those with a morning chronotype than evening and intermediate chronotypes. Assessment for morning chronotype may improve risk stratification for hypertension in patients with obstructive sleep apnea.