Comparative Analysis of Sleep Hygiene and Patterns among Adolescents in Two Russian Arctic Regions: A Pilot Study.

PURPOSE: The circumpolar habitat stands as one of the most vulnerable environments for human activity and health. The primary study objective was to compare sleep-related factors, light exposure, social cues, and potential confounding variables among schoolchildren residing in the European Arctic region from two settlements situated below and above the Polar Circle using validated self-reported questionnaires. MATERIALS AND METHODS: We recruited 94 children aged 13-15 years (40.4% males), matched by sex and age, from public educational institutions in two circumpolar settlements located below (Kem', Republic of Karelia; 64.6 NL) and above the Polar Circle (Apatity, Murmansk Region; 67.3 NL). Participants completed several surveys, including the Pediatric Daytime Sleepiness Scale, the Insomnia Severity Index, the Adolescent Sleep Hygiene Scale, and the Munich ChronoType Questionnaire, to evaluate sleep parameters and chronotype. The χ2 test was used to test for differences between proportions. Linear regression and multiple regression models with co-factors were applied to assess the relationship between studied indicators. RESULTS: A noteworthy increase in physical activity was observed in children residing in Kem' compared to those in Apatity. Children from Apatity showed higher alcohol consumption than their counterparts from Kem'. The overall rate of excessive daytime sleepiness in the sample was 17.1%. Moderate insomnia symptoms were reported in 18.4% of adolescents living in Kem' and in 25% of respondents living in Apatity, respectively. Notably, participants from Kem' attained higher academic scores and had longer exposure to sunlight on schooldays. On the other hand, children from Apatity tended to have later bedtimes and sleep-onset times on schooldays. According to the Munich ChronoType Questionnaire data, a reliance on alarm clocks on schooldays, and a higher Sleep Stability Factor based on the Adolescent Sleep Hygiene Scale. DISCUSSION: Our study indicating that higher physical activity and longer sunlight exposure among Kem' children on schooldays are associated with earlier wake-up times during schooldays, earlier bedtime whole week, reduced dependence on alarm clocks, and higher academic achievements. The results of older schoolchildren differ from many works published previously in the USA, Argentina, and Japan, which could be explained by the season when the study was performed. Here, we observed a negative impact on school performance and sleep parameters in children living in high latitudes, namely in circumpolar regions. CONCLUSIONS: Our study points out that adolescents living above the Polar Circle tend to have sleep problems, e.g., late sleep-onset times, higher excessive daytime sleepiness, and insomnia-related symptoms, because of experiencing reduced exposure to natural light. Future research encompassing assessments across all four seasons will provide a more comprehensive understanding.

The Association between Melatonin-Containing Foods Consumption and Students' Sleep-Wake Rhythm, Psychoemotional, and Anthropometric Characteristics: A Semi-Quantitative Analysis and Hypothetical Application.

Food is an important source of melatonin (MT), which belongs to a group known as chronobiotics, a class of substances that affect the circadian system. Currently, no studies have been conducted on how the consumption of foods containing MT (FMT) is associated with indicators characterizing the human circadian system. In this study, we tested the hypothesis that FMT consumption is associated with chronotype and social jetlag. A total of 1277 schoolchildren and university students aged M (SD) 19.9 (4.1) years (range: 16-25 years; girls: 72.8%) participated in a cross-sectional study. Each participant completed an online questionnaire with their personal data (sex, age, height, weight, waist circumference, and academic performance) and a sequence of tests to assess their sleep-wake rhythm (the Munich Chronotype Questionnaire), sleep quality (the Pittsburgh Sleep Quality Index), and depression level (the Zung Self-Rating Depression Scale). Study participants also completed a modified food frequency questionnaire that only included foods containing MT (FMT). They were asked how many foods containing MT (FMT) they had eaten for dinner, constituting their daily serving, in the past month. The consumption of foods containing MT (FMT) during the day (FMTday) and at dinner (FMTdinner) was assessed using this test. Multiple regression analyses were performed to assess the association between the studied indicators. We found that higher FMTday values were associated with early chronotype (ß = -0.09) and less social jetlag (ß = -0.07), better sleep quality (ß = -0.06) and lower levels of depression (ß = -0.11), as well as central adiposity (ß = -0.08). Higher FMTdinner values were associated with a lower risk of central adiposity (ß = -0.08). In conclusion, the data obtained confirm the hypothesis that the consumption of foods containing MT (FMT) is associated with chronotype and social jetlag in adolescents and young adults.

Appropriate Circadian-Circasemidian Coupling Protects Blood Pressure from Morning Surge and Promotes Human Resilience and Wellbeing.

Background: Blood pressure (BP) variability is involved in the appraisal of threat and safety, and can serve as a potential marker of psychological resilience against stress. The relationship between biological rhythms of BP and resilience was cross-sectionally assessed by 7-day/24-hour chronobiologic screening in a rural Japanese community (Tosa), with focus on the 12-hour component and the "circadian-circasemidian coupling" of systolic (S) BP. Subjects and Methods: Tosa residents (N = 239, 147 women, 23-74 years), free of anti-hypertensive medication, completed 7-day/24-hour ambulatory BP monitoring. The circadian-circasemidian coupling was determined individually by computing the difference between the circadian phase and the circasemidian morning-phase of SBP. Participants were classified into three groups: those with a short coupling interval of about 4.5 hours (Group A), those with an intermediate coupling interval of about 6.0 hours (Group B), and those with a long coupling interval of about 8.0 hours (Group C). Results: Residents of Group B who showed optimal circadian-circasemidian coordination had less pronounced morning and evening SBP surges, as compared to residents of Group A (10.82 vs 14.29 mmHg, P < 0.0001) and Group C (11.86 vs 15.21 mmHg, P < 0.0001), respectively. The incidence of morning or evening SBP surge was less in Group B than in Group A (P < 0.0001) or Group C (P < 0.0001). Group B residents showed highest measures of wellbeing and psychological resilience, assessed by good relation with friends (P < 0.05), life satisfaction (P < 0.05), and subjective happiness (P < 0.05). A disturbed circadian-circasemidian coupling was associated with elevated BP, dyslipidemia, arteriosclerosis and a depressive mood. Conclusion: The circadian-circasemidian coupling of SBP could serve as a new biomarker in clinical practice to guide precision medicine interventions aimed at achieving properly timed rhythms, and thereby resilience and wellbeing.

Food addiction and emotional eating are associated with intradaily rest-activity rhythm variability.

PURPOSE: The aim of the present investigation was to study the associations among parameters characterizing eating behavior and actimetry-derived indices of circadian rhythm of motor activity. METHODS: The study involved 81 healthy participants (average age: 21.5 ± 9.6 y, women: 77.8%). Each study participant provided personal data, filled out the Yale Food Addiction Scale and the Dutch Eating Behavior Questionnaire, and wore a wrist actimeter for 7 consecutive days to record motor activity. Using time series treatments, we obtained: (a) three cosinor-derived parametric indices [Medline Estimating Statistics of Rhythm (MESOR), amplitude, and acrophase], and (b) four non-parametric indices [interdaily stability, intradaily variability (I.V.), most active 10-h period (M10), and least active 5-h period] characterizing the 24-h rhythm of motor activity. A multiple regression analysis adjusted for age, sex, and BMI was performed to assess the associations among the studied indicators. RESULTS: It was shown that I.V. is a predictor of symptoms of food addiction (ß = 0.242, P = 0.037) and emotional eating (ß = 0.390, P = 0.004), MESOR is a predictor of symptoms of food addiction (ß = 0.342, P = 0.003), and M10 predicts restraint (ß = 0.257, P = 0.015) and emotional eating (ß = 0.464, P = 0.001). CONCLUSION: It was shown for the first time that an increase in symptom counts of food addiction is associated with an increase in the average level and fragmentation of 24-h rhythm of motor activity. LEVEL OF EVIDENCE: Level V, cross-sectional descriptive study.

Association between food addiction and time perspective during COVID-19 isolation.

PURPOSE: The concept of time perspective (TP) implies that a mental focus on past, present, or future affect a person makes decisions and take action. Inability to plan their life for a sufficiently long time perspective due to the COVID-19 pandemic appeared to have a pronounced impact on a human's lifestyle influencing their thoughts, feelings, and behaviors, including eating behavior. This study tested two hypotheses: (a) that during COVID-19 isolation, the incidence rate of food addiction is increased, and (b) people with present TP are more likely exhibited signs of food addiction (FA). METHODS: The final study sample included 949 people, mean age 21.8 ± 7.8 years (range: 17-71 years, women: 78.3%). Each participant indicated their personal data and completed Yale Food Addiction Scale and the Zimbardo Time Perspective Inventory. RESULTS: There was an increased incidence rate of FA (OR = 1.678, 95% CI = 1.324, 2.148, p = 0.000) during COVID-19 isolation. Individuals with balanced, future, and past positive TP were less likely to exhibit symptoms of FA. Persons with past negative, and present hedonistic TP were more likely to exhibit signs of FA. CONCLUSION: There was an increased incidence rate of FA during COVID-19 isolation. Persons with shortened time horizon are more likely to exhibit symptoms of FA. LEVEL OF EVIDENCE: Level V, cross-sectional descriptive study.

Social Jetlag and Excessive Daytime Sleepiness from a Sample of Russian Children and Adolescents.

PURPOSE: Insufficient nocturnal sleep is a primary source of excessive daytime sleepiness. Most previous research has focused on the disparity between sleep demands and study start times in adolescents. Fewer studies have focused on elementary schoolchildren. We hypothesize that late sleep timing is connected to excessive daytime sleepiness in a sample of Russian children and adolescents. The major goals of our study were to evaluate excessive daytime sleepiness in Russian schoolchildren and adolescents using the Russian version of the Pediatric Daytime Sleepiness Scale (PDSS) and to estimate its relationship with sleep-wake parameters using the Munich Chronotype Questionnaire (MCTQ). MATERIALS AND METHODS: Student subjects were from public educational facilities in the Republic of Karelia. They completed both the PDSS and the Munich Chronotype Questionnaire to estimate sleep parameters and chronotype (MSFsc). Five hundred and eleven students provided data for the PDSS and sleep-wake variables, and 479 for the full MCTQ data. RESULTS: The overall prevalence of Excessive Daytime Sleepiness (EDS) in our sample was 18%. The total PDSS score was inversely correlated with sleep length on school nights and was independent of respondents' sex. Higher PDSS scores were associated with later bedtimes on school days and free days, and shorter sleep duration on school days. Late chronotype and more pronounced social jetlag were both positively correlated with high PDSS scores. A negative correlation was found between chronotype and the duration of the sleep period on weekdays (p < 0.001) and a positive correlation was found on weekends (p < 0.001). Longer average sleep duration was positively related to less daytime sleepiness. CONCLUSION: This study suggests that excessive daytime sleepiness is chronotype-dependent. School start times could be shifted to a later hour to prolong sleep and reduce EDS.

Food addiction and weight in students with high academic performance.

OBJECTIVE: The purpose of this study was to analyse the relationships between food addiction (FA), anthropometric characteristics and academic performance. DESIGN: The average age (sd) of the participants was 17·5 (sd 2·7) years (64·1 % female). Each study participant indicated their sex, height, weight and academic performance and completed the Yale Food Addiction Scale. SETTING: Syktyvkar, Kirov, Tyumen, Yekaterinburg, Russia; Aizawl, India. PARTICIPANTS: The study involved 3426 people. RESULTS: FA was found in 8·7 % of participants from Russia and 14·6 % from India. In schoolchildren but not in university students, high academic performance was associated with a higher incidence rate of FA detection (OR = 1·16, 95 % CI 1·07, 1·26) and a lower BMI (OR = 0·72, 95 % CI 0·56, 0·94). CONCLUSIONS: These data showed an increased incidence rate of FA detection in adolescents with high academic performance.

Food preferences and YFAS/YFAS-C scores in schoolchildren and university students.

PURPOSE: Food addiction (FA) is one of the causes of widespread obesity in modern society. It was shown that there is an age-associated increase in incidence rate of FA in adolescents/young adults. The purpose of this study was to analyze food preferences in schoolchildren and university students with FA. METHODS: High school and university students (N = 1607; age: 17.8 ± 2.7 years; girls: 77.0%) located in four settlements of Russia anonymously took part in the study. Study participants provided personal data (age, sex, height, and weight) and completed the Yale Food Addiction Scale, the Zung Self-Rating Depression Scale and the Munich ChronoType Questionnaire. In addition, they indicated food products with which they had problems. RESULTS: The frequency of detection of FA among university students was twice as high as among schoolchildren. University students with FA were 20.2% more likely than schoolchildren to report the symptom 'use continues despite knowledge of adverse consequences,' and 13.7% more likely to report the symptom 'tolerance.' Schoolchildren and university students with FA most often noted that foods high in sugar and fat were problematic. University students with FA also reported that foods with a high carbohydrate content were problematic. CONCLUSION: In university students with FA, in comparison with schoolchildren with FA, there is an increase in list of problematic food products, mainly due to products with a high carbohydrate content. LEVEL OF EVIDENCE: Level V, cross-sectional descriptive study.

Impact of COVID-19 Lockdown in Eating Disorders: A Multicentre Collaborative International Study.

BACKGROUND: The COVID-19 lockdown has had a significant impact on mental health. Patients with eating disorders (ED) have been particularly vulnerable. AIMS: (1) To explore changes in eating-related symptoms and general psychopathology during lockdown in patients with an ED from various European and Asian countries; and (2) to assess differences related to diagnostic ED subtypes, age, and geography. METHODS: The sample comprised 829 participants, diagnosed with an ED according to DSM-5 criteria from specialized ED units in Europe and Asia. Participants were assessed using the COVID-19 Isolation Scale (CIES). RESULTS: Patients with binge eating disorder (BED) experienced the highest impact on weight and ED symptoms in comparison with other ED subtypes during lockdown, whereas individuals with other specified feeding and eating disorders (OFSED) had greater deterioration in general psychological functioning than subjects with other ED subtypes. Finally, Asian and younger individuals appeared to be more resilient. CONCLUSIONS: The psychopathological changes in ED patients during the COVID-19 lockdown varied by cultural context and individual variation in age and ED diagnosis. Clinical services may need to target preventive measures and adapt therapeutic approaches for the most vulnerable patients.

Food addiction in young adult residents of Russia: Associations with emotional and anthropometric characteristics.

The incidence of food addiction (FA) and associations between FA and anthropometric and psycho-emotional characteristics of young Russian adults were studied. In this study, 1,237 students (age, M = 20.6, SD = 4.6 years; 79% females) of universities located in four cities of Russia were attended. They provided demographics and filled in the Yale Food Addiction Scale (YFAS), the Dutch Eating Behavior Questionnaire, and the Zung Self-Rating Depression Scale. Data were analysed via Chi-squared tests, logistic regression analysis, and an analysis of covariance. 13.2% of participants met diagnostic criteria for FA based on the YFAS. On average, the participants reported 2.6 FA symptoms (SD = 1.5). FA was more commonly detected in females (OR = 1.86, 95% CI = 1.10, 3.15, p = .021). No relationship was found between age and the incidence of FA. Significant positive associations between FA, the severity of depression (OR = 2.31, 95% CI = 1.91, 2.80, p = .000), and an emotional eating behaviour (OR = 1.45, 95% CI = 1.20, 1.76, p = .000) were found. The waist-to-height ratio was found to be the anthropometric indicator most closely associated with FA (OR = 1.49, 95% CI = 1.27, 1.76, p = .000). HIGHLIGHTS: The prevalence of food addiction in the current sample was 13.2%. In young Russian adults, emotional eating behaviour and depression are associated with food addiction. In young Russian adults, the waist-to-height ratio is the anthropometric indicator most closely associated with food addiction.

Food addiction and symptoms of depression among inhabitants of the European North of Russia: Associations with sleep characteristics and photoperiod.

The purpose of this investigation was to study the sleep-wake rhythm characteristics of young persons with food addiction (FA) and symptoms of depression. A total of 2,360 young persons living in northern European Russia were included in the study. The average age of the respondents (± standard deviation [SD]) was 17.9 [4.6] years (66.6% female). Each participant provided personal data and filled in three questionnaires: the Munich Chronotype Questionnaire, the Zung Self-Rating Depression Scale, and the Yale Food Addiction Scale. FA was detected in 8.9% of respondents, and moderate-to-severe symptoms of depression were detected in 16.7% of respondents. FA and depressive symptoms were more often detected in females. Age and body mass index were shown to be significantly associated with FA. There were positive associations between the time of sunrise and FA and depressive symptoms. Persons who had symptoms of depression also tended to have a later chronotype, lower sleep efficiency, later sleep onset, higher sleep inertia, and greater sleep latency on school days. A positive relationship between FA and the time of sleep onset on school days was also revealed. Thus, the results indicate that prolonged wakefulness in the evening after sunset was associated with FA.

Age-Dependent Changes of the Temporal Order--Causes and Treatment.

This review summarizes current knowledge on deteriorations in temporal order with advanced age. Changes of the overt rhythms will be described but also their putative causes and possible treatments of the disturbances. In aging animals and humans, all rhythm characteristics change. The most prominent changes are a decrease of circadian amplitude, leading to an extra-circadian dissemination (ECD), and a diminished ability to synchronize with the periodic environment. ECD is a shift from circadian to ultradian and infradian frequencies, accompanied by the loss of day-to-day phase stability. Responsiveness to photic and non-photic cues is decreased. As a consequence, both internal and external temporal order are disturbed not only under steady-state conditions but and even more markedly after changes in the periodic environment or following stressful events. Many of the changes seem to occur within the suprachiasmatic nucleus (SCN), the central circadian pacemaker, itself. The number of functioning neurons decreases with advancing age as does the coupling between them. Accordingly, the SCN generates a weaker and less stable circadian signal, insufficient to entrain peripheral oscillators properly or to regulate body functions rhythmically. However, age-dependent disturbances in peripheral organs must also be considered. These changes may occur at different ages, thus causing further internal desynchronization. Several possibilities exist with regard to treating circadian disruptions or at least minimizing their consequences for health and fitness and preventing sleep disturbances. Benefits of bright light, melatonin and other chronobiotics, physical activity, social contacts and regular feeding schedules in preserving the temporal order of aged organisms are discussed.

Daily Melatonin Administration Attenuates Age-Dependent Disturbances of Cardiovascular Rhythms.

Increased blood pressure and reduced robustness of circadian rhythms are frequently reported in elderly subjects. The present study was aimed to investigate whether such changes can be reversed by daily melatonin ingestion. 97 normotensive and hypertensive volunteers of both genders and 63 to 91 years old participated. They lived in the Tyumen Elderly Veteran House on a self-chosen sleep-wake regimen to suit their personal convenience. The experiment lasted for three weeks. After one control week, part of the group (n=63) received 1.5 mg melatonin (Melaxen(TM)) each day at 22:30 h for two weeks. The other 34 subjects were placebo-treated. Systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) were measured using semi-automated devices at 03:00, 08:00, 11:00, 14:00, 17:00, 23:00 h each day of the first and the third week. Specially trained personnel made the measurements, taking care not to disturb subjects' sleep. Rhythm characteristics were estimated by means of single and population-mean cosinor analyses. Bingham test was used to compare rhythm parameters between groups and investigated physiologic variables. The 24-h HR rhythm was monophasic as described in other studies for young subjects though with a steeper increase in the morning. The daily SBP and DBP rhythms were bimodal. In reference to previously reported data of younger subjects, mean blood pressure of our cohort was elevated, particularly the nocturnal fall was less pronounced. Also, the overall SBP variability was higher as was the percentage of the 12-h component. Both values and also the SBP and DBP levels were reduced during melatonin treatment. The hypotensive effect of melatonin was most pronounced between 3:00 and 8:00 in the morning, i.e. at the time of the highest risk of adverse cardiovascular events, and in subjects with highest BP values before treatment. Moreover, the morning increase of HR was gentler what could have been of additional benefit. Melatonin has a direct hypotensive effect. Also, it stabilizes the internal temporal order enhancing the circadian component and the synchronization between rhythms of different physiological functions. This may further improve health and welfare of elderly subjects and particularly of those with hypertension. Taken together our data show the usefulness of melatonin for adjuvant medication.