Chronobiology International最新文献

Chronotype refers to individual differences in the circadian phase that affect a person's biological and psychological functioning. One of the most useful tools for measuring chronotype in children aged 4 - 11 years is the Children's Chronotype Questionnaire (CCTQ). Therefore, due to the importance of measuring chronotype in children and also the lack of a standard scale in Iran, this study aimed to examine the reliability and validity of the Persian version of this questionnaire for children. The participants of this cross-sectional study were 272 Iranian children aged five to eleven years with their parents, selected by convenience sampling method. To collect data, all participants completed the CCTQ and the Children's Sleep Habits Questionnaire (CSHQ), which were examined by the researchers for their construct and concurrent validity. Over a period of three weeks, 50 mothers participated in a test of the test-retest reliability of the CCTQ. During this time, their sleep patterns were monitored using a sleep diary to test for reliability. The Cronbach's alpha of the CCTQ-M/E was 0.71. Test-retest reliability using the Spearman correlation coefficient between two observations with an interval of three weeks was 0.83. The MSFsc index was significantly correlated with M/E, CT, and most of the parent-reported sleep/wake parameters. In addition, the three indicators of the CCTQ were significantly associated with most of the sleep/wake parameters of the sleep diary and the components of the CSHQ. The Persian version of the CCTQ has desirable psychometric properties for the assessment of chronotype in five- to eleven-year-old children.

Obesity, a major health concern, is influenced by an individual's genetic makeup and lifestyle factors (eating, sedentary lifestyle, and sleep disruptions) that affect circadian clock and metabolism. This study investigates the impact of Clock gene variants rs6843722 and rs4864548 on obesity measures in the Pakistani population. Genetic-behavior interaction studies have focused on Western populations, overlooking South Asians. We included 306 overweight/obese and 306 normal-weight controls, matched for age and gender. Anthropometric measures (BMI, waist circumference, waist-to-height ratio, and body fat percentage) were taken using standard procedures while behavioral data (dietary and sleep-related behaviors, shiftwork, and physical activity) was collected by questionnaire. Genotyping was performed by Taqman assays. Data was analyzed using SPSS 19.0. Rank-based inverse normal transformation was executed for quantitative non-normal variables. The linear regression revealed that both Clock gene variants interacted significantly with dietary and sleep-related behaviors and low physical activity, impacting adiposity measures regardless of age and gender. Shiftwork interacted specifically with rs6843722, increasing body fat percentage. This study indicates that Clock gene variants, when interacting with lifestyle factors, play a substantial role in increasing obesity risk highlighting the link between lifestyle choices and disturbances in circadian rhythms controlled by Clock gene variations, ultimately leading to obesity.

Anxiety is being increasingly linked to circadian rhythms, including chronotype, in addition to its intricate links with sleep quality. Emotional competence is thought to be a strong predictor of wellbeing and mental health. This study aimed to examine whether a combination of chronotype, sleep quality, and intrapersonal emotional competence can predict anxiety in emerging adults (aged 18-29), who have the greatest prevalence of adult anxiety. One hundred and seventeen participants completed self-report measures of chronotype, sleep quality, emotional competence, and anxiety. A multiple linear regression, with anxiety as the criterion variable, showed that while all predictors were significant, sleep quality was the strongest predictor of anxiety. A later chronotype, poorer sleep quality and lower intrapersonal emotional competence were related to higher anxiety. Thus, integrating intrapersonal emotional competence and chronotype considerations into interventions may address the interplay between sleep quality and anxiety in emerging adults more effectively.

The potential influence of circadian rhythm, seasonal variations, and alterations in meteorological parameters has been studied across various vascular events. However, there is a lack of evidence on the potential chronobiological impacts on thromboembolic events related to the most common peripheral aneurysm, the popliteal artery aneurysm (PAA). Data was obtained from a German PAA registry and the German Meteorological Service (Deutscher Wetterdienst). In this observational cohort study seasonality and chronobiology as well as associations with meteorological parameters of symptomatic PAA were investigated. In a multivariate logistic regression analysis, it was further analyzed whether meteorological parameters could distinguish asymptomatic from symptomatic patients in the registry. Of 1200 registered PAA, n = 142 PAA presented with acute limb ischemia between February 2011 and September 2022. More symptomatic patients (57.0%) presented to the hospital between January and June than in the second half of the year with a nadir in the fall season. Symptom onset was predominantly in the morning hours (39.5%). Atmospheric pressure and humidity values from the index dates diverged from a normal distribution showing a bimodal ("double-peak") configuration. Most patients developed symptoms after a reduction in temperatures compared to 1 or 2 d prior to the index date. However, we found evidence for an interaction between age and temperature difference, where the effects of a decreasing temperature fade with increasing age. Facing the complexity of individual-environment interactions, further investigations are needed to determine whether meteorological parameters are true risk modifiers or surrogates for seasonal differences and altered behaviors.

Melatonin is produced in the pineal gland under very tight control through the influences of light and the suprachiasmatic nucleus. As such, melatonin circulates in the blood at levels <3 pg/ml during the day and is only actively secreted at night reaching levels of approximately 100 pg/ml. As a consequence of binding to plasma proteins, free melatonin appears in saliva at approximately one third the plasma concentration. Measurement of melatonin is technically challenging because of these very low concentrations and while a number of commercial immunoassay kits are available and mass spectrometry assay methods have been published, not all are fit for purpose and can lead to unreliable conclusions. In this review I discuss the aspects of pineal melatonin production that saliva melatonin reflects, the factors influencing melatonin production or metabolism, saliva collection and analysis methods. Examples are provided of the appropriate use of saliva melatonin measurements; Dim Light Melatonin Onset (DLMO) assessment, impact of light on melatonin and the monitoring of rhythms prior to specific treatments. Examples of inappropriate use of saliva melatonin measurements are also provided including the use of poorly validated assays, morning saliva collections, attempts to stimulate melatonin, and linking specific illnesses to saliva melatonin levels.

Circadian rhythms are important biological contributors to health. Rest activity rhythms (RAR) are emerging as biomarkers of circadian behavior that are associated with chronic disease when abnormal. RAR have not yet been characterized in chronic kidney diseases (CKD). Leveraging the National Health and Nutrition Examination Survey (2011-2014), patients with CKD (n = 1114; Mean [95% CI]: Age, 50 [58-61] y; 52% female) were compared with non-CKD individuals (n = 5885; Age, 47 [46-48] y; 52% female). Actigraphy data were processed for RAR parameters including rhythmic strength (amplitude), the rhythm adjusted mean (mesor), the timing of peak activity (acrophase), activity regularity (inter-daily stability), and activity fragmentation (intra-daily variability). Cox regression was performed to assess RAR parameters for the prediction of all-cause mortality. Compared to non-CKD adults, patients with CKD had a lower rhythmic amplitude and mesor, and exhibited greater fragmentation and less day-to-day stability in RAR (ps < 0.001). Among CKD patients, a lower rhythmic amplitude (HR [95% CI]: 0.88 [0.82-0.96]; p < 0.001), a lower rhythm adjusted mean (0.87 [0.81-0.95]; p = 0.002), and a higher daily activity fragmentation (1.87 [1.10-3.18]; p = 0.023) were associated with an increased risk of all-cause mortality. Patients with CKD showed dampened rhythmic amplitudes and greater fragmentation of activity that were associated with a higher risk of all-cause mortality. These findings demonstrate a relationship between circadian disruption and prognosis in patients with CKD.

Plasma glucose spikes affect cardiac autonomic modulation resulting in a decrease of heart rate variability (HRV). We hypothesize that a later chronotype or a higher morning plasma melatonin level is associated with larger decreases of HRV following an early high glycaemic index (GI) breakfast. In persons with an early (n = 21) or a late (n = 15) chronotype who consumed a high GI breakfast at 7 a.m. glucose data were continuously monitored. Time domain HRV parameters were calculated from blood volume pulses derived by wireless wrist worn multisensor. HRV changes (values after minus values before breakfast) were associated with chronotype by multivariable linear regression adjusted for age, sex and baseline levels. Morning plasma melatonin levels were determined from samples drawn on the run-in day. Time domain parameters indicate a higher HRV before high GI breakfast in both chronotypes. A later chronotype tended to be associated with smaller decreases of mean interbeat intervals (p = 0.08) only; no associations were seen with morning melatonin levels. This exploratory analysis in a small sample provides a first indication that in young healthy adults later chronotype might be associated with reduced ANS activation following a high GI breakfast. Future studies should elucidate whether this indicates parasympathetic or sympathetic inhibition.

Actigraphy provides a unique method for objectively measuring sleep activity patterns, but confusion remains about how to use actigraphy data to determine chronotype. To determine the most suitable parameter, this study made a systematic comparison of actigraphy-derived parameters: the average midpoint of sleep of all record days (aMS-acti), cosine parameter (Bathyphase), and non-parametric parameter (L5-mid) in terms of the consistency with subjective chronotype parameters, test-retest reliability, and external validity. More importantly, we proposed multiple Munich Chronotype Questionnaire (MCTQ)-based actigraphy parameters: considering the difference between weekday (MSW-acti) with weekends (MSF-acti) and the sleep debt (MSFsc-acti). The study collected 5 days of actigraphy and scale data from 1,055 young adults, 138 of whom participated in the retest 2 years later. The results showed that, in terms of consistency with subjective chronotype, aMS-acti generally performed better than other actigraphy parameters. In addition, aMS-acti had the highest test-retest reliability and was more closely related to the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), and Self-Rating Depression Scale (SDS). The results suggest that the simplest parameter (aMS-acti) is superior to traditional cosine and non-parametric parameters and MCTQ-derived parameters for short-term assessment of chronotype.

The aim of the current study is to investigate whether the time of day at which exercise is performed affects metabolic, glucose and insulin responses to exercise in adults. Databases were searched for randomised controlled (parallel and crossover) trials with participants aged from 18 to 65 year, an intervention of any exercise carried out at a specific time of the day and compared to any exercise carried out at a different time of the day. From 2458 screened articles, 12 studies were included in the systematic review of which 5 studies were included in the meta-analyses which compared 24 h continuous glucose monitoring (CGM) data, between morning and afternoon/evening exercise, on the day exercise was performed (SMD = 0.12 [-0.22-0.46] p = 0.76) and the day after exercise (SMD = -0.02 [-0.36-0.33] p = 0.94. Similar findings were observed in the wider systematic review with a general unclear risk of bias and a low certainty in these data. The results indicate that there is no clear effect of the time of the day on metabolic responses to exercise and exercise at any time of day should be the goal of public health strategies.

This study investigated whether sleep-specific (e.g. chronotype) and traditional (e.g. resilience) protective factors were associated with reduced shift work disorder (SWD) risk and explored their role as moderators in the relationship between SWD risk and health. Shift workers (n = 126) participated in a cross-sectional study evaluating SWD risk (i.e. low vs. high; SWD-screening Questionnaire), mental health (Patient Health Questionnaire-9; Generalized Anxiety Disorder Questionnaire-7), physical health (Subjective Health Complaints Inventory), sleep (Pittsburgh Sleep Quality Index; Insomnia Severity Index; Epworth Sleepiness Scale), and protective factors (Resilience Scale; Social Provisions Scale; Survey of Perceived Organizational Support; Short Impulsive Behavior Scale; Circadian Type Inventory; reduced-Morningness-Eveningness Questionnaire). Logistic regressions revealed lower sleep languidity was associated with reduced odds (OR = 0.88 [0.79,0.96]) for having high SWD risk. Multiple regression analyses showed in shift workers with high social support or morningness, having high SWD risk was not associated with increased depression symptoms, or insomnia severity and poor sleep quality, respectively. Finally, in those with high or medium levels of perceived organizational support, high SWD risk was not associated with increased gastrointestinal and allergy complaints. Longitudinal research with larger samples is needed to confirm the moderating role of protective factors in the relationship between SWD risk and health.