Chronobiology International最新文献

Social jetlag (SJL) and, more recently, eating jetlag have been linked with an increased risk of non-communicable diseases. Here we aim to investigate lifestyle factors (diet, eating behavior, smoking, perceived stress, time spent sedentary/day) and social determinants (education level, employment status, and place of residence) associated with SJL corrected for sleep duration (SJLsc) and eating jetlag. Self-declared data on age, gender, lifestyle, and eating behavior were collected online from March 2021 to February 2022 of 432 adults. Principal component analysis was used to extract three dietary patterns (Prudent, Western, and Risky). Prevalence of SJLsc was 35.2%, with no significant difference between men and women (p = 0.558). Adults with SJLsc had significantly larger eating jetlag (56.0 min vs 41.2 min, p = 0.001). Increasing SJLsc duration was associated with an increased adherence to a Risky dietary pattern (standardized β coefficient = .165, p = 0.012); increasing eating jetlag duration was associated with an increased adherence to a Western dietary pattern (standardized β coefficient = .127, p = 0.039) and a shorter sleep duration (standardized βcoefficient = -0.147, p = 0.011). Among social determinants analyzed, only being a student or employed was associated with eating jetlag (standardized β coefficient = 0.125, p = 0.044), while none displayed any relationship with SJLsc. Our survey provides evidence on a risky behavior among young persons with SJLsc and eating jetlag, characterized by a higher alcohol consumption, and a diet rich in processed meat and high-fat food, eating during nights, and shorter sleep duration with potential long-term negative health outcomes.

The perception of short-term temporal intervals has been suggested to be modulated by the circadian clock, yet systematic studies investigating this relationship are scarce. In this study, we examined the diurnal variations in temporal reproduction around 2-3 seconds with different stimulus eccentricities. Eighteen female participants completed a visual temporal reproduction task at nine time points throughout the day. The results showed significant interactions between clock time and duration, implying diurnal rhythmic variations in temporal reproduction. The reproduction of shorter duration (1500 ms) was overestimated with its highest accuracy in the morning, while the reproduction of longer duration (4500 ms) was underestimated with an approximate 3-hour advancement in acrophase than the shorter duration (1500 ms). No significant eccentricity effects were observed, suggesting homogenous temporal processing across visual fields. The results suggest the presence of diurnal rhythms in the perception of short-term temporal durations, confirming a two-process model of time perception operating within a 2-3 second time window.

Circadian rhythms in the physiological and behavioral processes of humans play a crucial role in the quality of living and also in the magnitude of success and failure in various endeavors including competitive sports. The rhythmic activities of the body and performance in sportspersons do have a massive impact on their every cutthroat competition. It is essential to schedule sports activities and training of players according to their circadian typology and time of peak performance for improved performance and achievement. In this review, the focus is on circadian rhythms and diurnal variations in peak athletic performance in sportspersons. Accuracy and temporal variability in peak performance in an individual could be attributed to various factors, namely chronotype, time of the day, body temperature, jetlag, hormones, and prior light exposure. Circadian rhythm of mood, alertness, T-core, and ultimately athletic performance is not only affected by sleep but also by circadian variations in hormones, such as cortisol, testosterone, and melatonin. There are, however, a few reports that are not consistent with the conclusions drawn in this review. Nevertheless, circadian rhythm and performance among sportspersons and athletes are important areas of research. This review might be useful to the managers and policymakers associated with competitive sports and athletic events.

Temperature influences the survival, growth, and development of insects including the antlion. In the present study, we examined the 24-h rhythm in the pit-building behavior of the antlion larvae at three different temperature conditions, high (37°C), low (17°C), and room temperature (Control: 25.9 ± 0.2°C). We recorded pit-building activities by monitoring two variables: the Time Lag for the Initiation of Pit Reconstruction (TLIPR) after the demolition of the pit, and the Total Time for Pit Construction (TTPC). We monitored TLIPR and TTPC at four different time points with equidistant intervals (i.e. 08:00-10:00 h, 14:00-16:00 h, 20:00-22:00 h, and 02:00-04:00 h) each day over three consecutive days. We employed single Cosinor rhythmometry to evaluate the characteristics of 24-h rhythm in TLIPR and TTPC. We used one-way ANOVA to find out the effects of the temperature on TLIPR and TTPC. We detected a statistically significant 24-h rhythm in TLIPR at the group level, irrespective of the temperature conditions. 24-h rhythm in TTPC was abolished at high and low temperatures. Temperature significantly affected TLIPR and TTPC in general. It also significantly affected the mesor of the rhythms in both variables as well as the amplitude of TTPC. Finally, we noted that although high and low temperatures affected the pit-building behavior in general, the thermal conditions did not lead to a complete cessation of pit-building activities. The 24-h rhythmic pattern associated with TTPC is more susceptible to the effects of thermal regimes (17°C or 37°C) unlike that associated with TLIPR.

Sleep regularity and chronotype can affect health, performance, and overall well-being. This observational study examines how sleep regularity and chronotype affect sleep quality and cardiorespiratory metrics. Data was collected from 1 January 2019 through 30 December 2019 from over 330 000 Sleep Number smart bed users across the United States who opted into this at-home study. A pressure signal from the smart bed reflected bed presence, movements, heart rate (HR), and breathing rate (BR). Participants (mean age: 55.69 years [SD: 14.0]; 51.2% female) were categorized by chronotype (16.8% early; 62.2% intermediate, 20.9% late) and regularity of sleep timing. Participants who were regular sleepers (66.1%) experienced higher percent restful sleep and lower mean HR and BR compared to the 4.8% categorized as irregular sleepers. Regular early-chronotype participants displayed better sleep and cardiorespiratory parameters compared to those with regular late-chronotypes. Significant variations were noted in sleep duration (Cohen's d = 1.54 and 0.88, respectively) and restful sleep (Cohen's d = 1.46 and 0.82, respectively) between early and late chronotypes, particularly within regular and irregular sleep patterns. This study highlights how sleep regularity and chronotype influence sleep quality and cardiorespiratory metrics. Irrespective of chronotype, sleep regularity demonstrated a substantial effect. Further research is necessary to confirm these findings.

In modern 24-hour society, various round-the-clock services have entailed shift work, resulting in non-24-hour schedules. However, the extent of behavioral and physiological alterations by non-24-hour schedules remains unclear, and particularly, effective interventions to restore the circadian functions of non-24-hour shift workers are rarely explored. In this study, we investigate the effects of a simulated non-24-hour military shift work schedule on daily rhythms and sleep, and establish an intervention measure to restore the circadian functions of non-24-hour shift workers. The three stages of experiments were conducted. The stage-one experiment was to establish a comprehensive evaluation index of the circadian rhythms and sleep for all 60 participants by analyzing wristwatch-recorded physiological parameters and sleep. The stage-two experiment evaluated the effects of an intervention strategy on physiological rhythms and sleep. The stage-three experiment was to examine the participants' physiological and behavioral disturbances under the simulated non-24-hour military shift work schedule and their improvements by the optimal lighting apparatus. We found that wristwatch-recorded physiological parameters display robust rhythmicity, and the phases of systolic blood pressures and heart rates can be used as reliable estimators for the human body time. The simulated non-24-hour military shift work schedule significantly disrupts the daily rhythms of oxygen saturation levels, blood pressures, heart rates, and reduces sleep quality. Administration of blue light in the morning and no blue-ray light in the evening improves the amplitude and synchronization of daily rhythms of the non-24-hour participants. These findings demonstrate the harmful consequences of the non-24-hour shift work schedule and provide a non-invasive strategy to improve the well-being and work efficiency of the non-24-hour shift population.

Disturbed sleep and circadian disruption are reported to increase the risk of infections. People with an evening circadian preference and night workers typically report insufficient sleep, and the aims of the present study were to investigate possible associations between various types of infections and circadian preference and shift work status. Data were collected from an online cross-sectional survey of 1023 participants recruited from the Norwegian practice-based research network in general practice - PraksisNett. The participants completed questions about circadian preference (morning type, intermediate type, evening type), work schedule (day work, shift work without nights, shift work with night shifts), and whether they had experienced infections during the last three months (common cold, throat infection, ear infection, sinusitis, pneumonia/bronchitis, COVID-19, influenza-like illness, skin infection, gastrointestinal infection, urinary infection, venereal disease, eye infection). Data were analyzed with chi-square tests and logistic regression analyses with adjustment for relevant confounders (gender, age, marital status, country of birth, children living at home, and educational level). Results showed that evening types more often reported venereal disease compared to morning types (OR = 4.01, confidence interval (CI) = 1.08-14.84). None of the other infections were significantly associated with circadian preference. Shift work including nights was associated with higher odds of influenza-like illness (OR = 1.97, CI = 1.10-3.55), but none of the other infections. In conclusion, neither circadian preference nor shift work seemed to be strongly associated with risk of infections, except for venereal disease (more common in evening types) and influenza-like illness (more common in night workers). Longitudinal studies are needed for causal inferences.

Circadian rhythm and sleep are related to health, but there is little data on the relationship between the sleep/wake rhythm and mood at different stages of pregnancy. The aim of this prospective, longitudinal study was to investigate the associations of circadian rhythm and sleep disruptions with stress and depression among women in early and late pregnancy. The participants were 26 pregnant women. Objective and subjective estimations of circadian rhythm and sleep were administered, namely actigraphy and the Biological Rhythms Interview of Assessment in Neuropsychiatry in the form of a questionnaire. The Perceived Stress Scale and the Edinburgh Postnatal Depression Scale were also used. Subjectively perceived circadian rhythm disruptions were positively related to stress. Tendency to maintain a regular rhythm of sleep and activity in early pregnancy and subjectively perceived disruptions of circadian rhythms in late pregnancy were positively associated with prenatal depression in late pregnancy. Sleep fragmentation and long time spent in bed at night in early pregnancy were positively associated with stress and depression in late pregnancy. The results suggest the importance of flexibility and the ability to adapt one's circadian activities to the demands of the situation of pregnancy-related changes in lifestyle. They also indicate the significance of good-quality uninterrupted night sleep in early pregnancy.

Multiple aspects of brain functioning, including arousal, motivation, and cognitive performance, are governed by circadian rhythmicity. Although the recent rise in the use of magnetic resonance imaging (MRI) has enabled investigations into the macroscopic correlates of the diurnal brain processes, neuroanatomical studies are scarce. The current work investigated how time-of-day (TOD) impacts white (WM) and grey matter (GM) volumes using voxel-based morphometry (VBM) in a large dataset (N = 72) divided into two equal, comparable subsamples to assess the replicability of effects. Furthermore, we aimed to assess how the magnitude of these diurnal differences was related to actigraphy-derived indices of sleep health. The results extend the current knowledge by reporting that TOD is predominantly associated with regional WM volume decreases. Additionally, alongside corroborating previously observed volumetric GM decreases, we provide the first evidence for positive TOD effects. Higher replicability was observed for WM, with the only two replicated GM clusters being volumetric increases in the amygdala and hippocampus, and decreases in the retrosplenial cortex, with the latter more pronounced in individuals with shorter sleep times. These findings implicate the existence of region-specific mechanisms behind GM effects, which might be related to cognitive processes taking place during wakefulness and homeostatic sleep pressure.

We measured total anti-SARS-CoV-2 receptor-biding domain (RBD) antibodies in 249 healthcare workers (mean age: 44 ± 13 years; 151 women), who received the first dose of mRNA-based Comirnaty COVID-19 vaccine at different times of the day. Compared with the reference vaccination time point (i.e. <10:00h), vaccine injection at the following times of day elicited a comparable response (all p > 0.05). Under our experimental conditions, we can therefore exclude a possible influence of the timing of primary mRNA-based COVID-19 vaccination on the levels of total anti-SARS-CoV-2 antibodies.