Chronobiology International最新文献

Multiple studies have shown that individuals with an evening chronotype tend to report greater mental health problems, such as higher levels of depression and reduced well-being, compared to those with a morning chronotype. The adverse outcomes associated with eveningness appear to be linked to a combination of biological, social, and psychological factors. In the present study, the relationship between chronotype and two emotion regulation strategies: cognitive reappraisal and expressive suppression was invastigated. Furthermore, it was explored whether these strategies mediate the association between chronotype and indicators of mental health and well-being. Participants completed the Composite Scale of Morningness (CSM), and based on the established chronotype cut-off criteria, 76 individuals were classified as morning types and 81 as evening types. The total sample consisted of 157 participants (107 women, 50 men), aged 19-42 years (M ± SD: 25.12 ± 4.53). All participants completed questionnaires assessing emotion regulation strategies, depressive symptoms, life satisfaction, and positive and negative affect. Results show that evening types scored lower in cognitive reappraisal and well-being, and higher in expressive suppression and depressive symptoms. Controlling for age and gender, significant mediation effects were found, showing that the relationship between chronotype and depressive symptoms and between chronotype and subjective well-being might stem from lower cognitive reappraisal and higher expressive suppression among evening types. These findings suggest that adaptive emotion regulation strategies can positively impact well-being and reduce depressive symptoms, especially among evening types and highlight the importance of targeted interventions to improve emotion regulation strategies in this population.

This study aimed to investigate the chronobiological effects of exercise timing, specifically morning versus evening sessions, on biochemical responses in elite boxers. While both high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) protocols were applied, the primary focus was to examine how the time-of-day influences markers of muscle damage, oxidative stress, and hormonal activity. Twenty-one elite male boxers completed four exercise sessions, two HIIT and two MICT, conducted in the morning and evening on separate days. Venous blood samples were collected immediately after each exercise session and again one-hour post-exercise. A 3 × 2 × 2 mixed-design ANOVA with repeated measures was used to analyze the effects of exercise type, time of day, and sampling time on biochemical markers. Significant differences were observed in all muscle and cardiac output biomarkers (LDH, CK, CK-MB, TnT, MB) across sampling times (rest, immediately post-exercise, and one-hour post-exercise). Additionally, CK levels showed a significant difference based on the time of day, with higher values recorded in evening sessions. Regarding oxidative stress parameters, a significant three-way interaction (exercise type × time of day × sampling time) was observed for malondialdehyde (MDA), a serum oxidant marker. IL-6 levels differed significantly by both time of day, with higher levels observed in morning sessions and sampling time, with elevated concentrations immediately after and 1 hour after exercise compared to rest. A significant interaction between time of day and sampling time was also detected for IL-6. Based on the findings of this study, both HIIT and MICT appear to induce more favorable biochemical responses when performed in the morning. Morning exercise sessions were associated with reduced markers of muscle damage, oxidative stress, and pro-inflammatory activity compared to evening sessions. Therefore, morning exercise may be recommended to optimize recovery, minimize physiological strain, and support overall athletic performance in elite athletes.

Although delay-based shiftwork/jetlag schedules are often considered less disruptive than advances and are increasingly adopted in occupational settings, their long-term impact on physiological homeostasis remains underexplored. In this study, we investigated the consequences of repeated phase delays on circadian alignment, oxidative balance, endocrine function, and systemic inflammation in the diurnal rodent Funambulus pennantii. Animals were kept either under a stable 12:12 hour light-dark (LD) cycle or subjected to a successive delay rotational shift (SDRS) schedule for 28 days. In the SDRS schedule, the light phase was delayed by 8 hours every two days, and every seventh day, animals were returned to the normal LD cycle for rest. SDRS exposure led to marked circadian misalignment, evident from disrupted and desynchronized locomotor activity rhythms. Biochemical analyses revealed reduced serum melatonin and antioxidant enzyme activity (SOD, CAT), along with elevated corticosterone levels, indicating stress induction. Moreover, animals under SDRS showed significant increases in pro-inflammatory cytokines (TNF-α, IL-6, IL-1β), highlighting immune activation. Our results highlight that delay-based shift schedules, often considered less harmful, can significantly impair physiological resilience, warranting a re-evaluation of their perceived safety due to their stress and inflammatory effects in diurnal systems.

Lung cancer remains one of the most fatal cancers, with cigarette smoke (CS) exposure being a major risk factor due to its role in triggering oxidative stress. Disruption of circadian rhythms, increasingly common in modern lifestyles, has also been linked to cancer progression. Targeting both oxidative imbalance and circadian disruption may offer a more effective therapeutic approach. Toluquinol (TQ), a compound derived from marine fungi, has shown promising anti-tumor activity and potential relevance in circadian-based cancer strategies. The current study investigated the role of TQ as a potential circadian medicine in modulating the dysregulated circadian-regulatory gene expression in the CS-exposed NCI-H23 lung adenocarcinoma cell line. Among the core circadian regulatory genes, NR1D1 plays a crucial role as a transcriptional repressor, involved in maintaining the circadian rhythm, regulating redox homeostasis, and modulating inflammation. Dysregulation of NR1D1 has been linked to cancer progression and poor prognosis in lung cancer. This study offers valuable insights into the impact of CS on NR1D1 gene regulation and its role in lung cancer development, which is mediated through disrupted redox balance and inflammation, while highlighting the potential therapeutic role of TQ in mitigating this process.

We aimed to investigate whether bright light (BL) exposure affects sympathovagal activity in controlling heart rate (HR) before and after exercise. Eighteen healthy men (28 ± 4 years) underwent two experimental conditions: one under BL (5000 lux) and another under dim light (DL < 8 lux). In both conditions, subjects performed an aerobic exercise bout (cycle ergometer, 30 min at 50-60% of HRreserve). HR (electrocardiography) and respiratory rate (piezoelectric belt) were initially assessed at baseline light (500 lux). Measurements were repeated before and 10 min after the exercise in both light conditions, BL and DL. Cardiac autonomic modulation was evaluated using spectral analysis of HR variability. Before exercise, DL did not change HR but decreased low- to high-frequency ratio of HR variability (LF/HF_RR, DL = -0.35 ± 0.43 vs. BL = +0.00 ± 0.55, p < 0.01). From pre- to post-exercise, HR increased similarly, while LF/HF_RR increase was greater in DL than BL (+1.12 ± 0.87 vs. +0.60 ± 0.98, p = 0.04). Contrary to our hypothesis, in healthy men, BL did not exacerbate HR and cardiac sympathovagal balance. However, DL exposure decreased pre-exercise cardiac sympathovagal balance, a difference that no longer persisted postexercise.

Light serves as the main synchroniser of the circadian system. The amount of light and its spectral distribution throughout the day influence hormonal secretion and sleep-wake regulation. There is a knowledge gap regarding the impact of the spectrum and intensity reduction of short-wavelength light during the day on circadian system outputs. In the present study, 23 participants spent 5 working days in the reference office with full-spectrum lighting. In the experimental week, participants spent five working days in the office with reduced intensity and short-light spectrum up to 500 nm. We measured melatonin, cortisol, and salivary alpha-amylase (sAA) activity in morning and evening saliva under dim light or light exposure (LE) and sleep by wrist actigraphy. Daylight impacted sleep quality only in females. The melatonin did not differ due to a changed daylight, but the LE had a stronger suppressive effect during the experimental week. The cortisol in the morning was higher in females, with no differences between weeks. To conclude, modified daylight has an impact on sleep quality without significant hormonal or sAA changes. LE before sleep can influence melatonin and sleep quality depending on the previous light history with high interindividual differences.

Circadian dysregulation is implicated in Major Depressive Disorder (MDD). This study investigated the mediating roles of sleep disturbances and somatic symptoms in the circadian preference-depression relationship and explored moderating effects of NPAS2 variants in 257 MDD patients. The Hamilton Rating Scale for Depression (HAMD-17,17-item clinician-rated measure of depression severity), Morningness-Eveningness Questionnaire (MEQ, circadian preference scale), Pittsburgh Sleep Quality Index (PSQI, sleep quality measure), and Depression and Somatic Symptoms Scale (DSSS, somatic symptom inventory) were obtained in all subjects. Genotypes of single nucleotide polymorphisms (SNPs) of NPAS2 were determined by the PCR and MassArray SNP sequencing analysis. Spearman's correlation, bootstrap mediation, and moderated mediation analyses revealed that sleep disturbances and somatic symptoms sequentially mediated the circadian preference-depression link (preference→sleep: β = -0.075,p = 0.002; sleep→somatic: β = 0.711,p < 0.001; somatic→depression: β = 0.216,p < 0.001). NPAS2 variants moderated these effects: rs3768984 strengthened eveningness-sleep associations (β = 2.944,p < 0.05), while rs3811561 showed similar amplification (β = 3.942,p < 0.05). Rs3768984 additionally moderated the mediation pathway (β = -0.054,95%CI[-0.09,-0.02]). These findings elucidate mechanistic pathways connecting circadian rhythms and MDD, highlighting NPAS2 as a genetic moderator, which may inform targeted interventions. Future studies could explore circadian genetic influences on personalized depression interventions.

The African fig fly, Zaprionus indianus, is an invasive pest of global concern, infesting over 80 crop species - including high-value fruits such as figs, strawberries, and guavas - and driving significant economic losses. Its ecological success is closely linked to circadian-regulated mating behavior, which enhances reproductive efficiency and fosters adaptability to diverse environments. Like the popular model organism Drosophila melanogaster, Z. indianus exhibits robust locomotor rhythms. A key feature of the circadian clock is its ability to anticipate predictable events, such as light-dark transitions, by gradually increasing or decreasing activity in advance. Mating rhythm is uniquely synchronized to light cycles: mating peaks show anticipation of both lights-on and lights-off transitions, with lights-off anticipation persisting even under long photoperiods (16-h light:8-h dark), suggesting circadian control. Remarkably, Z. indianus rapidly adapts to simulated jetlag, underscoring its plasticity in shifting environments. A critical distinction from D. melanogaster is its persistently low mating activity under constant darkness, indicating an obligate light dependence for mating. This reliance on light cues, combined with circadian plasticity and rapid environmental acclimation, likely underpins its capacity to colonize ecologically diverse regions and expand its geographic range. These insights into Z. indianus's mating rhythm not only advance understanding of its invasive success but also offer actionable targets for disrupting its reproductive cycles, informing strategies to curb its spread and mitigate agricultural damage.

Therapy with local anesthetics (TLA) is known to provide long-lasting pain relief, raising the question of whether these effects are mediated by changes in autonomic nervous system (ANS) regulation. To address this, we examined alterations in 24-h heart rate variability (HRV) following TLA treatment. Twenty-four patients undergoing TLA and 11 controls were monitored with Holter-ECG over 24 h. HRV parameters including mean heart rate (HR), root mean square of successive differences (RMSSD), stress index (SI), low- and high-frequency power, and total power were calculated in 15-min epochs. Changes were analyzed separately for the day and subsequent night, and the standard deviation of change between consecutive 15-min intervals was introduced as an additional parameter. TLA was associated with significant shifts in HRV within 24 h: HR and SI decreased, whereas RMSSD and low-frequency power increased, with effects most pronounced during the night. Moreover, the variability of changes between epochs was reduced across several parameters, particularly HR, RMSSD, and SI, suggesting a "smoothing" effect in HRV dynamics. These findings indicate that 24-h HRV monitoring can capture autonomic effects of TLA beyond its immediate analgesic action. The reduction of variability in HRV changes introduces a novel metric for assessing ANS modulation, offering new insight into the mechanisms and therapeutic potential of TLA.

This study examines how dietary nutrient patterns vary among individuals with different chronotypes. In other words, this research explores the potential connections between nutrient intake and circadian rhythm. In this secondary data analysis, we used data from 3,072 adult participants (mean age: 30.16 y (SD = 10.92); 49.8% males) who completed a survey between September 2022 and July 2023. Chronotypes were assessed using the Morningness-Eveningness Questionnaire (MEQ), and dietary intake was measured through 24-h dietary recall. One-way ANOVA and Multinomial regression analysis were used to investigate the associations. The intermediate chronotype was the most common among participants (73% vs 13% early and 14% late chronotype). Unlike morning types, intermediate and evening chronotypes had similar demographic and dietary characteristics. Four nutrient patterns were identified: "Vit B-rich," "Plant-based," "Antioxidant," and "High-fat." "Vit B-rich pattern" was linked to a morning chronotype. Greater adherence to the "antioxidant pattern," characterized by nutrients such as vit A, vit C, and folate, was associated with a lower likelihood of being an evening type. Adherers of "high-fat pattern" were less likely to be intermediate types. "Plant-based" pattern characterized by fibre, magnesium, etc. was not associated with any chronotype. Morning chronotypes may gravitate toward or consume more foods rich in vit B. People with an intermediate chronotype may be less likely to follow a "high-fat" diet, and evening types may be less likely to follow an "antioxidant" diet. Longitudinal studies are needed to clarify the direction of the relationship between chronotype and dietary intake.