Pub Date : 2026-01-29DOI: 10.1080/07420528.2026.2623040
Vincent Bourgon, Joshua Fournier, Félix-Gabriel Duval, Geneviève Forest
There is a growing recognition of the impact of circadian rhythms on athletic performance, when teams crossing multiple time zones play at a different circadian alignment than their opponents. This study aimed to examine the association between circadian differences between NHL teams and increased penalty behavior. Data from NHL games played between 2009 and 2021 (n = 27,642) were analysed. A travel-adjusted time zone was computed for both teams, from which a Difference in alignment between teams was calculated: Ahead, same as, and behind opponent. A one-way ANOVA was done with the Difference in alignment on the number and minutes of penalties and results were significant for both variables. Post-hoc analyses revealed that teams behind received significantly fewer penalties (p < 0.001) than teams ahead or in the same time zone as their opponents (p < 0.001) and had fewer penalty minutes than teams who were in the same time zone as their opponent (p = 0.002). These results suggest that teams playing at a later point in their circadian cycle than their opponents were given more penalties, which highlights the importance of professional organisations understanding the potential influence of circadian rhythms and travel on behavior and performance outcomes during games.
{"title":"Travel-induced circadian shift between teams influences penalties in the National Hockey League.","authors":"Vincent Bourgon, Joshua Fournier, Félix-Gabriel Duval, Geneviève Forest","doi":"10.1080/07420528.2026.2623040","DOIUrl":"https://doi.org/10.1080/07420528.2026.2623040","url":null,"abstract":"<p><p>There is a growing recognition of the impact of circadian rhythms on athletic performance, when teams crossing multiple time zones play at a different circadian alignment than their opponents. This study aimed to examine the association between circadian differences between NHL teams and increased penalty behavior. Data from NHL games played between 2009 and 2021 (<i>n</i> = 27,642) were analysed. A travel-adjusted time zone was computed for both teams, from which a Difference in alignment between teams was calculated: Ahead, same as, and behind opponent. A one-way ANOVA was done with the Difference in alignment on the number and minutes of penalties and results were significant for both variables. Post-hoc analyses revealed that teams behind received significantly fewer penalties (<i>p</i> < 0.001) than teams ahead or in the same time zone as their opponents (<i>p</i> < 0.001) and had fewer penalty minutes than teams who were in the same time zone as their opponent (<i>p</i> = 0.002). These results suggest that teams playing at a later point in their circadian cycle than their opponents were given more penalties, which highlights the importance of professional organisations understanding the potential influence of circadian rhythms and travel on behavior and performance outcomes during games.</p>","PeriodicalId":10294,"journal":{"name":"Chronobiology International","volume":" ","pages":"1-5"},"PeriodicalIF":1.7,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146084472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-28DOI: 10.1080/07420528.2026.2621239
Mohammad Adnan Op, Ishant Kumar Arora, Moazzam Hussain Khan
Chronotype refers to an individual's natural preference for being active in the morning or evening and may influence physical and cognitive performance. This study examines its impact on balance, lower limb power, hand-eye coordination, and self-efficacy in collegiate athletes across morning and evening sessions. A total of 54 athletes (27 morning-type, 27 evening-type) completed physical, cognitive, and self-efficacy tests in two-time windows: early morning (07:00h-10:00h) and late afternoon (15:00h-18:00h) to assess time-of-day effects on performance. Morning chronotype exhibited superior performance in balance and lower limb power during morning sessions, while evening chronotypes excelled in these measures during evening sessions. Hand eye coordination and self-efficacy did not show significant changes across chronotypes or times of day, suggesting these abilities are less affected by the body's internal clock. These findings highlight the potential benefits of tailoring training schedules to an athlete's chronotype to enhance performance.
{"title":"Chronotype and its impact on balance, hand-eye coordination, lower limb power and self-efficacy among collegiate athletes: An observational study.","authors":"Mohammad Adnan Op, Ishant Kumar Arora, Moazzam Hussain Khan","doi":"10.1080/07420528.2026.2621239","DOIUrl":"https://doi.org/10.1080/07420528.2026.2621239","url":null,"abstract":"<p><p>Chronotype refers to an individual's natural preference for being active in the morning or evening and may influence physical and cognitive performance. This study examines its impact on balance, lower limb power, hand-eye coordination, and self-efficacy in collegiate athletes across morning and evening sessions. A total of 54 athletes (27 morning-type, 27 evening-type) completed physical, cognitive, and self-efficacy tests in two-time windows: early morning (07:00h-10:00h) and late afternoon (15:00h-18:00h) to assess time-of-day effects on performance. Morning chronotype exhibited superior performance in balance and lower limb power during morning sessions, while evening chronotypes excelled in these measures during evening sessions. Hand eye coordination and self-efficacy did not show significant changes across chronotypes or times of day, suggesting these abilities are less affected by the body's internal clock. These findings highlight the potential benefits of tailoring training schedules to an athlete's chronotype to enhance performance.</p>","PeriodicalId":10294,"journal":{"name":"Chronobiology International","volume":" ","pages":"1-8"},"PeriodicalIF":1.7,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146060643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-27DOI: 10.1080/07420528.2026.2621243
Elena Osipova, Natalia Pankova, Vera Pavlova, Daniil Sizov, Svetlana Zhdanova, Artem Dushko, Evgeny Izvekov, Viacheslav V Krylov
Circadian rhythms in the vertical distribution of adult zebrafish and their potential sensitivity to geomagnetic fluctuations remain poorly characterized. In this study, we investigated Danio rerio maintained under different light-dark regimes and exposed to natural diurnal geomagnetic variation (~30 nT, with a 24-h period) or slow magnetic oscillations (~100-150 nT, with periods of 26.8, 33.76, or 36 h). Behavioral endpoints included the proportion of time spent in the upper versus lower part of the water column and the frequency of midline crossings. Under standard and modified light-dark cycles, zebrafish exhibited a robust rhythm, occupying upper layers during darkness and shifting downward during the light phase. This pattern differs from that described for zebrafish in natural environments and probably reflects long-term adaptation to aquaculture. Under constant illumination, free-running rhythms with periods close to 24 h persisted across groups. Analysis of midline crossing frequency revealed a significant ~33.8 h rhythm in fish pre-exposed to the atypical 24:12 h light-dark cycle, consistent with the periodicity of the applied magnetic oscillation. These results suggest that geomagnetic fluctuations may function as an extremely weak zeitgeber compared to the dominant influence of the photoperiod. Prior exposure to an atypical light-dark regime, which may have reset the biochemical processes sustaining the endogenous oscillators, appears to be required for the manifestation of magnetically driven rhythm entrainment.
{"title":"Rhythm in the vertical distribution of <i>Danio rerio</i> under photic and magnetic zeitgebers.","authors":"Elena Osipova, Natalia Pankova, Vera Pavlova, Daniil Sizov, Svetlana Zhdanova, Artem Dushko, Evgeny Izvekov, Viacheslav V Krylov","doi":"10.1080/07420528.2026.2621243","DOIUrl":"https://doi.org/10.1080/07420528.2026.2621243","url":null,"abstract":"<p><p>Circadian rhythms in the vertical distribution of adult zebrafish and their potential sensitivity to geomagnetic fluctuations remain poorly characterized. In this study, we investigated <i>Danio rerio</i> maintained under different light-dark regimes and exposed to natural diurnal geomagnetic variation (~30 nT, with a 24-h period) or slow magnetic oscillations (~100-150 nT, with periods of 26.8, 33.76, or 36 h). Behavioral endpoints included the proportion of time spent in the upper versus lower part of the water column and the frequency of midline crossings. Under standard and modified light-dark cycles, zebrafish exhibited a robust rhythm, occupying upper layers during darkness and shifting downward during the light phase. This pattern differs from that described for zebrafish in natural environments and probably reflects long-term adaptation to aquaculture. Under constant illumination, free-running rhythms with periods close to 24 h persisted across groups. Analysis of midline crossing frequency revealed a significant ~33.8 h rhythm in fish pre-exposed to the atypical 24:12 h light-dark cycle, consistent with the periodicity of the applied magnetic oscillation. These results suggest that geomagnetic fluctuations may function as an extremely weak zeitgeber compared to the dominant influence of the photoperiod. Prior exposure to an atypical light-dark regime, which may have reset the biochemical processes sustaining the endogenous oscillators, appears to be required for the manifestation of magnetically driven rhythm entrainment.</p>","PeriodicalId":10294,"journal":{"name":"Chronobiology International","volume":" ","pages":"1-12"},"PeriodicalIF":1.7,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146060710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-25DOI: 10.1080/07420528.2026.2619014
Hilal Ertürk Yaşar
This study investigated the relationships between chronotype, physical activity, and fluid and nutrient intake in healthy young adults. A total of 935 participants (66.6% female), aged 18-30, were classified into morning, intermediate, or evening chronotypes using the Morningness - Eveningness Questionnaire. Physical activity was categorized as active or sedentary based on self-reported exercise frequency and duration. Nutrient intake was measured using 24-h dietary recall, a Food Frequency Questionnaire, and a structured fluid intake survey. Data collection occurred in June and July to minimize seasonal effects. Physically active individuals consumed significantly more water daily than sedentary participants (p < 0.001, η2 = .088). They also reported higher intake of black tea, herbal tea, iced tea, Turkish coffee, and milk (all p < 0.001). Evening chronotype individuals consumed significantly less black tea and milk (both p < 0.001) but showed no significant difference in water intake (p = 0.088). Evening types were also linked to lower consumption of red meat (B = -0.38, p = 0.034) and fish (B = -0.58, p = 0.002), while the decrease in egg consumption was not statistically significant (p = 0.082). These results suggest that morning chronotype and physical activity correlate with healthier fluid intake patterns, whereas evening chronotype may reduce intake of some animal proteins. Overall, hydration and diet appear influenced by lifestyle and biological rhythms. The study highlights the need for personalized nutrition counseling that considers chronotype and physical activity to promote healthier behaviors.
本研究调查了健康年轻人的睡眠类型、身体活动、液体和营养摄入之间的关系。共有935名参与者(66.6%为女性),年龄在18-30岁之间,使用晨型-晚型问卷将他们分为早晨型、中间型和晚上型。根据自我报告的运动频率和持续时间,身体活动被分为活跃或久坐。采用24小时饮食回顾、食物频率问卷和结构化液体摄入调查来测量营养摄入。数据收集在6月和7月进行,以尽量减少季节性影响。经常运动的人每天消耗的水明显多于不运动的人(p 2 = 0.088)。他们还报告说,红茶、凉茶、冰茶、土耳其咖啡和牛奶的摄入量更高(p p p = 0.088)。夜猫子还与红肉(B = -0.38, p = 0.034)和鱼(B = -0.58, p = 0.002)的消费量减少有关,而鸡蛋消费量的减少没有统计学意义(p = 0.082)。这些结果表明,早晨的睡眠类型和身体活动与更健康的液体摄入模式相关,而晚上的睡眠类型可能会减少某些动物蛋白质的摄入。总的来说,补水和饮食似乎受到生活方式和生物节律的影响。该研究强调了个性化营养咨询的必要性,该咨询考虑了时间类型和身体活动,以促进更健康的行为。
{"title":"Chronotype and physical activity associations with fluid and dietary habits in young adults.","authors":"Hilal Ertürk Yaşar","doi":"10.1080/07420528.2026.2619014","DOIUrl":"https://doi.org/10.1080/07420528.2026.2619014","url":null,"abstract":"<p><p>This study investigated the relationships between chronotype, physical activity, and fluid and nutrient intake in healthy young adults. A total of 935 participants (66.6% female), aged 18-30, were classified into morning, intermediate, or evening chronotypes using the Morningness - Eveningness Questionnaire. Physical activity was categorized as active or sedentary based on self-reported exercise frequency and duration. Nutrient intake was measured using 24-h dietary recall, a Food Frequency Questionnaire, and a structured fluid intake survey. Data collection occurred in June and July to minimize seasonal effects. Physically active individuals consumed significantly more water daily than sedentary participants (<i>p</i> < 0.001, η<sup>2</sup> = .088). They also reported higher intake of black tea, herbal tea, iced tea, Turkish coffee, and milk (all <i>p</i> < 0.001). Evening chronotype individuals consumed significantly less black tea and milk (both <i>p</i> < 0.001) but showed no significant difference in water intake (<i>p</i> = 0.088). Evening types were also linked to lower consumption of red meat (B = -0.38, <i>p</i> = 0.034) and fish (B = -0.58, <i>p</i> = 0.002), while the decrease in egg consumption was not statistically significant (<i>p</i> = 0.082). These results suggest that morning chronotype and physical activity correlate with healthier fluid intake patterns, whereas evening chronotype may reduce intake of some animal proteins. Overall, hydration and diet appear influenced by lifestyle and biological rhythms. The study highlights the need for personalized nutrition counseling that considers chronotype and physical activity to promote healthier behaviors.</p>","PeriodicalId":10294,"journal":{"name":"Chronobiology International","volume":" ","pages":"1-12"},"PeriodicalIF":1.7,"publicationDate":"2026-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146046198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-10-30DOI: 10.1080/07420528.2025.2579142
Ayla Canlı İşler, Mihriban Dalkıran
This study compared screen time, circadian rhythm patterns, and sleep quality in adults diagnosed with attention-deficit/hyperactivity disorder (ADHD) and healthy controls, and examined the associations among these parameters. The sample included 100 adults with ADHD and 100 healthy controls. Participants were assessed using a sociodemographic data form, the Diagnostic Interview for ADHD in Adults (DIVA 2.0), the Structured Clinical Interview for DSM-5 Disorders (SCID-5-CV), the Adult ADHD Self-Report Scale (ASRS), the Biological Rhythm Interview of Assessment in Neuropsychiatry (BRIAN), the Pittsburgh Sleep Quality Index (PSQI), and the Screen Exposure Questionnaire. All instruments except the DIVA 2.0 were administered to controls. Adults with ADHD reported significantly longer total daily screen time than controls (p < 0.001) and exhibited higher ASRS, BRIAN, and PSQI scores (all p < 0.001) In both groups, screen time was positively correlated with BRIAN and PSQI scores. Hierarchical regression analysis indicated that biological rhythm disruption (BRIAN scores) was a stronger predictor of poor sleep quality (PSQI scores) than ADHD symptom severity or screen time (p < 0.001)). Overall, adults with ADHD demonstrated greater screen exposure, more disrupted circadian rhythms, and poorer sleep quality compared to controls. Across the full sample, biological rhythm disruption emerged as the most robust predictor of impaired sleep, underscoring its potential clinical relevance for addressing sleep disturbances in adults with ADHD.
{"title":"Circadian rhythm patterns and screen time in relation to sleep quality in adults with attention-deficit/hyperactivity disorder.","authors":"Ayla Canlı İşler, Mihriban Dalkıran","doi":"10.1080/07420528.2025.2579142","DOIUrl":"10.1080/07420528.2025.2579142","url":null,"abstract":"<p><p>This study compared screen time, circadian rhythm patterns, and sleep quality in adults diagnosed with attention-deficit/hyperactivity disorder (ADHD) and healthy controls, and examined the associations among these parameters. The sample included 100 adults with ADHD and 100 healthy controls. Participants were assessed using a sociodemographic data form, the Diagnostic Interview for ADHD in Adults (DIVA 2.0), the Structured Clinical Interview for DSM-5 Disorders (SCID-5-CV), the Adult ADHD Self-Report Scale (ASRS), the Biological Rhythm Interview of Assessment in Neuropsychiatry (BRIAN), the Pittsburgh Sleep Quality Index (PSQI), and the Screen Exposure Questionnaire. All instruments except the DIVA 2.0 were administered to controls. Adults with ADHD reported significantly longer total daily screen time than controls (<i>p</i> < 0.001) and exhibited higher ASRS, BRIAN, and PSQI scores (all <i>p</i> < 0.001) In both groups, screen time was positively correlated with BRIAN and PSQI scores. Hierarchical regression analysis indicated that biological rhythm disruption (BRIAN scores) was a stronger predictor of poor sleep quality (PSQI scores) than ADHD symptom severity or screen time (<i>p</i> < 0.001)). Overall, adults with ADHD demonstrated greater screen exposure, more disrupted circadian rhythms, and poorer sleep quality compared to controls. Across the full sample, biological rhythm disruption emerged as the most robust predictor of impaired sleep, underscoring its potential clinical relevance for addressing sleep disturbances in adults with ADHD.</p>","PeriodicalId":10294,"journal":{"name":"Chronobiology International","volume":" ","pages":"21-29"},"PeriodicalIF":1.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145400097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The prevalence of night shifts is extensive in hospital settings, particularly among nursing staff. The increasing importance of night shift work in meeting the demands of modern social care services underscores the urgent need for research into the impact of these schedules on nurses' health. This study aimed to examine the relationship between night shifts and the physical and mental well-being of nurses. Data were collected through questionnaires to obtain general demographic information and responses to the Chinese Psychosomatic Health Scale (CPSHS). The data were initially entered into Excel 2018 for verification of accuracy before being analyzed using IBM SPSS 26.0 software. The findings indicated that nurses engaged in night shift work exhibited a higher susceptibility to symptoms associated with the digestive system, reproductive endocrine system, depression, and anxiety compared to their day shift counterparts. Furthermore, a significant correlation was observed between the frequency of night shifts and increased symptom scores for digestive issues and depression. Specifically, nurses who engaged in night shifts exceeding eight instances per month demonstrated significantly higher scores in comparison to those working night shifts between five to eight times per month or fewer than four times per month. A prominent finding from the data analysis revealed that nurses undertaking night shifts more than eight times monthly exhibited a markedly higher incidence of somatic symptom disorder. The study implies that the engagement in night shift work is correlated with the physical and mental health of nurses, with the frequency of night shifts exceeding eight times per month identified as a risk factor for physical disorders among this population.
{"title":"Association between night shift work and mental and physical health among Chinese nurses: A cross-sectional study.","authors":"Yuan Chen, Qianjin Su, Yuting Yang, Dawei Zhang, Qi Li, Jinxue Zhang","doi":"10.1080/07420528.2025.2581800","DOIUrl":"10.1080/07420528.2025.2581800","url":null,"abstract":"<p><p>The prevalence of night shifts is extensive in hospital settings, particularly among nursing staff. The increasing importance of night shift work in meeting the demands of modern social care services underscores the urgent need for research into the impact of these schedules on nurses' health. This study aimed to examine the relationship between night shifts and the physical and mental well-being of nurses. Data were collected through questionnaires to obtain general demographic information and responses to the Chinese Psychosomatic Health Scale (CPSHS). The data were initially entered into Excel 2018 for verification of accuracy before being analyzed using IBM SPSS 26.0 software. The findings indicated that nurses engaged in night shift work exhibited a higher susceptibility to symptoms associated with the digestive system, reproductive endocrine system, depression, and anxiety compared to their day shift counterparts. Furthermore, a significant correlation was observed between the frequency of night shifts and increased symptom scores for digestive issues and depression. Specifically, nurses who engaged in night shifts exceeding eight instances per month demonstrated significantly higher scores in comparison to those working night shifts between five to eight times per month or fewer than four times per month. A prominent finding from the data analysis revealed that nurses undertaking night shifts more than eight times monthly exhibited a markedly higher incidence of somatic symptom disorder. The study implies that the engagement in night shift work is correlated with the physical and mental health of nurses, with the frequency of night shifts exceeding eight times per month identified as a risk factor for physical disorders among this population.</p>","PeriodicalId":10294,"journal":{"name":"Chronobiology International","volume":" ","pages":"72-81"},"PeriodicalIF":1.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145457848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-11-03DOI: 10.1080/07420528.2025.2581799
Kübra Özkan, Dursun Barut, Hakim Çelik
Sleep quality plays a critical role in maintaining both mental and physical health. Circadian rhythm and sleep disorders involve disruptions in the alignment between internal biological rhythms and environmental or social cues. This study aims to investigate the relationship between circadian rhythm/sleep disturbances and neurodegenerative markers in shift-working healthcare professionals. This study was conducted at Harran University Medical Faculty Hospital and included 30 night-shift healthcare workers (subject group) and 29 daytime workers (control group). Data were collected via a 25-item questionnaire on sociodemographic characteristics and work conditions, administered through face-to-face interviews. Participants also completed the Pittsburgh Sleep Quality Index (PSQI) and the Morningness-Eveningness Questionnaire (MEQ). Single morning blood samples were analyzed for neurodegenerative biomarkers (a calcium-binding protein called S100B and neuron-specific enolase, NSE), and melatonin levels were assessed from a single morning blood plasma sample. Between-group comparisons were made for questionnaire scores and biomarker levels. In the subject group, pre- and post-shift biomarker levels were also compared. The relationship between sleep quality and biomarker levels was examined. The subject group included 14 females (46.7%) and 16 males (53.3%); the control group included 15 females (51.7%) and 14 males (48.3%). The median duration of shift work was 12 h (range: 8-24). Compared to the control group, the shift workers had significantly higher PSQI scores (p = 0.002), lower MEQ scores (p = 0.003), elevated S100B levels (p = 0.003), and reduced melatonin levels (p = 0.037). Within the subject group, NSE levels were significantly higher after the shift compared to pre-shift values (p = 0.010). This study suggests that post-shift insomnia in night-shift healthcare workers is associated with elevated NSE levels, while chronic shift work is linked to increased S100B and decreased melatonin. These findings support a potential association between circadian rhythm/sleep disturbances and neurodegenerative markers.
{"title":"The association between circadian rhythm and sleep disorder on neurodegenerative parameters in shift-working healthcare workers.","authors":"Kübra Özkan, Dursun Barut, Hakim Çelik","doi":"10.1080/07420528.2025.2581799","DOIUrl":"10.1080/07420528.2025.2581799","url":null,"abstract":"<p><p>Sleep quality plays a critical role in maintaining both mental and physical health. Circadian rhythm and sleep disorders involve disruptions in the alignment between internal biological rhythms and environmental or social cues. This study aims to investigate the relationship between circadian rhythm/sleep disturbances and neurodegenerative markers in shift-working healthcare professionals. This study was conducted at Harran University Medical Faculty Hospital and included 30 night-shift healthcare workers (subject group) and 29 daytime workers (control group). Data were collected via a 25-item questionnaire on sociodemographic characteristics and work conditions, administered through face-to-face interviews. Participants also completed the Pittsburgh Sleep Quality Index (PSQI) and the Morningness-Eveningness Questionnaire (MEQ). Single morning blood samples were analyzed for neurodegenerative biomarkers (a calcium-binding protein called S100B and neuron-specific enolase, NSE), and melatonin levels were assessed from a single morning blood plasma sample. Between-group comparisons were made for questionnaire scores and biomarker levels. In the subject group, pre- and post-shift biomarker levels were also compared. The relationship between sleep quality and biomarker levels was examined. The subject group included 14 females (46.7%) and 16 males (53.3%); the control group included 15 females (51.7%) and 14 males (48.3%). The median duration of shift work was 12 h (range: 8-24). Compared to the control group, the shift workers had significantly higher PSQI scores (<i>p</i> = 0.002), lower MEQ scores (<i>p</i> = 0.003), elevated S100B levels (<i>p</i> = 0.003), and reduced melatonin levels (<i>p</i> = 0.037). Within the subject group, NSE levels were significantly higher after the shift compared to pre-shift values (<i>p</i> = 0.010). This study suggests that post-shift insomnia in night-shift healthcare workers is associated with elevated NSE levels, while chronic shift work is linked to increased S100B and decreased melatonin. These findings support a potential association between circadian rhythm/sleep disturbances and neurodegenerative markers.</p>","PeriodicalId":10294,"journal":{"name":"Chronobiology International","volume":" ","pages":"63-71"},"PeriodicalIF":1.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145430417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-11-06DOI: 10.1080/07420528.2025.2584193
Fábio Monteiro, José Leitão, Eduardo J R Santos, Paulo Rodrigues, Isabel M Santos, Fátima Simões, Carla S Nascimento
Working memory (WM) is a cognitive system comprising multiple components, including simultaneous storage and processing of information, updating mental representations, and binding elements into coherent structures. While various studies investigated whether WM performance varies throughout the day, their findings are inconsistent. These discrepancies have been partly attributed to methodological differences, such as variations in participant chronotypes and experimental protocols. Some evidence suggested that WM components may exhibit independent diurnal variations and thus may also contribute to these inconsistent findings. Considering this, we examined whether tasks targeting distinct WM dimensions present independent diurnal fluctuations. Participants completed complex spans, updating, and binding tasks at different time-of-day (ToD): morning, midday, afternoon, and evening. A composite score was also computed to evaluate ToD effects on general WM performance. Our findings indicated that not all aspects of WM are equally affected by ToD: tasks involving simultaneous processing and storage, particularly within the visuospatial domain, showed greater diurnal variability than updating and binding tasks. Composite RTs were faster in the morning. These findings imply that task selection could have contributed to the mixed results in prior research. Future investigations should consider using multiple paradigms targeting diverse WM dimensions to better understand how ToD influences WM performance.
{"title":"Do functional components of working memory exhibit independent diurnal variations under semi-ecological conditions? Evidence from a time-of-day protocol.","authors":"Fábio Monteiro, José Leitão, Eduardo J R Santos, Paulo Rodrigues, Isabel M Santos, Fátima Simões, Carla S Nascimento","doi":"10.1080/07420528.2025.2584193","DOIUrl":"10.1080/07420528.2025.2584193","url":null,"abstract":"<p><p>Working memory (WM) is a cognitive system comprising multiple components, including simultaneous storage and processing of information, updating mental representations, and binding elements into coherent structures. While various studies investigated whether WM performance varies throughout the day, their findings are inconsistent. These discrepancies have been partly attributed to methodological differences, such as variations in participant chronotypes and experimental protocols. Some evidence suggested that WM components may exhibit independent diurnal variations and thus may also contribute to these inconsistent findings. Considering this, we examined whether tasks targeting distinct WM dimensions present independent diurnal fluctuations. Participants completed complex spans, updating, and binding tasks at different time-of-day (ToD): morning, midday, afternoon, and evening. A composite score was also computed to evaluate ToD effects on general WM performance. Our findings indicated that not all aspects of WM are equally affected by ToD: tasks involving simultaneous processing and storage, particularly within the visuospatial domain, showed greater diurnal variability than updating and binding tasks. Composite RTs were faster in the morning. These findings imply that task selection could have contributed to the mixed results in prior research. Future investigations should consider using multiple paradigms targeting diverse WM dimensions to better understand how ToD influences WM performance.</p>","PeriodicalId":10294,"journal":{"name":"Chronobiology International","volume":" ","pages":"116-137"},"PeriodicalIF":1.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145451224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-11-27DOI: 10.1080/07420528.2025.2584191
Lauren Pickel, Rosa Sommer, Lei Yu, Georg A Bjarnason, Aron S Buchman, David A Bennett, Sheldon W Tobe, Andrew S P Lim
As the global burden of chronic kidney disease (CKD) continues to rise, it is important to identify factors that may support preservation of kidney function with age. Circadian rhythmicity declines with age, and evidence suggests that circadian rhythms influence renal physiology, yet their role in long-term kidney health remains underexplored. We tested the hypothesis that lower circadian rhythmicity would be associated with an elevated risk of kidney function decline. About 1315 older adults participating in the Rush Memory and Aging Project, a prospective community-based cohort study of the chronic conditions of aging, were studied. The median age of participants was 81.5 years [IQR: 71.8-91.2], 76.3% were female, and 93.7% identified as Caucasian. The stability of the circadian activity rhythm was quantified from up to 10 consecutive days of wrist activity using interdaily stability (IS) metric. Lower baseline IS was associated with lower eGFR (estimate = -1.9 ml/min/1.73 m2 per 1SD lower IS, SE 0.4, p = 5.0 × 10-6). Among those without baseline CKD (eGFR < 60 ml/min/1.73 m2), lower IS was associated with a ~ 25% higher future risk of developing CKD (HR 1.26, 95% CI 1.11-1.43) over a 5-years period, approaching the increased hazard associated with diabetes (HR 1.37). Effects were independent of known CKD risk factors including age, sex, obesity, hypertension, and diabetes, as well as multiple measures of sleep quality. Reduced circadian rhythmicity may therefore represent a novel modifiable risk factor for age-related decline in kidney function and CKD.
随着慢性肾脏疾病(CKD)的全球负担持续上升,确定可能支持随年龄保持肾功能的因素是很重要的。昼夜节律性随着年龄的增长而下降,有证据表明昼夜节律影响肾脏生理,但其在长期肾脏健康中的作用仍未得到充分探讨。我们验证了一个假设,即较低的昼夜节律性与肾功能下降的风险升高有关。约有1315名老年人参加了拉什记忆与衰老项目,这是一项前瞻性社区慢性衰老队列研究。参与者的中位年龄为81.5岁[IQR: 71.8-91.2], 76.3%为女性,93.7%为白种人。使用每日间稳定性(IS)指标,从连续10天的手腕活动中量化昼夜活动节律的稳定性。较低的基线IS与较低的eGFR相关(估计= -1.9 ml/min/1.73 m2 / 1SD, SE 0.4, p = 5.0 × 10-6)。在没有基线CKD (eGFR < 60 ml/min/1.73 m2)的患者中,较低的IS与未来5年内发生CKD的风险增加约25%相关(HR 1.26, 95% CI 1.11-1.43),接近与糖尿病相关的风险增加(HR 1.37)。影响独立于已知的CKD危险因素,包括年龄、性别、肥胖、高血压和糖尿病,以及多种睡眠质量指标。因此,昼夜节律性降低可能是与年龄相关的肾功能下降和CKD的一个新的可改变的危险因素。
{"title":"Lower circadian rhythmicity of rest-activity patterns is associated with a higher risk of chronic kidney disease in older adults.","authors":"Lauren Pickel, Rosa Sommer, Lei Yu, Georg A Bjarnason, Aron S Buchman, David A Bennett, Sheldon W Tobe, Andrew S P Lim","doi":"10.1080/07420528.2025.2584191","DOIUrl":"10.1080/07420528.2025.2584191","url":null,"abstract":"<p><p>As the global burden of chronic kidney disease (CKD) continues to rise, it is important to identify factors that may support preservation of kidney function with age. Circadian rhythmicity declines with age, and evidence suggests that circadian rhythms influence renal physiology, yet their role in long-term kidney health remains underexplored. We tested the hypothesis that lower circadian rhythmicity would be associated with an elevated risk of kidney function decline. About 1315 older adults participating in the Rush Memory and Aging Project, a prospective community-based cohort study of the chronic conditions of aging, were studied. The median age of participants was 81.5 years [IQR: 71.8-91.2], 76.3% were female, and 93.7% identified as Caucasian. The stability of the circadian activity rhythm was quantified from up to 10 consecutive days of wrist activity using interdaily stability (IS) metric. Lower baseline IS was associated with lower eGFR (estimate = -1.9 ml/min/1.73 m<sup>2</sup> per 1SD lower IS, SE 0.4, <i>p</i> = 5.0 × 10<sup>-6</sup>). Among those without baseline CKD (eGFR < 60 ml/min/1.73 m<sup>2</sup>), lower IS was associated with a ~ 25% higher future risk of developing CKD (HR 1.26, 95% CI 1.11-1.43) over a 5-years period, approaching the increased hazard associated with diabetes (HR 1.37). Effects were independent of known CKD risk factors including age, sex, obesity, hypertension, and diabetes, as well as multiple measures of sleep quality. Reduced circadian rhythmicity may therefore represent a novel modifiable risk factor for age-related decline in kidney function and CKD.</p>","PeriodicalId":10294,"journal":{"name":"Chronobiology International","volume":" ","pages":"94-103"},"PeriodicalIF":1.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145630797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-01Epub Date: 2025-11-17DOI: 10.1080/07420528.2025.2584196
Kyohei Kondo, Yoko Komada, Shingo Kitamura, Vadim Tkachev, Till Roenneberg, Maria Korman
Modern societal factors frequently impede the attainment of good sleep quality by many healthy adults. We investigated the chronotype-specific predictors of changes in subjective sleep quality following the relaxation of social time pressure during COVID-19 pandemic social restrictions in Japan. One thousand two hundred and fifty-two Japanese participants were surveyed during the initial COVID-19 social restrictions. Logistic regression analyses were used to assess changes under modified social time pressure in sleep quality by chronotype group (early, intermediate, or late) from changes in patterns of daily behaviors. During social restrictions, subjective sleep quality deteriorated with delays in sleep timing across all chronotypes. Early and intermediate chronotypes' reduction in sleep quality was associated with decreased sleep duration, whereas improved subjective sleep quality was associated with increased sleep duration and minimal sleep timing delay in the early and intermediate chronotypes. In late chronotypes, improved sleep quality was also associated with longer outdoor light exposure. These findings indicate that the determinants of changes in subjective sleep quality under modified social time pressure are at least partially chronotype-specific. Maintaining sleep timing may universally enhance subjective sleep quality during perturbations of social schedules. Moreover, in late chronotypes, the exposure to daylight may improve sleep quality, regardless of changes in sleep behaviors. These insights may contribute to the development of effective strategies for promoting better sleep quality in modern societies where insufficient sleep is becoming increasingly widespread.
{"title":"Chronotype-specific changes in subjective sleep quality: Differential responses to the relaxation of social time pressure in Japan.","authors":"Kyohei Kondo, Yoko Komada, Shingo Kitamura, Vadim Tkachev, Till Roenneberg, Maria Korman","doi":"10.1080/07420528.2025.2584196","DOIUrl":"10.1080/07420528.2025.2584196","url":null,"abstract":"<p><p>Modern societal factors frequently impede the attainment of good sleep quality by many healthy adults. We investigated the chronotype-specific predictors of changes in subjective sleep quality following the relaxation of social time pressure during COVID-19 pandemic social restrictions in Japan. One thousand two hundred and fifty-two Japanese participants were surveyed during the initial COVID-19 social restrictions. Logistic regression analyses were used to assess changes under modified social time pressure in sleep quality by chronotype group (early, intermediate, or late) from changes in patterns of daily behaviors. During social restrictions, subjective sleep quality deteriorated with delays in sleep timing across all chronotypes. Early and intermediate chronotypes' reduction in sleep quality was associated with decreased sleep duration, whereas improved subjective sleep quality was associated with increased sleep duration and minimal sleep timing delay in the early and intermediate chronotypes. In late chronotypes, improved sleep quality was also associated with longer outdoor light exposure. These findings indicate that the determinants of changes in subjective sleep quality under modified social time pressure are at least partially chronotype-specific. Maintaining sleep timing may universally enhance subjective sleep quality during perturbations of social schedules. Moreover, in late chronotypes, the exposure to daylight may improve sleep quality, regardless of changes in sleep behaviors. These insights may contribute to the development of effective strategies for promoting better sleep quality in modern societies where insufficient sleep is becoming increasingly widespread.</p>","PeriodicalId":10294,"journal":{"name":"Chronobiology International","volume":" ","pages":"138-147"},"PeriodicalIF":1.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145539484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}