Chronobiology International最新文献

{"title":"Effects of concurrent versus sequential presentation in dynamic visualizations on tactical knowledge acquisition: A time-of-day protocol with sport science undergraduates.","authors":"Yosra Belkhir, Eya Mhamdi, Ghada Jouira, Yung-Sheng Chen, Ghazi Rekik","doi":"10.1080/07420528.2026.2731160","DOIUrl":"https://doi.org/10.1080/07420528.2026.2731160","url":null,"abstract":"<p><p>Recent studies show that tactical knowledge acquisition from dynamic visualizations fluctuates across the day, with a morning advantage over afternoon sessions. However, these investigations relied exclusively on concurrent presentation of information. It remains unknown whether these findings hold when learners receive sequential presentation of information. We addressed this gap by examining how concurrent versus sequential presentation of soccer animations affects tactical knowledge acquisition at different times of day. Fifty sport science undergraduates (Mage = 18.4 ± 1.2 y) voluntarily participated. They completed morning (08:00 h-09:00 h) and afternoon (16:00 h-17:00 h) sessions, studying animated counterattacks in either concurrent or sequential format, followed by an immediate recall test. Heart rate and feeling states were measured at the start of each session. Recall accuracy was higher in the morning than in the afternoon for both groups. This morning advantage was accompanied by lower heart rate and more positive feelings. Diurnal changes in recall accuracy correlated negatively with heart rate and positively with feeling states. Sequential presentation of information led to better recall than concurrent presentation at both times of day, with no interaction between format and time of day. These findings suggest that, pending replication in more ecologically valid settings, physical education teachers may consider using sequential presentation of information in soccer animations - particularly during morning sessions - when communicating tactical instructions to novice learners.</p>","PeriodicalId":10294,"journal":{"name":"Chronobiology International","volume":" ","pages":"1-14"},"PeriodicalIF":2.5,"publicationDate":"2026-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148905144","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}

{"title":"Relationship between genetic risk, social jetlag, and obesity traits in a Turkish adult population.","authors":"Kubra Isgin-Atici, Busra Turan-Demirci, Suleyman Nahit Sendur, Incilay Lay, Mehmet Alikasifoglu, Tomris Erbas, Karani Santhanakrishnan Vimaleswaran, Zehra Buyuktuncer","doi":"10.1080/07420528.2026.2727573","DOIUrl":"https://doi.org/10.1080/07420528.2026.2727573","url":null,"abstract":"<p><p>Social jetlag (SJL), a misalignment between circadian rhythms and social schedules, is associated with obesity susceptibility. This cross-sectional study investigated how a metabolic-genetic risk score (GRS), based on Fat Mass and Obesity Associated (<i>FTO</i>), Melanocortin 4 Receptor (<i>MC4R</i>), and Transcription Factor 7-Like 2 (<i>TCF7L2</i>) genes, influences the relationship of SJL and obesity‑related traits in 223 adults (24-50 y) recruited from an outpatient clinic in Ankara, Turkiye. Anthropometric, clinical, and biochemical data were collected. Blood-derived DNA was genotyped using real-time PCR.SJL was calculated as the difference between weekday and free-day sleep midpoint, and sleep quality was assessed with Pittsburgh Sleep Quality Index. Participants with SJL had significantly higher Body Mass Index (BMI), waist and hip circumference, body fat mass (BFM), and insulin levels (<i>p</i> < 0.05). Although SJL was associated with higher BMI (26.1 ± 4.52; 24.9 ± 4.20 kg/m², <i>p</i> = 0.004), this association was attenuated after adjustment for metabolic-GRS (<i>p</i> = 0.062). Individuals carrying > 2 risk alleles had higher BMI than those with ≤2 alleles (<i>p</i> = 0.036). Among participants with SJL, metabolic-GRS was positively associated with BMI (<i>p</i> = 0.005), BFM (<i>p</i> = 0.047), and visceral fat percentage (<i>p</i> = 0.046). In conclusion, SJL may interact with genetic susceptibility for obesity, emphasizing the importance of regular sleep patterns in combating obesity.</p>","PeriodicalId":10294,"journal":{"name":"Chronobiology International","volume":" ","pages":"1-11"},"PeriodicalIF":2.5,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148900195","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}

{"title":"Time-of-day variation in endurance and strength performance, and physiological state across the waking day.","authors":"Stuart J Hesketh, Kazi D Jahan, Mariam S Luvna, Rojan Pakka, Subash Sing Lo, Ismat J Talukder","doi":"10.1080/07420528.2026.2730559","DOIUrl":"https://doi.org/10.1080/07420528.2026.2730559","url":null,"abstract":"<p><p>The goal of this study was to characterise time-of-day variation in short-duration cycling performance, handgrip strength, and associated physiological and perceptual responses under standardised laboratory conditions. Fifteen healthy recreationally active adults (8 males, 7 females; aged 26.9 ± 2.9 y) completed five experimental trials at 06:00, 10:00, 14:00, 18:00, and 22:00 h in a randomised, counterbalanced repeated-measures design. At each visit, participants completed a 10-min self-paced cycling time trial and assessments of handgrip strength, tympanic temperature, blood glucose, blood lactate, haemoglobin concentration, subjective sleepiness, and perceived exertion. Linear mixed-effects models were used to assess time-of-day effects, and mixed-effects 24-h cosinor analyses were performed as a secondary analysis to estimate peak timing of performance outcomes. Mean cycling power output varied significantly across the day (<i>p</i> < 0.001, ηp² = 0.507), increasing by 8.4% from 06:00 h to a peak at 18:00 h. Handgrip strength also exhibited significant temporal variation (<i>p</i> < 0.001, ηp² = 0.495), increasing by 9.0% between 06:00 h and 18:00 h. Cosinor analyses estimated similar acrophases for cycling performance (17:51 h) and handgrip strength (17:27 h). Pre-exercise tympanic temperature (<i>p</i> < 0.001, ηp² = 0.698), sleepiness (<i>p</i> < 0.001, ηp² = 0.437), blood glucose (<i>p</i> < 0.001, ηp² = 0.435), and blood lactate concentrations (<i>p</i> = 0.019, ηp² = 0.186) varied significantly across the day. Exercise-induced changes in blood glucose (<i>p</i> < 0.001, ηp² = 0.347) and blood lactate (<i>p</i> < 0.001, ηp² = 0.295) were also influenced by testing time, whereas post-exercise perceived exertion (<i>p</i> = 0.270, ηp² = 0.070) and exercise-induced temperature responses (<i>p</i> = 0.140, ηp² = 0.114) were unaffected. Short-duration cycling performance and handgrip strength are enhanced during the late afternoon and early evening and occur alongside coordinated temporal variation in physiological and perceptual state. These findings highlight time-of-day as a meaningful source of variation in exercise capacity and an important consideration in exercise testing and research design.</p>","PeriodicalId":10294,"journal":{"name":"Chronobiology International","volume":" ","pages":"1-20"},"PeriodicalIF":2.5,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148900189","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}

{"title":"DRP-1 and circadian rhythms: deciphering their impact on PCOS.","authors":"Aparna Eledath Kolasseri, Indrani Paramasivan Latha Laxmi, Sivaraman Jayanthi, Ramasamy Tamizhselvi","doi":"10.1080/07420528.2026.2723197","DOIUrl":"https://doi.org/10.1080/07420528.2026.2723197","url":null,"abstract":"<p><p>Polycystic ovarian syndrome (PCOS) is a complex reproductive disorder that impacts metabolic, endocrine, and circadian functions. Disruption in circadian rhythm can trigger PCOS due to an elevation in oxidative and inflammatory markers. Studies reveal that the increase in oxidative damage can occur due to defects in mitochondrial dynamics, through Dynamin-related protein 1 (DRP-1), in the development of PCOS. However, the mechanism of pathogenesis of PCOS through circadian rhythm and mitochondrial dynamics remains unclear. DRP-1 is a crucial regulator of mitochondrial fission, influencing ovarian physiology and steroidogenesis, contributing to hormonal imbalances in PCOS. Additionally, DRP-1 plays a role in the hypothalamus, where it links mitochondrial dynamics to circadian rhythms, suggesting a potential connection between circadian disruptions and PCOS symptoms. This review explores the function of DRP-1 in ovarian steroidogenesis and hypothalamic pathways, examining its contribution to PCOS-related complications. Understanding the effects of DRP-1 on mitochondrial function and circadian rhythm could contribute to potential therapeutic targets focused on mitochondrial health and circadian regulation in PCOS.</p>","PeriodicalId":10294,"journal":{"name":"Chronobiology International","volume":" ","pages":"1-14"},"PeriodicalIF":2.5,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148900151","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}

{"title":"The relationship of peripheral circadian gene mRNAs, antisense lncRNAs, and serum protein levels with chronotype, biological, and social rhythm in euthymic patients with bipolar disorder.","authors":"Aslıhan Gümüşlü Ağcabay, Bahadır Demir, Murat Korkmaz, Pınar Yumrutaş, Muhammet Sancaktar, Gülçin Elboğa, Feridun Bülbül, Abdurrahman Altındağ","doi":"10.1080/07420528.2026.2726296","DOIUrl":"10.1080/07420528.2026.2726296","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Circadian and sleep-wake dysregulation have been implicated in episode recurrence and clinical heterogeneity in bipolar disorder (BD), supporting peripheral circadian markers as candidates for further investigation. This study examined the peripheral expression of selected circadian rhythm-related gene mRNAs and antisense long non-coding RNAs (lncRNAs), alongside corresponding serum protein levels and self-report-based rhythm phenotyping, in euthymic patients with BD. Sixty euthymic patients with BD (20 BD-1, 20 BD-2, and 20 with antidepressant-associated hypo/manic switch [ASHH], treated as an exploratory group) and 20 healthy controls were enrolled. Euthymia was verified by HAM-D &lt; 7 and YMRS &lt; 6, and chronotype and rhythm phenotypes were assessed using the MEQ, SRM-5, and BRIAN. Morning fasting blood was collected (08:00-10:00) with the morning medication dose withheld; because sampling was confined to a single morning window, the reported values represent morning transcript abundance rather than circadian rhythmicity, amplitude, or phase position. Three core clock gene mRNAs (&lt;i&gt;CIART, ARNTL, CLOCK&lt;/i&gt;) and two antisense lncRNAs (&lt;i&gt;CRY1AS, PER2AS&lt;/i&gt;) were quantified by qRT-PCR (2^-ΔΔCt, β-actin reference), and serum CIART, CRY1, PER2, and ARNTL proteins were measured by ELISA. Between-group comparisons used nonparametric tests (Mann-Whitney U; Kruskal-Wallis H with Bonferroni post hoc), and correlations used Spearman's coefficient with Benjamini-Hochberg FDR correction. Compared with healthy controls, patients showed statistically significantly higher expression of the lncRNAs &lt;i&gt;PER2AS&lt;/i&gt; (r = 0,57) and &lt;i&gt;CRY1AS&lt;/i&gt; (r = 0,49) and the mRNAs &lt;i&gt;CIART&lt;/i&gt; (r = 0,35) and &lt;i&gt;CLOCK&lt;/i&gt; (r = 0,29), all p ≤ 0,007, whereas &lt;i&gt;ARNTL&lt;/i&gt; mRNA did not differ (p = 0,654). In exploratory subgroup analyses, differences were concentrated in BD-2 and ASHH: BD-2 showed the highest expression and BD-1 the lowest, with BD-1 not differing from controls for any marker. Serum protein levels did not differ between groups or subgroups, and MEQ, BRIAN, and SRM-5 scores did not differ; however, a sensitivity analysis excluding shift workers revealed a chronotype difference masked in the full sample. Across 174 correlational tests, none survived FDR correction (lowest q = 0,063); nominal uncorrected associations are reported as preliminary only. In euthymic BD, peripheral expression of selected circadian rhythm-related markers-particularly the antisense lncRNAs &lt;i&gt;PER2AS&lt;/i&gt; and &lt;i&gt;CRY1AS&lt;/i&gt; and the mRNAs of &lt;i&gt;CIART&lt;/i&gt; and &lt;i&gt;CLOCK&lt;/i&gt; - differed from healthy controls, whereas corresponding serum protein levels and behavioral rhythm phenotypes did not. This divergence across measurement levels can be considered a substantive finding, and the subgroup patterns are exploratory and hypothesis-generating. Longitudinal, episode-inclusive, and subtype-stratified studies incorporating objective circadian phase markers and repeated sampling are needed to establis","PeriodicalId":10294,"journal":{"name":"Chronobiology International","volume":" ","pages":"1-22"},"PeriodicalIF":2.5,"publicationDate":"2026-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148886484","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}

{"title":"Circadian alignment as a dimension of adolescent sleep health and self-regulation.","authors":"Jomel M Mabborang, Emily T Mabborang, Darwin F Dumlao","doi":"10.1080/07420528.2026.2727572","DOIUrl":"https://doi.org/10.1080/07420528.2026.2727572","url":null,"abstract":"","PeriodicalId":10294,"journal":{"name":"Chronobiology International","volume":" ","pages":"1-2"},"PeriodicalIF":2.5,"publicationDate":"2026-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148886578","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}

{"title":"Effects of artificial light sources on retinal melanopsin-mediated reproductive endocrine function and glucose-lipid metabolism in guinea pigs.","authors":"Yi Fan, Linfang Li, Jianbao Yuan, Min Peng, Zhengtao Deng, Yuliang Wang","doi":"10.1080/07420528.2026.2714931","DOIUrl":"https://doi.org/10.1080/07420528.2026.2714931","url":null,"abstract":"<p><p>Modern lifestyle changes have contributed to a marked increase in myopia and visual impairments in recent decades. However, the systemic biological effects and underlying mechanisms of prolonged exposure to different artificial light sources remain poorly understood. To address this gap, two-week-old female guinea pigs were randomly assigned to three groups: an indoor natural light (IN) control group, a light-emitting diode (LED) group, and a screen video (SV) group. Animals were maintained under a 12:12-h light-dark cycle (lights on 08:00 h, lights off 20:00 h) for 12 weeks. Ocular axial length, peripheral hormone profiles, and systemic glucose-lipid metabolism were evaluated across the three lighting environments. Compared with the IN group, both the LED and SV groups exhibited significant ocular axial elongation, dysregulated lipid metabolism, and altered endocrine profiles. Retinal expression of melanopsin - the photopigment in intrinsically photosensitive retinal ganglion cells (ipRGCs) that regulates non-image-forming visual functions and circadian photoentrainment - was significantly upregulated in the artificial light groups. Molecular analyses further revealed downregulation of key reproductive and metabolic genes (<i>Gnrh1</i>, <i>Cyp17a1</i>, and <i>Flt4</i>) alongside upregulation of hypothalamic circadian clock genes and <i>Kiss1</i>. These findings suggest that artificial light spectra elevate retinal melanopsin expression, which, combined with altered hypothalamic clock gene activity, disrupts reproductive, and metabolic homeostasis. This work highlights a potential role for melanopsin-mediated non-image-forming pathways in light-induced endocrine and metabolic disorders, warranting further mechanistic investigation.</p>","PeriodicalId":10294,"journal":{"name":"Chronobiology International","volume":" ","pages":"1-14"},"PeriodicalIF":2.5,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148873242","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}

{"title":"Association between sleep duration and risk of new-onset gastric diseases in middle-aged and older adults: A prospective cohort study in China.","authors":"Jing Li, Shengbo Liu, Zhimin Chen, Min Zhao","doi":"10.1080/07420528.2026.2726294","DOIUrl":"https://doi.org/10.1080/07420528.2026.2726294","url":null,"abstract":"<p><p>Insufficient sleep has been linked to an increased risk of gastric diseases among middle-aged and older adults. However, prospective evidence on the relationship between sleep duration and the incidence of gastric diseases remains limited. This study aimed to investigate the longitudinal associations of nighttime sleep and daytime nap duration with the risk of new-onset gastric diseases in an elderly Chinese population. Data were obtained from the China Health and Retirement Longitudinal Study (CHARLS), conducted from 2011 to 2020. A total of 7,539 participants aged ≥ 45 y and free of gastric diseases at baseline were included and followed for up to 9 y. Nighttime sleep duration and daytime nap duration were collected through self-reported questionnaires at baseline. Cox proportional hazards models were used as the primary analysis to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Multiple logistic regression models were employed for predictive metrics (C-statistic, continuous Net Reclassification Improvement [NRI], and Integrated Discrimination Improvement [IDI]). Restricted cubic spline analyses were employed to explore the dose-response relationship between sleep duration and the risk of new-onset gastric diseases. Among the 7,539 individuals included in the cohort, 1,452 (19. 3%) were diagnosed with new-onset gastric diseases. Participants with shorter nighttime sleep duration had a significantly higher risk of developing gastric diseases. Specifically, each interquartile range increase in nighttime sleep duration was associated with a 14% reduction in risk (HR: 0. 86; 95% CI: 0. 79-0. 95). Compared to those in the shortest sleep quartile, participants in the longest quartile experienced an approximately 20% lower risk (HR: 0. 80; 95% CI: 0. 64-1. 01; <i>p</i> = 0. 06). No significant association was found between daytime nap duration and the incidence of gastric diseases. Stratified analyses yielded consistent results across demographic and clinical subgroups, with stronger associations observed among females, married individuals, and rural residents. Shorter nighttime sleep duration was independently associated with an increased risk of new-onset gastric diseases in middle-aged and older adults. In contrast, daytime napping showed no significant relationship with gastric disease risk. These findings underscore nighttime sleep duration as a potentially modifiable factor for gastric disease prevention among older populations.</p>","PeriodicalId":10294,"journal":{"name":"Chronobiology International","volume":" ","pages":"1-8"},"PeriodicalIF":2.5,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148873328","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}

{"title":"Greater fragmentation of the daily rhythm of energy intake is associated with better insulin sensitivity in rotating shift workers.","authors":"Luisa Pereira Marot, María Fernanda Zerón-Rugerio, Trinitat Cambras, Laura Cristina Tibiletti Balieiro, Dayane Eusenia Rosa, Tássia Do Vale Cardoso Lopes, Claudia Roberta de Castro Moreno, Maria Izquierdo-Pulido, Cibele Aparecida Crispim","doi":"10.1080/07420528.2026.2670680","DOIUrl":"10.1080/07420528.2026.2670680","url":null,"abstract":"<p><p>Shift workers are essential to sustaining the modern 24 h society. However, they experience a higher risk of developing metabolic syndrome, a vulnerability thought to arise from recurrent misalignment between their sleep-wake and fasting-eating schedules. This study aimed to investigate the association between the daily rhythms of energy and macronutrient intake, motor activity (MA), and wrist temperature (WT) with anthropometric and biochemical parameters in rotating shift workers (RSW). Thirty male RSW participated in this 10 d cross-sectional study. Anthropometric and biochemical measurements were collected, and a 10 d 24 h food recall was used to assess energy and macronutrient intake. From these data, daily rhythms of energy intake were characterized, and actigraphy was used to evaluate daily rhythms of MA and WT. Daily rhythms were analyzed using non-parametric analyses including the intradaily variability (IV) and interdaily stability (IS), and associations with outcome variables were tested using partial correlations. A negative association was observed between the IV of the daily rhythms of energy and carbohydrate intake with insulin levels (<i>p</i> < 0.05), HOMA-IR (<i>p</i> < 0.05), and triglycerides (<i>p</i> < 0.05). In contrast, higher IV in the daily rhythm of WT was associated with higher total cholesterol (<i>p</i> < 0.05) and LDL-cholesterol (<i>p</i> < 0.05). These results suggest that a higher fragmentation (higher IV) of the daily rhythm of energy intake is associated with better glucose tolerance among RSW.</p>","PeriodicalId":10294,"journal":{"name":"Chronobiology International","volume":" ","pages":"1309-1315"},"PeriodicalIF":2.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147940112","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}

{"title":"Classifying weekday-weekend sleep pattern subtypes via latent class analysis: Associations with daytime functioning.","authors":"Fan-Chi Hsiao, Hsiu-Ting Yu, Jiunn-Horng Kang, Chien-Ming Yang","doi":"10.1080/07420528.2026.2671352","DOIUrl":"10.1080/07420528.2026.2671352","url":null,"abstract":"<p><p>Individuals commonly exhibit different sleep patterns between weekdays and weekends, notably weekend catch-up sleep (wCUS: increased duration) and social jet lag (SJL: delayed timing). This study simultaneously examined both sleep timing and duration to identify distinct patterns of weekday-weekend sleep differences using latent class analysis and to explore their associations with chronotype, sleep disturbance, and well-being. A total of 850 adults (aged 20-55) without diagnosed sleep or psychiatric disorders and not engaged in shift work participated in an online survey assessing their sleep patterns and daytime functioning, including levels of sleepiness, fatigue, depressive symptoms, and stress. Four distinct latent classes of sleep patterns were identified: Regular Sleepers with minimal SJL and no wCUS, Mild Weekend Shift Sleepers with minimal SJL and mild wCUS, Moderate Weekend Shift Sleepers with moderate SJL and wCUS, and Extreme Weekend Shift Sleepers with high SJL and high wCUS. Individuals in the Extreme Weekend Shift Sleepers group reported significantly higher levels of sleepiness, depressive emotions, and insomnia symptoms compared to the other groups, while no significant differences were found among the remaining three groups. These findings suggest that extreme weekend sleep shifts are associated with poorer symptom profiles, consistent with the possibility that larger timing delays and weekday sleep restrictions jointly characterize this subgroup. The pattern indicates a non-linear association in which modest weekend extensions did not correlate with worse symptoms in this sample. These results are descriptive and highlight the need for longitudinal studies to confirm these associations.</p>","PeriodicalId":10294,"journal":{"name":"Chronobiology International","volume":" ","pages":"1411-1423"},"PeriodicalIF":2.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148014030","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}