Journal of Biological Rhythms最新文献

{"title":"Time-of-Day Variation in Knee Extensor Strength and Fatigue Is Associated With Circadian Phenotype in Healthy Young Adults.","authors":"Stuart J Hesketh, Kazi D Jahan, Mariam S Luvna, Rojan Pakka, Subash Sing Lo, Ismat J Talukder","doi":"10.1177/07487304261491813","DOIUrl":"https://doi.org/10.1177/07487304261491813","url":null,"abstract":"<p><p>Time-of-day variation in neuromuscular performance is well established, but the contribution of circadian phenotype remains unclear. This study examined whether maximal knee-extensor strength and fatigue resistance differ between morning and evening and whether chronotype and actigraphy-derived sleep-timing are associated with diurnal performance variation. Forty-four healthy young adults (21 males, 23 females) completed a randomised-crossover protocol consisting of neuromuscular testing in the morning (0700-0900) and evening (1700-1900). Participants completed 7 days of actigraphy monitoring and the Composite Morningness Questionnaire to characterise behavioural circadian phenotype. Sleep timing was assessed using habitual sleep midpoint (between sleep-onset and wake-time), with night-to-night variability in sleep midpoint used as an index of sleep-timing variability. Maximal voluntary isometric contraction (MVIC) torque, fatigue index, contractions completed, and time-to-exhaustion were assessed during each trial. Baseline MVIC torque was greater in the evening compared with the morning (2.96 ± 0.80 vs 2.85 ± 0.77 N m kg⁻¹; <i>P</i> < .0001), with post-fatigue torque also remaining higher in the evening (2.00 ± 0.60 vs 1.84 ± 0.54 N m kg⁻¹; <i>P</i> < .0001). Participants demonstrated a lower fatigue-index (32.57 ± 6.99 vs 35.58 ± 6.26%; <i>P</i> < .0001), completed more contractions (37.95 ± 8.29 vs 35.09 ± 7.58; <i>P</i> < .0001), and exhibited longer time-to-exhaustion (6.36 ± 1.51 vs 5.85 ± 1.26 minutes; <i>P</i> < .0001) during evening testing. Chronotype was strongly associated with the PM-AM difference in MVIC torque (<i>r</i> = -.684, <i>P</i> < .0001), explaining 47% of the variance in diurnal performance responses. Neither habitual sleep midpoint (<i>r</i> = -.029, <i>P</i> = .848) nor night-to-night variability in sleep midpoint (<i>r</i> = -.055, <i>P</i> = .721) was associated with performance differences. No significant sex-related differences were observed. Maximal knee extensor strength and fatigue resistance were enhanced during evening compared with morning testing. The magnitude of this response was strongly associated with behavioural circadian phenotype, but not actigraphy-derived sleep-timing. Findings suggest that chronotype influences time-of-day differences in neuromuscular performance and should be considered when evaluating exercise performance.</p>","PeriodicalId":15056,"journal":{"name":"Journal of Biological Rhythms","volume":" ","pages":"7487304261491813"},"PeriodicalIF":3.0,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149167485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of 24-Hour Rhythms in Vital Signs in Intensive Care Populations: A Scoping Review.","authors":"Floor W Hiemstra, Lot van Winden, Roos Bos, David J van Westerloo, Jeroen Dudink, Jan W Schoones, Marc D Ruben, Laura Kervezee","doi":"10.1177/07487304261487544","DOIUrl":"https://doi.org/10.1177/07487304261487544","url":null,"abstract":"<p><p>Circadian rhythms in intensive care unit (ICU) patients are vulnerable to disruption, which may contribute to adverse clinical outcomes. Continuously monitored vital signs offer a unique opportunity to assess 24-hour rhythms in real-world ICU settings. The aim of this scoping review is to systematically map methodological approaches used to characterize 24-hour rhythms in vital signs in ICU populations and to summarize reported associations with patient characteristics, clinical outcomes, or interventions. A systematic literature search was conducted to identify studies that assessed 24-hour rhythms in routinely collected vital signs in adult, pediatric and neonatal ICU patients published between January 2015 and December 2025. Thirty-five studies comprising nearly 288 000 patients were included, with most studies conducted in adult ICUs (n = 32), 3 in neonatal ICUs, and none in pediatric ICUs. Substantial heterogeneity existed in preprocessing strategies, assessment windows, analytical methods, and derived rhythmicity metrics that were used to determine 24-hour variation, as well as in the level of detail with which these were reported. Cosinor analysis was the most frequently used method to characterize rhythmicity, followed by day-night comparisons, and max-min approaches. Across studies, rhythmicity analyses revealed that 24-hour rhythms in vital signs were detectable in ICU patients, although methodological heterogeneity and lack of detail on analytical decisions limit evidence synthesis. In addition, the direction and magnitude of associations between rhythmic properties (such as amplitude or acrophase) and mortality and other clinically relevant outcomes varied considerably among studies. While most, though not all, studies reported that higher amplitudes were associated with mortality, it remains unclear whether this reflects circadian physiology rather than clinical instability. Harmonization of reporting practices and the development of a core outcome set on circadian parameters derived from vital signs in critical care contexts will help to guide future research in this burgeoning field.</p>","PeriodicalId":15056,"journal":{"name":"Journal of Biological Rhythms","volume":" ","pages":"7487304261487544"},"PeriodicalIF":3.0,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149170856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Circadian Timekeeping in the Tropics: Rhythmic Transcriptome and Diurnal Regulatory Networks in <i>Rubroshorea leprosula</i>.","authors":"Shashank Kumar Singh, Motohide Seki, Hiroshi Ito, Naoki Tani, Yuka Ikezaki, Kayoko Ohta, Suat Hui Yeoh, Ng Ching Ching, Akiko Satake","doi":"10.1177/07487304261488074","DOIUrl":"https://doi.org/10.1177/07487304261488074","url":null,"abstract":"<p><p>Circadian rhythms allow plants to regulate internal processes to align with daily rhythms in the environment. Comparing circadian clocks across environments is essential because latitude-dependent variation in light and temperature imposes distinct selection pressures that shape the evolution and function of circadian timing systems. However, circadian clock studies have largely focused on temperate and subtropical species, leaving transcriptional circadian networks in tropical plants poorly understood. We report the comprehensive circadian transcriptome of <i>Rubroshorea leprosula</i>, a dominant species in tropical rainforests in Southeast Asia. One sapling was sampled every 4 hours over 48-hour period under constant darkness and used for transcriptomic analyses. Only 283 of 20 748 expressed genes (~1.3%) exhibited significant circadian oscillations, with periods strongly concentrated between 23 and 25 hours. Hierarchical clustering revealed 4 temporal clusters with alternate phases of expression and functional specialization. Comparative analysis identified clear orthologs for all major <i>Arabidopsis</i> circadian clock components, with conserved synteny to <i>Parashorea chinensis</i>, a close relative of <i>R leprosula</i>. Time-lagged cross-correlation network reconstruction identified a characteristic circadian topological similarity with <i>Arabidopsis</i>, including coupled morning and evening feedback loops and paralog expansion that maintained overall structure. Peak expression timing of these core clock genes in the tropical tree was largely consistent with that observed in <i>Arabidopsis thaliana</i>. In contrast, <i>Rubroshorea</i> orthologs showed reduced amplitudes and lower coefficients of variation under this single constant darkness, single-individual condition; because dark-induced damping is common across plants, this pattern is consistent with, but does not establish, reduced circadian robustness in <i>R leprosula</i> linked to tropical adaptation. This study lays the molecular foundation for circadian regulation in dipterocarps and offers a system for integrating rhythmic gene expression to ecological function and forest productivity in tropical communities.</p>","PeriodicalId":15056,"journal":{"name":"Journal of Biological Rhythms","volume":" ","pages":"7487304261488074"},"PeriodicalIF":3.0,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149165989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Is the FEO Food-Entrainable? Reexamining the Classic Fred Stephan Experiment Using Canonical-Clock-Less <i>Period 1/2/3</i> Triple Knockout Mice.","authors":"S K Tahajjul Taufique, David E Ehichioya, Sofia Farah, Melody Shen, Shin Yamazaki","doi":"10.1177/07487304261445542","DOIUrl":"10.1177/07487304261445542","url":null,"abstract":"<p><p>When nocturnal rodents are subjected to daytime restricted feeding, in which food is only available for a few hours per day, they typically become active a few hours before the onset of the scheduled mealtime. This so-called food-anticipatory activity (FAA) is controlled by an autonomous circadian pacemaker, which is independent from the central circadian pacemaker in the suprachiasmatic nucleus (SCN). Fred Stephan named this pacemaker the food-entrainable oscillator (FEO) because FAA re-entrains to a shifted feeding schedule. We recently developed a method to measure food-seeking nose-poking behavior by an operant feeding device and found that anticipatory food-seeking nose-poking for scheduled daily food availability shifts in parallel with phase-shifted environmental light-dark cycles, raising the possibility that anticipatory food-seeking behavior is controlled by an oscillator entrained to the environmental light-dark cycle. With this possible light-entrainability of the FEO, we revisited Stephan's historical experiment-testing whether the FEO entrains to feeding cycle in the absence of a light-dark cycle without functional SCN-using <i>Period 1/2/3</i> triple knockout (KO) mice, in which the canonical circadian oscillators in the SCN and peripheral tissues are disabled. KO mice were subjected to restricted feeding under constant darkness. The food-seeking nose-poking activity of a subset of the KO mice indeed occasionally entrained to the feeding cycle and re-entrained to a shifted feeding cycle. Despite our previous study showing that anticipatory food-seeking behavior shifted with the environmental light-dark cycle, these data demonstrate that it can also entrain to the feeding cycle in the absence of an environmental light-dark cycle, supporting Stephan's observation that the FEO is indeed food-entrainable.</p>","PeriodicalId":15056,"journal":{"name":"Journal of Biological Rhythms","volume":" ","pages":"653-662"},"PeriodicalIF":3.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13143339/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147815428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Light-induced Desynchrony of a Multi-oscillatory Circadian System in <i>Per2</i>-deficient Mice.","authors":"Nana N Takasu, Isao T Tokuda, Hitoshi Uchida, Yasukazu Nakahata, Takahiro J Nakamura, Wataru Nakamura","doi":"10.1177/07487304261448768","DOIUrl":"10.1177/07487304261448768","url":null,"abstract":"<p><p>The <i>Period (Per)</i> gene was first identified in <i>Drosophila</i> as a key regulator of circadian rhythms, with mutations that altered or abolished behavioral rhythmicity. Mammals possess 3 homologs, <i>Per1</i>, <i>Per2</i>, and <i>Per3</i>. Here, we systematically compared the circadian properties of mice deficient in each <i>Per</i> gene, singly and in combination, under constant darkness (DD). We analyzed their free-running periods (τ) and phase response curves (PRCs) to 6-h light pulses (6-h LPs). Each <i>Per</i>-deficient line exhibited distinct circadian characteristics. <i>Per1</i>-deficient mice (including <i>Per1</i>^-/- <i>Per3</i>^-/- double mutants) showed high-amplitude PRCs with large phase shifts near CT18, consistent with Type 0 resetting. <i>Per2</i>-deficient mice displayed shorter τ and Type 1 PRCs with crossover points near CT17. Remarkably, some <i>Per2</i>-deficient mice lost circadian rhythmicity after a single 6-h LP delivered near the crossover but regained rhythmicity following a second pulse 12 days later. In contrast, <i>Per1</i>^-/- <i>Per2</i>^-/- mice, which retain <i>Per3</i>, failed to maintain stable rhythms in DD yet transiently reestablished a short-period (~19.5 h) rhythm in response to a 6-h LP. These findings indicate that rhythm loss in <i>Per2</i>-deficient mice does not represent oscillation stop but rather light-induced desynchrony among multiple oscillators that constitute the circadian pacemaker. Collectively, our results demonstrate that <i>Per1</i> sustains oscillator strength, <i>Per2</i> maintains inter-oscillator coupling, and together they ensure the robustness of the mammalian circadian system against strong photic perturbation.</p>","PeriodicalId":15056,"journal":{"name":"Journal of Biological Rhythms","volume":" ","pages":"605-614"},"PeriodicalIF":3.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147972720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variations in the Timing of Bipolar Mood Cycles Associated With Interactions of the Moon's Synodic, Tropical, and Anomalistic Cycles.","authors":"Thomas A Wehr, David H Avery","doi":"10.1177/07487304261443610","DOIUrl":"10.1177/07487304261443610","url":null,"abstract":"<p><p>The Moon's motion around the Earth is complex, governed by interactions among several types of cycles that arise from different aspects of its orbit. The 29.53-day synodic cycle occurs as the Moon passes through new-moon and full-moon alignments (syzygies) with the Earth and the Sun. The 27.32-day tropical cycle occurs as the Moon moves back and forth between its northernmost and southernmost positions (standstills) relative to the plane of the Earth's equator. The 27.55-day anomalistic cycle occurs as the Moon moves back and forth from its nearest and farthest distances from the Earth (perigees and apogees). The Moon's effects on luminance and gravity at the Earth's surface are greatest at times of syzygies, standstills, and perigees. Here, based on periodogram analyses of 14.5 patient-year records of a circular, rapid cycling type of bipolar disorder, we show that onsets of mania in a given individual can recur in association with 2 or more lunar cycles simultaneously, and with conjunctions of syzygies of the synodic cycle with standstills of the tropical cycle or with perigees of the anomalistic cycle. The results are consistent with the fact that the Moon's effects at the Earth's surface are the result of interactions among all of its constituent cycles, and they highlight the potential importance of long-term longitudinal designs in studies of lunar influence.</p>","PeriodicalId":15056,"journal":{"name":"Journal of Biological Rhythms","volume":" ","pages":"636-652"},"PeriodicalIF":3.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13538899/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147929840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Journey Through Chronotype Changes in University Students.","authors":"Esther D Domenie, Davide Erminelli, Gianluca Giusti, Chiara Mangini, Lisa Zarantonello, Rodolfo Costa, Sara Montagnese","doi":"10.1177/07487304261445541","DOIUrl":"10.1177/07487304261445541","url":null,"abstract":"<p><p>Chronotype reflects an individual's preferred timing of sleep/daily activities and is typically regarded as a stable trait, though it varies across the lifespan and may fluctuate also over shorter periods of time. Here, we investigate the temporal stability of self-assessed chronotype and its modulation by behavioral advice in a large cohort of University students participating in a 2-arm circadian hygiene education initiative (either encouraging consistency or advancement of sleep, meals, and exercise timing). Students provided demographic and sleep quality information, and repeated chronotype assessments (2-22 months) using the Self-Morningness/Eveningness (Self-ME) question, which offers a choice among 4 categories (definitely morning, morning, evening, definitely evening) and the Ultrashort Munich ChronoType Questionnaire (μMCTQ), which has midsleep and social jetlag as outcomes. Two main samples were analyzed: students completing baseline/2-month follow-up assessments (<i>n</i> = 1902) and students completing baseline/one later assessment, at any time (<i>n</i> = 2820); a subgroup with 3 available assessments (<i>n</i> = 1257) was also examined. Agreement between subsequent Self-ME assessments was good in all samples (0.6 < Cohen's <i>k</i> < 0.8), with approximately 70% of students confirming their first assessment at 2 months, with variations (62%-73%) depending on time between assessments and behavioral advice; transitions mostly occurred between adjacent Self-ME categories. Nonetheless, approximately 30% of participants changed category between 2 assessments, and those who moved once were more likely to move again. \"Non movers\" exhibited more extreme sleep-wake habits. Furthermore, midsleep and social jetlag changed over the calendar year in ways that seemed to reflect the time-course/constraints of the academic year. The 2 circadian hygiene interventions influenced chronotype stability slightly and differently, particularly in morning types, who probably found it easier to comply with the suggestion of advancing sleep-wake timing. In conclusion, chronotype in young adults shows relative stability but is plastic within limits, also in relation to the way it is measured.</p>","PeriodicalId":15056,"journal":{"name":"Journal of Biological Rhythms","volume":" ","pages":"536-548"},"PeriodicalIF":3.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147868276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GIGEM (Group Isolation Gauge Effect Metrics), a Software Suite for Analyzing Social Isolation-induced Sleep Loss and Multi-batch Experiments in <i>Drosophila</i>.","authors":"Esther I Doria, Feda Hammood, Jingjing Yan, Wanhe Li","doi":"10.1177/07487304261449840","DOIUrl":"10.1177/07487304261449840","url":null,"abstract":"<p><p>We introduce Group Isolation Gauge Effect Metrics (GIGEM), a high-throughput software suite for <i>Drosophila</i> sleep analysis designed to manage large population datasets from multi-batch experiments. In this study, we characterized social isolation-induced sleep phenotypes across 38 Sleep Inbred Panel (SIP) lines after both acute and chronic social isolation. Beyond this specific study, GIGEM is broadly suited for diverse <i>Drosophila</i> sleep research involving large-scale and multi-batch datasets. GIGEM enabled an extensive analysis of sleep parameters and allowed systematic identification of sleep changes in response to social isolation. Following acute social isolation, SIP line animals showed heterogeneous responses, including sleep loss, sleep gain, and no change in sleep. In contrast, chronic social isolation led to significant sleep loss in nearly all lines, though to varying degrees. While most SIP lines were sensitive to chronic social isolation, a select few were resistant to it. These results were obtained across 38 SIP lines and wild-type controls (totaling 5687 animals). Collectively, our results demonstrate that chronic social isolation-induced sleep loss is a robust yet variable trait and establish GIGEM as a powerful, generalizable tool for <i>Drosophila</i> sleep phenotyping in large-scale, multi-batch studies.</p>","PeriodicalId":15056,"journal":{"name":"Journal of Biological Rhythms","volume":" ","pages":"585-593"},"PeriodicalIF":3.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13267738/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148205050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Defining Clock Neurons Within Distributed Circadian Circuits Through Multiscale Technologies.","authors":"Burgundy Walters, Shubham Garg, Diego C Fernandez","doi":"10.1177/07487304261448254","DOIUrl":"10.1177/07487304261448254","url":null,"abstract":"<p><p>The mammalian circadian system has traditionally been viewed as a hierarchical network organized around a master pacemaker in the suprachiasmatic nucleus (SCN), which synchronizes peripheral clocks to coordinate daily rhythms in physiology and behavior. While this framework has provided a foundational model for circadian regulation, recent advances in molecular profiling, circuit tracing, and neuronal manipulation reveal a more complex architecture. Multiple brain regions outside the SCN contain neurons with intrinsic circadian properties that actively participate in processing temporal information, challenging the classical central-peripheral model. These findings raise a fundamental conceptual question: what defines a circadian clock neuron? Here, we synthesize recent molecular, cellular, and systems-level studies to examine the defining features of neurons embedded within brain circadian clocks. By integrating high-resolution molecular profiling with functional circuit analysis, we propose an operational framework for identifying clock neurons across brain circuits. Specifically, we outline four criteria that characterize circadian clock neurons: molecular oscillation, autonomy, physiological rhythmicity, and circuit influence. This framework reflects current experimental capabilities and highlights how multiscale approaches-from single-cell transcriptomics to causal circuit manipulation-are reshaping our understanding of circadian organization in the brain. Clarifying the identity of clock neurons will be essential for mapping distributed circadian circuits and for developing targeted interventions for neurological and neurodegenerative disorders associated with circadian and sleep disruption.</p>","PeriodicalId":15056,"journal":{"name":"Journal of Biological Rhythms","volume":" ","pages":"515-535"},"PeriodicalIF":3.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13215142/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148005314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biological Rhythms of Vital Signs in Newborns in a Neonatal Intensive Care Unit: A Prospective Observational Study.","authors":"Vanderlei Amadeu da Rocha, Mariana Bueno, Isília Aparecida Silva, Sanseray da Silveira Cruz-Machado","doi":"10.1177/07487304261443611","DOIUrl":"10.1177/07487304261443611","url":null,"abstract":"<p><p>To characterize the presence and relationships between the rhythms of axillary temperature, heart rate, respiratory rate, blood pressure, and peripheral oxygen saturation, from the first (D1) to the third day of life (D3) in newborns (NBs) hospitalized in the neonatal intensive care unit (NICU). Primary, descriptive, nested clinical study within a primary, observational, and prospective clinical study, conducted in the NICU of a public hospital in the city of São Paulo, Brazil. Demographic data and vital signs (axillary temperature, heart rate, respiratory rate, blood pressure, and peripheral oxygen saturation) recorded in clinical charts were collected between the first and third day of life (D1-D3) at 4-h intervals (8 h; 12 h; 16 h; 20 h; 24 h; 4 h). The biological rhythms of the vital signs were analyzed using the Cosinor algorithm. Eighty-eight NBs participated (44 preterm and 44 term). Incipient variability of vital signs was observed in the first days, with reduced amplitudes and unstable phases. There was a correlation between the amplitude of axillary temperature and length of hospital stay in preterm infants, and between the amplitude of diastolic blood pressure and length of stay in term infants, suggesting the clinical potential of variability as a marker of neonatal maturation and clinical vulnerability. Altogether, the findings indicate the presence of early physiological rhythmicity and reinforce the importance of chronosensitive care and the incorporation of chronobiological parameters in clinical management, aiming to optimize the development and outcomes of hospitalized newborns.</p>","PeriodicalId":15056,"journal":{"name":"Journal of Biological Rhythms","volume":" ","pages":"571-584"},"PeriodicalIF":3.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147972730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}