Rest-activity Rhythm Research Articles

Around the clock: unveiling giraffe rest-activity rhythms and social dynamics

Understanding the daily activity patterns and social dynamics of giraffes (Giraffa camelopardalis) is crucial for their management and conservation. In this study, a comprehensive 24-hour observational analysis of three female reticulated giraffes kept for three weeks at the Opel-Zoo in Kronberg, Germany, was conducted. Using infrared-sensitive cameras, the study captured behavioral data across baseline and two intervention phases involving changes in group composition. Social network analysis was performed using the Mantel test to assess changes in social interactions between day and night and across different study periods, while the MRQAP was applied to evaluate the influence of individual subtypes on the social structure. During the day, the giraffes exhibited a high level of activity, primarily engaging in walking, standing, and feeding behaviors. Diurnal resting was minimal, with sporadic lying phases. Night-time behavior was markedly different, with the giraffes spending most of the night lying down, interspersed with periods of feeding. The presence of a male giraffe during one intervention phase significantly altered diurnal activity patterns, increasing standing behaviors and decreasing feeding time. Social interactions, including nearest neighbor preferences, varied across day and night periods and changed with alterations in group composition. The study highlights the complexity of giraffe social dynamics and their adaptation to different social contexts. These findings provide valuable insights into the natural behavioral rhythms and social behaviors of giraffes, which are essential for effective zoo management and conservation strategies.

Disrupted rest-activity circadian rhythms are associated with all-cause mortality in patients with chronic kidney diseases

ABSTRACT Circadian rhythms are important biological contributors to health. Rest activity rhythms (RAR) are emerging as biomarkers of circadian behavior that are associated with chronic disease when abnormal. RAR have not yet been characterized in chronic kidney diseases (CKD). Leveraging the National Health and Nutrition Examination Survey (2011–2014), patients with CKD (n = 1114; Mean [95% CI]: Age, 50 [58–61] y; 52% female) were compared with non-CKD individuals (n = 5885; Age, 47 [46–48] y; 52% female). Actigraphy data were processed for RAR parameters including rhythmic strength (amplitude), the rhythm adjusted mean (mesor), the timing of peak activity (acrophase), activity regularity (inter-daily stability), and activity fragmentation (intra-daily variability). Cox regression was performed to assess RAR parameters for the prediction of all-cause mortality. Compared to non-CKD adults, patients with CKD had a lower rhythmic amplitude and mesor, and exhibited greater fragmentation and less day-to-day stability in RAR (ps < 0.001). Among CKD patients, a lower rhythmic amplitude (HR [95% CI]: 0.88 [0.82–0.96]; p < 0.001), a lower rhythm adjusted mean (0.87 [0.81–0.95]; p = 0.002), and a higher daily activity fragmentation (1.87 [1.10–3.18]; p = 0.023) were associated with an increased risk of all-cause mortality. Patients with CKD showed dampened rhythmic amplitudes and greater fragmentation of activity that were associated with a higher risk of all-cause mortality. These findings demonstrate a relationship between circadian disruption and prognosis in patients with CKD.

Reliable measures of rest-activity rhythm fragmentation: how many days are needed?

BackgroundA more fragmented, less stable rest-activity rhythm (RAR) is emerging as a risk factor for health. Accelerometer devices are increasingly used to measure RAR fragmentation using metrics such as inter-daily stability (IS), intradaily variability (IV), transition probabilities (TP), self-similarity parameter (α), and activity balance index (ABI). These metrics were proposed in the context of long period of wear but, in real life, non-wear might introduce measurement bias. This study aims to determine the minimum number of valid days to obtain reliable fragmentation metrics.MethodsWrist-worn accelerometer data were drawn from the Whitehall accelerometer sub-study (age: 60 to 83 years) to simulate different non-wear patterns. Pseudo-simulated data with different numbers of valid days (one to seven), defined as < 1/3 of non-wear during both day and night periods, and with omission or imputation of non-wear periods were compared against complete data using intraclass correlation coefficient (ICC) and mean absolute percent error (MAPE).ResultsFive days with valid data (97.8% of participants) and omission of non-wear periods allowed an ICC ≥ 0.75 and MAPE ≤ 15%, acceptable cut points for reliability, for IS and ABI; this number was lower for TPs (two-three days), α and IV (four days). Overall, imputation of data did not provide better estimates. Findings were consistent across age and sex groups.ConclusionsThe number of days of wrist accelerometer data with at least 2/3 of wear time for both day and night periods varies from two (TPs) to five (IS, ABI) days for reliable RAR measures among older adults.

Attenuated melanopsin-mediated post-illumination pupillary response (PIPR) is associated with reduced actigraphic amplitude and mesor in older adults.

This study aimed to explore the relationship between post-illumination pupillary response (PIPR) with sleep and circadian measures in a community sample of healthy older adults. Eligible participants were invited to complete a one-week sleep diary, actigraphy and provide an overnight urine sample to measure urinary 6-sulfatoxymelatonin (aMT6s). PIPR was defined as the as the pupil constriction at 6s post-stimulus (PIPR-6s), and ii) for 30s beginning 10s after stimulus (PIPR-30s) normalized as a percentage to the baseline pupil diameter, after 1s of blue and 1s of red-light stimulus, respectively. The Net-PIPRs were reported by subtracting the PIPR to red stimulus from the PIPR to blue stimulus. The relationship between PIPR metrics to aMT6s and actigraphic rest-activity rhythm parameters was examined by generalized linear models. A total of 48 participants were recruited (Mean age: 62.6 ± 7.1 years, Male: 44%). Both Net PIPR-6s and Net PIPR-30s were significantly associated with actigraphic rest-activity amplitude (B=0.03, p=0.001 and B=0.03, p=0.01, respectively), and actigraphic rest-activity mesor (B=0.02, p=0.001 and B=0.03, p=0.004, respectively). Additionally, the Net PIPR-30s were positively associated with overnight aMT6s level (B=0.04, p=0.03), and negatively associated with actigraphic rest-activity acrophase (B=-0.01, p=0.004) in the fully adjusted models. Attenuated PIPR is associated with a reduced actigraphic amplitude and mesor. The reduced retinal light responsivity may be a potential pathway contributing to impaired photic input to the circadian clock and resulted in the age-related circadian changes in older adults.

Cognitive correlates of circadian rhythm and sleep-wake behaviour in chronic obstructive pulmonary disease patients

ABSTRACT Chronic obstructive pulmonary disease (COPD) patients often experience reduced physical activity, sleep disturbances, and cognitive impairment. However, reports on measurement of rest-activity rhythm and sleep-wake behavior and their impact on cognitive functions in COPD patients are limited. This study aimed to objectively measure circadian rhythms (rest-activity and ambient illuminance) and sleep behaviors in clinically stable COPD patients and their relationship with cognitive functions. The study involved 65 male COPD patients and 50 age-matched controls, monitored over 3–7 days using actigraphy. Cognitive status was assessed using the Montreal Cognitive Assessment (MoCA) followed by short interbal time estimation via time production and reproduction with reaction time measurement using TimeProd software. Findings indicated significant disruptions in circadian rhythms in COPD patients, characterized by lower mesor, amplitude, and autocorrelation coefficients compared to controls. Patients also reported poorer sleep quality and higher sleep fragmentation, with 85.7% displaying cognitive impairment. Notably, longer time estimations, increased variability in task performance, and slower reaction times suggested cognitive deterioration. Positive correlations emerged between rhythm parameters (amplitude and circadian quotient) and cognitive performance metrics. This highlights the relevance of circadian and sleep disturbances in COPD, suggesting that addressing these rhythms could help mitigate cognitive decline, potentially through chronotherapeutic strategies.

Associations between rest–activity/light-exposure rhythm characteristics and depression in United States adults: A population-based study

This cross-sectional study investigated the association between 24-hour rest-activity rhythm (RAR), light exposure rhythm (LER), and depression symptoms in American adults, using data from the National Health and Nutrition Examination Survey (2011–2014, N = 6852). RAR and LER characteristics were derived from a 24-hour activity recorder and analyzed using the extended cosine model, focusing on intradaily variability (IV), interdaily stability (IS), and relative amplitude (RA). Depression was assessed via the Patient Health Questionnaire-9 (PHQ-9).Multiple logistic and linear regression models showed that higher IV in RAR and LER were associated with increased depression risk (RAR-IV OR = 1.92 [95 % CI: 0.89–4.13]; LER-IV OR = 2.5 [1.45–4.30]), while higher IS and RA in both rhythms were linked to lower depression risk (RAR-IS OR = 0.22 [0.10–0.48], RAR-RA OR = 0.20 [0.11–0.37], LER-IS OR = 0.22 [0.10–0.49], LER-RA OR = 0.29 [0.15–0.56]). Participants in the highest tertile for IS and RA had a significantly lower depression risk compared to the lowest tertile. Subgroup analyses indicated interactions between age and RAR-IV, gender and LER-IV, and BMI and LER-RA (p-interaction < 0.05). Disruptions in RAR and LER are positively associated with depression, emphasizing the need for rhythm regulation interventions considering age, gender, and BMI factors.

Phenotypes of sleep health among adults with chronic heart failure in a randomized controlled trial of cognitive behavioral therapy for insomnia.

Poor sleep contributes to adverse health in heart failure. However, studies are limited to isolated sleep characteristics. To evaluate changes in sleep health phenotypes after cognitive behavioral therapy for insomnia or attention control and associations between sleep health phenotypes, symptoms, stress, functional performance, and emergency department visits and hospitalizations. Secondary analysis of a randomized controlled trial of cognitive behavioral therapy for insomnia among adults with heart failure. We measured sleep (rest-activity rhythms, sleep duration, quality, and efficiency, insomnia severity, daytime sleepiness), symptoms, cognitive ability, vigilance, and 6-minute walk distance at baseline and 3-, 6-, and 12-month postintervention and collected hospitalizations and emergency department visits. We used K-means cluster analysis and generalized linear mixed models, generalized estimating equations, and Cox proportional hazard models. Among 166 participants (M age=63.2 (SD=12.6) years; 57% male; 23% NewYork Heart Association Class III/IV), there were four sleep health phenotypes ("Unstable Sleep" (15%); "Short Sleep" (39%); "Low Sleep Efficiency" (25%); and "Good Sleep" (21%)) at baseline. The healthiest phenotype was associated with the lowest fatigue. The proportions of participants in the healthiest sleep group increased from pre- to post-treatment. Low sleepiness (p=.0188) and a robust circadian quotient (p=.007) predicted transition to the healthiest phenotype. The poorest sleep phenotype at baseline predicted time to hospitalizations and emergency department visits (hazard ratios 0.35-0.60) after adjusting for covariates. Sleep phenotypes predict heart failure outcomes. Tailored interventions targeting phenotypes may be more effective than approaches that focus on single sleep characteristics.

Association between rest-activity rhythm and diabetic retinopathy among US middle-age and older diabetic adults.

The disruption of circadian rhythm has been reported to aggravate the progression of diabetic retinopathy (DR). Rest-activity rhythm (RAR) is a widely used method for measuring individual circadian time influencing behavior. In this study, we sought to explore the potential association between RAR and the risk of DR. Diabetic participants aged over 40 from 2011-2014 National Health and Nutrition Examination Survey (NHANES) were enrolled. Data from the wearable device ActiGraph GT3X was used to generate RAR metrics, including interdaily stability (IS), intradaily variability (IV), most active 10-hour period (M10), least active 5-hour period (L5), and Relative amplitude (RA). Weighted multivariable logistic regression analysis and restricted cubic spline analysis were conducted to examine the association between RAR metrics and DR risk. Sensitivity analysis was also conducted to examine the robustness of the findings. An unsupervised K-means clustering analysis was conducted to identify patterns in IV and M10. A total of 1,096 diabetic participants were enrolled, with a DR prevalence of 20.53%. The mean age of participants was 62.3 years, with 49.57% being male. After adjusting covariates, IV was positively associated with DR (β: 3.527, 95%CI: 1.371-9.073). Compared with the lowest quintile of IV, the highest quintile of IV had 136% higher odds of DR. In contrast, M10 was negatively associated with DR (β: 0.902, 95%CI: 0.828-0.982), with participants in the highest M10 quintile showing 48.8% lower odds of DR. Restricted cubic spline analysis confirmed that these associations were linear. Meanwhile, sensitivity analysis confirmed the robustness. K-means clustering identified three distinct clusters, with participants in Cluster C (high-IV, low-M10) had a significantly higher risk of DR comparing with Cluster A (low-IV, high-M10). A more fragmented rhythm and lower peak activity level might be associated with an increased risk of DR. These findings indicate that maintaining a more rhythmic sleep-activity behavior might mitigate the development of DR. Further research is necessary to establish causality and understand the underlying mechanisms, and focus on whether interventions designed to enhance daily rhythm stability and increase diurnal activity level can effectively mitigate the risk of progression of DR.

Biobehavioral mechanisms underlying symptoms in cancer patients with chronic graft-versus-host disease

Chronic graft-versus-host disease (cGVHD) is a complication of allogeneic hematopoietic cell transplant (HCT) and is associated with morbidity and high symptom burden. This study evaluated two biobehavioral mechanisms, inflammation and circadian rest-activity rhythms, that may underly commonly reported psychological and physical symptoms in cGVHD patients. Adults with cGVHD (N=57) wore a wrist actigraph for 7 days, provided a blood sample, and completed patient-reported outcome (PRO) measures. 24-hour rest-activity indices were derived from actigraphy. Cytokines and chemokines relevant to cGVHD were measured in peripheral blood plasma using multi-analyte immunoassays. Multiple regression evaluated the extent to which rest-activity indices and inflammatory biomarkers predicted PROs. Higher levels of circulating IL-8 and MIP-1α were associated with worse depression (β = 0.35, p = 0.01; β = 0.33, p = 0.02) and sexual function (β = -0.41, p = 0.01; β = -0.32, p = 0.03). MIP-1α was associated with more severe insomnia (β = 0.36, p = 0.01). Higher circulating MIF was associated with more severe anxiety (β = 0.28, p = 0.048) and fatigue (β = 0.35, p = 0.02). Il-6, TNFα, and MCP-1 showed few associations with PROs. There were few associations between actigraphy indices and PROs; however, participants with a later daily activity peak (acrophase) reported poorer sexual function (β = -0.31, p = 0.04). Models covarying for age, cGVHD severity, and time since HCT yielded a similar pattern of results. Results suggest that pro-inflammatory cytokines and chemokines associated with cGVHD may contribute to PROs, identifying a biobehavioral mechanism that may be a useful target for future interventions.

Rest-Activity Rhythm Phenotypes in Adults with Epilepsy and Intellectual Disability.

Sleep and rest-activity rhythms (RARs) are perturbed in many forms of neuropsychiatric illness. In this study, we applied wrist actigraphy to describe the extent of RAR perturbations in adults with epilepsy and intellectual disability ("E+ID"), using a cross-sectional case-control design. We examined whether RAR phenotypes correlated with epilepsy severity, deficits in adaptive function and/or comorbid psychopathology. Primary caregivers of E+ID adults provided informed consent during routine ambulatory clinic visits and were asked to complete standardized surveys of overall epilepsy severity (GASE, Global Assessment of Severity of Epilepsy), adaptive function (ABAS-3, Adaptive Behavior Assessment System-3) and psychopathology (ABCL, Adult Behavior Checklist). Caregivers were also asked to ensure that subjects wore an Actiwatch-2 device continuously on their nondominant wrist for at least ten days. From recorded actograms, we calculated RAR amplitude, acrophase, robustness, intradaily variability (IV), interdaily stability (IS) and estimates of sleep quantity and timing. We compared these RAR metrics against those from (i) a previously published cohort of adults with epilepsy without ID (E-ID), and (ii) a cohort of age- and sex-matched intellectually able subjects measured within the Study of Latinos (SOL) Ancillary actigraphy study (SOL). Within E+ID subjects, we applied k-means analysis to divide subjects into three actigraphically distinct clusters. 46 E+ID subjects (median age 26 [20-68], 47% female) provided a median recording duration of 11 days [range 6-27]. Surveys reflected low to extremely low levels of adaptive function (ABAS3 General Adaptive Composite score: median 50 [49-75]), and low/subclinical levels of psychopathology (ABCL total score: median 54.5 [25-67]). Compared with E-ID (n=57) and SOL (n=156) cohorts, E+ID subjects displayed significantly lower RAR amplitude, robustness and IS, with significantly higher IV and total daily sleep. K-means clustering of E+ID subjects recognized an intermediate cluster "B", with RAR values indistinguishable to E-ID. Cluster "A" subjects displayed pronounced hypoactivity and hypersomnia with high rates of rhythm fragmentation, while cluster "C" subjects featured hyper-robust and high amplitude RARs. All three clusters were similar in age, body mass index, antiseizure medication (ASM) polytherapy, ABAS3 and ABCL scores. We qualitatively describe RAR examples from all three clusters. We show that adults with epilepsy and intellectual disability display a wide spectrum of RAR phenotypes that do not neatly correlate with measures of adaptive function or epilepsy severity. Prospective studies are necessary to determine whether continuous actigraphic monitoring can sensitively capture changes in chronobiological health that may arise with disease progression, iatrogenesis (e.g., ASM toxicity) or acute health deteriorations (e.g., seizure exacerbation, pneumonia). Similar long-term data is necessary to recognize whether behavioral interventions targeted to 'normalize' RARs may promote improvements in adaptive function and therapy engagement.

Sleep During the COVID-19 Pandemic: Longitudinal Observational Study Combining Multisensor Data With Questionnaires.

The COVID-19 pandemic prompted various containment strategies, such as work-from-home policies and reduced social contact, which significantly altered people's sleep routines. While previous studies have highlighted the negative impacts of these restrictions on sleep, they often lack a comprehensive perspective that considers other factors, such as seasonal variations and physical activity (PA), which can also influence sleep. This study aims to longitudinally examine the detailed changes in sleep patterns among working adults during the COVID-19 pandemic using a combination of repeated questionnaires and high-resolution passive measurements from wearable sensors. We investigate the association between sleep and 5 sets of variables: (1) demographics; (2) sleep-related habits; (3) PA behaviors; and external factors, including (4) pandemic-specific constraints and (5) seasonal variations during the study period. We recruited working adults in Finland for a 1-year study (June 2021-June 2022) conducted during the late stage of the COVID-19 pandemic. We collected multisensor data from fitness trackers worn by participants, as well as work and sleep-related measures through monthly questionnaires. Additionally, we used the Stringency Index for Finland at various points in time to estimate the degree of pandemic-related lockdown restrictions during the study period. We applied linear mixed models to examine changes in sleep patterns during this late stage of the pandemic and their association with the 5 sets of variables. The sleep patterns of 27,350 nights from 112 working adults were analyzed. Stricter pandemic measures were associated with an increase in total sleep time (TST) (β=.003, 95% CI 0.001-0.005; P<.001) and a delay in midsleep (MS) (β=.02, 95% CI 0.02-0.03; P<.001). Individuals who tend to snooze exhibited greater variability in both TST (β=.15, 95% CI 0.05-0.27; P=.006) and MS (β=.17, 95% CI 0.03-0.31; P=.01). Occupational differences in sleep pattern were observed, with service staff experiencing longer TST (β=.37, 95% CI 0.14-0.61; P=.004) and lower variability in TST (β=-.15, 95% CI -0.27 to -0.05; P<.001). Engaging in PA later in the day was associated with longer TST (β=.03, 95% CI 0.02-0.04; P<.001) and less variability in TST (β=-.01, 95% CI -0.02 to 0.00; P=.02). Higher intradaily variability in rest activity rhythm was associated with shorter TST (β=-.26, 95% CI -0.29 to -0.23; P<.001), earlier MS (β=-.29, 95% CI -0.33 to -0.26; P<.001), and reduced variability in TST (β=-.16, 95% CI -0.23 to -0.09; P<.001). Our study provided a comprehensive view of the factors affecting sleep patterns during the late stage of the pandemic. As we navigate the future of work after the pandemic, understanding how work arrangements, lifestyle choices, and sleep quality interact will be crucial for optimizing well-being and performance in the workforce.

Exploration of sleep quality and rest-activity rhythms characteristics in Bilateral Vestibulopathy patients

Sleep and circadian timing systems are constantly regulated by both photic and non-photic signals. Connections between the vestibular nuclei and the biological clock raise the question of the effect of peripheral vestibular loss on daily rhythms, such as the sleep-wake cycle and circadian rhythm. To answer this question, we compared the sleep and rest-activity rhythm parameters of 15 patients with bilateral vestibulopathy (BVP) to those of 15 healthy controls. Sleep and rest-activity cycle were recorded by a device coupling actimetry with the heart rate and actigraphy at home over 7 days. Subjective sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI). Sleep efficiency and subjective sleep quality were significantly reduced, and sleep fragmentation was increased in BVP patients compared to controls. BVP patients displayed a damped amplitude of the rest-activity rhythm and higher sleep fragmentation, reflected by a higher nocturnal activity compared to controls. These results suggest that both rest-activity and sleep cycles are impaired in BVP patients compared to healthy controls. BVP patients seem to have greater difficulty maintaining good sleep at night compared to controls. BVP pathology appears to affect the sleep-wake cycle and disturb the circadian rhythm synchronization. Nevertheless, these results need further investigation to be confirmed, particularly with larger sample sizes.

The association between maternal sleep and circadian rhythms during pregnancy and infant sleep and socioemotional outcomes.

Studies have established that maternal sleep and circadian rhythm disturbances during pregnancy are associated with poor prenatal and perinatal outcomes for mothers and offspring. However, little work has explored its effects on infant sleep or socioemotional outcomes. The current study examined the relationship between maternal sleep and circadian rhythm disturbances during pregnancy and infant sleep and socioemotional outcomes in a diverse sample of N = 193 mothers and their infants (51% White; 52% Female; Mage = 11.95months). Maternal sleep and circadian rhythms during pregnancy were assessed using self-reports and actigraphy. Mothers reported on infants' sleep and socioemotional outcomes when infants were one year old. When controlling for infant sex, age, gestational age at birth, family income-to-needs ratios, and maternal depression, mothers who reported more sleep problems during pregnancy had infants with more sleep disturbances when they were one year old. Moreover, mothers who had later sleep timing (i.e., went to bed and woke up later, measured via actigraphy) during pregnancy had infants with more dysregulation (e.g., increased feeding difficulties, sensory sensitivities) and externalizing problems, and mothers with increased intra-daily variability in rest-activity rhythms (as measured via actigraphy) had infants with more externalizing problems. Findings suggest that maternal sleep and circadian rhythm disturbances during pregnancy may be a risk factor for infant sleep problems and socioemotional difficulties.

Improvement of social frailty is associated with stability of nonparametric characteristics of the rest-activity rhythm and improvement of the usual walking ability in the elderly

ABSTRACT Our study, conducted between April 2022 and January 2024, was aimed at clarifying components of the rest-activity rhythm (RAR) involved in improvement of social frailty state before or after a 3-month multi-component exercise intervention in the elderly. Participants were recruited from the general population in Akita prefecture, Japan. We administered a four-item social frailty screening questionnaire to classify the severity of social frailty in each participant before and after the 3-month intervention. The RAR parameters were measured on an Actiwatch Spectrum Plus device worn by the subjects for 7 continuous days. As the final sample, 65 participants classified into the improved/maintained group (n = 36) or the deteriorated group (n = 29) according to the change in the social frailty classification after the intervention were included in the analysis. The results of a binomial logistic regression analysis showed significantly higher values of interdaily stability (IS) and usual walking speed at the post-test after the intervention. Based on our findings, we propose that stability of the rest-activity rhythm related to synchronization with external stimuli (such as social effect and physical activity) might have clinical impact on improvement of social frailty state in elderly community-dwellers.

Insomnia prehabilitation in newly diagnosed breast cancer patients: Protocol for a pilot, multicentre, randomised controlled trial comparing nurse delivered sleep restriction therapy to sleep hygiene education (INVEST trial).

Insomnia is a prevalent sleep disorder that negatively impacts daytime functioning and quality of life. Breast cancer patients report higher rates of insomnia and more circadian disruption than other cancer groups. Approximately 50% of patients experience acute insomnia following breast cancer diagnosis, which often persists during cancer treatment and rehabilitation. Sleep Restriction Therapy (SRT) is a clinically effective and tolerable treatment for persistent insomnia in breast cancer survivors. However, SRT has never been tested on patients with early signs of sleep disturbance who are undergoing cancer treatment. The aim of this pilot randomised controlled trial is to explore the feasibility and preliminary effectiveness of nurse delivered SRT for newly diagnosed breast cancer patients with acute insomnia. The trial has been registered on ClinicalTrials.gov (identifier: NCT06294041). The INVEST (INvestigating the Value of Early Sleep Therapy) trial will recruit 50 newly diagnosed breast cancer patients who meet criteria for acute insomnia. Patients will be recruited from breast cancer results clinics within two Scottish health boards (NHS Grampian and NHS Greater Glasgow and Clyde) and will be block randomised (1:1) to receive nurse delivered SRT or Sleep Hygiene Education (SHE). SRT will be delivered over 4 weekly sessions comprising two face-to-face meetings (either in person or online) and two telephone calls, whereas SHE will be administered in booklet form. Outcomes will be collected at baseline, 6 weeks, and 12 weeks post-randomisation. Primary outcomes in this trial relate to the feasibility of SRT for newly diagnosed breast cancer patients with acute insomnia. Specifically, we will explore (i) rates of patient recruitment and retention, (ii) intervention fidelity, (iii) data collection procedures and outcome measure completion, (iv) intervention acceptability. Secondary outcomes will focus on preliminary evaluation of patient responses to SRT, including insomnia severity, rest-activity rhythms, and mental health. Our dissemination plan comprises publishing trial outcomes in high-impact, peer-reviewed journals and on breast cancer charity websites and other patient resources. The outcomes from this pilot trial will also inform the development of a full-scale, multicentre RCT of SRT for acute insomnia in newly diagnosed breast cancer patients. University of Strathclyde is the sponsor (reference: UEC23/52). Protocol version v1.2 4 October 2023. This trial is the first to explore the value of sleep prehabilitation for newly diagnosed breast cancer patients.This will be the first trial to assess the feasibility of delivering SRT during breast cancer treatment, providing valuable insight into its tolerability and preliminary effectiveness.An embedded process evaluation will assess the acceptability of SRT, providing insight into potential optimisation of the intervention and recommendations for enhancing its future scalability and translation within cancer care.Due to the nature of the SRT intervention, nurse therapists and patients cannot be blinded to treatment allocation, increasing the risk of bias.

Violet Light Effects on the Circadian Rest-Activity Rhythm and the Visual System.

Rooms illuminated by "black light" (<400 nm wavelength) has become popular, but there is not enough scientific evidence to support its implementation. This study aims to assess the effects of violet light (392 nm) on the circadian rest-activity rhythm and the visual system through animal experimentation. Five groups of four mice were exposed to different white light, violet light, and dark periods, and their circadian rhythm was analyzed by measuring the circadian period using rest-activity cycles. Electroretinographic recordings and structural analysis of the retina were also performed on experimental animals. Our study demonstrates that mice present normal circadian activity during exposure to violet light, taking rest not only under white light but under violet lighting periods. However, mice suffered a decrease in electrical retinal response after exposure to violet light as measured by electroretinography. Nevertheless, no structural changes were observed in the retinas of the animals under different lighting conditions. Violet light elicits circadian rest-activity rhythm in mice but alters their visual function, although no structural changes are observed after short periods of violet light exposure.

Exploration of effects of galvanic vestibular stimulation on circadian rhythms and its associations with sleep and spatial memory in patients with breast cancer: The ICANSLEEP-2 protocol.

Patients with breast cancer (BC) exhibit circadian rhythm disruptions, mainly of rest-activity rhythm (RAR), of which sleep is an essential component, and cortisol rhythm. Sleep complaints such as insomnia and cognitive impairments are prevalent in BC. In general population, sleep is known to contribute greatly to cognition. Thus, improving RAR (and particularly sleep) could help limiting cognitive impairments in BC patients. It has recently been suggested that, in addition to its essential role in spatial memory, the vestibular system contributes to RAR synchronization. Its stimulation could therefore limit both sleep disturbances and spatial memory deficits in BC. The main aim of the ICANSLEEP-2 study is to assess the effects of galvanic vestibular stimulation (GVS) on circadian rhythms. The secondary aim is to assess whether GVS improves sleep and spatial memory in BC patients. Two groups with insomnia complaints (Insomnia Severity Index > 7) will be included: a patients' group with BC (n = 50) and a healthy control group without history of cancer (n = 25). There will be two assessment sessions, before and after 2 weeks of GVS. Patients will be randomly assigned to either a GVS group or a sham group (noneffective stimulation). Controls will receive GVS. GVS effects will be quantified and compared between groups. Assessments will include actigraphy, salivary cortisol, polysomnography, a cognitive test battery (including a computer-based task for spatial memory) and validated questionnaires (for psychological functioning and sleep complaints). Current methods for improving sleep in BC have had controversial outcomes regarding sleep structure. We expect GVS to offer a new mean of directly targeting RAR disruptions in BC patients, with beneficial effects on sleep structure. Given the crucial impact of sleep on cognitive functioning, notably spatial memory, improving sleep of BC patients should enhance their cognitive functioning. This study received ethical approval from the Ile de France IV institutional review board on 19 April 2022 (no. ID-RCB: 2022-A00437-36). The findings yielded by this protocol will be presented at various conferences and in peer-reviewed journals. NCT05414357.

Five-year changes in 24-hour sleep-wake activity and dementia risk in oldest old women.

Sleep disruptions are associated with cognitive aging in older adults. However, it is unclear whether longitudinal changes in 24-hour multidimensional sleep-wake activity are linked to cognitive impairment in the oldest old. We studied 733 cognitively unimpaired women (mean age=82.5±2.9 years) who completed two actigraphy assessments over five years. We performed hierarchical clustering on principal components in nine sleep, napping, and circadian rest-activity rhythm parameters to identify multidimensional sleep-wake change profiles and multinomial logistic regression to evaluate the associations between sleep-wake changes and risk of cognitive impairment at follow-up. We identified three sleep-wake change profiles: Stable Sleep (43.8%), Declining Nighttime Sleep (34.9%), and Increasing Sleepiness (21.3%). After adjustment for demographics and comorbidities, women with Increasing Sleepiness had approximately doubled (odds ratio=2.21, p=0.018) risk of dementia compared to those with Stable Sleep. Increasing sleepiness may be an independent marker or risk factor for dementia in oldest old women.

The optimal measurement period of actigraphy for circadian rhythm in relation to adiposity: A retrospective case-control study

BackgroundThis study focused on the relationship between adiposity and Rest-Activity Rhythms (RAR), utilizing both parametric cosine-based models and non-parametric algorithms. The emphasis was on the impact of varying measurement periods (7–28 days) on this relationship. MethodsWe retrieved actigraphy data from two datasets, encompassing a diverse cohort recruited from an obesity outpatient clinic and a workplace health promotion program. Participants were required to wear a research-grade wrist actigraphy device continuously for a minimum of four weeks. The final dataset included 115 individuals (mean age 40.7 ± 9.5 years, 51 % female). We employed both parametric and non-parametric methods to quantify RAR using six standard variables. Additionally, the study evaluated the correlations between three key adiposity indices — Body Mass Index (BMI), Visceral Adipose Tissue (VAT) area, and Body Fat Percentage (BF%) — and circadian rhythm indicators, controlling for factors like physical activity, age, and gender. ResultsThe obesity group displayed a significantly lower relative amplitude (RA) as per non-parametric algorithm findings, with a decreased amplitude noted in the parametric algorithm analysis, in comparison to the overweight and control groups. The relationship between circadian rhythm indicators and adiposity metrics over 7- to 28-day periods was examined. A notable negative correlation was observed between RA and both BMI and VAT, while correlation coefficients between adiposity indicators and non-parametric circadian parameters increased with extended durations of actigraphy data. Specifically, RA over a 28-day period was significantly correlated with BF%, a trend not seen in the 7-day measurement (p = 0.094) in multivariate linear regression. The strength of the correlation between BF% and 28-day RA was more pronounced than that in the 7-day period (p = 0.044). However, replacing RA with amplitude as per parametric cosinor fitting yielded no significant correlations for any of the measurement periods. ConclusionThe study concludes that a 28-day measurement period more effectively captures the link between disrupted circadian rhythms and adiposity. Non-parametric algorithms, in particular, were more effective in characterizing disrupted circadian rhythms, especially when extending the measurement period beyond the standard 7 days.

Exploring actigraphy as a digital phenotyping measure: A study on differentiating psychomotor agitation and retardation in depression.

Psychomotor activity stands out as a crucial symptom in characterizing behaviors associated with depression. This study aims to explore the potential of actigraphy as a tool for digital phenotyping in characterizing symptoms of psychomotor agitation and retardation, which are clinically challenging dimensions to capture, in patients diagnosed with major depressive episode (MDE) according to DSM-5 criteria. We compared rest-activity circadian rhythm biomarkers measured by the Motion Watch 8 actigraphy between 58 (78.4%) patients with MDE and psychomotor retardation (PMR), and 16 (21.6%) patients with MDE and psychomotor agitation (PMA), according to DSM-5 criteria. Actigraphy allowed to objectively report PMA through heightened activity over a 24-h period, while PMR manifests as reduced activity during the most active 10 h. Lower rest-activity rhythm (RAR) amplitude in PMR was accompanied by increased irregularities in intra- and inter-day rhythms. Interestingly, actigraphy emerges as an objective tool to measure the characteristics of the active and rest periods, free from the confounding effects of sleep disturbances. Indeed, no differences in sleep disturbances were identified between patients exhibiting psychomotor agitation and those displaying PMR. Digital phenotyping through actigraphy may aid in distinguishing psychomotor retardation and psychomotor agitation allowing for a more precise characterization of the depression phenotype. When integrated with clinical assessment, measurements from actigraphy could offer additional insights into activity rhythms alongside subjective assessments and hold the potential to augment existing clinical decision-making processes in psychiatry.