BACKGROUND: To characterize sleep disturbance in patients with established rheumatoid arthritis (RA) and explore the relationship between sleep and mechanisms of central nervous system pain regulation.
METHODS: Forty-eight RA participants completed wrist-worn actigraphy monitoring and daily sleep diaries for 14 days to assess sleep-wake parameters. Participants underwent quantitative sensory testing to assess pressure pain thresholds, temporal summation, and conditioned pain modulation. Data were analyzed using descriptive statistics, Spearman\'s correlation, and multivariable median regression analyses.
RESULTS: Median actigraphy and sleep diary derived sleep duration was 7.6 h (interquartile range (IQR) 7.0, 8.2) and 7.1 h (IQR 6.7, 7.6), respectively. Actigraphy based sleep fragmentation (rho = 0.34), wake after sleep onset (rho = 0.36), and sleep efficiency (rho = -0.32) were each related to higher temporal summation values in unadjusted analyses, but these relationships did not persist after controlling for age, body mass index, disease duration, and swollen joint count. No significant relationships were observed between sleep with pressure pain thresholds and conditioned pain modulation.
CONCLUSIONS: Actigraphy and sleep diary monitoring are well tolerated in established RA patients. Future investigations should include both subjective and objective assessments, as they may provide information relating to different components and mechanisms.

BACKGROUND: Disturbed sleep is frequently identified in adult patients with cancer and their caregivers, with detrimental impact on physical health. Less known is the extent to which self-reported and actigraph-measured sleep patterns are similar between patients and their sleep-partner caregivers, and how these different modes of sleep measurements are related to physical health.
METHODS: Patients diagnosed with colorectal cancer and their sleep-partner caregivers (81 dyads) completed a questionnaire for physical functioning and collected saliva samples for seven consecutive days, from which cortisol slope was quantified. Additionally, participants completed a daily sleep diary and wore actigraph for 14 consecutive days, from which sleep duration, sleep onset latency (SOL), and duration of wake after sleep onset (WASO) were calculated.
RESULTS: Participants reported sleep patterns that fell within or close to the optimal range, which were similar between patients and their caregivers. Self-reported and actigraph-measured sleep duration had moderate levels of agreement (ICC = 0.604), whereas SOL and WASO had poor agreement (ICC = 0.269). Among patients, longer self-reported WASO was associated with poorer physical health and flatter cortisol slope (p ≤ 0.013). Among caregivers, longer self-reported SOL was associated with poorer physical functioning, actigraph-measured WASO was associated with steeper cortisol slope, and longer self-reported sleep markers studied than actigraph-measured were associated with poorer physical functioning (p ≤ 0.042).
CONCLUSIONS: Findings suggest that employing multiple assessment modes for sleep and physical health is vital for comprehensive understanding of sleep health. Furthermore, when addressing patients\' sleep health, it may be beneficial to include their sleep-partner caregivers who may experience similar disturbed sleep.

BACKGROUND: Patients with myocardial infarction (MI) can have disturbed sleep, but little is known about the efficacy of light therapy on sleep and prognosis of patients with MI. We conducted a randomized controlled study to investigate its efficacy.
METHODS: This preliminary study included 34 patients with MI. They were randomized into the blue light and the white light groups during their stay in intensive care unit. 17 age and gender matched healthy controls were also enrolled. Actigraphy was used to evaluate objective sleep since enrollment. Delirium scales were used to screen delirium. Lab work-up including vitamin D level was performed at the baseline and discharge. We used Mann-Whitney U test or Wilcoxon signed-rank test to compare the difference between the MI group and the healthy control group, and the group difference after receiving light therapy.
RESULTS: Patients with MI had significantly lower vitamin D level than healthy controls (p<0.001). They also had significantly poorer sleep, as indicated by actigraphy parameters including sleep onset latency (p=0.01), sleep efficiency (p=0.002), wake after sleep onset (p<0.001) and awake times (p=0.002). No significant group difference was found by actigraphy after light therapy except a non-significant higher relative amplitude of the blue light group (p=0.061). Besides, vitamin D level of the blue light group increased significantly (p1=0.047, p2=0.045).
CONCLUSIONS: Patients with MI had poorer sleep, highlighting the needs to develop interventions. Significantly increased vitamin D level and a non-significant better rest-active rhythm after light therapy suggest its potential with sleep and prognosis which warrants further investigation.

BACKGROUND: The aims of this cross-sectional study were to (a) assess actigraphy-based sleep parameters (total sample and gender differences), (b) assess differences in morphological parameters and physical function between short- versus normal-sleepers and poor- versus good-sleepers, and (c) assess the possible correlations between sleep variables and morphological and physical function parameters in older subjects.
METHODS: This study enrolled 42 healthy older participants (60-80 years). Participants completed the following clinical evaluations: (1) whole-body dual-energy X-ray absorptiometry to assess the appendicular skeletal muscle mass index; (2) magnetic resonance imaging acquisition to determine the cross-sectional muscle area of thigh muscles and intermuscular adipose tissue; (3) risk of fall assessment through the mini-Balance Evaluation Systems Test; (4) strength assessment: (a) chair stand test and (b) handgrip strength test; (5) sleep monitoring by actigraphy to assess total sleep time, sleep efficiency, wake after sleep onset, sleep latency, fragmentation index, mobile time, and subjective sleep quality.
RESULTS: 31.0% of subjects were short-sleepers (total sleep time < 6 hr), 19.1% were poor-sleepers (sleep efficiency < 85%), and gender differences were detected in mobile time (males: 15.8 ± 6.0 and females: 13.4 ± 6.8; p < .001) and fragmentation index (males: 35.3 ± 14.3 and females: 29.6 ± 14.6; p < .001); no significant differences were observed between groups (short- vs. normal-sleepers and poor- vs. good-sleepers) in morphological and physical function variables; correlation analysis showed that sleep latency negatively correlated with Mini-Balance Evaluation Systems Test (r = -.352; p = .022) and a positive correlation was detected between cross-sectional muscle area and mobile time (r = .349, p = .023).
CONCLUSIONS: No differences were observed in morphological and function parameters between good- versus poor-sleepers, those subjects with worse sleep onset latency (i.e., longer time to fall asleep) registered higher for risk of fall. The potential role of sleep in the physiological mechanisms of muscular aging must be explored through cross-sectional cohort studies with a larger population.

BACKGROUND: This 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.
METHODS: We 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.
RESULTS: The 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.
CONCLUSIONS: The 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.

UNASSIGNED: Non-Invasive Ventilation (NIV) is the first choice approach in neonates with sufficient respiratory effort that require respiratory support. The type of nasal interface used in NIV affects both efficacy and patient comfort. The aim of this study is to investigate the effects of different nasal interfaces used in NIV support on neonatal patient comfort.
UNASSIGNED: Our study evaluated patients who received NIV support for 24 hours. The patients were randomly divided into two groups according to the type of nasal interface used, which were RAM cannula and short binasal prong (SBP). The patients\' demographic and clinical data were noted. Their sleep was monitored for 24 hours with an actigraphy device.
UNASSIGNED: A total of 82 patients were evaluated. The sleep efficiency in the RAM cannula group was significantly higher (respectively, 65.7% [10.22-95.25] vs. 57.81% [2.49-77], p=0.004). Although not statistically significant, the neonates in the RAM cannula group exhibited longer total sleep time (respectively, 10.4 ± 4.28 hours vs. 9.02 ± 3.73 hours, p=0.161). Comparison of heart rates and respiratory rates indicate that the patients in the RAM cannula group were more comfortable.
UNASSIGNED: Our study found that infants who received NIV support through a RAM cannula experienced more efficient sleep. Holistic approaches in neonatal intensive care units are vital for better neurodevelopmental outcomes in newborns. Although non-invasive, the interface used in NIV should also be a part of this holistic approach.

Sleep-wake (SW) cycle detection is a key step for extracting temporal sleep metrics from actigraphy. Various supervised learning algorithms have been developed, yet their generalizability from sensor to sensor or study to study is questionable. In this paper, we detail and validate an unsupervised algorithm-CircaCP-for detecting SW cycles from actigraphy. It first uses a robust cosinor model to estimate circadian rhythm, then searches for a single change point (CP) within each circadian cycle. Using CircaCP, we estimated sleep/wake onset times (S/WOTs) from 2125 individuals\' data in the MESA sleep study and compared the estimated S/WOTs against self-reported S/WOT event markers, using Bland-Altman analysis as well as variance component analysis. On average, SOTs estimated by CircaCP were 3.6 min behind those reported by event markers, and WOTs by CircaCP were less than 1 min behind those reported by markers. These differences accounted for less than 0.2% variability in S/WOTs, considering other sources of between-subject variations. Rooted in first principles of human circadian rhythms, our algorithm transferred seamlessly from children\'s hip-worn ActiGraph data to ageing adults\' wrist-worn Actiwatch data. The generalizability of our algorithm suggests that it can be widely applied to actigraphy collected by other sensors and studies.

UNASSIGNED: Few studies of middle-aged and older adults have examined the association between age and sleep using objective sleep measures. We examined these associations in adults aged ≥40 years using wrist actigraphy, and investigated whether these associations differed by sex and race.
UNASSIGNED: Participants were 468 cognitively normal adults aged ≥40 years enrolled in the Baltimore Longitudinal Study of Aging who completed wrist actigraphy. We used Generalized Least Squares Models to examine the associations of age with actigraphic sleep parameters, including total sleep time (TST), sleep efficiency, sleep onset latency, and wake after sleep onset (WASO). We conducted interaction and stratification analyses to test whether cross-sectional age-sleep associations were modified by sex and race.
UNASSIGNED: In analyses adjusting for sex, body mass index, and individual medical conditions, older age was associated with longer TST from ages 40-70 that plateaued after age 70. Older age also was associated with lower sleep efficiency, longer sleep onset latency, and greater WASO. In men only, after age 70, older age was associated with shorter TST, lower sleep efficiency, longer onset latency, and greater WASO. However, we did not observe any significant interactions of race with age.
UNASSIGNED: Older age was associated with longer TST from ages 40 to 70 and with poorer sleep quality after age 40, and these relationships might vary by sex. Future studies with larger sample sizes are needed to investigate mechanisms that may account for sex differences in the observed age-sleep associations.

Insufficient sleep duration may lead to a series of immune dysfunctions. One of the factors influencing this effect could be physical activity (PA). The study aimed to assess the impact of deprivation of sleep (DS) on selected inflammatory parameters. Seventy-seven participants completed the protocol consisting of polysomnography (PSG) conducted in a sleep laboratory and DS, monitored with an actigraph. PA was assessed with actigraphy, which categorized participants as active or inactive. White blood cells (WBC) values negatively correlated with sleep efficiency based on sleep diaries and PSG parameters (total sleep time, sleep efficiency, and REM duration), but regression analysis showed that WBC depends only on the sleep diary parameter. Granulocytes (GRA) positively correlated with REM latency, and negatively with sleep efficiency. After DS, all participants exhibited an elevated GRA count. The number of WBC and GRA increased also in the active group; inactive participants showed no changes in inflammatory parameters. The overall number of WBC depends primarily on the quality of sleep over a period of several days. Under the influence of sleep deprivation, the number of GRA increases, but the number of leukocytes depends on the level of physical activity during DS.

Background: Sleep and affective states are closely intertwined. Nevertheless, previous methods to evaluate sleep-affect associations have been limited by poor ecological validity, with a few studies examining temporal or dynamic interactions in naturalistic settings. Objectives: First, to update and integrate evidence from studies investigating the reciprocal relationship between daily sleep and affective phenomena (mood, affect, and emotions) through ambulatory and prospective monitoring. Second, to evaluate differential patterns based on age, affective disorder diagnosis (bipolar, depression, and anxiety), and shift work patterns on day-to-day sleep-emotion dyads. Third, to summarise the use of wearables, actigraphy, and digital tools in assessing longitudinal sleep-affect associations. Method: A comprehensive PRISMA-compliant systematic review was conducted through the EMBASE, Ovid MEDLINE(R), PsycINFO, and Scopus databases. Results: Of the 3024 records screened, 121 studies were included. Bidirectionality of sleep-affect associations was found (in general) across affective disorders (bipolar, depression, and anxiety), shift workers, and healthy participants representing a range of age groups. However, findings were influenced by the sleep indices and affective dimensions operationalised, sampling resolution, time of day effects, and diagnostic status. Conclusions: Sleep disturbances, especially poorer sleep quality and truncated sleep duration, were consistently found to influence positive and negative affective experiences. Sleep was more often a stronger predictor of subsequent daytime affect than vice versa. The strength and magnitude of sleep-affect associations were more robust for subjective (self-reported) sleep parameters compared to objective (actigraphic) sleep parameters.