Rest-activity rhythm disturbance in liver cirrhosis and association with cognitive impairment

Sleep disturbances in chronic liver disease

Sleep disturbances are common in chronic liver disease and significantly impact patient outcomes and quality of life. The severity and nature of sleep disturbances vary by liver disease etiology and severity. While there is ongoing research into the association between liver disease and sleep-wake dysfunction, the underlying pathophysiology varies and, in many cases, is poorly understood. Liver disease is associated with alterations in thermoregulation, inflammation, and physical activity, and is associated with disease-specific complications, such as HE, that may directly affect sleep. In this article, we review the relevant pathophysiologic processes, disease-specific sleep-wake disturbances, and clinical management of CLD-associated sleep-wake disturbances.

Stability and Volatility of Human Rest-Activity Rhythms: Insights from Very Long Actograms (VLAs)

Importance

Wrist-worn activity monitors provide biomarkers of health by non-obtrusively measuring the timing and amount of rest and physical activity (rest-activity rhythms, RARs). The morphology and robustness of RARs vary by age, gender, and sociodemographic factors, and are perturbed in various chronic illnesses. However, these are cross-sectionally derived associations from recordings lasting 4-10 days, providing little insights into how RARs vary with time.

Objective

To describe how RAR parameters can vary or evolve with time (~months).

Design Setting and Participants

48 very long actograms ("VLAs", ≥90 days in duration) were identified from subjects enrolled in the STAGES (Stanford Technology, Analytics and Genomics in Sleep) study, a prospective cross-sectional, multi-site assessment of individuals > 13 years of age that required diagnostic polysomnography to address a sleep complaint. A single 3-year long VLA (author GD) is also described.

Exposures/Intervention

None planned.

Main Outcomes and Measures

For each VLA, we assessed the following parameters in 14-day windows: circadian/ultradian spectrum, pseudo-F statistic ("F"), cosinor amplitude, intradaily variability, interdaily stability, acrophase and estimates of "sleep" and non-wearing.

Results

Included STAGES subjects (n = 48, 30 female) had a median age of 51, BMI of 29.4kg/m2, Epworth Sleepiness Scale score (ESS) of 10/24 and a median recording duration of 120 days. We observed marked within-subject undulations in all six RAR parameters, with many subjects displaying ultradian rhythms of activity that waxed and waned in intensity. When appraised at the group level (nomothetic), averaged RAR parameters remained remarkably stable over a ~4 month recording period. Cohort-level deficits in average RAR robustness associated with unemployment or high BMI (>29.4) also remained stable over time.

Conclusions and Relevance

Through an exemplary set of months-long wrist actigraphy recordings, this study quantitatively depicts the longitudinal stability and dynamic range of human rest-activity rhythms. We propose that continuous and long-term actigraphy may have broad potential as a holistic, transdiagnostic and ecologically valid monitoring biomarker of changes in chronobiological health. Prospective recordings from willing subjects will be necessary to precisely define contexts of use.

Abnormalities of Rest-Activity and Light Exposure Rhythms Associated with Cognitive Function in Patients with Mild Cognitive Impairment (MCI)

We aimed to examine the difference in rest-activity rhythm (RAR) and light exposure rhythm (LER) between patients with mild cognitive impairment (MCI) and normal controls (NC), and to verify their relationships with cognitive functions. The neuropsychological battery was administered to participants above 50 years old. The MCI diagnosis was made according to Petersen's criteria. Ten patients with MCI (77.90 ± 6.95 years) and eight NC (74.75 ± 5.06 years) were studied. Actigraphy (Actiwatch 2; Philips Respironics) was recorded at home for 5 days. RAR and LER variables, including interdaily stability (IS), intradaily variability (IV) and relative amplitude, were calculated using nonparametric analyses. The associations between cognitive performance and RAR and LER variables were explored using generalized linear models. There were no significant differences in RAR or LER variables between MCI and NC. There was a significant main effect of RAR-IS on the Stroop Color and Word Test (SCWT), indicating a positive relationship between RAR stability and SCWT performance. There was a significant group by RAR-IS interaction on Trail Making Test-A, indicating a negative relationship in MCI compared to NC. There was a significant group by LER-IV interaction on the Boston Naming Test, indicating a positive relationship in MCI compared to NC. There was no disruption in RAR and LER in patients with MCI. Our study showed that circadian rhythm abnormality was associated with a decline in executive function. However, circadian rhythm abnormality was not associated with declines in processing speed and language function in patients with MCI, implying an altered pathophysiology compared to NC.

Hepatic encephalopathy complications are diminished by piracetam via the interaction between mitochondrial function, oxidative stress, inflammatory response, and locomotor activity

Background

of the study: Hepatic encephalopathy (HE) is a complication in which brain ammonia (NH4+) levels reach critically high concentrations because of liver failure. HE could lead to a range of neurological complications from locomotor and behavioral disturbances to coma. Several tactics have been established for subsiding blood and brain NH4+. However, there is no precise intervention to mitigate the direct neurological complications of NH4+.

Purpose

It has been found that oxidative stress, mitochondrial damage, and neuro-inflammation play a fundamental role in NH4+ neurotoxicity. Piracetam is a drug used clinically in neurological complications such as stroke and head trauma. Piracetam could significantly diminish oxidative stress and improve brain mitochondrial function.

Research methods

In the current study, piracetam (100 and 500 mg/kg, oral) was used in a mice model of HE induced by thioacetamide (TA, 800 mg/kg, single dose, i.p).

Results

Significant disturbances in animals' locomotor activity, along with increased oxidative stress biomarkers, including reactive oxygen species formation, protein carbonylation, lipid peroxidation, depleted tissue glutathione, and decreased antioxidant capacity, were evident in the brain of TA-treated mice. Meanwhile, mitochondrial permeabilization, mitochondrial depolarization, suppression of dehydrogenases activity, and decreased ATP levels were found in the brain of the TA group. The level of pro-inflammatory cytokines was also significantly high in the brain of HE animals.

Conclusion

It was found that piracetam significantly enhanced mice's locomotor activity, blunted oxidative stress biomarkers, decreased inflammatory cytokines, and improved mitochondrial indices in hyperammonemic mice. These data suggest piracetam as a neuroprotective agent which could be repurposed for the management of HE.

Light at night in older age is associated with obesity, diabetes, and hypertension

Light at night (LAN) has been associated with negative health consequences and metabolic risk factors. Little is known about the prevalence of LAN in older adults in the United States and its association with CVD risk factors. We tested the hypothesis that LAN in older age is associated with higher prevalence of individual CVD risk factors. Five hundred and fifty-two community-dwelling adults aged 63-84 years underwent an examination of CVD risk factor profiles and 7-day actigraphy recording for activity and light measures. Associations between actigraphy-measured LAN, defined as no light vs. light within the 5-hour nadir (L5), and CVD risk factors, including obesity, diabetes, hypertension, and hypercholesterolemia, were examined, after adjusting for age, sex, race, season of recording, and sleep variables. LAN exposure was associated with a higher prevalence of obesity (multivariable-adjusted odds ratio [OR] 1.82 [95% CI 1.26-2.65]), diabetes (OR 2.00 [1.19-3.43]), and hypertension (OR 1.74 [1.21-2.52]) but not with hypercholesterolemia. LAN was also associated with (1) later timing of lowest light exposure (L5-light) and lowest activity (L5-activity), (2) lower inter-daily stability and amplitude of light exposure and activity, and (3) higher wake after sleep onset. Habitual LAN in older age is associated with concurrent obesity, diabetes, and hypertension. Further research is needed to understand long-term effects of LAN on cardiometabolic risks.

Circadian rhythms and the liver

This narrative review briefly describes the mammalian circadian timing system, the specific features of the liver clock, also by comparison with other peripheral clocks, the role of the liver clock in the preparation of food intake, and its relationship with energy metabolism. It then goes on to provide a chronobiological perspective of the pathophysiology and management of several types of liver disease, with a particular focus on metabolic-associated fatty liver disease (MAFLD), decompensated cirrhosis and liver transplantation. Finally, it provides some insight into the potential contribution of circadian principles and circadian hygiene practices in preventing MAFLD, improving the prognosis of advanced liver disease and modulating liver transplantation outcomes.

MidCog study: a prospective, observational cohort study investigating health literacy, self-management skills and cognitive function in middle-aged adults

INTRODUCTION

The lack of definitive means to prevent or treat cognitive impairment or dementia is driving intense efforts to identify causal mechanisms. Recent evidence suggests clinically meaningful declines in cognition might present as early as middle age. Studying cognitive changes in middle adulthood could elucidate modifiable factors affecting later cognitive and health outcomes, yet few cognitive ageing studies include this age group. The purpose of the MidCog study is to begin investigations of less-studied and potentially modifiable midlife determinants of later life cognitive outcomes.

METHODS AND ANALYSIS

MidCog is a prospective cohort study of adults ages 35-64, with two in-person interviews 2.5 years apart. Data will be collected from interviews, electronic health records and pharmacy fill data. Measurements will include health literacy, self-management skills, cognitive function, lifestyle and health behaviours, healthcare use, health status and chronic disease outcomes. Associations of health literacy and self-management skills with health behaviours and cognitive/health outcomes will be examined in a series of regression models, and moderating effects of modifiable psychosocial factors.Finally, MidCog data will be linked to an ongoing, parallel cohort study of older adults recruited at ages 55-74 in 2008 ('LitCog'; ages 70-90 in 2023), to explore associations between age, health literacy, self-management skills, chronic diseases, health status and cognitive function among adults ages 35-90.

ETHICS AND DISSEMINATION

The Institutional Review Board at Northwestern University has approved the MidCog study protocol (STU00214736). Results will be published in peer-reviewed journals and summaries will be provided to the funders of the study as well as patients.

Associations of Multiple Serum Trace Elements with Abnormal Sleep Duration Patterns in Hospitalized Patient with Cirrhosis

The associations of circulating trace elements with sleep health have attracted increasing attention given their potential link. However, there is scant data on the relationship between serum trace elements and abnormal sleep duration patterns in cirrhosis. We aimed to investigate these associations with the purpose of identifying modifiable risk factors. The blood samples were collected from inpatients with cirrhosis, and serum levels of several trace elements were assessed by inductively coupled plasma mass spectrometry. Self-reported sleep duration was categorized to short- (< 7 h/night), optimal (7-8 h/night), and long-sleep duration (> 8 h/night). The dose-response trends and associations of trace elements levels with sleep duration were determined by restricted cubic splines (RCS) and logistic regression, respectively. Cirrhotic patients with optimal sleep duration experienced the highest levels of serum Zinc (Zn) and the lowest values of copper to zinc ratio (CZr). RCS model corroborated non-linear associations of serum Zn and CZr against sleep duration. Multiple regression analysis showed that both CZr (short vs optimal sleep duration: OR 4.785, P < 0.001; long vs optimal sleep duration: OR 4.150, P = 0.019) and serum Zn levels (short vs optimal sleep duration: OR 0.985, P = 0.040; long vs optimal sleep duration: OR 0.956, P = 0.008) serve as independent risk factors for sleep duration abnormalities. In conclusion, our findings unraveled a close relationship of serum Zn and CZr with sleep duration in cirrhosis. Further trace element-based therapy such as Zn supplementation may be novel approach to reverse this sleep problem.

Executive Performance Is Associated With Rest-Activity Rhythm in Nurses Working Rotating Shifts

Purpose

Rest-activity rhythms (RAR) is one of the most fundamental biological patterns that influence basic physical and mental health, as well as working performance. Nowadays, with the utilization of actigraphy device in detecting and analyzing RAR objectively, evidence has confirmed that RAR could be interrupted by shift work. Nurses need to participate shift work in their daily routine. The aim of the present study is to identify the RAR of nurses working rotating shifts and find out the relationship between RAR and executive function.

Methods

A total of 11 female nurses on day-shift (DS), 11 female nurses on rotating-shift (RS) were recruited. Demographic features, non-parametric variables of RAR as well as sleep variables according to actigraphy data, and a series of cognitive function evaluations during work time were collected.

Results

The Student’s t-test comparison revealed that RS group nurses showed significant shorter total sleep time (TST), lower level of interdaily stability (IS) and relative amplitude (RA), as well as poorer executive performance compared with DS nurses. The linear regression analysis demonstrated that several aspects of executive performance such as choice reaction test (CRT) (reflecting attention and concentration) and trail making test (TMT) -B (reflecting cognitive flexibility) were associated with IS in RS group nurses.

Conclusion

These results elucidated that RAR was disrupted for nurses working rotating shifts, and executive performance was associated with IS from day to day in nurses working rotating shifts.