Sleep and risk of parkinsonism and Parkinson's disease: a population-based study

Sleep disturbances and associated factors in patients with Parkinson's disease

AIMS

This study aimed to describe clinical characteristics and sleep quality of Parkinson's Diseases (PD) patients and identify associated factors with sleep quality.

METHODS

A cross-sectional study was conducted at the National Geriatric Hospital, Hanoi, Vietnam, from December 2022 to April 2023. A total of 130 Parkinson's disease patients undergoing treatment at the hospital were invited. Demographic and clinical characteristics were obtained. The diagnosis of sleep disorders was based on the standards outlined in the DSM-V. A multivariate logistic regression model was employed.

RESULTS

90.9 % experienced sleep disorder, with the significant types including insomnia (76.2 %) and restless legs syndrome (56.2 %). The majority of patients suffered two (33.1 %) and one kind of sleep disorder (32.3 %). Most patients experienced sleep disorders after diagnosis of PD (80.0 %). Only having shoulder and neck pain was positively associated with a likelihood of having sleep disturbances (OR=4.87, 95 %CI=1.18-20.15).

CONCLUSION

This study found a high rate of sleep disorders among PD patients in our sample. Shoulder and neck pain was found to be associated with a risk of sleep disorders. Pain management should be performed to improve the sleep quality of PD patients.

Interplay between the glymphatic system and neurotoxic proteins in Parkinson's disease and related disorders: current knowledge and future directions

Parkinson's disease is a common neurodegenerative disorder that is associated with abnormal aggregation and accumulation of neurotoxic proteins, including α-synuclein, amyloid-β, and tau, in addition to the impaired elimination of these neurotoxic protein. Atypical parkinsonism, which has the same clinical presentation and neuropathology as Parkinson's disease, expands the disease landscape within the continuum of Parkinson's disease and related disorders. The glymphatic system is a waste clearance system in the brain, which is responsible for eliminating the neurotoxic proteins from the interstitial fluid. Impairment of the glymphatic system has been proposed as a significant contributor to the development and progression of neurodegenerative disease, as it exacerbates the aggregation of neurotoxic proteins and deteriorates neuronal damage. Therefore, impairment of the glymphatic system could be considered as the final common pathway to neurodegeneration. Previous evidence has provided initial insights into the potential effect of the impaired glymphatic system on Parkinson's disease and related disorders; however, many unanswered questions remain. This review aims to provide a comprehensive summary of the growing literature on the glymphatic system in Parkinson's disease and related disorders. The focus of this review is on identifying the manifestations and mechanisms of interplay between the glymphatic system and neurotoxic proteins, including loss of polarization of aquaporin-4 in astrocytic endfeet, sleep and circadian rhythms, neuroinflammation, astrogliosis, and gliosis. This review further delves into the underlying pathophysiology of the glymphatic system in Parkinson's disease and related disorders, and the potential implications of targeting the glymphatic system as a novel and promising therapeutic strategy.

Insomnia in Parkinson's Disease: Causes, Consequences, and Therapeutic Approaches

Sleep disorders represent prevalent non-motor symptoms in Parkinson's disease (PD), affecting over 90% of the PD population. Insomnia, characterized by difficulties in initiating and maintaining sleep, emerges as the most frequently reported sleep disorder in PD, with prevalence rates reported from 27 to 80% across studies. Insomnia not only significantly impacts the quality of life of PD patients but is also associated with cognitive impairment, motor disabilities, and emotional deterioration. This comprehensive review aims to delve into the mechanisms underlying insomnia in PD, including neurodegenerative changes, basal ganglia beta oscillations, and circadian rhythms, to gain insights into the neural pathways involved. Additionally, the review explores the risk factors and comorbidities associated with insomnia in PD, providing valuable insights into its management. Special attention is given to the challenges faced by healthcare providers in delivering care to PD patients and the impact of caregiving roles on patients' quality of life. Overall, this review provides a comprehensive understanding of insomnia in PD and highlights the importance of addressing this common sleep disorder in PD patients.

Efficacy of acupuncture as adjunct therapy for sleep disorders in Parkinson's disease: A systematic review and meta-analysis

OBJECTIVE

The purpose of this study was to summarize existing clinical studies through a systematic review to explore the efficacy of acupuncture in treating sleep disorders in PD patients.

METHODS

According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we retrieved the papers through 30 April 2023 from eight databases. The experimental group was treated with acupuncture plus conventional therapy, while the control group was treated with conventional therapy alone or combined with sham acupuncture. The sleep quality was the primary outcome. A team of researchers meticulously performed literature screening, data extraction and risk of bias assessment following the Cochrane Handbook. A meta-analysis was synthesized using Review Manager Version 5.4 software if feasible. The quality of the evidence was assessed by the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) tool.

RESULTS

A total of 973 papers were identified, with 15 papers involving 957 patients were included in this systematic review. The results showed that acupuncture interventions included manual acupuncture, electroacupuncture, moxibustion and bleeding, with 1-7 times every week implemented during 2-12 weeks. Acupuncture as an adjunct therapy compared to conventional therapy alone showed better effect in sleep quality and overall symptoms of PD. Risk of bias assessment showed deficiencies in blinding and allocation concealment. All included studies were synthesized in a meta-analysis, as the result of which, acupuncture improved PDSS scores(MD =16.57; 95% CI, 7.24-25.90; I2 = 97%) and effective rate for sleep disorders (OR = 5.91; 95% CI, 1.71-20.39; I2 = 54%); meanwhile, acupuncture reduced UPDRS scores(MD = -4.29; 95% CI, -6.54 - -2.03; I2 = 77%) and improved effective rate for PD (OR = 3.22; 95% CI, 1.81-5.72; I2 = 0%). The quality of evidence ranged from low to moderate by GRADE.

CONCLUSION

This study provides initial evidence that acupuncture as an adjunct therapy might be associated with improvement of sleep disorders in PD. Due to the lack of high-quality studies, larger sample size studies with sham acupuncture groups should be conducted in future.

REGISTRATION NUMBER

CRD42022364249 (PROSPERO).

Vitamin B6 alleviates chronic sleep deprivation-induced hippocampal ferroptosis through CBS/GSH/GPX4 pathway

Several studies have found that sleep deprivation (SD) can lead to neuronal ferroptosis and affect hippocampal function. However, there are currently no effective interventions. Vitamin B6 is a co-factor for key enzymes in the transsulfuration pathway which is critical for maintaining cell growth in the presence of cysteine deprivation. The results showed that SD inhibited cystine-glutamate antiporter light chain subunit xCT protein expression and caused cysteine deficiency, which reduced the synthesis of the glutathione (GSH) to trigger neuronal ferroptosis. Nissl staining further revealed significant neuronal loss and shrinkage in the CA1 and CA3 regions of the hippocampus in SD mice. Typical ferroptotic indicators characterized by lipid peroxidation and iron accumulation were showed in the hippocampus after sleep deprivation. As expected, vitamin B6 could alleviate hippocampal ferroptosis by upregulating the expression of cystathionine beta-synthase (CBS) in the transsulfuration pathway, thereby replenishing the intracellular deficient GSH and restoring the expression of GPX4. Similar anti-ferroptotic effects of vitamin B6 were demonstrated in HT-22 cells treated with ferroptosis activator erastin. Furthermore, vitamin B6 had no inhibitory effect on erastin-induced ferroptosis in CBS-knockout HT22 cells. Our findings suggested chronic sleep deprivation caused hippocampal ferroptosis by disrupting the cyst(e)ine/GSH/GPX4 axis. Vitamin B6 alleviated sleep deprivation-induced ferroptosis by enhancing CBS expression in the transsulfuration pathway.

Sleep features and long-term incident neurodegeneration: a polysomnographic study

STUDY OBJECTIVES

Sleep is altered early in neurodegenerative diseases (NDDs) and may contribute to neurodegeneration. Long-term, large sample-size studies assessing NDDs association with objective sleep measures are scant. We aimed to investigate whether video-polysomnography (v-PSG)-based sleep features are associated with long-term NDDs incidence.

METHODS

Retrospective cohort study of patients referred 2004-2007 to the Sleep Disorders Unit, Neurology, Medical University Innsbruck, Austria. All patients ≥ 18 years undergoing v-PSG and without NDDs at baseline or within 5 years were included. Main outcome was NDDs diagnosis ≥5 years after v-PSG.

RESULTS

Of 1454 patients assessed for eligibility, 999 (68.7%) met inclusion criteria (68.3% men; median age 54.9 (IQR 33.9-62.7) years). Seventy-five patients (7.5%) developed NDDs and 924 (92.5%) remained disease-free after a median of 12.8 (IQR 9.9-14.6) years. After adjusting for demographic, sleep, and clinical covariates, a one-percentage decrease in sleep efficiency, N3-, or rapid-eye-movement (REM)-sleep was associated with 1.9%, 6.5%, or 5.2% increased risk of incident NDDs (HR 1.019, 1.065, and 1.052). One-percentage decrease in wake within sleep period time represented a 2.2% reduced risk of incident NDDs (HR 0.978). Random-forest analysis identified wake, followed by N3 and REM-sleep percentages, as the most important feature associated with NDDs diagnosis. Additionally, multiple sleep features combination improved discrimination of incident NDDs compared to individual sleep stages (concordance-index 0.72).

CONCLUSIONS

These findings support contribution of sleep changes to NDDs pathogenesis and provide insights into the temporal window during which these differences are detectable, pointing to sleep as early NDDs marker and potential target of neuroprotective strategies.

Correlation of slow-wave sleep with motor and nonmotor progression in Parkinson's disease

OBJECTIVE

This study aimed to explore the association between slow-wave sleep and the progression of motor and nonmotor symptoms in patients with PD.

METHODS

Data were collected from the Parkinson's Progression Markers Initiative study. Slow-wave sleep, also known as deep non-rapid eye movement (DNREM) sleep, was objectively assessed using the Verily Study Watch. Motor function was assessed using the Movement Disorder Society-Unified Parkinson's Disease Rating Scale Part III score, Hoehn and Yahr stage, freezing of gait, motor fluctuations, and dyskinesia severity. Comprehensive assessments were conducted on nonmotor symptoms, including depression, anxiety, global cognitive function, and autonomic dysfunction. Statistical analyses involved repeated-measures analysis of variance and linear regression.

RESULTS

A total of 102 patients with PD were included in the study, with a median follow-up duration of 3.4 years. In the long DNREM sleep duration group (n = 55), better motor function (DNREM × time interaction: F(1,100) = 4.866, p = 0.030), less severe sexual dysfunction (p = 0.026), and improved activities of daily living (p = 0.033) were observed at the last follow-up visit compared with the short DNREM sleep duration group (n = 47). Reduced DNREM sleep duration is a risk factor for motor progression (β = -0.251, p = 0.021; 95% confidence interval = -0.465 to -0.038).

INTERPRETATION

The findings suggest an association between longer DNREM sleep duration and slower motor and nonmotor progression in patients with PD.

Physical activity and sleep pattern in relation to incident Parkinson's disease: a cohort study

BACKGROUND

How physical activity (PA) and different sleep traits and overall sleep pattern interact in the development of Parkinson's disease (PD) remain unknown.

OBJECTIVE

To prospectively investigate the joint associations of PA and sleep pattern with risk of PD.

METHODS

Included were 339,666 PD-free participants from the UK Biobank. Baseline PA levels were grouped into low (< 600 MET-mins/week), medium (600 to < 3000 MET-mins/week) and high (≥ 3000 MET-mins/week) according to the instructions of the UK Biobank. Healthy sleep traits (chronotype, sleep duration, insomnia, snoring, and daytime sleepiness) were scored from 0 to 5 and were categorized into "ideal sleep pattern" (≥ 3 sleep scores) and "poor sleep pattern" (0-2 sleep scores). Hazard ratios (HRs) and 95% confidence intervals (CIs) of PD were estimated by Cox proportional hazards models.

RESULTS

During a median of 11.8 years of follow-up, 1,966 PD events were identified. The PD risk was lower in participants with high PA (HR = 0.73; 95% CI: 0.64, 0.84), compared to those with low PA; and participants with ideal sleep pattern also had a lower risk of PD (HR = 0.78; 95% CI: 0.69, 0.87), compared to those with poor sleep pattern. When jointly investigating the combined effect, participants with both high PA and ideal sleep pattern had the lowest risk of incident PD (HR = 0.55; 95% CI: 0.44, 0.69), compared to those with low PA and poor sleep pattern; notably, participants with high PA but poor sleep pattern also gained benefit on PD risk reduction (HR = 0.74; 95% CI: 0.55, 0.99).

CONCLUSIONS

Both high PA and ideal sleep pattern were independently associated with lower risk of developing PD, and those with both high PA level and ideal sleep pattern had the lowest risk. Our results suggest that improving PA levels and sleep quality may be promising intervention targets for the prevention of PD.

Different risks of early-onset and late-onset Parkinson disease in individuals with mental illness

We aimed to investigate the association of various mental illnesses, including depression, bipolar disorder, schizophrenia, insomnia, and anxiety, with the risk of early-onset Parkinson's disease (EOPD) (age <50 years) and compare it with that of late-onset PD (LOPD) (age ≥50 years). This nationwide cohort study enrolled 9,920,522 people who underwent a national health screening examination in 2009, and followed up until 31 December 2018. There was a significantly increased risk of EOPD and LOPD in individuals with mental illness, and EOPD showed a stronger association than LOPD (EOPD, hazard ratio (HR) = 3.11, 95% CI: 2.61‒3.72; LOPD, HR = 1.70, 95% CI: 1.66‒1.74; p for interaction <0.0001). Our results suggest that people with mental illnesses aged < 50 years are at a higher risk of PD than those aged ≥50 years. Future studies are warranted to elucidate the pathomechanism of EOPD in relation to mental illness.

Association of time spent outdoors with the risk of Parkinson's disease: a prospective cohort study of 329,359 participants

BACKGROUND

Studies on the association between time spent outdoors and the development of Parkinson's disease (PD) are lacking, and whether this relationship differs in different subgroups (age, sex) remains unclear.

OBJECTIVE

We here examined the association between time spent outdoors and the incidence of PD in different seasons.

METHODS

This study included 329,359 participants from the UK Biobank. Data regarding hours spent outdoors during a typical day were obtained through questionnaires. Cox proportional hazard regression models were used to estimate hazard ratios (HRs) for the association between exposure to outdoors duration and PD incidence. Restricted cubic spline was used to explore the potential nonlinear relationship between time spent outdoors and PD risk. To explore the potential mechanisms of time spent outdoors effecting the risk of PD incidence, their association with serum vitamin D was further analysed separately.

RESULTS

During a median follow-up of 13.57 years, 2,238 participants developed PD. In summer, time spent outdoors > 5.0 h/day was associated with a reduced PD risk compared with ≤ 2.0 h/day (HR = 0.84, 95% CI, 0.74-0.95). In winter too, time spent outdoors > 2.0 h/day was also associated with a reduced PD risk compared with ≤ 1.0 h/day (HR = 0.85, 95% CI, 0.76-0.94). For annual average time spent outdoors, participants who went outdoors for more than 3.5 h/day had a reduced PD risk than those who went outdoors for ≤ 1.5 h/day (HR = 0.85, 95% CI, 0.75-0.96). Additionally, sex and age differences were observed in the association between time spent outdoors and the PD risk. Moreover, Time spent outdoors was observed to be positively associated with serum vitamin D levels. Compared with serum vitamin D-deficient participants, the risk of PD was reduced by 15% in the sufficient participants.

CONCLUSION

In the total population, higher time spent outdoors was linked to a reduced PD risk. However, this association may vary among different age or sex groups.

Mechanisms behind changes of neurodegeneration biomarkers in plasma induced by sleep deprivation

Acute sleep deprivation has been shown to affect cerebrospinal fluid and plasma concentrations of biomarkers associated with neurodegeneration, though the mechanistic underpinnings remain unknown. This study compared individuals who, for one night, were either subject to total sleep deprivation or free sleep, (i) examining plasma concentrations of neurodegeneration biomarkers the morning after sleep deprivation or free sleep and (ii) determining how overnight changes in biomarkers plasma concentrations correlate with indices of meningeal lymphatic and glymphatic clearance functions. Plasma concentrations of amyloid-β 40 and 42, phosphorylated tau peptide 181, glial fibrillary acid protein and neurofilament light were measured longitudinally in subjects who from Day 1 to Day 2 either underwent total sleep deprivation (n = 7) or were allowed free sleep (n = 21). The magnetic resonance imaging contrast agent gadobutrol was injected intrathecally, serving as a cerebrospinal fluid tracer. Population pharmacokinetic model parameters of gadobutrol cerebrospinal fluid-to-blood clearance were utilized as a proxy of meningeal lymphatic clearance capacity and intrathecal contrast-enhanced magnetic resonance imaging as a proxy of glymphatic function. After one night of acute sleep deprivation, the plasma concentrations of amyloid-β 40 and 42 were reduced, but not the ratio, and concentrations of the other biomarkers were unchanged. The overnight change in amyloid-β 40 and 42 plasma concentrations in the sleep group correlated significantly with indices of meningeal lymphatic clearance capacity, while this was not seen for the other neurodegeneration biomarkers. However, overnight change in plasma concentrations of amyloid-β 40 and 42 did not correlate with the glymphatic marker. On the other hand, the overnight change in plasma concentration of phosphorylated tau peptide 181 correlated significantly with the marker of glymphatic function in the sleep deprivation group but not in the sleep group. The present data add to the evidence of the role of sleep and sleep deprivation on plasma neurodegeneration concentrations; however, the various neurodegeneration biomarkers respond differently with different mechanisms behind sleep-induced alterations in amyloid-β and tau plasma concentrations. Clearance capacity of meningeal lymphatics seems more important for sleep-induced changes in amyloid-β 40 and 42 plasma concentrations, while glymphatic function seems most important for change in plasma concentration of phosphorylated tau peptide 181 during sleep deprivation. Altogether, the present data highlight diverse mechanisms behind sleep-induced effects on concentrations of plasma neurodegeneration biomarkers.

Glymphatic system impairment in sleep disruption: diffusion tensor image analysis along the perivascular space (DTI-ALPS)

PURPOSE

This study aimed to evaluate the relationship between sleep quality as assessed using the Pittsburgh Sleep Quality Index (PSQI) and the index of diffusivity along the perivascular space (ALPS index), a possible indirect indicator of glymphatic system activity.

MATERIALS AND METHODS

This study included the diffusion magnetic resonance imaging (MRI) data of 317 people with sleep disruption and 515 healthy controls (HCs) from the Human Connectome Project (WU-MINN HCP 1200). The ALPS index was calculated automatically based on diffusion tensor image analysis (DTI)-ALPS of diffusion MRI. The ALPS index of the sleep disruption and HC groups was compared using general linear model (GLM) analysis with covariates, such as age, sex, level of education, and intracranial volume. In addition, to confirm the relationship between sleep quality and the ALPS index in the sleep disruption group as well as evaluate the effect of each PSQI component on the ALPS index, correlation analyses between the ALPS indices and PSQI scores of all the components and between the ALPS index and each PSQI component was performed using GLM analysis with the abovementioned covariates, respectively.

RESULTS

The ALPS index was significantly lower in the sleep disruption group than in the HC group (p = 0.001). Moreover, the ALPS indices showed significant negative correlations with the PSQI scores of all the components (false discovery rate [FDR]-corrected p < 0.001). Two significant negative correlations were also found between the ALPS index and PSQI component 2 (sleep latency, FDR-corrected p < 0.001) and 6 (the use of sleep medication, FDR-corrected p < 0.001).

CONCLUSION

Our findings suggest that glymphatic system impairment contributes to sleep disruption in young adults.

Sleep Behaviors and Progression of Multimorbidity in Middle-Aged and Older Adults: A Prospective Cohort Study From China

BACKGROUND

Sleep behavior (eg, sleep duration, sleep quality, and nap) is closely related to many chronic conditions. However, less is known about its association with multiple chronic conditions (multimorbidity), particularly evidence from cohort studies.

METHODS

Data were collected from a cohort of 8 937 individuals aged 45 and older from the China Health and Retirement Longitudinal Study (2011-2018). Sleep duration, sleep quality, and nap duration were collected in 2011 and 2013. Progression of multimorbidity was defined as the first report of 2 or more chronic conditions for participants without multimorbidity or the new report of 1 or more conditions for those with multimorbidity. Cox regression models were performed to calculate the hazard ratios and 95% confidence intervals (CIs) of the associations between sleep behaviors and the progression of multimorbidity.

RESULTS

Short sleep duration and poor sleep quality were associated with the progression of multimorbidity independently and jointly, especially in those less than 65 years and females. The U-shaped dose-response relationships were observed between nighttime and total sleep duration and the progression of multimorbidity. Persistent short and unsteadily changed sleep behaviors increased the risk of multimorbidity progression. Individuals sleeping ≤5 h/night with 5-7 restless days/week had 1.53 times higher risk of multimorbidity progression (95% CI: 1.37-1.71), compared to those sleeping 7-8 h/night with <1 restless day/week.

CONCLUSIONS

Short sleep duration and poor sleep quality were independently and jointly associated with a higher risk of multimorbidity progression in a mid-to-older population. Optimal sleep duration and sleep quality should be emphasized in multimorbidity prevention and control.

How sleep quality affects activities of daily living in Parkinson's disease: the mediating role of disease severity and the moderating role of cognition

Objective

The aim of this study was to explore the influential mechanism of the relationship between sleep quality and activities of daily living (ADL) in patients with Parkinson's disease (PD), we hypothesized disease severity as a mediator and assumed the mediating process was regulated by cognition.

Methods

194 individuals with PD (95 women and 99 men) were enrolled in study. The Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality of PD patients. Patients' ADL, disease severity and cognition were measured by the Unified Parkinson's Disease Rating Scale-II (UPDRSII), Hoehn-Yahr (H-Y) Scale, and Mini-Mental State Examination (MMSE). We investigated the mediating role of disease severity and the moderating effect of cognition on the association between sleep quality and ADL in PD patients.

Results

The score of UPDRSII was positively correlated with the score of PSQI and H-Y stage, while the score of MMSE was negatively correlated with the score of H-Y stage and UPDRSII. Sleep quality predicts disease severity, and disease severity predicts ADL. Disease severity mediated the relationship between sleep quality and ADL, and the mediating effect was 0.179. Cognition alone did not affect ADL, but the interaction between disease severity and cognition was significantly affected ADL, confirming the moderating effect of cognition in PD patients.

Conclusion

Disease severity mediated the association between sleep quality and ADL, good cognition significantly reduced disease severity's mediating influence on the relationship between sleep quality and ADL. Our study indicated a close relationship between ADL and sleep and cognition in PD, and also provided new insights into the overall management of PD and a better quality of life of PD patients.

Effects of digital psychological interventions on physical symptoms in cancer patients: A systematic review and meta-analysis

PURPOSE

This meta-analysis was to assess the efficacy of digital psychological interventions to improve physical symptoms (i.e., fatigue, pain, disturbed sleep, and physical well-being) among cancer patients, as well as to evaluate the variables that possibly moderate intervention effects.

METHODS

Nine databases were searched for the literature up to February 2023. Two reviewers independently conducted a quality assessment. Effect sizes were reported as the standardized mean difference (Hedge's g) and estimated using a random-effects model.

RESULTS

The meta-analysis included 44 randomized clinical trials comprising 7200 adults with cancer. Digital psychological interventions were associated with significant improvements in short-term fatigue (g = -0.33; 95% CI, -0.58 to -0.07) and disturbed sleep (g = -0.36; 95% CI, -0.57 to -0.15), but with non-significant changes in pain (g = -0.23; 95% CI, -0.68 to 0.21) and physical well-being (g = 0.31; 95% CI, -0.18 to 0.80). Additionally, no alleviation in long-term physical symptoms was observed. In subgroup analysis, results suggest that the country significantly moderated the effectiveness of digital psychological interventions in alleviating fatigue.

CONCLUSIONS

Digital psychological interventions can be effective for improving short-term fatigue and disturbed sleep in patients with cancer. Clinicians could consider digital psychological interventions as a possible and efficient addition to better manage some of the physical symptoms during and after cancer treatment.

Reduced coupling of global brain function and cerebrospinal fluid dynamics in Parkinson's disease

Dysfunction of the glymphatic system, an intracranial clearance pathway that drains misfolded proteins, has been implicated in the onset of Parkinson's disease (PD). Recently, the coupling strength of global blood-oxygen-level-dependent (gBOLD) signals and cerebrospinal fluid (CSF) inflow dynamics have been suggested to be an indicator of glymphatic function. Using resting-state functional magnetic resonance imaging (MRI), we quantified gBOLD-CSF coupling strength as the cross-correlation between baseline gBOLD and CSF inflow signals to evaluate glymphatic function and its association with the clinical manifestations of PD. We found that gBOLD-CSF coupling in drug-naïve PD patients was significantly weaker than that in normal controls, but significantly stronger in patients less affected by sleep disturbances than in those more affected by sleep disturbances, based on the PD sleep scale. Furthermore, we collected longitudinal data from patients and found that baseline gBOLD-CSF coupling negatively correlated with the rate of change over time, but positively correlated with the rate of change in UPDRS-III scores. In conclusion, severe gBOLD-CSF decoupling in PD patients may reflect longitudinal motor impairment, thereby providing a potential marker of glymphatic dysfunction in PD.

Association between Sleep Factors and Parkinson's Disease: A Prospective Study Based on 409,923 UK Biobank Participants

INTRODUCTION

Limited evidence indicates an association between sleep factors and the risk of Parkinson's disease (PD). However, large prospective cohort studies including both sexes are needed to verify the association between daytime sleepiness, sleep duration, and PD risk. Furthermore, other sleep factors like chronotype and snoring and their impact on increased PD risk should be explored by simultaneously considering daytime sleepiness and snoring.

METHODS

This study included 409,923 participants from the UK Biobank. Data on five sleep factors (chronotype, sleep duration, sleeplessness/insomnia, snoring, and daytime sleepiness) were collected using a standard self-administered questionnaire. PD occurrence was identified using linkages with primary care, hospital admission, death register, or self-report. Cox proportional hazard models were used to investigate the association between sleep factors and PD risk. Subgroup (age and sex) and sensitivity analyses were performed.

RESULTS

During a median follow-up of 11.89 years, 2,158 incident PD cases were documented. The main association analysis showed that prolonged sleep duration (hazard ratio [HR]: 1.20, 95% confidence interval [CI]: 1.05, 1.37) and occasional daytime sleepiness (HR: 1.15, 95% CI: 1.04, 1.26) increased the PD risk. Compared to those who self-reported never or rarely having sleeplessness/insomnia, participants who reported usually having sleeplessness/insomnia had a decreased risk of PD (HR: 0.85, 95% CI: 0.75, 0.96). Subgroup analysis revealed that women who self-reported no snoring had a decreased PD risk (HR: 0.85; 95% CI: 0.73, 0.99). Sensitivity analyses indicated that the robustness of the results was affected by potential reverse causation and data completeness.

CONCLUSION

Long sleep duration increased the PD risk, especially among men and participants ≥60 years, while snoring increased the risk of PD in women. Additional studies are needed to (i) further consider other sleep traits (e.g., rapid eye movement sleep behavior disorder and sleep apnea) that might be related to PD, (ii) objectively measure sleep-related exposure, and (iii) confirm the effects of snoring on PD risk by considering the impact of obstructive sleep apnea and investigating its underlying mechanisms.

Sleep behaviors and Parkinson's disease: A bidirectional Mendelian randomization analysis

OBJECTIVE

Whether the quantity and quality of sleep are the risk factors for the development of Parkinson's disease remains unclear though it has now been confirmed that the quality of sleep among patients with Parkinson's disease is affected at the prodromal and clinical stages. Accordingly, this study aimed to examine the bidirectional causal relationships of multiple sleep-related phenotypes with Parkinson's disease using a two-sample Mendelian randomization (MR) method.

METHODS

The summary-level data collected from the published genome-wide association studies was used for analysis. Besides, the genetic relationships between different sleep-related phenotypes, including self-reported and accelerometer measured traits, were estimated for the risk and age at the onset of Parkinson's disease. To conduct MR analysis, inverse variance weighted, weight median, MR-Egger, and MR-PRESSO method were mainly used. Moreover, sensitivity analyses were carried out to examine the pleiotropic effect.

RESULTS

In general, there was insufficient evidence to support the causal effect of sleep-related phenotypes on risk (N cases/controls = 33,674/449,056) and age at the onset (N cases = 28,568) of Parkinson's disease. However, the results of this study indicated that the later onset age of Parkinson's disease was related to the frequent occurrence of insomnia (OR [95% CI] 1.007 [1.003, 1.011], P < 0.001) after the adjustment for multiple testing.

CONCLUSIONS

The results of this study suggest that insomnia-associated single nucleotide polymorphisms are more frequent in later onset Parkinson's disease patients compared to earlier onset patients. However, given the limitations of statistical power and potential bias, further validation should be still conducted through larger population research.

Circadian disruption and sleep disorders in neurodegeneration

Disruptions of circadian rhythms and sleep cycles are common among neurodegenerative diseases and can occur at multiple levels. Accumulating evidence reveals a bidirectional relationship between disruptions of circadian rhythms and sleep cycles and neurodegenerative diseases. Circadian disruption and sleep disorders aggravate neurodegeneration and neurodegenerative diseases can in turn disrupt circadian rhythms and sleep. Importantly, circadian disruption and various sleep disorders can increase the risk of neurodegenerative diseases. Thus, harnessing the circadian biology findings from preclinical and translational research in neurodegenerative diseases is of importance for reducing risk of neurodegeneration and improving symptoms and quality of life of individuals with neurodegenerative disorders via approaches that normalize circadian in the context of precision medicine. In this review, we discuss the implications of circadian disruption and sleep disorders in neurodegenerative diseases by summarizing evidence from both human and animal studies, focusing on the bidirectional links of sleep and circadian rhythms with prevalent forms of neurodegeneration. These findings provide valuable insights into the pathogenesis of neurodegenerative diseases and suggest a promising role of circadian-based interventions.

Is insufficient sleep duration a risk indicator for periodontal disease? A systematic review

OBJECTIVES

In this study, we conducted a systematic review and meta-analysis to assess whether people who achieved <7 h of sleep were more likely to develop periodontal disease (PD).

SOURCES

We executed electronic searches in the PubMed, EMBASE and Cochrane Library, as well as a manual search of articles published by leading journals in related fields, for observational studies, published in English from 1 January 1966 to 31 March 2021.which evaluated the relationship between sleep duration and PD. The Agency for Healthcare Research and Quality (AHRQ) quality evaluation scale was used for the cross-sectional studies, and the random effects model was used to summarize the effect sizes in the included studies with a 95% confidence interval (CI).

RESULTS

A total of six cross-sectional studies met the inclusion criteria, totaling 107,777 participants, of which 69,773 had PD. The results of the present indicated that shorter sleep duration (<7 h) is significantly associated with PD (Odd ratio [OR], 1.19; 95% CI, 1.16-1.23; p < 0.001; I² , 0.0%, I² interval, 0%-75%). The strength of the sensitivity analysis and cumulative meta-analysis confirmed the reliability of the results.

CONCLUSION

Although the inclusion of only six studies makes it difficult to explore whether there is a publication bias, we found that insufficient sleep duration was closely related to PD, and we therefore speculated that getting enough sleep may help prevent PD.

Association of sleep abnormalities in older adults with risk of developing Parkinson's disease

STUDY OBJECTIVES

Parkinson's disease (PD) is associated with abnormalities of sleep macro- and microstructure as measured using polysomnography (PSG). Whether these abnormalities precede the development of PD is unknown. This study investigated the association between PSG measured sleep abnormalities in older adults and the risk of incident PD.

METHODS

A total of 2,770 men from the ancillary sleep study of the Osteoporotic Fractures in Men Study (MrOS), a population-based cohort from the United States, who were free from PD baseline and underwent overnight PSG, were included in this longitudinal analysis. Incident PD was based on a clinical diagnosis from a medical professional. Multivariable logistic regression was used to estimate odds ratios (OR) for incident PD by quartiles of PSG measures, with adjustment for sociodemographic characteristics, medical comorbidities, and lifestyle factors.

RESULTS

During a median follow-up of 9.8 years, 70 (2.5%) cases of incident PD were identified. Longer total sleep time, lower rapid eye movement sleep (REM) percentage, a lower α/θ ratio during non-REM sleep and higher minimum oxygen saturations during REM sleep, were each associated with an increased risk of developing PD. Conversely, a higher awakening index was associated with a decreased risk of developing PD. The OR for the highest risk quartiles compared to the lowest risk quartiles, ranged from 2.1 to 3.7 (p's < .05). The associations remained significant when cases occurring within the first two years of follow-up were excluded from the analyses.

CONCLUSIONS

Macro- and micro-structural sleep abnormalities precede the development of PD by several years and can identify individuals at high risk of developing PD in the future.

Glymphatic System Dysfunction and Sleep Disturbance May Contribute to the Pathogenesis and Progression of Parkinson’s Disease

Parkinson’s disease (PD) is a multisystem alpha-synucleinopathic neurodegenerative disease and the most prevalent neurodegenerative disorder after Alzheimer’s disease with a high incidence rate in the elderly population. PD is highly multifactorial in etiology and has complex and wide-ranging pathogenic mechanisms. Environmental exposures and genetic predisposition are prominent risk factors. However, current evidence suggests that an intimate link may exist between the risk factor of sleep disturbance and PD pathogenesis. PD is characterized by the pathological hallmarks of alpha-synuclein aggregations and dopaminergic neuron degeneration in the substantia nigra. The loss of dopamine-producing neurons results in both motor and non-motor symptoms, most commonly, bradykinesia, tremor, rigidity, psychiatric disorders, sleep disorders and gastrointestinal problems. Factors that may exacerbate alpha-synuclein accumulation and dopamine neuron loss include neuroinflammation and glymphatic system impairment. Extracellular alpha-synuclein can induce an inflammatory response which can lead to neural cell death and inhibition of neurogenesis. The glymphatic system functions most optimally to remove extracellular brain solutes during sleep and therefore sleep disruption may be a crucial progression factor as well as a risk factor. This literature review interprets and analyses data from experimental and epidemiological studies to determine the recent advances in establishing a relationship between glymphatic system dysfunction, sleep disturbance, and PD pathogenesis and progression. This review addresses current limitations surrounding the ability to affirm a causal link between improved glymphatic clearance by increased sleep quality in PD prevention and management. Furthermore, this review proposes potential therapeutic approaches that could utilize the protective mechanism of sleep, to promote glymphatic clearance that therefore may reduce disease progression as well as symptom severity in PD patients.

High PSQI score is associated with the development of dyskinesia in Parkinson's disease

Dyskinesia is one of the most disabling motor complications in Parkinson's Disease (PD). Sleep is crucial to keep neural circuit homeostasis, and PD patients often suffer from sleep disturbance. However, few prospective studies have been conducted to investigate the association of sleep quality with dyskinesia in PD. The objective of the current study is to investigate the association between sleep quality and dyskinesia and build a prediction model for dyskinesia in PD. We prospectively followed a group of PD patients without dyskinesia at baseline for a maximum of 36 months. Univariable and multivariable Cox regression with stepwise variable selection was used to investigate risk factors for dyskinesia. The performance of the model was assessed by the time-dependent area under the receiver-operating characteristic curve (AUC). At the end of follow-up, 32.8% of patients developed dyskinesia. Patients with bad sleep quality had a significantly higher proportion of dyskinesia compared with those with good sleep quality (48.1% vs. 20.6%, p = 0.023). Multivariable Cox regression selected duration of PD, sleep quality, cognition, mood, and levodopa dose. Notably, high Pittsburgh sleep quality index (PSQI) score was independently associated with an increased risk of dyskinesia (HR = 2.96, 95% CI 1.05-8.35, p = 0.041). The model achieved a good discriminative ability, with the highest AUC being 0.83 at 35 months. Our results indicated that high PSQI score may increase the risk of developing dyskinesia in PD, implying that therapeutic intervention targeting improving sleep quality may be a promising approach to prevent or delay the development of dyskinesia in PD.

Association between prevalence rate of dementia with Lewy bodies and sleep characteristics in Chinese old adults

Introduction: Few studies are available on the prevalence and sleep-related factors of dementia with Lewy bodies (DLB) in Chinese older adults, aiming to explore the associations between sleep characteristics and DLB.

Methods: A cross-sectional study with 7,528 individuals aged ≥65 years in 106 communities in Northern China was conducted from April 2019 to January 2020. Questionaries (including demographic characteristics, comorbidities, lifestyles, and sleep characteristics) were administered, and neuropsychological assessments and physical examination were conducted in phase I; screening for probable DLB was done in phase II. Logistic regressions were used to assess associations.

Results: A total of 919 (12.2%, 919/7,528) participants had dementia, and 101 (1.3%, 101/7,528) participants were diagnosed with DLB. The prevalence of dementia and DLB were slightly higher or equal in women, increased with age, and roughly decreased with nighttime sleep duration. Of the 101 participants, all of them (100.0%) had cognitive impairment, 46 (44.54%) displayed fluctuating cognition, 72 (71.29%) of them showed visual hallucination, 22 (21.78%) individuals reported RBD, and 27.71% showed Parkinsonism. Sleeping for <5 h (adjusted OR = 1.795, 95%CI: 1.055–3.054, p < 0.05) or having hypersomnolence (adjusted OR = 31.213, 95% CI: 17.618–55.301, p < 0.001) were significantly associated with the occurrence of DLB. Sleep duration of <5 h or >8 h had combined diagnostic value for DLB (AUC = 0.783, 95%CI: 0.734–0.831, p < 0.001).

Conclusions: The current prevalence of DLB is 1.3% in Northern China. Short or long nighttime sleep duration is independently associated with the occurrence of dementia and DLB.

Altered glymphatic enhancement of cerebrospinal fluid tracer in individuals with chronic poor sleep quality

Chronic sleep disturbance is a risk factor for dementia disease, possibly due to impaired sleep-dependent clearance of toxic metabolic by-products. We compared enrichment of a cerebrospinal fluid (CSF) tracer within brain of patients reporting good or poor sleep quality, assessed by the Pittsburgh Sleep Quality Index (PSQI) questionnaire. Tracer enrichment in a selection of brain regions was assessed using multiphase magnetic resonance imaging up to 48 hours after intrathecal administration of the contrast agent gadobutrol (0.5 ml of 1 mmol/ml) serving as tracer. Tracer enrichment differed between patients with good (PSQI ≤5) and poor (PSQI >5) sleep quality in a cohort of non-dementia individuals (n = 44; age 42.3 ± 14.5 years), and in patients with the dementia subtype idiopathic normal pressure hydrocephalus (n = 24; age 71.0 ± 4.9 years). Sleep impairment was associated with increased CSF tracer enrichment in several brain regions. Cortical brain volume as well as entorhinal cortex thickness was reduced in the oldest cohort and was correlated with the severity of sleep disturbance and the degree of cortical tracer enrichment. We suggest chronic sleep disturbance is accompanied by altered glymphatic function along enlarged perivascular spaces.

Sleep and affective disorders in relation to Parkinson's disease risk among older women from the Women's Health Initiative

OBJECTIVES

To evaluate sleep and affective (mood/anxiety) disorders as clinical predictors of incident Parkinson's disease (PD) among women ≥65 years of age.

METHODS

We performed secondary analyses with available data from the Women's Health Initiative Clinical Trials and Observational Study linked to Medicare claims. Sleep, mood and anxiety disorders at baseline were defined using diagnostic codes. Incident PD was defined using self-reported PD, first PD diagnosis, use of PD medications, and/or deaths attributed to PD. Cox regression was applied to estimate hazard ratios (HR) with 95 % confidence intervals (CI), controlling for socio-demographic/lifestyle/health characteristics. Time-to-event was calculated from baseline (1993-1998) to year of PD event, loss to follow-up, death, or December 31, 2018, whichever came first.

RESULTS

A total of 53,996 study-eligible WHI participants yielded 1756 (3.25 %) PD cases over ~14.39 (±6.18) years of follow-up. The relative risk for PD doubled among women with affective disorders (HR = 2.05, 95 % CI: 1.84, 2.27), mood disorders (HR = 2.18, 95 % CI: 1.97, 2.42) and anxiety disorders (HR = 1.97, 95 % CI: 1.75, 2.22). Sleep disorders alone (without affective) were not significantly associated with PD risk (HR = 0.85, 95 % CI: 0.69, 1.04), whereas affective disorders alone (without sleep) (HR = 1.93, 95 % CI: 1.72, 2.17) or in combination with sleep disorders (HR = 2.18, 95 % CI: 1.85, 2.56) were associated with twice the PD risk relative to no sleep/affective disorders.

LIMITATIONS

Observational design; Selection bias; Information bias; Generalizability.

CONCLUSIONS

Among older women, joint sleep/affective disorders and affective disorders alone are strong clinical predictors of incident PD over 14 years.

Association of Pyridoxal 5′-Phosphate with Sleep-Related Problems in a General Population

The evidence on the relationship of pyridoxal 5′-phosphate (PLP) with sleep-related problems is limited and controversial. Notably, there is a lack of studies on the general population and studies of the dose–response relationship. Therefore, we conducted a cross-sectional study to examine the associations between serum PLP concentration and sleep-related problems (sleep quality and sleep duration) in adults, using the data of the National Health and Nutrition Examination Survey 2005–2010. High-performance liquid chromatography (HPLC) was used to test PLP in blood samples. Sleep quality and sleep duration were based on self-reported data, with sleep quality categorized as sleep disorder, trouble falling asleep, waking up during the night, and daytime sleepiness. The primary analyses utilized logistic regression models and restricted cubic spline. Compared with the first quartile (Q1), the odds ratios (ORs) and 95% confidence intervals (CIs) of daytime sleepiness for the Q2 and Q3 of serum PLP concentrations were 0.76 (0.59–0.99) and 0.78 (0.62–0.98), respectively. The relationship was only significant for males. Furthermore, a non-linear dose–response relationship was observed between serum PLP concentration and the risk of daytime sleepiness. Compared with the normal sleep duration group, serum PLP concentrations were negatively associated with the risks of very short, short, and long sleep duration, with relative risk ratios (RRRs) of 0.58 (0.43–0.81) (Q4), 0.71 (0.61–0.83) (Q4) and 0.62 (0.34–0.94) (Q3), respectively. The average serum PLP concentrations were higher in people with normal sleep duration, suggesting a non-linear dose–response relationship. Our study indicated that serum PLP concentrations were negatively associated with daytime sleepiness, and this association may only exist in males. Moreover, it was also inversely related to abnormal sleep duration (very short, short, long) compared to normal sleep duration.

Imaging of sleep disorders in pre-Parkinsonian syndromes

PURPOSE OF REVIEW

Neuroimaging has been advanced in the last years and enabled clinicians to evaluate sleep disorders, especially isolated rapid eye movement sleep disorder (iRBD), which can be seen in alpha-synucleinopathies. iRBD is the best prodromal clinical marker for phenoconversion to these neurodegenerative diseases. This review aims to provide an update on advanced neuroimaging biomarkers in iRBD.

RECENT FINDINGS

Advanced structural MRI techniques, such as diffusion tensor imaging and functional MRI, neuromelanin-sensitive MRI, and scintigraphic neuroimaging such as cholinergic PET, dopamine transporter imaging - single-photon emission computerized tomography, perfusional single-photon emission computerized tomography, and cardiac metaiodobenzylguanidine can provide diagnostic and prognostic imaging biomarkers for iRBD, in isolation and more robustly when combined.

SUMMARY

New advanced neuroimaging can provide imaging biomarkers and aid in the appropriate clinical assessment and future therapeutic trials.

Bidirectional Relationship Between Sleep Disturbances and Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disease after Alzheimer's disease (AD). Both diseases share common clinical and pathological features: the gradual progression of neurological and psychiatric symptoms caused by neuronal dysfunction and neuronal cell death due to the accumulation of misfolded and neurotoxic proteins. Furthermore, both of them are multifactorial diseases in which both genetic and non-genetic factors contribute to the disease course. Non-genetic factors are of particular interest for the development of preventive and therapeutic approaches for these diseases because they are modifiable; of these, sleep is a particularly intriguing factor. Sleep disturbances are highly prevalent among both patients with AD and PD. To date, research has suggested that sleep disturbances are a consequence as well as a risk factor for the onset and progression of AD, which implies a bidirectional relationship between sleep and AD. Whether such a relationship exists in PD is less certain, albeit highly plausible given the shared pathomechanisms. This review examines the current evidence for the bidirectional relationship between sleep and PD. It includes research in both humans and animal models, followed by a discussion of the current understanding of the mechanisms underlying this relationship. Finally, potential avenues of research toward achieving disease modification to treat or prevent PD are proposed. Although further efforts are crucial for preventing the onset and slowing the progress of PD, it is evident that sleep is a valuable candidate target for future interventions to improve the outcomes of PD patients.

Worse Sleep Quality Aggravates the Motor and Non-Motor Symptoms in Parkinson's Disease

Backgrounds

Sleep disorders are the most common and disabling symptoms in patients with Parkinson's disease (PD). Understanding the associations between sleep characteristics and motor and non-motor symptoms (NMSs) in PD can provide evidence to guide therapeutic interventions and nursing strategies. We aimed to investigate the association between sleep characteristics and motor function and NMSs in PD using multiple approaches.

Methods

A total of 328 participants were included, and all participants underwent Pittsburgh Sleep Quality Index (PSQI) evaluation and clinical assessments of PD symptoms. We conducted Spearman's correlation to evaluate the associations between sleep and PD symptoms, nonlinear regression to assess the relationships between sleep habits and PD, and mediated analyses to test the effects of NMSs on global PSQI and PD severity, quality of life, and motor symptoms.

Results

Poor sleep was associated with more severe PD symptoms. In addition, the reflection point for bedtime was around 21:52, associated with motor symptoms, and insufficient and excessive total time spent in bed and nocturnal sleep duration were correlated with higher NMS burdens. The optimal points were 8–9.2 and 6.2–6.9 h, respectively. It was also discovered that NMSs played the mediating roles in global sleep with the quality of life, PD stages, and motor symptoms to a varying range of 6.8–95.4%.

Conclusions

Sleep disorders have a significant effect on the burden of PD symptoms. The current findings provide new insights into the monitoring and management of sleep and PD and need to be further explored in the future studies.

Life style and Parkinson's disease

The question whether life style may impair the advent or course of the disease in patients with Parkinsonism is of great importance for patients and physicians alike. We present here comprehensive information on the influence of the environment, diet (especially caffeine, nicotine, alcohol, chocolate and dairy products), physical activity and sleep on risk and course of Parkinson’s disease.

Applications of tetrahedral DNA nanostructures in wound repair and tissue regeneration

Tetrahedral DNA nanostructures (TDNs) are molecules with a pyramidal structure formed by folding four single strands of DNA based on the principle of base pairing. Although DNA has polyanionic properties, the special spatial structure of TDNs allows them to penetrate the cell membrane without the aid of transfection agents in a caveolin-dependent manner and enables them to participate in the regulation of cellular processes without obvious toxic side effects. Because of their stable spatial structure, TDNs resist the limitations imposed by nuclease activity and innate immune responses to DNA. In addition, TDNs have good editability and biocompatibility, giving them great advantages for biomedical applications. Previous studies have found that TDNs have a variety of biological properties, including promoting cell migration, proliferation and differentiation, as well as having anti-inflammatory, antioxidant, anti-infective and immune regulation capabilities. Moreover, we confirmed that TDNs can promote the regeneration and repair of skin, blood vessels, muscles and bone tissues. Based on these findings, we believe that TDNs have broad prospects for application in wound repair and regeneration. This article reviews recent progress in TDN research and its applications.

Association Between Sleep Duration and Parkinson's Disease Varied Across Related Orphan Receptor A rs2028122 Genotypes

Background

The purpose of the study was to examine the association of long and short sleep duration with risk of Parkinson's disease (PD) across RORA rs2028122 genotypes.

Methods

In the present prospective study with a large sized UK Biobank cohort, we performed multivariate logistic regression analyses, generalized additive model, interaction terms, stratification analysis, and mediation analysis to evaluate the association of long and short sleep duration with risk of PD across RORA rs2028122 genotypes.

Results

The GG genotype [1.16 (1.01, 1.33)], a short sleep duration [1.23 (1.10, 1.37)], and a long sleep duration [1.19 (1.03, 1.37)] were identified as the independent risk factors for PD. Sleep duration exhibited a curvilinear U-shaped correlation with the risk of PD; first, the risk of PD gradually decreased as the length of sleep increase, but then, the risk began to increase as the length of sleep increase. Among habitual long sleepers, AG carriers had a higher risk of PD compared with AA carriers [1.67 (1.09, 2.55)]. Among AG carriers, both habitual short [1.28 (1.09, 1.50)] and long [1.38 (1.13, 1.69)] sleepers increased the risk of PD compared with habitual normal sleepers. Among GG carriers, habitual short sleepers have a higher risk of PD [1.26 (1.06, 1.50)] compared with habitual normal sleepers. A mediation model suggested that the rs2028122 genotype partially mediated the causal pathway of sleep duration leading to the development of PD on a positive effect.

Conclusion

Our study demonstrated that the association between sleep duration and PD risk varied across different RORA rs2028122 genotypes. Our findings could help individuals to identify their potential risk profile and take timely actions to prevent the PD.

Sleep Disorders and Future Diagnosis of Parkinsonism: A Prospective Study Using the Canadian Longitudinal Study on Aging

BACKGROUND

Earlier detection of parkinsonism, specifically during its prodromal stage, may be key to preventing its progression. Previous studies have produced contradictory results on the association between sleep symptoms and prodromal parkinsonism.

OBJECTIVE

We conducted a prospective study within the Canadian Longitudinal Study on Aging (CLSA) to determine whether self-reported symptoms of insomnia, somnolence, apnea, and restless legs syndrome predate the diagnosis of parkinsonism after three years of follow-up.

METHODS

At baseline, amongst other information, participants completed a questionnaire for difficulty initiating or maintaining sleep, daytime somnolence, snoring or stopping breathing during sleep, and symptoms of restless legs syndrome. After 3 years of follow-up, baseline responses from participants who self-reported a new diagnosis of parkinsonism (cases) were compared to those who did not (controls). For each case, 10 controls were individually matched by age, sex, education, BMI, caffeine, smoking, and alcohol. Binary unconditional logistic regression models were used to estimate the association between sleep symptoms and new-onset parkinsonism, adjusting for age, sex, education, BMI, smoking, alcohol, and caffeine.

RESULTS

We identified 58 incident-parkinsonism cases and 580 matched controls (65.5%male, mean age = 69.60, SD = 8.0). Baseline symptoms of sleep-onset insomnia (12.1%vs. 13.0%, Adjusted OR[95%CI] = 0.87[0.32,2.33]), sleep-maintenance insomnia (24.1%vs. 20.2%, AOR = 1.01[0.46,2.20]), daytime somnolence (8.6%vs. 7.4%, AOR = 1.11[0.37,3.39]), obstructive sleep apnea (27.3%vs. 26.2%, AOR = 0.84[0.40,1.79]), and restless leg syndrome (20.6%vs. 9.9%, AOR = 1.34[0.42,4.25]) were similar among those who developed parkinsonism and those who did not.

CONCLUSION

Symptoms of insomnia, somnolence, apnea, and restless legs did not predate a new diagnosis of parkinsonism over 3 years.

Association between Sleep, Alzheimer's, and Parkinson's Disease

The majority of neurodegenerative diseases are pathologically associated with protein misfolding and aggregation. Alzheimer's disease (AD) is a type of dementia that slowly affects memory and cognitive function, and is characterized by the aggregation of the β-amyloid protein and tau neurofibrillary tangles in the brain. Parkinson's disease (PD) is a movement disorder typically resulting in rigidity and tremor, which is pathologically linked to the aggregation of α-synuclein, particularly in dopaminergic neurons in the midbrain. Sleep disorders commonly occur in AD and PD patients, and it can precede the onset of these diseases. For example, cognitively normal older individuals who have highly fragmented sleep had a 1.5-fold increased risk of subsequently developing AD. This suggests that sleep abnormalities may be a potential biomarker of these diseases. In this review, we describe the alterations of sleep in AD and PD, and discuss their potential in the early diagnosis of these diseases. We further discuss whether sleep disturbance could be a target for the treatment of these diseases.

Soluble Triggering Receptor Expressed on Myeloid Cells 2 From Cerebrospinal Fluid in Sleep Disorders Related to Parkinson's Disease

Background: Triggering receptor expressed on myeloid cells 2 (TREM2) is a microglial receptor exclusively expressed in the central nervous system (CNS). It contributes to abnormal protein aggregation in neurodegenerative disorders, but its role in Parkinson’s disease (PD) is still unclear.

Methods: In this case-control study, we measured the concentration of the soluble fragment of TREM2 (sTREM2) in PD patients, evaluated their sleep conditions by the PD sleep scale (PDSS), and analyzed the relationship between sTREM2 and PD symptoms.

Results: We recruited 80 sporadic PD patients and 65 healthy controls without disease-related variants in TREM2. The concentration of sTREM2 in the CSF was significantly higher in PD patients than in healthy controls (p < 0.01). In the PD group, the concentration of sTREM2 had a positive correlation with α-syn in the CSF (Pearson r = 0.248, p = 0.027). Receiver operating characteristic curve (ROC) analyses showed that sTREM2 in the CSF had a significant diagnostic value for PD (AUC, 0.791; 95% CI, 0.711–0.871, p < 0.05). The subgroup analysis showed that PD patients with sleep disorders had a significantly higher concentration of sTREM2 in their CSF (p < 0.01). The concentration of sTREM2 in the CSF had a negative correlation with the PDSS score in PD patients (Pearson r = −0.555, p < 0.01). The ROC analyses showed that sTREM2 in the CSF had a significant diagnostic value for sleep disorders in PD (AUC, 0.733; 95% CI, 0.619–0.846, p < 0.05).

Conclusion: Our findings suggest that CSF sTREM2 may be a potential biomarker for PD and it could help predict sleep disorders in PD patients, but multicenter prospective studies with more participants are still needed to confirm its diagnostic value in future.

Aberrant waste disposal in neurodegeneration: why improved sleep could be the solution

Sleep takes up a large percentage of our lives and the full functions of this state are still not understood. However, over the last 10 years a new and important function has emerged as a mediator of brain clearance. Removal of toxic metabolites and proteins from the brain parenchyma generated during waking activity and high levels of synaptic processing is critical to normal brain function and only enabled during deep sleep. Understanding of this process is revealing how impaired sleep contributes an important and likely causative role in the accumulation and aggregation of aberrant proteins such as β-amyloid and phosphorylated tau, as well as inflammation and neuronal damage. We are also beginning to understand how brain slow-wave activity interacts with vascular function allowing the flow of CSF and interstitial fluid to drain into the body's lymphatic system. New methodology is enabling visualization of this process in both animals and humans and is revealing how these processes break down during ageing and disease. With this understanding we can begin to envisage novel therapeutic approaches to the treatment of neurodegeneration, and how reversing sleep impairment in the correct manner may provide a way to slow these processes and improve brain function.

Association of Circadian Abnormalities in Older Adults With an Increased Risk of Developing Parkinson Disease

Importance

Disruption in circadian activity rhythms is very common in older adults, particularly among those with neurodegenerative diseases, including Parkinson disease (PD). However, whether circadian disruption could be a prodrome for PD is unclear.

Objective

To determine the association between rest-activity rhythm (RAR) and risk of incident PD and to explore whether this association is independent of nighttime sleep disturbances.

Design, Setting, and Participants

The ancillary sleep study of the longitudinal cohort Osteoporotic Fractures in Men Study (MrOS) was conducted from December 1, 2003, to March 31, 2005. Of the 3135 community-dwelling men enrolled in the MrOS sleep study, 3049 had technically adequate RAR data; of these, 119 were excluded for having prevalent PD or missing incident data, leaving 2930 men without PD at baseline. Data were analyzed from February 1 through August 31, 2019.

Exposures

Twenty four-hour RAR parameters (amplitude, mesor, robustness, and acrophase) generated by wrist actigraphy-extended cosinor analysis.

Main Outcomes and Measures

Incident PD based on physician diagnosis. Multivariable logistic regression was used to determine the association between quartiles of RAR parameters and risk of incident PD.

Results

Among the 2930 men included in the analysis (mean [SD] age, 76.3 [5.5] years), 78 (2.7%) developed PD during 11 years of follow-up. After accounting for all covariates, the risk of PD increased with decreasing circadian amplitude (strength of the rhythm) (odds ratio [OR] per 1-SD decrease, 1.77; 95% CI, 1.30-2.41), mesor (mean level of activity) (OR per 1-SD decrease, 1.64; 95% CI, 1.22-2.21), or robustness (how closely activity follows a cosine 24-hour pattern) (OR per 1-SD decrease, 1.54; 95% CI, 1.14-2.07) (P < .005 for trend). Those in the lowest quartile of amplitude, mesor, or robustness had approximately 3 times the risk of developing PD compared with those in the highest quartile of amplitude (OR, 3.11; 95% CI, 1.54-6.29), mesor (OR, 3.04; 95% CI, 1.54-6.01), and robustness (OR, 2.65; 95% CI, 1.24-5.66). The association remained after further adjustment for nighttime sleep disturbances and duration in the lowest compared with the highest quartile (OR for amplitude, 3.56 [95% CI, 1.68-7.56]; OR for mesor, 3.24 [95% CI, 1.52-6.92]; and OR for robustness, 3.34 [95% CI, 1.45-7.67]). These associations were somewhat attenuated, but the pattern remained similar after excluding PD cases developed within 2 years after baseline in the lowest compared with the highest quartile (OR for amplitude, 2.40 [95% CI, 1.15-5.00]; OR for mesor, 2.76 [95% CI, 1.35-5.67]; and OR for robustness, 2.33 [95% CI, 1.07-5.07]). Acrophase was not significantly associated with risk of PD.

Conclusions and Relevance

In this cohort study, reduced circadian rhythmicity was associated with an increased risk of incident PD, suggesting it may represent an important prodromal feature for PD. Future studies are needed to determine whether circadian disruption could also be a risk factor for PD and whether strategies to improve circadian function affect the risk of PD.

[Insomnia in the context of neurological diseases]

This article provides an overview of the prevalence, cause and treatment of insomnia in common neurological diseases (restless legs syndrome, stroke, multiple sclerosis, Parkinson´s disease and Alzheimer´s disease) with an additional focus on the bidirectional relationship between sleep and neurological disorders.Insomnia is prevalent, but frequently unrecognized in the context of neurological diseases. Although it is widely known that sleep has a relevant impact on quality of life in general and cerebral function in particular, sleep disorders receive little attention in the prevention and treatment of neurological diseases.

Sleep Disorders in Parkinson Disease

Sleep disorders in Parkinson disease have attracted the attention of clinicians and researchers for decades. Recently, major advances in their clinical characterization, polysomnographic description, pathophysiologic understanding, and treatment took place. Parkinson disease encompasses the whole spectrum of sleep medicine: every category of sleep disorder can be observed in these patients. Video polysomnography frequently is indicated, sometimes followed by multiple sleep latency/maintenance of wakefulness tests. Additional studies may include actigraphy, cardiorespiratory polygraphy, and dim light melatonin assessment. Treatment needs to be specific to the underlying sleep disorder and can include medications and nondrug treatments, for example, behavioral therapy and light therapy.

A Validation Study of PROMIS Sleep Disturbance (PROMIS-SD) and Sleep Related Impairment (PROMIS-SRI) Item Banks in Individuals with Idiopathic Parkinson's Disease and Matched Controls

BACKGROUND

Parkinson's disease (PD) is associated with sleep disturbance (SD) and sleep-related impairment (SRI). Validation of self-report measures of these problems is needed in PD. The Patient-Reported Outcomes Measurement Information System (PROMIS) includes tools that assess these problems (PROMIS-SD and PROMIS-SRI, respectively).

OBJECTIVE

This study aimed to further validate these measures in individuals with PD and matched controls.

METHODS

Individuals with early-stage PD (n=50) and matched controls (n=48) completed measures of SD including the PROMIS-SD, Pittsburgh Sleep Quality Index (PSQI), and Insomnia Severity Index (ISI). They also completed measures of daytime impairment including the PROMIS-SRI, Epworth Sleepiness Scale, State-Trait Anxiety Inventory, Beck Depression Inventory 2nd edition, and Parkinson's Disease Questionnaire-39. Internal consistency for the PROMIS measures were assessed using Cronbach's α coefficient and item-total correlations in the total sample. Convergent and divergent validity of the PROMIS item banks were assessed using Spearman correlations.

RESULTS

The PROMIS item banks had excellent internal consistency (α>0.94). Supporting convergent validity, the PROMIS-SD had strong correlations with other measures of SD (ρ>0.68, for PSQI and ISI) and the PROMIS-SRI had moderate to strong correlations with all measures of daytime impairment (ρ=0.41-0.72). Supporting divergent validity within the PD group, the PROMIS-SD correlated more strongly with SRI than with the Parkinson's Disease Questionnaire total score, a metric of PD related impairment.

CONCLUSION

In middle-aged and older adults, with and without early-stage PD, the PROMIS-SD and PROMIS-SRI are reliable and valid measures of SD and SRI, respectively.

Who are the individuals with the worst perceived quality of sleep? A population-based survey in southern Brazil

This study aimed to investigate the factors associated with poorer sleep quality. It consisted of a population-based cross-sectional study conducted in Southern Brazil with individuals aged 18 years or older. Participants were selected through a two-stage random sampling strategy and data collection was conducted in 2016. The outcome was self-perceived quality of sleep. Questions regarding the number of hours of sleep and the use of medicines to sleep each week were also asked. Demographic, socioeconomic, behavioral and health conditions were collected through questionnaire. The study sample was composed of 1,300 individuals whose mean age was 46.1 years (SD = 17.3). The prevalence of poor sleep quality was 10.7% (95% CI 9.3% to 12.1%). The poorer the quality of sleep was, the higher the prevalence of the use of medicines to sleep (22.3% versus 10.0% in the overall sample; p < 0.001) and the lower the average amount of daily sleep (6.0 h/day versus 7.3 h/day in the overall sample; p < 0.001). Groups with the worst quality of sleep, in the adjusted analyses, were female (p = 0.012), younger (18 to 39 years versus 60 years or more) (p = 0.048), with poorer perceived diet (p < 0.001), most stressed (p < 0.001), with chronic back pain (p = 0.002), with chronic respiratory disease (p = 0.012), with worse quality of life (p = 0.018) and depression (p = 0.034). Concluding, one out of ten individuals reported poor sleep quality. The results suggest that lifestyle changes could improve the quality of sleep.

Molecular Mechanisms Underlying Reciprocal Interactions Between Sleep Disorders and Parkinson's Disease

Sleep-wake disruptions are among the most prevalent and burdensome non-motor symptoms of Parkinson's disease (PD). Clinical studies have demonstrated that these disturbances can precede the onset of typical motor symptoms by years, indicating that they may play a primary function in the pathogenesis of PD. Animal studies suggest that sleep facilitates the removal of metabolic wastes through the glymphatic system via convective flow from the periarterial space to the perivenous space, upregulates antioxidative defenses, and promotes the maintenance of neuronal protein homeostasis. Therefore, disruptions to the sleep-wake cycle have been associated with inefficient metabolic clearance and increased oxidative stress in the central nervous system (CNS). This leads to excessive accumulation of alpha-synuclein and the induction of neuronal loss, both of which have been proposed to be contributing factors to the pathogenesis and progression of PD. Additionally, recent studies have suggested that PD-related pathophysiological alterations during the prodromal phase disrupt sleep and circadian rhythms. Taken together, these findings indicate potential mechanistic interactions between sleep-wake disorders and PD progression as proposed in this review. Further research into the hypothetical mechanisms underlying these interactions would be valuable, as positive findings may provide promising insights into novel therapeutic interventions for PD.

Circadian and Sleep Dysfunctions in Neurodegenerative Disorders-An Update

Disruptions of sleep and circadian rhythms are among the most debilitating symptoms in patients with neurodegenerative diseases. Their underlying pathophysiology is multilayered and multifactorial. Recent evidence suggests that sleep and circadian disturbances may influence the neurodegenerative processes as well as be their consequence. In this perspective, we provide an update of the current understanding of sleep and circadian dysregulation in Alzheimer's, Parkinson's, and Huntington's diseases.

Associations of sleep characteristics with alpha-synuclein in cerebrospinal fluid in older adults

OBJECTIVE

Sleep disorders as a preclinical symptom of synucleinopathies become more prevalent in older adults. Synucleinopathies might be caused by the abnormal aggregation of alpha-synuclein in the brain, which was indicated by alpha-synuclein levels in cerebrospinal fluid (CSF). We aimed to investigate associations of sleep characteristics with CSF alpha-synuclein in older adults.

METHODS

Our study recruited 536 cognitively intact individuals (aged between 40 and 90 years old) from the Chinese Alzheimer's Biomarker and Lifestyle study. Sleep behaviors were assessed by Pittsburgh Sleep Quality Index and total alpha-synuclein in CSF was measured by enzyme-linked immune-sorbent assay. We used multiple linear and non-linear regression models for research.

RESULTS

Significant non-linear associations of CSF alpha-synuclein with sleep time and duration were revealed. Individuals who went to bed and fell asleep too early or late tended to have lower CSF alpha-synuclein (reflection point for time to bed and fall asleep were 10:26 p.m. and 10:40 p.m.). Lower CSF alpha-synuclein was also observed in individuals with either excessive or insufficient sleep duration (reflection point: 7.24 hours). Besides, overall poor sleep quality (β = -0.0621; P = 0.0242), longer sleep latency (β = -0.0415; P = 0.0174) and lower sleep efficiency (β = 0.0036; P = 0.0017) showed linear associations with lower CSF alpha-synuclein. Sleep disturbances and daytime dysfunction were not significantly associated with CSF alpha-synuclein.

INTERPRETATION

Poor sleep was associated with lower levels of CSF alpha-synuclein in older adults, which may provide new insight into the prevention of synucleinopathies.

Investigation on sleep and mental health of patients with Parkinson's disease during the Coronavirus disease 2019 pandemic

Background

The coronavirus disease 2019 (COVID-19) pandemic is adversely affecting sleep quality and mental health, especially in individuals with chronic disease such as Parkinson's disease (PD).

Methods

We conducted a quantitative study, which included 119 Chinese PD patients who had been treated in an outpatient neurology clinic in Wuhan and 169 age- and sex-matched healthy controls. The questionnaire survey focused on the impact of the COVID-19 pandemic on sleep, mental status, symptoms, and daily life and medical treatment of PD patients.

Results

Compared to healthy controls, PD patients had significantly higher scores in both the Pittsburgh Sleep Quality Index (PSQI) (8.13 vs 5.36, p < 0.001) and the Hospital Anxiety and Depression Scale (HADS) -Depression (4.89 vs 3.82, p = 0.022), as well as a higher prevalence of sleep disturbances with PSQI > 5 points (68.9% vs 44.4%, p < 0.001). Sleep disturbance was identified in 68.9% of PD patients. A logistic regression analysis showed that sleep disturbance of PD patients was independently associated with exacerbation of PD symptoms (OR = 3.616, 95%CI= (1.479, 8.844), p = 0.005) and anxiety (OR = 1.379, 95%CI= (1.157, 1.642), p < 0.001). Compared to male PD patients, female ones had higher PSQI scores (9.28 ± 4.41 vs 7.03 ± 4.01, p = 0.009) and anxiety (32.8% vs 0.1%, p = 0.002) and depression prevalence (34.5% vs 11.5%, p = 0.003).

Conclusion

The findings of the present study emphasize the importance of mental and sleep health interventions in PD patients during the COVID-19 pandemic. Additional attention should be paid to the difficulty encountered by PD patients in seeking medical treatment.

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Patients with Parkinson's disease (PD) experience mental health and sleep disturbance during the COVID-19 pandemic.

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Anxiety, lack of medical consultation and exacerbation of symptoms affects the sleep health of PD patients profoundly.

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The exacerbation of PD related symptoms, was independently and closely associated with sleep quality.

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The sleep and mental health of female PD patient need more consideration and treatment.

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Special attention should be paid to the difficulty in seeking medical treatment for PD patients during the epidemic.