Sleep Quality Mediates the Association Between Cerebral Small Vessel Disease Burden and Frailty: A Community-Based Study

Effects of sleep fragmentation on white matter pathology in a rat model of cerebral small vessel disease

STUDY OBJECTIVES

Mounting evidence indicated the correlation between sleep and cerebral small vessel disease (CSVD). However, little is known about the exact causality between poor sleep and white matter injury, a typical signature of CSVD, as well as the underlying mechanisms.

METHODS

Spontaneously hypertensive rats (SHR) and control Wistar Kyoto rats were subjected to sleep fragmentation (SF) for 16 weeks. The effects of chronic sleep disruption on the deep white matter and cognitive performance were observed.

RESULTS

SHR were validated as a rat model for CSVD. Fragmented sleep induced strain-dependent white matter abnormalities, characterized by reduced myelin integrity, impaired oligodendrocytes precursor cells (OPC) maturation and pro-inflammatory microglial polarization. Partially reversible phenotypes of OPC and microglia were observed in parallel following sleep recovery.

CONCLUSIONS

Long-term SF-induced pathological effects on the deep white matter in a rat model of CSVD. The pro-inflammatory microglial activation and the block of OPC maturation may be involved in the mechanisms linking sleep to white matter injury.

The glymphatic system and cerebral small vessel disease

OBJECTIVES

Cerebral small vessel disease is a group of pathologies in which alterations of the brain's blood vessels contribute to stroke and neurocognitive changes. Recently, a neurotoxic waste clearance system composed of perivascular spaces abutting the brain's blood vessels, termed the glymphatic system, has been identified as a key player in brain homeostasis. Given that small vessel disease and the glymphatic system share anatomical structures, this review aims to reexamine small vessel disease in the context of the glymphatic system and highlight novel aspects of small vessel disease physiology.

MATERIALS AND METHODS

This review was conducted with an emphasis on studies that examined aspects of small vessel disease and on works characterizing the glymphatic system. We searched PubMed for relevant articles using the following keywords: glymphatics, cerebral small vessel disease, arterial pulsatility, hypertension, blood-brain barrier, endothelial dysfunction, stroke, diabetes.

RESULTS

Cerebral small vessel disease and glymphatic dysfunction are anatomically connected and significant risk factors are shared between the two. These include hypertension, type 2 diabetes, advanced age, poor sleep, obesity, and neuroinflammation. There is clear evidence that CSVD hinders the effective functioning of glymphatic system.

CONCLUSION

These shared risk factors, as well as the model of cerebral amyloid angiopathy pathogenesis, hint at the possibility that glymphatic dysfunction could independently contribute to the pathogenesis of cerebral small vessel disease. However, the current evidence supports a model of cascading dysfunction, wherein concurrent small vessel and glymphatic injury hinder glymphatic-mediated recovery and promote the progression of subclinical to clinical disease.

Sleep quality, frailty and overall health among community-dwelling older people: A longitudinal study

AIMS

The aims of the study were to describe sleep quality among community-dwelling older people; determine the association between sleep quality (total and multidimensional), frailty and overall health; study frailty as a mediator in the association between sleep quality and overall health.

DESIGN

This longitudinal, correlative study used data from 2020 to 2022.

METHODS

A total of 181 community-dwelling older people in a city in Southeast China were assessed twice. Sleep quality was measured using the Pittsburgh Sleep Quality Index at Time 1 (year 2020); frailty was measured using the FRAIL scale, and overall health was measured using the EuroQol visual analogue scale at Time 1 and 2 (1 year later). Associations and indirect effects were examined using linear regression analyses using the PROCESS Macro (Model 4).

RESULTS

Poor sleep quality (higher scores) was associated with increased frailty over time (total scale), as well as subjective sleep quality, sleep duration, sleep efficiency and daytime dysfunction. Mediation analyses indicated that frailty change had an indirect effect on the association between sleep quality total score Time (T) 1 and overall health T2 and between the dimensions subjective sleep quality, sleep duration, sleep efficiency and daytime dysfunction and overall health. All analyses were adjusted for age, multimorbidity and overall health T1.

CONCLUSIONS

Poor sleep quality is a common problem associated with poor overall health after 1 year, and the progression of frailty mediates this association.

IMPACT

The findings provide a better understanding of the association between sleep quality and overall health and elucidate the mediating effect of frailty. Regular screening and effective treatment by healthcare providers for sleep problems and frailty in older people are necessary to improve their overall health and enhance healthy ageing.

PATIENT OR PUBLIC CONTRIBUTION

Participants in the study provided the data used for all data analysis in the manuscript. Patient or public were not involved in data analysis, interpretation or manuscript preparation. Staff in the community health centre helped with data collection.

Type A personality, sleep quality, and cerebral small vessel disease: investigating the mediating role of sleep in a community-based study

Purpose

Type A behavior pattern (TABP) is a personality type characterized by rapid speech, impatience, competition, and hostility. Asymptomatic cerebral small vessel disease (CSVD) is often endemic in older adults. Individuals with TABP commonly experience suboptimal sleep quality, and a correlation exists between sleep disturbances and CSVD. We investigated the relationship between TABP and CSVD markers and further explored the mediating role of sleep quality in the relationship between TABP and CSVD.

Methods

A cross-sectional survey included 764 community-dwelling adults aged 55-85 years. The TABP Scale and the Pittsburgh Sleep Quality Index (PSQI) were used to assess personality and sleep quality, respectively. Linear and logistic regression analyses were used to examine relationships between variables of interest. In addition, mediation analyses with bootstrapping were used to test whether sleep quality mediated the relationship between TABP and CSVD.

Results

Of the 764 participants [median age 65 (61-69) years, 59.9% female], the population with type A personality accounted for 44.8%. After adjusting for covariates, TABP scores (p = 0.03) and PSQI scores (p < 0.001) were significantly correlated with CSVD. In addition, sleep quality partially mediated the association between type A behavior and CSVD, and the mediating effect was 10.67%.

Conclusion

This study showed that type A behavior was a risk factor for CSVD among older community-dwelling adults and that sleep quality mediated the relationship between type A behavior and CSVD. Changing type A behavior may help improve sleep quality, which may in turn reduce the prevalence of CSVD.

Association between frailty index based on routine laboratory tests and risk of cerebral small vessel disease in elderly patients: a hospital-based observational study

BACKGROUND

The association between frailty and cerebral small vessel disease (CSVD) remains controversial due to the use of different methods to assess frailty, including physical frailty phenotype and frailty scores containing measures of cognition. A frailty index based on laboratory tests (FI-Lab), which assesses frailty by the combination of routine laboratory measures and several vital signs, is independent of cognition and function status. We aimed to evaluate the association of FI-Lab with CSVD.

METHODS

An observational study was carried out in a hospitalized cohort of older patients with minor ischemic stroke or TIA. The FI-Lab was constructed by 20 routine laboratory tests, plus systolic blood pressure, diastolic blood pressure, and pulse pressure. Manifestations of CSVD including white matter hyperintensity (WMH), silent lacunar infarcts, microbleed, enlarged perivascular spaces (EPVS), as well as deep brain atrophy, were measured on magnetic resonance imaging (MRI). An ordinal score system constructed by WMH, EPVS, silent lacunar infarcts, and microbleed was used to reflect the total burden of CSVD. The associations between FI-lab and CSVD were examined by logistic regression analysis and ordinal regression.

RESULTS

A total of 398 patients were recruited from January 2016 to December 2018. The mean FI-Lab value was 0.26 ± 0.11. The prevalence of extensive periventricular WMH, extensive deep WMH, extensive basal ganglia EPVS, extensive centrum semiovale EPVS, silent lacunar infarcts, and deep microbleed was 26.1, 66.6, 68.6, 80.7, 32.9, and 6.5%, respectively. A higher FI-Lab value was associated with increased risks of extensive deep WMH (OR = 1.622; 95% CI, 1.253 ~ 2.100), extensive basal ganglia EPVS (OR = 1.535; 95% CI, 1.187 ~ 1.985), extensive centrum semiovale EPVS (OR = 1.584; 95% CI, 1.167 ~ 2.151), silent lacunar infarcts (OR = 1.273; 95% CI, 1.007 ~ 1.608), and higher total burden of CSVD. These associations remained after the adjustment of potential confounding factors.

CONCLUSION

This study demonstrated that a higher FI-Lab score might be associated with the presence of WMH, EPVS, silent lacunar infarcts, as well as severe total CSVD burden in older patients with minor stroke or TIA. The FI-Lab provides a basis for the prediction of CSVD.

Detecting apathy in patients with cerebral small vessel disease

Background

Apathy is attracting more and more attention in clinical practice. As one of the most common features of cerebral small vessel disease (CSVD), the assessment of apathy still mainly relies on observers. With the development of Information and Communication Technologies (ICTs), new objective tools take part in the early detection of apathy.

Objectives

To detect apathy in patients with CSVD and find out the relationship between apathy and actigraphic data sampled from the diurnal and nocturnal periods.

Methods

A total of 56 patients with CSVD were recruited for a cross-sectional observational study. Apathy was diagnosed by the diagnostic criteria for apathy in neurocognitive disorders. The presence of lacunes, white matter hyperintensities, cerebral microbleeds (CMBs), and perivascular spaces (PVS) in magnetic resonance imaging (MRI) images were rated independently. Actigraph devices were worn in the non-dominant hands of each subject for 7 consecutive days to collect samples of raw data, and diurnal vector magnitude (VM) and a series of sleep quality variables were obtained.

Results

We found that the frequency of apathy in Chinese patients with CSVD reached 37.50%. Patients in the Apathy+ group showed more lacunes and CMBs, and higher Fazekas scores in comparison to apathy-group individuals. Diurnal VM, instead of other sleep quality variables, was lower in CSVD patients with apathy relative to those without apathy. Lastly, we discovered that diurnal VM and total time in bed (TTB) correlated negatively with apathy severity in patients with CSVD.

Conclusion

Actigraphy is a promising choice to evaluate apathy in patients with CSVD.

Neuropsychiatric symptoms and altered sleep quality in cerebral small vessel disease

BACKGROUND

Sleep disturbance and neuropsychiatric symptoms are common clinical symptoms of cerebral small vessel disease (CSVD), but the underlying mechanism is unclear. Here, we investigated the relationship between sleep quality and neuropsychiatric performance in patients with CSVD.

METHODS

A total of 30 patients with CSVD and 35 healthy controls (HCs) were recruited. The 13-item Beck Depression Inventory (BDI-13), Beck Anxiety Inventory (BAI), and Symptom Check List 90 (SCL90) were used to assess depression, anxiety, and other psychological symptoms, respectively. Sleep quality was assessed using Pittsburgh Sleep Quality Index (PSQI), and cognitive function was tested using Montreal Cognitive Assessment (MoCA).

RESULTS

When compared to the HC group, the patients with CSVD showed increased anxiety and neuropsychiatric symptoms, worse sleep quality, and impaired cognition (p < 0.05). The prevalence of comorbid poor sleep quality in the patients with CSVD was approximately 46%. The patients with CSVD with poor sleep quality also had more severe neuropsychiatric symptoms. After controlling for demographic variables, sex and anxiety significantly predicted sleep quality.

CONCLUSION

This study suggests that the prevalence of CSVD with poor sleep quality is high, and that sex and anxiety are independent risk factors for CSVD comorbid sleep quality.