| 1. |
- Varga, A. W., et al.
(författare)
-
Reduced Slow-Wave Sleep Is Associated with High Cerebrospinal Fluid A beta 42 Levels in Cognitively Normal Elderly
- 2016
-
Ingår i: Sleep. - : Oxford University Press (OUP). - 0161-8105 .- 1550-9109. ; 39:11, s. 2041-2048
-
Tidskriftsartikel (refereegranskat)abstract
- Study Objectives: Emerging evidence suggests a role for sleep in contributing to the progression of Alzheimer disease (AD). Slow wave sleep (SWS) is the stage during which synaptic activity is minimal and clearance of neuronal metabolites is high, making it an ideal state to regulate levels of amyloid beta (A beta). We thus aimed to examine relationships between concentrations of A beta 42 in the cerebrospinal fluid (CSF) and measures of SWS in cognitively normal elderly subjects. Methods: Thirty-six subjects underwent a clinical and cognitive assessment, a structural MRI, a morning to early afternoon lumbar puncture, and nocturnal polysomnography. Correlations and linear regression analyses were used to assess for associations between CSF A beta 42 levels and measures of SWS controlling for potential confounders. Resulting models were compared to each other using ordinary least squared linear regression analysis. Additionally, the participant sample was dichotomized into "high" and "low" A beta 42 groups to compare SWS bout length using survival analyses. Results: A significant inverse correlation was found between CSF A beta 42 levels, SWS duration and other SWS characteristics. Collectively, total SWA in the frontal lead was the best predictor of reduced CSF A beta 42 levels when controlling for age and ApoE status. Total sleep time, time spent in NREM1, NREM2, or REM sleep were not correlated with CSF A beta 42. Conclusions: In cognitively normal elderly, reduced and fragmented SWS is associated with increases in CSF A beta 42, suggesting that disturbed sleep might drive an increase in soluble brain A beta levels prior to amyloid deposition.
|
|
| 2. |
- Sharma, Ram A, et al.
(författare)
-
Obstructive Sleep Apnea Severity Affects Amyloid Burden in Cognitively Normal Elderly: A Longitudinal Study.
- 2018
-
Ingår i: American Journal of Respiratory and Critical Care Medicine. - 1073-449X .- 1535-4970. ; 197:7, s. 933-943
-
Tidskriftsartikel (refereegranskat)abstract
- Recent evidence suggests that Obstructive Sleep Apnea (OSA) may be a risk factor for developing Mild Cognitive Impairment and Alzheimer's disease. However, how sleep apnea affects longitudinal risk for Alzheimer's disease is less well understood.To test the hypothesis that there is an association between severity of OSA and longitudinal increase in amyloid burden in cognitively normal elderly.Data was derived from a 2-year prospective longitudinal study that sampled community-dwelling healthy cognitively normal elderly. Subjects were healthy volunteers between the ages of 55 to 90, were non-depressed and had a consensus clinical diagnosis of cognitively normal. CSF Amyloid beta was measured using ELISA. Subjects received Pittsburgh compound B Positron Emission Tomography scans following standardized procedures. Monitoring of OSA was completed using a home sleep recording device.We found that severity of OSA indices (lnAHIall [F1,88=4.26, p<.05] and lnAHI4% [F1,87=4.36, p<.05]) were associated with annual rate of change of CSF Aβ42 using linear regression after adjusting for age, sex, BMI and ApoE4 status. LnAHIall and lnAHI4 were not associated with increases in ADPiB-mask most likely due to the small sample size although there was a trend for lnAHIall (F1,28=2.96, p=.09 and F1,28=2.32, n.s. respectively).In a sample of cognitively normal elderly, OSA was associated with markers of increased amyloid burden over the 2 year follow-up. Sleep fragmentation and/or intermittent hypoxia from OSA are likely candidate mechanisms. If confirmed, clinical interventions for OSA may be useful in preventing amyloid build-up in cognitively normal elderly.
|
|
| 3. |
|
|
