Frequency of alcohol consumption and amyloid beta deposition: Results from the ALBION study
April 2025Archontoula Drouka, Klairi Ntetsika, Dora Brikou, Angeliki Tsapanou, Eirini Mamalaki, Eva Ntanasi, Kostas Patas, Stylianos Chatzipanagiotou, Christopher Papandreou, Nikolaos Scarmeas, Mary Yannakoulia
AD/PD: 19th International Conference on Alzheimer’s & Parkinson’s Diseases, Vienna, Austria
Objectives: The association between alcohol and cognitive function is complex. Several pathways
are involved. In this work we focus on the potential associations between drinking frequency and
cerebrospinal fluid (CSF) biomarkers of neurodegenerationin a cohort of dementia-free middle-
aged-adults.
Methods: This analysis is part of the ALBION study. Each volunteer went throughan extensive
neuropsychological assessment. Sociodemographic characteristics were alsorecorded.Dietary
intake, including energy and alcohol intakes, was assessed through four 24-hour recalls. Diet
quality was evaluated through the adherence to the Mediterranean diet (MedDietScore). Other
lifestyle parameters were recorded, such as sleep duration, which using a wrist actigraph for 7
days, and physical activity, assessed (through the International Physical Activity Questionnaire).
CSF sample was collected. Multiple logistic regression analyses were conducted using drinking
frequency subgroups (abstainers, less than 2 standard drinks/week, above 2 standard drinks/week)
as independent variables and CSF Alzheimer Disease (AD) biomarkers [amyloid-β (Aβ)
accumulation, Tau/Aβ and Phospho-tau/Aβ ratios] as dependent variables.
Results: Of the 195 individuals without dementia, the majority were female (66%), with an
average age of 65±9.4 years and 13.8±3.6 years of education. The average sleep duration, as
assessed by wrist actigraph, was 5.91±4.48 hours. A weekly alcohol intake exceeding 2 standard
drinks was associated with higher Aβ positivity compared to alcohol abstinence [OR:2.98 (1.29-
6.90)], even after adjusting for confounders (age, sex, education years, energy intake and diet
quality).
Conclusions: The present study showed that light-to-moderate alcohol consumption was
associated with increased Aβ accumulation in cognitively intact adults. These findings potentially
increase our understanding of how alcohol consumption might influence vulnerability to AD.
Sleep apnea severity, mild cognitive impairment and amyloid pathology: Insights from the ALBION Cohort
April 2025Foukarakis Ioannis, Androni Xenia, Gelbesi Iliana, Ntanasi Eva, Mamalaki Eirini, Tsapanou Aggeliki, Manolakos Ilias, Yannakoulia Mary, Patas Kostas, Chatzipanagiotou Stylianos, Scarmeas Nikolaos
AD/PD: 19th International Conference on Alzheimer’s & Parkinson’s Diseases, Vienna, Austria
Objectives: The pathophysiological mechanism linking sleep apnea and cognitive impairment
remains poorly understood. We aimed to explore the association between the Apnea-
Hypopnea Index (AHI), cognitive state, and cerebrospinal fluid biomarker pTau181/aβ42
(Amyloid status) in non-demented individuals.
Methods: In this cross-sectional study, 115 non-demented participants from the ALBION cohort
underwent a one week actigraphy assessment and a one-night WatchPAT evaluation to
determine sleep microarchitecture and AHI, respectively.Total sleep time (TST) was calculated
as the median of one week assessments of daily TST through actigraphy.Participants were
categorized by both cognitive status (patients with Mild Cognitive Impairment (MCI) or
cognitively normal individuals (CN)) and Amyloid status ((A+) or (A-).Binary logistic regression
analysis, adjusted for age, sex, years of education, BMI and TST was used to assess the presence
of an association with AHI, respectively. Participants were further divided by AHI levels (Low <
15 or High ≥ 15) and regression analysis evaluated its interaction with amyloid status, using
cognitive status as the outcome.
Results: For each unit increase in AHI, the odds of being classified as MCI were 7% higher (OR=1.07
,p=0.003) and the odds of being classified as A+ were 4% higher (OR=1.04, p=0.043).Compared to
the reference group [A(-)/AHI(low)], the odds ratio for MCI was 3.84 (p=0.100) in A(+)/AHI(low)
group, 4.48, p=0.022 in the A(-)/AHI(high) and 15.30(p=0.0017) in the A(+)/AHI(high) group.
Conclusions: We find significant associations between AHI, MCI and amyloid-beta brain
pathology. Although more longitudinal studies are needed, higher AHI levels could potentially
contribute to cognitive impairment either by interacting with amyloid-beta or independently.
Sleep fragmentation and cognitive decline in older people
October 2025Eva Ntanasi, Eirini Mamalaki, Angeliki Tsapanou, Dora Brikou, Archontoula Drouka, Artemis Margoni, Christopher Papandreou, Elias S Manolakos, Mary Yannakoulia, Nikolaos Scarmeas
35th Alzheimer Europe Conference, Bologna, Italy
Wake After Sleep Onset (WASO) — the amount of time spent awake after initially falling
asleep — is a key marker of sleep fragmentation. Elevated WASO has been previously
associated with elevated risk of Alzheimer's disease (AD). Less is known about its association
with cognitive decline in non-demented population. In the current study, we opted to
investigate the association between WASO, measured via actigraphy, and cognitive
performance in dementia-free adults (>40 years).
Data were gathered form the Aiginition Longitudinal Biomarker Investigation Of
Neurodegeneration (ALBION). A total of 183 people (65% women, mean age 64.9, SD 9.6
years) without dementia were included in the current study. Participants completed
actigraphy monitoring (Philips Actiwatch) for 7 consecutive nights to quantify sleep
parameters, including WASO. Cognitive function was assessed using a detailed standardized
neuropsychological battery. CSF samples were analyzed for amyloid-β and tau to classify
participants based on the ATN criteria. Regression models evaluated the relationship
between a) mean WASO and Mild Cognitive Impairment diagnosis (MCI) b) mean WASO and
cognitive decline, adjusting for age, sex, and education.
WASO was not associated with MCI diagnosis or participants’ cognitive performance.
However, we used ATN criteria and divided our sample in a) people without AD pathology,
b) with amyloid pathology and c) with AD biomarkers (amyloid and tau pathology). We
found that in the group of people without AD pathology, higher WASO was significantly
associated with poorer performance in memory (β = -0.016, p=0.003) and attention/speed
(β = -0.009, p=0.06) after adjusting for covariates.
According to the study results, greater sleep fragmentation was associated with worse
memory and attention performance in older individuals without evidence of AD pathology.
These findings highlight sleep disruption as a potential independent risk factor for cognitive
decline and suggest that better sleep continuity may help preserve cognitive health.
Prospecitve prediction of cognitive decline from actigraphy: A repeated nested cross-validation machine learning study on the ALBION dataset
March 2026Eleni Panagiotopoulou, Glykeria Spyrou, Ioannis Mystakidis, Violetta Gkika, Mary Yannakoulia, Vasiliki Amaryllis Skyfa, Christopher Papandreou, Nikolaos Scarmeas, Elias Manolakos
AD/PD: 20th International Conference on Alzheimer’s & Parkinson’s Diseases, Copenhagen, Denmark
Aims:This study investigates whether baseline actigraphy features can predict subsequent
cognitive decline using wearable-derived measures as early risk markers.
Methods: We analyzed actigraphy data from 101 participants in the ALBION dataset. Cognitive
performance was assessed using neuropsychological tests across five domains and
summarized as z-scores, standardized against a cognitively normal reference group and
adjusted for age and sex. Cognitive trajectories were defined using the average composite z-
scores between baseline (T0) and follow-up (T1), where T1-T0 ≤ 2 years. Cognitive status was
classified as "stable" if the composite z-score remained unchanged or improved, and
"declined" if decreased (Δzscore < 0), resulting in 53 stable and 48 declined samples. We
extracted seventeen actigraphy features, including multi-cosinor and nonparametric
parameters, from one-day averaged actigraphy time series at baseline. To address the
limited sample size, we employed repeated nested cross-validation (rnCV) with 10 rounds ×
5 outer × 5 inner folds for unbiased performance estimation. Feature selection employed
Minimum Redundancy Maximum Relevance (mRMR) to identify informative, non-redundant
predictors.
Results: We used rnCV to compare baseline models, including Logistic Regression, Linear
Discriminant Analysis, Gaussian Naive Bayes, and ensemble tree estimators such as Random
Forest, Light radient Boosting Machine, and eXtreme Gradient Boosting, confirming that
both model types achieve good performance. LDA emerged as the best estimator without
feature selection, reaching median recall 0.70 ± 0.03, specificity 0.70 ± 0.04 and MCC 0.39 ±
0.05. Notably, LightGBM achieved the same median recall and specificity with MCC 0.40 ±
0.05, using only three mRMR-selected features.
Conclusions: Actigraphy-based ML shows promise for predicting cognitive decline, with performance
achievable using minimal features, supporting further investigation.
