Sleep Quality and Cognitive Abilities in the Greek Cohort of Epirus Health Study.

Purpose: Sleep is essential to all human body functions as well as brain functions. Inadequate sleep quantity and poor sleep quality have been shown to directly affect cognitive functioning and especially memory. The primary aim of the present study was to investigate the association of sleep quality with cognitive abilities cross-sectionally in a middle-aged Greek population and secondarily to examine this association prospectively in a smaller group of these participants. Patients and Methods: A total of 2112 healthy adults aged 25-70 years (mean: 46.7±11.5) from the Epirus Health Study cohort were included in the analysis and 312 of them participated in secondary prospective analysis. Sleep quality was measured by the Pittsburgh Sleep Quality Index (PSQI) scale and cognition was assessed in primary cross-sectional analyses with three neuropsychological tests, namely the Verbal Fluency test, the Logical Memory test and the Trail Making test, and in secondary prospective analyses with online versions of Posner cueing task, an emotional recognition task, the Corsi block-tapping task and the Stroop task. Statistical analysis was performed using multivariable linear regression models adjusted for age, sex, education, body mass index and alcohol consumption. Results: Attention/processing speed was the only cognitive domain associated cross-sectionally with PSQI score. Specifically, participants with better self-reported sleep quality performed faster on the Trail Making Test - Part A (ß= 0.272 seconds, 95% CI 0.052, 0.493). Conclusion: Further studies are needed to clarify the association of sleep quality with cognition, especially in middle-aged people that are still in productive working years.

Metabolic syndrome and cognitive deficits in the Greek cohort of Epirus Health Study.

BACKGROUND: Metabolic syndrome is considered an important risk factor for cognitive decline and dementia. However, the evidence in middle-aged individuals is still conflicting. The aim of the study was to explore the association between metabolic syndrome and its individual components with cognitive function and to investigate possible interaction between sex, age and genetic predisposition for metabolic syndrome and Alzheimer's disease in a middle-aged Greek cohort. METHODS: A total of 2,077 healthy adults (mean age: 46.7 years) were included in the primary cross-sectional analysis and 305 of them in secondary prospective analyses. Metabolic syndrome was defined by the revised National Cholesterol Education-Adult Treatment Panel III and the International Diabetes Federation criteria. Cognitive function was measured primarily with the Trail Making, Verbal fluency and Logical Memory test, and in secondary prospective analyses with online versions of Posner cueing task, an emotional recognition task, Corsi block-tapping task and Stroop task. RESULTS: Multivariable linear regressions showed an association of metabolic syndrome with lower performance in attention (ß=1.62 seconds, 95% CI=0.20, 3.04) and memory (ß=-0.62 words, 95% CI=-1.19, -0.05) that could be driven by associations with elevated fasting glucose and abdominal obesity. Similar associations were observed in the secondary prospective analyses. CONCLUSION: In summary, metabolic syndrome was associated with cognitive deficits in domains related with the cognitive profile of vascular cognitive impairment.

Mediterranean diet related metabolite profiles and cognitive performance.

BACKGROUND & AIMS: Evidence suggests that adherence to the Mediterranean diet (MedDiet) affects human metabolism and may contribute to better cognitive performance. However, the underlying mechanisms are not clear. OBJECTIVE: We generated a metabolite profile for adherence to MedDiet and evaluated its cross-sectional association with aspects of cognitive performance. METHODS: A total of 1250 healthy Greek middle-aged adults from the Epirus Health Study cohort were included in the analysis. Adherence to the MedDiet was assessed using the 14-point Mediterranean Diet Adherence Screener (MEDAS); cognition was measured using the Trail Making Test, the Verbal Fluency test and the Logical Memory test. A targeted metabolite profiling (n = 250 metabolites) approach was applied, using a high-throughput nuclear magnetic resonance platform. We used elastic net regularized regressions, with a 10-fold cross-validation procedure, to identify a metabolite profile for MEDAS. We evaluated the associations of the identified metabolite profile and MEDAS with cognitive tests, using multivariable linear regression models. RESULTS: We identified a metabolite profile composed of 42 metabolites, mainly lipoprotein subclasses and fatty acids, significantly correlated with MedDiet adherence (Pearson r = 0.35, P-value = 5.5 × 10-37). After adjusting for known risk factors and accounting for multiple testing, the metabolite profile and MEDAS were not associated with the cognitive tests. CONCLUSIONS: A plasma metabolite profile related to better adherence to the MedDiet was not associated with the tested aspects of cognitive performance, in a middle-aged Mediterranean population.

Metabolic syndrome and cognition: A systematic review across cognitive domains and a bibliometric analysis.

The aim of this review is to investigate the association between metabolic syndrome (MetS) and cognitive decline in distinct cognitive domains, and to perform a complementary study description through the bibliometric analysis. PubMed and Scopus databases were searched from inception to 15 December 2021 to identify longitudinal studies that examined the association of MetS with incident decline, in order to prevent reverse causality. The Preferred Reporting Items for Systematic Review and Meta-Analysis checklist was used to conduct the present systematic review. Thirty studies were included and results were analyzed across the cognitive domains of global cognition, memory, executive functions, attention, visuoconstructive abilities, and language. The majority of the studies reviewed did not report statistically significant results for most cognitive domains investigated, and decline in specific cognitive domains was not consistently associated with the presence of MetS. Meta-analyses were not conducted due to the high degree of between-study heterogeneity regarding the MetS definitions, the cognitive domains examined, the specific tests used for each cognitive domain and the different measures of association used. Bibliometric analysis revealed that most studies are conducted by research teams from USA and China, and that cognitive tasks that reflect real-life abilities are rarely examined. Future studies should employ larger sample sizes, longer follow-up periods, a global consensus for MetS definition and standardized tests of the above mentioned cognitive domains as well as problem-solving tasks with high sensitivity and specificity to clarify the impact of MetS on cognition and its underlying mechanisms.

The Parkinson's Disease-Cognitive Rating Scale: Greek Normative Data, Clinical Utility and Cultural Considerations.

BACKGROUND: The Parkinson's Disease-Cognitive Rating Scale (PD-CRS) is a comprehensive screening procedure for the evaluation of cognitive impairment in patients with Parkinson's disease (PD). OBJECTIVES: In the present study we adjusted the PD-CRS for the Greek population, developed normative data and examined its clinical utility for the assessment of cognitive functioning in Greek PD patients. In addition, the correlation of clinical characteristics with cognitive performance in PD patients was examined. METHODS: Three hundred four community-dwelling healthy adults and 59 patients with PD, completed the adapted PD-CRS. RESULTS: Healthy adults outperformed the PD patients on the total, the cortical and subcortical scores of the PD-CRS. Normative data indicated effects of both education and age on the PD-CRS. The optimal total PD-CRS cutoff score for the identification of cognitive impairment in a heterogeneous sample of PD patients, with regard to the severity of cognitive difficulties, was 79, yielding a modest sensitivity and specificity. Clinical characteristics of the patients (i.e., disease duration and functional disease burden) were related to poor performance on the PD-CRS. CONCLUSIONS: The Greek version of the PD-CRS is a useful instrument for the assessment of cognition in PD. Future prospective studies should examine its clinical utility to identify PD-cognitive subtypes (i.e., PD patients with mild cognitive impairment), to monitor cognitive changes, as well as its predictive accuracy for subsequent dementia.

Adherence to Mediterranean Diet and Cognitive Abilities in the Greek Cohort of Epirus Health Study.

The Mediterranean diet is commonly proposed as a major modifiable protective factor that may delay cognitive impairment in the elderly. The aim of the study was to investigate the cross-sectional association of adherence to the Mediterranean diet with cognitive abilities in a younger Greek population. A total of 1201 healthy adults aged 21-77 years (mean: 47.8) from the Epirus Health Study cohort were included in the analysis. Adherence to the Mediterranean diet was measured using the 14-point Mediterranean Diet Adherence Screener (MEDAS) and cognition was measured using the Trail Making Test, the Verbal Fluency test and the Logical Memory test. Statistical analysis was performed using multiple linear regression models adjusted for age, sex, education, body mass index, smoking status, alcohol consumption and physical activity. Overall, no association was found between the MEDAS score and cognitive tests, which could be explained by the young mean age and high level of education of the participants. Future studies should target young and middle-aged individuals to gain further understanding of the association between Mediterranean diet and cognition in this age group.