The Longitudinal Association of Lifestyle with Cognitive Health and Dementia Risk: Findings from the HELIAD Study.

The aim of the current study was to investigate whether a Total Lifestyle Index (TLI), including adherence to the Mediterranean diet, sleep duration, physical activity and engagement in activities of daily living, is associated with cognitive health over time and dementia risk, in a representative cohort of older people. A total of 1018 non-demented community-dwelling older adults ≥65 years old (60% women) from the HELIAD study were included. A comprehensive neurological and neuropsychological assessment was conducted at baseline and at the 3-year follow-up evaluating cognitive functioning, and a dementia diagnosis was set. Diet, physical activity, sleep duration and engagement in activities of daily living were assessed using standard, validated questionnaires at baseline. Sixty-one participants developed dementia at follow-up; participants who developed dementia were older and had fewer years of education compared with participants with normal cognition. With the exception of sleep duration, participants with normal cognition at follow-up scored higher in the individual lifestyle factors compared to those who developed dementia. Regarding TLI, values were lower for participants with dementia compared with those with normal cognition. Each additional unit of the TLI was associated with 0.5% of a standard deviation less decline per year of the Global Cognition score, whereas for each additional unit of the TLI, the risk for dementia was reduced by 0.2% per year (p < 0.05). Our results suggest that greater adherence to a healthy lifestyle pattern is associated with a slower decline of cognitive function and reduced dementia risk.

Dietary Inflammatory Index score and prodromal Parkinson's disease incidence: The HELIAD study.

The aim of the present study was to investigate the association of the inflammatory potential of diet with prodromal Parkinson's disease (pPD) probability and incidence among community-dwelling older individuals without clinical features of parkinsonism at baseline. The sample consisted of 1,030 participants 65 years old or older, drawn from a population-based cohort study of older adults in Greece (Hellenic Longitudinal Investigation of Aging and Diet - HELIAD). We calculated pPD probability, according to International Parkinson and Movement Disorder Society research criteria. Dietary Inflammatory Index (DII) was used to measure the dietary inflammatory potential, with higher index score reflecting a more pro-inflammatory diet. Associations of baseline DII with pPD probability cross-sectionally, and with possible/probable pPD incidence (pPD probability ≥30%) during the follow-up period, were examined via general linear models and generalized estimating equations, respectively. Cross-sectionally, one unit increase of DII score [DII (min, max) = -5.83, 6.01] was associated with 4.9% increased pPD probability [ß=0.049, 95%CI (0.025-0.090), p<0.001]. Prospectively, 62 participants developed pPD during 3.1±0.9 (mean±SD) years of follow-up. One unit increase in DII was associated with 20.3% increased risk for developing pPD [RR=1.203, 95%CI (1.070-1.351), p=0.002]. Participants in the highest tertile of DII score were 2.6 times more likely to develop pPD [ß=2.594, 95%CI (1.332-5.050), p=0.005], compared to those in the lowest tertile. More pro-inflammatory diet was related with higher pPD probability and pPD incidence (pPD probability ≥30%) in a community-dwelling older adult population. Further studies are needed to confirm these findings.

Association Between Sleep Disturbances and Frailty: Evidence From a Population-Based Study.

OBJECTIVE: To explore the association between both self-reported quality and quantity sleep characteristics and frailty status in a large non-sex-specific population of older individuals in Greece. DESIGN: Cross-sectional study. SETTING AND PARTICIPANTS: In total, 1984 older individuals (≥65 years old) were drawn from the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD). MEASURES: Frailty was assessed using 3 different definitions, the Frailty Index (FI), the Tilburg Frailty Indicator (TFI), and the Groningen Frailty Indicator (GFI). Sleep quality was evaluated through the Sleep Index II, which includes 9 of the 12 self-reported items of the Medical Outcomes Study-Sleep Scale. To examine sleep duration, participants were asked to report on how many hours they slept each night during the past 4 weeks. Logistic regression models adjusted for multiple covariates were explored. Additional analyses, stratified by gender, adjusting for sleep-related medications and excluding participants diagnosed with dementia, were also performed. RESULTS: In total, 389 (20%), 619 (31.9%), and 608 (31.3%) participants were categorized as frail according to the FI, the TFI, and the GFI respectively. Sleep quality was significantly associated with frailty in all models. Even after adjusting for subjective sleep duration, compared with participants who subjectively reported high sleep quality, those with low sleep quality had 3.7, 2.6, and 2.5 more times to be frail as measured with FI, TFI, and GFI respectively. Regarding the associations between frailty and self-reported sleep duration, sex-specific associations were observed: prolonged sleep duration was associated with frailty in the subsample of male participants. CONCLUSIONS AND IMPLICATIONS: The present study shows a strong correlation between subjective sleep quality and frailty status, contributing substantial information to the growing literature demonstrating that sleep is associated with older people's overall health. Sleep complaints should not be underestimated, and older individuals who self-report sleep disorders should be further assessed for frailty.