Subjective Cognitive Decline (SCD) in older adults has been identified as a risk factor for dementia, although the literature is inconsistent, and it is unclear which factors moderate progression from SCD to dementia. Through separate meta-analyses, we aimed to determine if SCD increased the risk of developing dementia or mild cognitive impairment (MCI). Furthermore, we examined several possible moderators. Longitudinal studies of participants with SCD at baseline, with data regarding incident dementia or MCI, were extracted from MEDLINE and PsycINFO.Articles were excluded if SCD occurred solely in the context of dementia, MCI, or as part of a specific disease. Pooled estimates were calculated using a random-effects model, with moderator analyses examining whether risk varied according to SCD definition, demographics, genetics, recruitment source, and follow-up duration. Risk of study bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies(QUADAS)-2 tool. 46 studies with more than 74, 000 unique participants were included. SCD was associated with increased risk of developing dementia

SUMMARYResearch on the relationship between habitual sleep patterns and memory performance in older adults is limited. No previous study has used objective and subjective memory measures in a large, older-aged sample to examine the association between sleep and various domains of memory. The aim of this study was to examine the association between objective and subjective measures of sleep with memory performance in older adults, controlling for the effects of potential confounds. Onehundred and seventy-three community-dwelling older adults aged 65-89 years in Victoria, Australia completed the study. Objective sleep quality and length were ascertained using the Actiwatch 2 Mini-Mitter, while subjective sleep was measured using the Pittsburgh Sleep Quality Index. Memory was indexed by tests of retrospective memory (Hopkins Verbal Learning Test -Revised), working memory (n-back, 2-back accuracy) and prospective memory (a habitual button pressing task). Compared with normative data, overall performance on retrospective memory function was within the average range. Hierarchical regression was used to determine whether objective or subjective measures of sleep predicted memory performances after controlling for demographics, health and mood. After controlling for confounds, actigraphic sleep indices (greater wake after sleep onset, longer sleep-onset latency and longer total sleep time) predicted poorer retrospective (ΔR 2 = 0.05, P = 0.016) and working memory (ΔR 2 = 0.05, P = 0.047). In contrast, subjective sleep indices did not significantly predict memory performances. In community-based older adults, objectively-measured, habitual sleep indices predict poorer memory performances. It will be important to follow the sample longitudinally to determine trajectories of change over time. IN TROD UCTI ONReductions in the length and quality of sleep are common in normal ageing (Ohayon et al., 2004), and while recent research has evaluated the importance of sleep for general cognition (Yaffe et al., 2007) and memory consolidation postlearning (see Scullin and Bliwise, 2015 for comprehensive review), the relationship between habitual sleep patterns and memory in older adults has not been sufficiently studied (Cochrane et al., 2012;Naismith et al., 2011;Seelye et al., 2015;Wilckens et al., 2014). Deterioration in various domains of memory is common with age, and evaluating the relationship between habitual sleep patterns and domains of memory (such as retrospective memory, working memory and prospective memory) will contribute to strategies for improving cognitive health in ageing populations.In studies using polysomnography, which examines cerebral sleep-wake states in addition to other physiological changes that occur with sleep, and is the gold standard of objective sleep measurement, indices of good sleep quality have been associated with better subsequent memory performance (Lafortune et al

Background: Dementia is a devastating condition for older adults, with both modifiable (e.g., diabetes mellitus) and unmodifiable risk factors (e.g., APOE 4 allele). It remains unclear how, and to what extent, diabetes impacts dementia risk via both cerebrovascular and amyloid-␤ pathways. Objective: We conducted a quantitative meta-analysis to investigate the contribution of diabetes to incident dementia risk in people with 4 and, based on the vascular-related neuropathology of diabetes, whether the combination of these factors increases risk for vascular dementia versus Alzheimer's disease (AD). Methods: Systematic literature searches were conducted using EMBASE, MEDLINE, PsycINFO, and CINAHL databases. Pooled relative risk (RR) estimates were calculated using a random effects model, and subgroup analyses conducted across dementia subtypes. Results: Twelve studies were included, with a total of 16,200 participants. Considered concurrently, diabetes increased incident dementia risk an additional 35% for those with 4 (RR = 1.35, 95% CI = 1.13-1.63). Similar patterns were observed for AD and vascular dementia. Conclusion: Interventions to prevent co-morbid diabetes, and diabetes-related complications and neuropathological changes, may be one way of modifying dementia risk in the vulnerable 4 population.

These unexpected results may suggest a non-linear trajectory between sleep and memory decline in aging. The findings are discussed in relation to previous research, which taken together, may indicate compensatory sleep patterns of reduced sleep disruption in people with high levels of SMD. These preliminary findings suggest the utility of including analysis of sleep behavior in further longitudinal research of this at-risk group of older people.

Key Points Question Is neighborhood-level socioeconomic status (SES) associated with differences in cognition and dementia risk scores? Findings In this cross-sectional study of 4656 Australian adults aged 40 to 70 years enrolled in the population-based Healthy Brain Project cohort, higher neighborhood-level SES was associated with better memory and lower dementia risk scores. Meaning This study’s findings suggest that dementia research would benefit from including participants living in areas with lower SES to better understand relevant factors and potential interventions.