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The state between aging with no cognitive impairment and dementia has become a major focus for intervention. The neuropathological and neurobiological correlates of this intermediate state are therefore of considerable interest, particularly from population representative samples. Here we investigate the neuropathological profile associated with different cognitive ability levels measured using strata defined by Mini Mental State Examination (MMSE) scores. One hundred and fifty one individuals were stratified into three cognitive groups including: non-, mildly, and moderately impaired at death. Alzheimer's disease, atrophy, and vascular pathologies were investigated. Mild impairment was associated with an increased risk of vascular pathologies including small vessel disease and lacunes. In contrast, the moderately impaired group showed a more extensive pattern of pathology, including tangles and neuritic plaques (entorhinal/hippocampus), atrophy (cortical and hippocampal), and vascular disease (small vessel disease, lacunes, and infarcts). In a population-based sample of older people, MMSE score defined strata are associated with multiple pathologies. The profile of AD and vascular changes becomes more complex with increased cognitive impairment and these changes are likely to constitute a major substrate for age associated cognitive impairment. The results highlight the need for rigorous investigation of both neurodegenerative and vascular risks factors in old age. [ABSTRACT FROM AUTHOR]

Background: Metabolic syndrome (MetS) is associated with an increased risk of coronary heart diseases and stroke. Results on the association of MetS with dementia and cognitive decline have been inconsistent., Objective: The aim of this study was to examine the association between MetS and longitudinal changes in cognitive function., Methods: Medline, EMBASE, and Scopus databases were searched from inception to June 2013. Longitudinal cohort studies that reported on the association between MetS and change in cognitive function (over two or more time points), were included., Results: Random-effects models were used to assess the pooled effect sizes of longitudinal changes in cognitive function associated with MetS. Thirteen studies were included. The total sample size was 19,522 subjects. Follow up duration ranged from 1 to 16 years. In the total sample, a small association of MetS with cognitive decline was observed (SDM 0.06, 95%CI: -0.001, 0.12; p = 0.05). When age-stratified, a marginal significant association between MetS and cognitive decline was observed in the younger old group (≤70 years; SDM = 0.09, 95%CI: -0.003, 0.19; p = 0.05) but not in the older group (>70 years; SDM = 0.03, 95%CI: -0.05, 0.11; p = 0.48). The meta-regression showed that duration of follow up was not associated with changes in cognitive estimates (β = 0.005; p = 0.30)., Conclusions: Age appears to modify the association between MetS and cognitive decline. These results emphasize the importance of age-stratified risk prediction models of dementia in subjects with chronic metabolic disorders.

Accurate detection of individuals with cognitive impairment and dementia in addition to identification of those at high risk of future disease is important to guide clinical care, and has research implications regarding clinical trial recruitment and development of dementia preventative strategies. In this narrative review, we describe new proposed criteria for early diagnosis of Alzheimer's disease (AD). We also explore risk factors for dementia and evaluate methods for screening for increased risk of incident disease. We highlight variability in different diagnostic approaches. Additional work needs to be done to validate new methods across different settings (such as population-based, primary care, and memory clinics), age, and ethnic groups. Having an accurate method to assess for dementia and predict risk in routine clinical care will aid decision making and could ultimately lead to disease prevention.