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Metabolic syndrome (MetS) has been found to be a risk factor for dementia, mild cognitive impairment, and its associated states. However, a definitive conclusion cannot be drawn from the available data. Discrepancies between the results are due to several factors, e.g., study design, heterogeneity of the population enrolled, reliability and sensitivity of detection tools for cognitive changes, cut-offs and criteria used to diagnose MetS, the outcome measures considered, MetS duration before the onset of cognitive decline, and also the analytical approach performed. Recently, a systematic review and meta-analysis including 19,522 subjects aged 59-85 years from 13 longitudinal population-based studies has been conducted to examine the association between MetS and longitudinal changes in cognitive functions. While a marginal significant association was found in the younger old group, this relationship was not observed in older group (>70 years). It is not yet clear how age can influence this relationship. Apart from methodological issues, other biological factors are likely involved in this direction reversal.

Cognition has already been considered as a component of frailty, and it has been demonstrated that it is associated with adverse health outcomes. We estimated the prevalence of frailty syndrome in an Italian older population and its predictive role on all-cause mortality and disability in nondemented subjects and in demented patients. We evaluated 2,581 individuals recruited from the Italian Longitudinal Study on Aging, a population-based sample of 5,632 subjects, aged 65-84 years old. Participants received identical baseline evaluation at the 1st survey (1992-1993) and were followed at 2nd (1995-1996) and 3rd survey (2000-2001). A phenotype of frailty according to partially modified measurement of Cardiovascular Health Study criteria was operationalized. The overall prevalence of frailty syndrome in this population-based study was 7.6% (95% confidence interval (CI) 6.55-8.57). Frail individuals noncomorbid or nondisable were 9.1% and 39.3%, respectively, confirming an overlap but not concordance in the co-occurrence among these conditions. Frailty was associated with a significantly increased risk of all-cause mortality over a 3-year follow-up (hazard ratio (HR) 1.98, 95% confidence interval (CI) 1.52-2.60) and over a 7-year follow-up (HR 1.74, 95% CI 1.44-2.16), but with significant increased risk of disability only over a 3-year follow-up (HR 1.32, 95% CI 1.06-1.86 over a 3-year follow-up and HR 1.16, 95% CI 0.88-1.56 over a 7-year follow-up). Frail demented patients were at higher risk of all-cause mortality over 3- (HR 3.33, 95% CI 1.28-8.29) and 7-year follow-up periods (HR 1.89, 95% CI 1.10-3.44), but not of disability. Frailty syndrome was a short-term predictor of disability in nondemented older subjects and short- and long-term predictor of all-cause mortality in nondemented and demented patients.

We investigated the relationship of metabolic syndrome (MetS) and its individual components with incidence of mild cognitive impairment (MCI) and its progression to dementia in a large longitudinal Italian population-based sample with a 3.5-year follow-up. A total of 2097 participants from a sample of 5632 65-84-year-old subjects from the Italian Longitudinal Study on Aging were evaluated. MetS was defined according to the Third Adults Treatment Panel of the National Cholesterol Education Program criteria. MCI, dementia, Alzheimer's disease (AD), and vascular dementia (VaD) were classified using current published criteria. Among MCI patients those with MetS (N=49) had a higher risk of progression to dementia (HR, 4.40; 95% CI, 1.30-14.82) compared with those without MetS (N=72). After a multivariate adjustment, the risk in MCI patients with MetS approximately doubled (multivariate adjusted HR, 7.80, 95% CI 1.29-47.20) compared with those MCI without MetS. Finally, among non-cognitively impaired individuals there were no significant differences in risks of developing MCI in those who were affected by MetS (N=608) in comparison with those without MetS (N=837), as well as excluding those individuals with undernutrition or low inflammatory status with or without undernutrition. In our population, among MCI patients the presence of MetS independently predicted an increased risk of progression to dementia over 3.5 years of follow-up., (Copyright © 2009 Elsevier Inc. All rights reserved.)

Late-life depressive syndromes often arise in the context of predementia, dementia syndromes, and Alzheimer's disease (AD). Conversely, patients with a history of mood disorders are at higher risk of developing cognitive impairment. The high rate of co-occurrence of these two disorders is becoming a major health problem in older subjects for both their epidemiological impact and the negative outcomes in terms of disability and increased mortality. In this perspective, it is possible to speculate on the presence of a mirror relationship between depressive and cognitive disorders in late-life. Indeed, although a causal contribution of genetic, environmental, and social factors is widely recognized in these disorders, the neurobiological links still remain largely unknown. l-glutamic acid and γ-aminobutyric acid are the principal excitatory and inhibitory neurotransmitters in the central nervous system, respectively, and increasing evidence suggests that alterations in this neurotransmitter system may contribute to the neurobiology linking depression and cognitive impairment. In the present review article, we examined the neurobiological bases of the relationship between late-life depressive syndromes and AD, with a particular attention to glutamatergic pathway signalling like a bridge connecting these two conditions. In addition, attempts have been made to explain changes in glutamatergic pathway, depression in older age, and dementia through the analysis of signal transduction mechanisms associated with these disabling disorders., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Objective: The authors investigated the relationship of metabolic syndrome (MetS) and its individual components with incident dementia in a prospective population-based study with a 3.5-year follow-up., Methods: A total of 2097 participants from a sample of 5632 subjects (65-84 years old) from the Italian Longitudinal Study on Ageing were evaluated. MetS was defined according to the Third Adults Treatment Panel of the National Cholesterol Education Program criteria. Dementia, Alzheimer disease (AD) and vascular dementia (VaD) were classified using current published criteria., Results: MetS subjects (N=918) compared with those without MetS (N=1179) had an increased risk for VaD (1.63% vs 0.85%, adjusted hazard ratio (HR) 3.71, 95% CI 1.40 to 9.83). After excluding 338 subjects with baseline undernutrition, MetS subjects compared with those without MetS had an elevated risk of VaD (adjusted HR, 3.82; 95% CI 1.32 to 11.06). Moreover, those with MetS and high inflammation had a still further higher risk of VaD (multivariate adjusted HR, 9.55; 95% CI 1.17 to 78.17) compared with those without MetS and high inflammation. On the other hand, those with MetS and low inflammation compared with those without MetS and low inflammation did not exhibit a significant increased risk of VaD (adjusted HR, 3.31, 95% CI 0.91 to 12.14). Finally, a synergistic MetS effect versus its individual component effects was verified on the risk of VaD., Conclusion: In our population, MetS subjects had an elevated risk of VaD that increased after excluding patients with baseline undernutrition and selecting MetS subjects with high inflammation.

Drugs currently used in the treatment of cognitive impairment and dementia have a very limited therapeutic value, suggesting the necessity to potentially individualize new strategies able to prevent and to slow down the progression of predementia and dementia syndromes. An increasing body of epidemiological evidence suggested that elevated saturated fatty acids (SFA) could have negative effects on age-related cognitive decline (ARCD) and mild cognitive impairment (MCI). Furthermore, a clear reduction of risk for cognitive decline has been found in population samples with elevated fish consumption, high intake of monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA), particularly n-3 PUFA. Epidemiological findings demonstrated that high PUFA intake appeared to have borderline non-significant trend for a protective effect against the development of MCI. Several hypotheses could explain the association between dietary unsaturated fatty acids and cognitive functioning, including mechanisms through the co-presence of antioxidant compounds in food groups rich in fatty acids, via atherosclerosis and thrombosis, inflammation, accumulation of b-amyloid, or via an effect in maintaining the structural integrity of neuronal membranes, determining the fluidity of synaptosomal membranes that thereby regulate neuronal transmission. However, recent findings from clinical trials with n-3 PUFA supplementation showed efficacy on depressive symptoms only in non-apolipoprotein E (APOE) epsilon4 carriers, and on cognitive symptoms only in very mild Alzheimer's disease (AD) subgroups, MCI patients, and cognitively unimpaired subjects non-APOE epsilon4 carriers. These data together with epidemiological evidence support a possible role of fatty acid intake in maintaining adequate cognitive functioning and possibly for the prevention and management of cognitive decline and dementia, but not when the AD process has already taken over., (Copyright 2009 Elsevier Ireland Ltd. All rights reserved.)

Among possible determinants of vascular events, the role of high lipoprotein(a) (Lp[a]) serum levels represents a still uncertain independent risk factor in elderly populations. Moreover, the cumulative incidence of nonfatal vascular events due to high Lp(a) serum levels is conditioned by the competing risk of death from any causes that are a function of age. After a 6.3-year median follow up, we tested the competing risks of all-cause mortality, cumulative fatal-nonfatal stroke events, cumulative fatal-nonfatal coronary artery disease (CAD) events, and nonfatal stroke or CAD events due to high Lp(a) serum levels in a population-based, prospective study conducted in one of the eight centers of the Italian Longitudinal Study on Aging (ILSA), Casamassima, Bari, Italy. Of 704 elderly individuals (65-84 years), 372 (169 women and 203 men) agreed to participate in the study. As compared with those in the lowest Lp(a) tertile serum levels, subjects in the highest tertile (>20 mg/dL) had a higher partially adjusted risk of nonfatal CAD (hazard ratio, 4.19; 95% confidence interval [CI], 1.36-12.94) and nonfatal stroke (hazard ratio, 3.38; 95% CI, 1.00-11.56). Compared with those in the lowest tertile, subjects in the highest tertile had a higher fully adjusted risk of nonfatal CAD (hazard ratio, 3.41; 95% CI, 1.08-10.78). Finally, overall no statistically significant association was found between Lp(a) and the risk of all-cause mortality, cumulative fatal-nonfatal stroke, and cumulative fatal-nonfatal CAD events. In our population, Lp(a) was not a significant independent predictor of stroke and death from all causes, but it was an independent predictor of nonfatal CAD. Finally competing risk, conditioning the timing and occurrence of vascular events in our study population, could be a correct approach for evaluating the role of Lp(a) lipoprotein in vascular disease among elderly people.

The temporal relationship between depression and cognitive decline has not been extensively investigated in prospective population-based studies, and most of these have only looked in one direction. We estimated the bidirectional temporal relationship between depressive symptoms and cognitive function in older subjects, excluding subjects with a clinical diagnosis of dementia or mild cognitive impairment (MCI). In a total of 2,963 individuals from the Italian Longitudinal Study on Aging, depressive symptoms, global cognitive function, and episodic memory were measured. Dementia, Alzheimer's disease, vascular dementia, and MCI were classified using current clinical criteria. Depressive symptoms at baseline were associated with an accelerated global cognitive function decline and an accelerated rate of episodic memory delayed recall decline in a 3.5-year follow-up. Finally, an accelerated increase with time of depressive symptoms during the same follow-up period was not associated with global cognitive function and episodic memory (immediate and delayed recall). In older subjects non-cognitively impaired, depressive symptoms at baseline predicted change over time of global cognitive decline and episodic memory delayed recall. Global cognitive function and episodic memory at baseline were not associated with the course of depressive symptoms during the follow-up.

Among lifestyle-related factors, low to moderate alcohol drinking has been proposed as a protective factor against the development of age-related changes in cognitive function, predementia syndromes, and cognitive decline of degenerative (Alzheimer's disease, AD) or vascular origin (vascular dementia, VaD) in several longitudinal studies, but contrasting findings also exist. Furthermore, many of these studies were limited by cross-sectional design, restriction by age or sex, or incomplete ascertainment. Different outcomes, beverages, drinking patterns, or follow-up periods, or possible interactions with other lifestyle-related (i.e., smoking) or genetic factors [i.e., apolipoprotein E (APOE) genotyping] may be sources of great variability. Light to moderate alcohol use may be associated with a reduced risk of unspecified incident dementia and AD, while for VaD, cognitive decline, and predementia syndromes, the current evidence is only suggestive of a protective effect. In conclusion, as intervention studies are not feasible in this area, the best evidence comes from an overview of epidemiological studies, suggesting that the protective effects are more likely with wine consumption and the absence of an APOE e4 allele. At present, there is no indication that light to moderate alcohol drinking would be harmful to cognition and dementia, and it is not possible to define a specific beneficial level of alcohol intake.