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Objective: High BMI, which poorly represents specific fat depots, is linked to poorer cognition and higher dementia risk, with different associations between sexes. This study examined associations of abdominal fat depots with cognition and brain volumes and whether sex modifies this association. Methods: A total of 204 healthy middle‐aged offspring of Alzheimer's dementia patients (mean age = 59.44, 60% females) underwent abdominal magnetic resonance imaging to quantify hepatic, pancreatic, visceral, and subcutaneous adipose tissue and to assess cognition and brain volumes. Results: In the whole sample, higher hepatic fat percentage was associated with lower total gray matter volume (β = −0.17, p < 0.01). Primarily in males, higher pancreatic fat percentage was associated with lower global cognition (males: β = −0.27, p = 0.03; females: β = 0.01, p = 0.93) executive function (males: β = −0.27, p = 0.03; females: β = 0.02, p = 0.87), episodic memory (males: β = −0.28, p = 0.03; females: β = 0.07, p = 0.48), and inferior frontal gyrus volume (males: β = −0.28, p = 0.02; females: β = 0.10, p = 0.33). Visceral and subcutaneous adipose tissue was inversely associated with middle frontal and superior frontal gyrus volumes in males and females. Conclusions: In middle‐aged males at high Alzheimer's dementia risk, but not in females, higher pancreatic fat was associated with lower cognition and brain volumes. These findings suggest a potential sex‐specific link between distinct abdominal fat with brain health. [ABSTRACT FROM AUTHOR]

Introduction: Molecular responses in the brains of persons with mild cognitive impairment (MCI), the earliest transitional state between normal aging and early Alzheimer's disease (AD), are poorly understood. Methods: We examined AD‐related neuropathology and transcriptome changes in the neocortex of individuals with MCI relative to controls and temporal responses to the mild hypoxia in mouse brains. Results: Subsets of vascular early response to hypoxia genes were upregulated in MCI prior to the buildup of AD neuropathology. Early activation of pro‐angiogenic hypoxia‐inducible factor signaling in response to mild hypoxia was detected in mouse brains similar to those that were altered in MCI. Protracted responses to hypoxia were characterized by activation of phosphoinositide 3‐kinase (PI3K)‐protein kinase B (Akt)‐the mammalian target of rapamycin (mTOR) pathways in brain microvessel isolates. Discussion: These findings suggest that cerebrovascular remodeling is an important antecedent to the development of dementia and a component of the homeostatic response to reduced oxygen tension in aging prior to the onset of AD. [ABSTRACT FROM AUTHOR]

Introduction: Understanding the relationship between different depression presentations and cognitive outcome may elucidate high‐risk sub‐groups for cognitive decline. Methods: In this study we utilized longitudinal data from the National Alzheimer's Coordinating Center (NACC) on 16,743 initially not demented older adults followed every 12 months for an average of 5 years. Depression dimensions were defined based on the 15‐item Geriatric Depression Scale (GDS‐15), that is, dysphoric mood, Withdrawal‐Apathy‐Vigor (WAV), anxiety, hopelessness, and subjective memory complaint (SMC). Results: After adjustment for sociodemographic and clinical covariates, SMC and hopelessness were associated with faster decline in global cognition and all cognitive domains and WAV with decline executive function. Dysphoric mood and anxiety were not associated with a faster cognitive decline in any of the cognitive domains. Discussion: Different depression dimensions had different associations with the rate of cognitive decline, suggesting distinct pathophysiology and the need for more targeted interventions. [ABSTRACT FROM AUTHOR]

Abstract: Type 2 diabetes (T2D) is associated with increased risk of Alzheimer's disease (AD). There is evidence for impaired blood–brain barrier (BBB) in both diseases, but its role in the interplay between them is not clear. Here, we investigated the effects of high‐fat diet (HFD), a model for T2D, on the Tg2576 mouse model of AD, in regard to BBB function. We showed that HFD mice had higher weight, more insulin resistance, and higher serum HDL cholesterol levels, primarily in Tg2576 mice, which also had higher brain lipids content. In terms of behavior, Tg2576 HFD mice were less active and more anxious, but had better learning in the Morris Water Maze compared to Tg2576 on regular diet. HFD had no effect on the level of amyloid beta 1–42 in the cortex of Tg2576 mice, but increased the transcription level of insulin receptor in the hippocampus. Tg2576 mice on regular diet demonstrated more BBB disruption at 8 and 12 months accompanied by larger lateral ventricles volume in contrast to Tg2576 HFD mice, whose BBB leakage and ventricular volume were similar to wild‐type (WT) mice. Our results suggest that in AD, HFD may promote better cognitive function through improvements of BBB function and of brain atrophy but not of amyloid beta levels. Lipid metabolism in the CNS and peripheral tissues and brain insulin signaling may underlie this protection. [ABSTRACT FROM AUTHOR]

Introduction Waist circumference is associated with type 2 diabetes (T2D) and cognition, yet the relationship between waist circumference and cognition in individuals with T2D is not well understood. Methods We studied the relationship of waist circumference with five cognitive outcomes (executive functioning, language/semantic categorization, attention/working memory, episodic memory, and an overall cognition measure) in 845 cognitively normal elderly with type 2 diabetes (T2D). Results In women, waist circumference was correlated with significantly lower language and/or semantic categorization performance ( P < .0001), executive functioning ( P = .026), and overall cognition ( P = .003) after controlling for age, education, BMI, and cardiovascular, diabetes-related, APOE ε4, and inflammatory potential confounders. Attention/working memory ( P = .532) and episodic memory ( P = .144) were not associated with waist circumference. These correlations were not found in men. Discussion These results suggest that central adiposity in elderly women with T2D may increase their risk for dementia. [ABSTRACT FROM AUTHOR]

Objective: The haptoglobin (Hp) genotype has been associated with cognitive function in type 2 diabetes. Because ethnicity/culture has been associated with both cognitive function and Hp genotype frequencies, we examined whether it modulates the association of Hp with cognitive function.Methods: This cross-sectional study evaluated 787 cognitively normal older individuals (>65 years of age) with type 2 diabetes participating in the Israel Diabetes and Cognitive Decline study. Interactions in two-way analyses of covariance compared Group (Non-Ashkenazi versus Ashkenazi Jews) on the associations of Hp phenotype (Hp 1-1 versus non- Hp 1-1) with five cognitive outcome measures. The primary control variables were age, gender, and education.Results: Compared with Ashkenazi Jews, non-Ashkenazi Jews with the Hp 1-1 phenotype had significantly poorer cognitive function than non-Hp 1-1 in the domains of Attention/Working Memory (p = 0.035) and Executive Function (p = 0.023), but not in Language/Semantic Categorization (p = 0.432), Episodic Memory (p = 0.268), or Overall Cognition (p = 0.082). After controlling for additional covariates (type 2 diabetes-related characteristics, cardiovascular risk factors, Mini-mental State Examination, and extent of depressive symptoms), Attention/Working Memory (p = 0.038) and Executive Function (p = 0.013) remained significant.Conclusions: Older individuals from specific ethnic/cultural backgrounds with the Hp 1-1 phenotype may benefit more from treatment targeted at decreasing or halting the detrimental effects of Hp 1-1 on the brain. Future studies should examine differential associations of Hp 1-1 and cognitive impairment, especially for groups with high prevalence of both, such as African-Americans and Hispanics. [ABSTRACT FROM AUTHOR]

There is growing evidence of the involvement of advanced glycation end products ( AGEs) in the pathogenesis of neurodegenerative processes including Alzheimer's disease ( AD) and their function as a seed for the aggregation of Aβ, a hallmark feature of AD. AGEs are formed endogenously and exogenously during heating and irradiation of foods. We here examined the effect of a diet high in AGEs in the context of an irradiated diet on memory, insoluble Aβ42, AGEs levels in hippocampus, on expression of the receptor for AGEs ( RAGE), and on oxidative stress in the vasculature. We found that AD-like model mice on high- AGE diet due to irradiation had significantly poorer memory, higher hippocampal levels of insoluble Aβ42 and AGEs as well as higher levels of oxidative stress on vascular walls, compared to littermates fed an isocaloric diet. These differences were not due to weight gain. The data were further supported by the overexpression of RAGE, which binds to Aβ42 and regulates its transport across the blood-brain barrier, suggesting a mediating pathway. Because exposure to AGEs can be diminished, these insights provide an important simple noninvasive potential therapeutic strategy for alleviating a major lifestyle-linked disease epidemic. [ABSTRACT FROM AUTHOR]

Objective: Glycated hemoglobin (HbA1c) and C-reactive protein (CRP) have been associated with cognitive impairment independently. However, it is unclear if their combination exacerbates poor cognitive function. We assessed whether long-term glycemic level and glycemic variability modulate the association of systemic inflammation with cognitive function, in a sample of cognitively normal older people with type 2 diabetes.Methods: A retrospective cohort study of 777 randomly selected participants from ~11,000 patients in the Maccabi Healthcare Services Diabetes Registry, as part of the Israel Diabetes and Cognitive Decline study. Subjects averaged 18 (±9.4) HbA1c measures in the Maccabi Healthcare Services Registry, which were used to calculate long-term glycemic level (HbA1c-mean) and glycemic variability (HbA1c-standard deviation (SD)). Linear regression models assessed the interactions of CRP, a marker of systemic inflammation, with HbA1c-mean and HbA1c-SD on subjects' performance in tests of Memory, Executive Functions, Attention, and Semantic Categorization.Results: Quadratic interactions of CRP with HbA1c-SD approached significance for executive functions and overall cognition. However, after Bonferroni adjustment, none of the interactions of CRP with HbA1c were statistically significant. In partial correlations according to HbA1c-SD tertiles, CRP was weakly correlated in the middle tertile with decreased performance in the domains of semantic categorization (r = -0.166, p = 0.011), executive functions (r = -0.136, p = 0.038), and overall cognition (r = -0.157, p = 0.016).Conclusions: Glycated hemoglobin does not substantially modulate the association of CRP with cognition in a sample of cognitively normal, community dwelling older people with relatively well-managed type 2 diabetes. [ABSTRACT FROM AUTHOR]

Objective To evaluate the relationships of age, education, and gender with performance on neuropsychological tests in a cognitively intact, older Israeli sample with type 2 diabetes (T2D). Methods We examined 862 participants, 65-84 years old, enrolled in the Israel Diabetes and Cognitive Decline study. Multiple regression assessed associations of performance on 17 neuropsychological tests, including the Consortium to Establish a Registry for Alzheimer's Disease neuropsychological battery, with age, education, and gender. Results Higher education and younger age were consistently associated with better performance. Women outperformed men on all memory tasks; men outperformed women on two non-verbal measures. These patterns of demographic associations with cognitive performance were very similar to those of US cohorts. Conclusions In a cognitively intact, older Israeli sample with T2D, better test performance is associated primarily with higher education, followed by younger age and gender differences. Although T2D is associated with cognitive deficits, it recapitulates the patterns of relationships between cognitive performance and demographic characteristics seen in non-T2D diabetic samples. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Background: APOE‐ε4 is a strong and consistent risk gene for Alzheimer's disease (AD). Depression and depressive symptoms have been shown to precede AD and are highly prevalent in older adults with type 2 diabetes (T2D). However, the relationship of APOE‐ε4 with depression has rarely been investigated T2D. We examined whether trajectories of depression symptoms over time differ by APOE‐ε4 carriership in older adults with T2D. Method: Participants (n=754 (99 APOE‐ε4 carriers; 13.1%) were initially cognitively normal individuals from the Israel Diabetes and Cognitive Decline (IDCD) study who underwent evaluations of depression approximately every 18 months using the 15‐item version of the Geriatric Depression Scale (GDS) and the depression subscale of the Neuropsychiatric Inventory (NPI). We used Hierarchical Linear Mixed Models (HLMM) that modeled the effects of APOE status on repeated GDS and NPI depression scores adjusting for demographic (Model 1), and adding cardiovascular risk factors (Model 2) and global cognition (Model 3). Result: Participants' mean age was 73 (SD=4.7); 38% female. In comparison to non‐carriers, APOE‐ε4 carriers had a lower mean GDS scores (β=‐0.46, p=0.018; Plot 1) and lower NPI‐depression scores (β=‐0.170, p=0.038; Plot 2) throughout all study follow period, but the groups did not differ in the slope of change over time in GDS (β=‐0.005 for interaction of APOE with time, p=0.252) or NPI‐depression (β=‐0.001, p=0.994) scores. Additional adjustment for cardiovascular risk factors and global cognition did not alter these results. Conclusion: In older adults with T2D, APOE‐ε4 carriers have consistently lower depression scores in successive measurements. The lack of difference between the groups' slopes over time suggests that APOE‐ε4 (or lack of) does not have a progressive effect on depression or its underlying pathology. APOE‐ε4 carriers may be less susceptible to depression. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the relationships of age, education, and gender with performance on neuropsychological tests in a cognitively intact, older Israeli sample with type 2 diabetes (T2D). Methods: We examined 862 participants, 65–84 years old, enrolled in the Israel Diabetes and Cognitive Decline study. Multiple regression assessed associations of performance on 17 neuropsychological tests, including the Consortium to Establish a Registry for Alzheimer's Disease neuropsychological battery, with age, education, and gender. Results: Higher education and younger age were consistently associated with better performance. Women outperformed men on all memory tasks; men outperformed women on two non-verbal measures. These patterns of demographic associations with cognitive performance were very similar to those of US cohorts. Conclusions: In a cognitively intact, older Israeli sample with T2D, better test performance is associated primarily with higher education, followed by younger age and gender differences. Although T2D is associated with cognitive deficits, it recapitulates the patterns of relationships between cognitive performance and demographic characteristics seen in non-T2D diabetic samples. [ABSTRACT FROM AUTHOR]

Life expectancy is a familial trait. However, the effectiveness of using the age at death of a deceased parent to estimate life expectancy in their offspring can vary depending on whether death in the parent was due to extrinsic versus intrinsic causes, as well as demographic characteristics such as sex. While Alzheimer's disease (AD) risk increases with increased age, mortality for individuals with AD is increased in contrast to comparably aged individuals without AD. Yet in most cases it is not the defining neuropathology of AD that directly terminates life but instead conditions and illnesses extrinsic to AD pathology that nevertheless have increased likelihood in its presence. For this reason, we hypothesized that offspring of AD mothers would have greater longevity than offspring of mothers without AD (insufficient numbers prevented a comparable analysis using fathers with AD). The longevity of 345 offspring of 100 deceased 60+ year old AD mothers was compared with 5,465 offspring in 1,312 deceased 60+ year old non-AD mothers. We used a proportional hazards model that accounted for clustered (nonindependent) observations due to the inclusion of several offspring from the same family. In both an unadjusted model and one that adjusted for the age at death in the mother, and the sex and birth year in the offspring we found evidence for increased longevity in the offspring of AD mothers. The results suggest that, in addition to genes that might directly affect pathways leading to AD, there may be familial/genetic factors not connected to specific pathophysiological processes in AD but instead associated with increased longevity that contribute to the familial aggregation observed in AD., (2007 Wiley-Liss, Inc.)

Survival from Alzheimer's disease (AD) and other dementias into late old age may be a useful phenotype for genetic studies of successful cognitive aging. To support molecular genetics studies for successful cognitive aging, we conducted a two-stage study to determine an optimal age phenotype for successful cognitive aging. First, risk of AD was evaluated, through informant interviews, in 4,794 parents and siblings of 976 elderly nondemented probands who were divided into three different proband age groups: those aged 60-74, 75-89, and 90+. Relatives of probands aged 90+ had a significantly lower risk than the relatives of the other two proband groups. Second, this sample was combined with an earlier sample (combined nondemented elderly probands: n = 2,025; relatives: n = 10,506), and a series of proband age groups (i.e., 75-79, 80-84, 85-89, 90+) were used to determine which optimally identifies a group of relatives with low AD risk. Using the relatives of the nondemented proband aged 60-74 as the reference group, there were reductions in cumulative risk among relatives of probands aged 85-89 and 90+, but only the latter group also showed significant reductions to the relatives of probands aged 75-79, 80-84, and 85-89. This pattern of results varied little by sex. Finally, cumulative AD risk curves were similar between relatives of probands aged 90-94 and 95+. These results suggest that age 90 is an optimal age threshold to use for both men and women in genetic studies seeking to identify genes associated with successful cognitive aging., ((c) 2007 Wiley-Liss, Inc.)