Objective: To examine the association between diabetes in midlife (1963–1968) and dementia more than three decades later (1999–2001). Methods: The authors characterized dementia using standard methods for 1,892 participants among 2,606 survivors of 10,059 participants in the Israeli Ischemic Heart Disease study, a longitudinal investigation of the incidence of and risk factors for cardiovascular disease among Jewish male civil servants in Israel. Face to face interviews were conducted with the 652 subjects identified as possibly demented by the Modified Telephone Interview for Cognitive Status. Logistic regression analysis was performed to assess the association of diabetes with dementia controlling for sociodemographic and cardiovascular variables compared to those with no cognitive impairment. Results: Of 1,892 assessed subjects (mean age 82 at assessment), 309 (16.3%) had dementia. Diabetic subjects had significantly more dementia than non-diabetic subjects (χ² = 7.54, df = 1, p = 0.006, OR 2.83 [95% CI = 1.40 to 5.71]). Those who survived to the time of this study were younger and healthier than those who died. Conclusions: Evidence for diabetes as a risk factor for dementia was found, similar to other epidemiologic studies. In contrast to the earlier studies, however, the authors linked diabetes in midlife to dementia more than three decades later in the very old survivors of a large male cohort.

Objective: To examine the association between treatment for diabetes and Alzheimer disease (AD) neuropathology. Methods: This postmortem study matched 124 subjects with diabetes to 124 without diabetes from the Mount Sinai School of Medicine Brain Bank, on age (mean = 81.2 + 9.3), sex (57.3% F), and severity of dementia (Clinical Dementia Rating [CDR] 2.4 + 1.7). Densities of neuritic plaques (NPs) and of neurofibrillary tangles (NFTs) were assessed in several neocortical regions and in the hippocampus, entorhinal cortex, and amygdala. Diabetic subjects were classified according to their recorded lifetime antidiabetic medications: none (n = 29), insulin only (n = 49), diabetes medications other than insulin only (n = 28), or concomitant use of both insulin and any oral antidiabetic medications (n = 18). For each dependent variable, analysis of covariance controlling for age at death, sex, and CDR distinguished among the nondiabetic patients and four diabetic subgroups. Results: There were differences among the five groups for NP ratings in the entorhinal cortex (p = 0.003), amygdala (p = 0.009), and overall NP (p = 0.014) as well as counts of NPs in all regions examined (p values ranging from 0.009 to 0.04). NP ratings in the hippocampus (p = 0.057) and the combined neocortical measure (p = 0.052) approached significance. In each analysis, the concomitant medication group had significantly fewer NPs (∼20%) than any of the other groups, which were relatively similar. No significant NFT differences were found. Conclusion: The results of this study suggest that the combination of insulin with other diabetes medication is associated with substantially lower neuritic plaque density consistent with the effects of both on the neurobiology of insulin.

Objective: To examine the associations between postmortem Alzheimer disease (AD) neuropathology and autopsy-verified cardiovascular disease. Methods: The authors examined 99 subjects (mean age at death = 87.6; SD = 8.7) from the Mount Sinai School of Medicine Department of Psychiatry Brain Bank who were devoid of cerebrovascular disease–associated lesions or of non–AD-related neuropathology. Density of neuritic plaques (NPs) and neurofibrillary tangles (NFTs) as well as coronary artery and aortic atherosclerosis, left ventricular wall thickness, and heart weight were measured. Partial correlations were used to assess the associations of the four cardiovascular variables with NPs and NFTs in the hippocampus, entorhinal cortex, and multiple regions of the cerebral cortex after controlling for age at death, sex, dementia severity, body mass index, and ApoE genotype. These analyses were also repeated separately for ApoE4 carriers and noncarriers. Results: The extent of coronary artery disease and to a lesser extent atherosclerosis were significantly associated with the density of cardinal neuropathologic lesions of AD in this autopsy sample (significant correlations between 0.22 and 0.29). These associations were more pronounced for the ApoE4 allele carriers (n = 42; significant correlations between 0.34 and 0.47). Conclusions: The degree of coronary artery disease is independently associated with the cardinal neuropathological lesions of Alzheimer disease. These associations are primarily attributable to individuals with the ApoE4 allele.

Objective: To evaluate the performance of nondemented subjects 85 years and older on the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) neuropsychological battery, and to assess its relationship with sociodemographic variables. Methods: We studied 196 subjects enrolled in an Alzheimer’s Disease Research Center study who had a complete CERAD neuropsychological assessment. We used multiple regression analysis to predict performance on the neuropsychological tests from age, education, and sex. Eight representative hypothetical individuals were created (for example, an 87-year-old man, with high education). For each test, estimates of performance at the 10th, 25th, 50th, and 75th percentiles were reported for the eight representative hypothetical individuals. Results: Mean age was 89.2 years (SD = 3.2), mean years of education was 14.9 (SD = 3.2), and 66% of the sample were women. For 11 of the 14 neuropsychological tests, there was a significant multiple regression model using education, age, and sex as predictors. Neither the models nor the predictors used individually were significant for Delayed Recall, Savings, or correct Recognition. Among the significant results, seven had education as the strongest predictor. Lower age and higher education were associated with better performance. Women performed better than men in three of four tests with significant results for sex. Conclusions: In a sample of oldest old whose primary language is English, neuropsychological testing is influenced mainly by education and age. Cutoff scores based on younger populations and applied to the oldest old might lead to increased false-positive misclassifications.