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O1‐01‐04: Increases in Pib Retention are Associated with Increased Cerebral Glucose Metabolism in Cognitively Normal Elderly: Role for Compensatory Hypermetabolism?
Author(s) -
Curtis Brett,
Snitz Beth E.,
Tudorascu Dana L.,
Price Julie,
Mathis Chester,
Aizenstein Howard J.,
Klunk William E.,
Cohen Ann D.
Publication year - 2016
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2016.06.295
Subject(s) - hypermetabolism , pittsburgh compound b , psychology , medicine , cognitive impairment , nuclear medicine , endocrinology , disease
ient brain aging. These investigations included reserve/lifestyle approaches, the study of older people with outstanding cognitive abilities or of those that show normal cognition in the setting of Alzheimer’s Disease (AD) pathology. The goal of the present study was to further our understanding of brain resilience by exploring the cognitive, lifestyle, psychoaffective and neuroimaging features of older adults showing normal cognition despite very high risk for AD: i) older age, ii) predisposing genetic backgrounds and iii) amyloid (Ab) positivity. Methods: Thirteen percent (n1⁄423) of the participants from the Berkeley Aging Cohort with available neuroimaging and genetic information met the criteria (i.e., >70 yrs, APOE+ and/or Family history of AD and Ab+) (age 75.763.9, 18 females, education 16.163.3). First, we assessed the demographic, lifestyle/reserve and psychoaffective characteristics of these high risk (HR) individuals as compared to participants >70 years, without these risk factors (low risk group, LR) (n1⁄4 63). Second, we evaluated baseline cognitive and metabolic characteristics (FDG-PET) as compared to a LR sex, age, education-matched sample (LRmatched) (n1⁄423). Finally, in a repeated measures ANOVA, we evaluated the group (HR vs LR-matched) by time (18.466.4 months) interaction on memory performance. Results: The HR group did not differ in demographic, lifestyle and psychoaffective variables from the LR group. However, the HR group showed significantly higher memory performance as compared to the matched-LR group (Fig1A). Voxel-wise FDG-PET analyses revealed increased metabolism in medial prefrontal and medial parietal regions in the HR group as compared to the LR-matched group (Fig 2). Finally, we observed a group*time interaction such that only the HR group showed decrease memory performance over time (Fig1 B). Conclusions: In cognitively normal, high risk adults, greater memory ability and metabolism might counter the effects of multiple risk factors on cognition. They may have started with higher levels of memory and metabolism and/or may be showing functional compensation. Regardless of the exact mechanism, these data suggest that over time they become more susceptible and may begin to progress towards AD.