title: Impaired glucose tolerance in midlife and longitudinal changes in brain function during aging.
abstract: We investigated whether individuals with impaired glucose tolerance (IGT) in midlife subsequently show regionally specific longitudinal changes in regional cerebral blood flow (rCBF) relative to those with normal glucose tolerance (NGT). Sixty-four cognitively normal participants in the neuroimaging substudy of the Baltimore Longitudinal Study of Aging underwent serial (15)O-water positron emission tomography scans (age at first scan, 69.6 ± 7.5 years) and oral glucose tolerance tests 12 years earlier (age at first oral glucose tolerance test, 57.2 ± 11.1 years). Using voxel-based analysis, we compared changes in rCBF over an 8-year period between 15 participants with IGT in midlife and 49 with NGT. Significant differences were observed in longitudinal change in rCBF between the IGT and NGT groups. The predominant pattern was greater rCBF decline in the IGT group in the frontal, parietal, and temporal cortices. Some brain regions in the frontal and temporal cortices also showed greater longitudinal increments in rCBF in the IGT group. Our findings suggest that IGT in midlife is associated with subsequent longitudinal changes in brain function during aging even in cognitively normal older individuals.
authors.affiliation: Clinical and Translational Neuroscience Unit, Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA. thambisettym@mail.nih.gov
authors.forename: Madhav
authors.initials: M
authors.lastname: Thambisetty
authors.forename: Lori L
authors.initials: LL
authors.lastname: Beason-Held
authors.forename: Yang
authors.initials: Y
authors.lastname: An
authors.forename: Michael
authors.initials: M
authors.lastname: Kraut
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Metter
authors.forename: Josephine
authors.initials: J
authors.lastname: Egan
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrucci
authors.forename: Richard
authors.initials: R
authors.lastname: O'Brien
authors.forename: Susan M
authors.initials: SM
authors.lastname: Resnick
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology*; D002540:Cerebral Cortex / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000502:physiology*; D002560:Cerebrovascular Circulation; D005260:Female; D005500:Follow-Up Studies; D018149:Glucose Intolerance / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005951:Glucose Tolerance Test; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D013997:Time Factors
keywords: Aging; Alzheimer's; Brain function; Cerebral blood flow; Impaired glucose tolerance; Insulin resistance; PET