O3‐06‐02: Impaired glucose tolerance predicts longitudinal changes in brain function during aging in nondemented elderly
Year: 2012
Type: article
Study design: Observational Study
Abstract: Impaired glucose tolerance (IGT) is a risk factor for Alzheimer's disease (AD). However, the precise mechanisms underlying this association are unknown. Few studies have examined whether impaired glucose tolerance in non-demented individuals predicts subsequent changes in brain function during aging. Using cognitively normal individuals, we compared longitudinal changes in resting state regional cerebral blood flow (rCBF), measured using 15O-water positron emission tomography (PET), in those with and without impaired glucose tolerance. Serial oral glucose tolerance test (OGTT) data were available in 64 non-demented Baltimore Longitudinal Study of Aging (BLSA) participants (mean age at first OGTT; 57.1±10.8 years) and were collected over a mean interval of 7.6 years. We categorized individuals as those with IGT (N=15) (average 2-h postload glucose 140-199 mg/dl) or normal glucose tolerance (NGT) (N=49) (average 2-h postload glucose <140 mg/dl). 15O-water PET measurements of rCBF were available at initial neuroimaging evaluation (mean age 69.3±7.3 years) and up to 8 annual follow-up visits. For each participant, rates of change in rCBF were calculated across all scans using voxel-wise linear modeling and extraction of the estimated fit parameter. Age at the first 15O-water PET scan and sex were included as covariates. The IGT and NGT groups did not differ significantly in age at first OGTT, age at first 15O-water PET scan, years of education and sex. Differences in longitudinal changes in rCBF were observed in several brain regions between the IGT and NGT groups. The predominant pattern was that of greater rCBF decline over time in the IGT group. These brain regions included medial frontal (R), superior frontal (R), superior temporal (L), medial temporal (L) and post-central (L) gyri, as well as inferior parietal lobule (R). Greater longitudinal increases in rCBF were observed in the IGT group in the inferior frontal (L) and pre-central gyri. Impaired glucose tolerance is associated with subsequent longitudinal changes in neuronal function during aging in non-demented elderly individuals. The brain regions involved include those vulnerable to AD pathology and important in memory processes. These results suggest mechanisms underlying increased risk for AD in individuals with impaired glucose tolerance.
Source: Alzheimer s & Dementia
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2049504950