title: Long-term measures of free testosterone predict regional cerebral blood flow patterns in elderly men.
abstract: We previously reported that high circulating free testosterone (T) was associated with better performance on tests of memory, executive function, and spatial ability, and with a reduced risk for Alzheimer's disease. In this study, we report that free T levels, measured on multiple occasions over 14 years, predict regional cerebral blood flow (rCBF) measured by PET in 40 older men. Voxel-based regression, indicated that higher Free T was associated with increased rCBF in the hippocampus bilaterally (extending to the parahippocampal gyrus on the right), anterior cingulate gyrus, and right inferior frontal cortex. Total T concentrations were positively correlated with rCBF in the left putamen, bilateral thalamus, and left inferior frontal cortex and negatively correlated with amygdala rCBF bilaterally. These findings suggest that endogenous T influences brain physiology in regions critical for memory and attention and provide one mechanism through which T may affect cognitive function.
authors.affiliation: Laboratory of Personality and Cognition, Intramural Research Program, National Institute on Aging, Baltimore, MD 21224, United States.
authors.forename: Scott D
authors.initials: SD
authors.lastname: Moffat
authors.forename: Susan M
authors.initials: SM
authors.lastname: Resnick
mesh_terms: D000368:Aged; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000378:metabolism*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D015577:Geriatric Assessment; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007118:Immunoassay / Q000379:methods; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D012039:Regional Blood Flow / Q000502:physiology; D012189:Retrospective Studies; D013739:Testosterone / Q000378:metabolism*; D014055:Tomography, Emission-Computed / Q000379:methods
chemical_list: D013739:Testosterone