Long-term measures of free testosterone predict regional cerebral blood flow patterns in elderly men.
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.
Moffat
Scott D
SD
Laboratory of Personality and Cognition, Intramural Research Program, National Institute on Aging, Baltimore, MD 21224, United States.
Resnick
Susan M
SM
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
D013739:Testosterone