Testosterone Prevents Mental Decline in Aging Males
The Journal of Clinical Endocrinology & Metabolism. Vol. 87, No. 11 5001-5007
Longitudinal Assessment of Serum Free Testosterone Concentration Predicts Memory
Performance and Cognitive Status in Elderly Men
Scott D. Moffat, Alan B. Zonderman, E. Jeffrey Metter, Marc R. Blackman, S. Mitchell Harman
and Susan M. Resnick
Circulating testosterone (T) levels have behavioral and neurological effects in both human and nonhuman species. Both T concentrations and neuropsychological function decrease substantially with age in men. The purpose of this prospective, longitudinal study was to investigate the relationships between age-associated decreases in endogenous serum T (testosterone) and free T concentrations and declines in neuropsychological performance. Participants were volunteers from the Baltimore Longitudinal Study of Aging, aged 50–91 yr at baseline T assessment. Four hundred seven men were followed for an average of 10 yr, with assessments of multiple cognitive domains and contemporaneous determination of serum total T, SHBG, and a free T index (FTI). We administered neuropsychological tests of verbal and visual memory, mental status, visuomotor scanning and attention, verbal knowledge/language, visuospatial ability, and depressive symptomatology. Higher free testosterone was associated with better scores on visual and verbal memory, visuospatial functioning, and visuomotor scanning and a reduced rate of longitudinal decline in visual memory. Men classified as hypogonadal (low testosterone) had significantly lower scores on measures of memory and visuospatial performance and a faster rate of decline in visual memory. These results suggest a possible beneficial relationship between circulating free Testosterone concentrations and specific domains of cognitive performance in older men.