Androgen receptor CAG repeat polymorphism is associated with cognitive function in older men.
BACKGROUND
Androgen receptors are located throughout the brain, especially in regions involved with learning and memory. Different lengths of a CAG (glutamine) repeat polymorphism in exon 1 of the androgen receptor gene may influence androgen action, with longer repeat lengths conferring decreased androgen sensitivity.


METHODS
We sought to determine if this CAG polymorphism was associated with cognition in older men.


RESULTS
Among 301 community-dwelling white men (mean age, 73.0 +/- 7.1), greater CAG repeat length was associated with lower scores on three cognitive tests (p <.05 for all). In addition, 12 participants (9.8%) had cognitive impairment in the low tertile of CAG repeat length whereas 29 (16.3%) had cognitive impairment in the two higher tertiles (odds ratio = 1.8; 95% confidence interval =.9-3.7).


CONCLUSIONS
Research should be directed at identifying the mechanism for this association and to determine if treatment with testosterone prevents cognitive decline.
Department of Psychiatry, University of California, San Francisco 94121, USA.
Kristine
K
Yaffe
Emily R
ER
Edwards
Li-Yung
LY
Lui
Joseph M
JM
Zmuda
Robert E
RE
Ferrell
Jane A
JA
Cauley
D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders / Q000235:genetics*; D015331:Cohort Studies; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic; D011944:Receptors, Androgen / Q000235:genetics*; D018911:Trinucleotide Repeats
D011944:Receptors, Androgen