Androgen receptor CAG repeat length correlates with semen PSA levels in adolescence.
Giwercman YL., Richthoff J., Lilja H., Anderberg C., Abrahamsson P-A., Giwercman A.
BACKGROUND: Androgens exert their action through the androgen receptor (AR). The length of the AR CAG repeat is inversely correlated to receptor function and short CAG length might be a risk factor for development of prostate cancer. Our aim was to investigate whether CAG repeat number might have an impact on prostate function in adolescence. METHODS: AR genotyping was performed by direct sequencing of leukocyte DNA from 274 military conscripts. All men underwent endocrine evaluation and semen analysis. RESULTS: PSA in seminal plasma, total sperm count and motility all are inversely correlated with CAG numbers (rho = -0.128, P = 0.038; rho = -0.156, P = 0.010; rho = -0.158, P = 0.011), whereas serum levels of free testosterone (rho = 0.132; P = 0.029) and luteinizing hormone (rho = 0.126; P = 0.037) are positively correlated to CAG length. No correlation between seminal PSA and serum testosterone, neither free nor total, was found. CONCLUSIONS: In adolescence, AR genotype, but not serum testosterone, is associated with the level of seminal PSA.