CAG repeat within the androgen receptor gene and incidence of surgery for benign prostatic hyperplasia in US physicians

BACKGROUND. CAG repeat length in exon I of the androgen receptor (AR) gene correlates inversely with transcriptional transactivation activity of the A R. Men with shorter AR CAG repeat lengths are at higher risk of prostate ca ncer. Because benign prostatic hyperplasia (BPH) is an androgen-dependent c ondition, we examined the hypothesis that a shorter AR gene CAG repeat leng th increases the risk or developing of BPH. METHODS. Among 14,916 men of the Physicians' Health Study who had provided a blood sample in 1982, we measured AR gene CAG repeat lengths for 310 men who had surgery for; BPH up to 7.5 years of follow-up and 1,041 controls. RESULTS. Risk of surgery for BPH increased linearly with decreasing AR CAG repeat length (P (trend) = 0.03). Relative to men with a CAG repeat length greater than or equal to 25, men with a repeat length less than or equal to 19 had an odds ratio of BPH surgery of 1.76 (95% confidence interval, 1.16 -2.65). CONCLUSIONS. Variability in the AR gene CAG repeat influences the developme nt of symptomatic BPH, (C) 1999 Wiley-Liss, Inc.