Polymorphisms in the 5alpha reductase type 2 gene and urologic measures of BPH

The objective of the study was to examine associations between SRD5A2 polymorphisms and measures of benign prostatic hyperplasia (BPH).

Participants were 510 Caucasian men (median age 60 years), randomly selected from the Olmsted County, MN community to participate in a longitudinal study of BPH. From 1990 through 2000, biennial measurements of lower urinary tract symptom severity (assessed from the American Urological Association Symptom Index, AUASI), peak urinary flow rates (Qmax), and prostate volume were made. Genotyping of SRD5A2 V89L, A49T, and TA repeat polymorphisms were performed.

Compared with the VV genotype, the LL genotype was associated with an enlarged prostate (Hazard ratio (HR)=1.62, 95% confidence interval (CI)=1.06, 2.43) but not with AUASI, Qmax, or PSA. The A49T and TA repeat polymorphisms were not associated with BPH. When the LL/VL, AT/TT, and TA0/TA0 genotypes were considered high risk, the number of high risk genotypes increased with increasing prostate volume (32.3, 30.7, 34.1, and 38.7, respectively, P for trend=0.04).

These findings do not demonstrate consistent associations between SRD5A2 genotypes and BPH. However, they suggest that the associations of V89L polymorphisms and prostate volume should be investigated further.