Benign prostatic hyperplasia (BPH) develops more likely with increasing age and changing serum concentrations of circulating estradiol (E₂) and/or testosterone (T). In this study, we explored the relationship between serum E₂/T ratio and BPH risk in rats by fitting a mathematical model. A total of 176 rats were randomized to one of the following treatment groups: normal control, castrated control, and 20 more groups of castrated animals treated with increasing dose combinations of T and E₂, once daily for 30 days. Serial blood samples were obtained to determine serum T and E₂ levels by magnetic bead enzyme-linked immunosorbent assay. Prostate tissue was taken to measure prostate volume. MATLAB software was used to simulate the relationship between prostate/body weight ratio (PBR) and E₂/T ratio with a mathematical equation. The values of PBR, E₂ and T in the treatment groups were significantly higher than those in the control groups. Stepwise regression showed that PBR was a function of E₂ and T. PBR = –0.1782 + 0.0081 E₂ + 0.063 T – 0.6 × 10–⁵ E₂² – 0.28 × 10–³ T². E₂/T ratio change may be one of the risk factors for PBR, which is associated with the development of BPH.

Summary Sentence

E₂ /T ratio change may be one of the risk factors for PBR, which is associated with the development of BPH.