Prostatic anatomical parameters correlate with clinical characteristics suggestive of benign prostatic hyperplasia

We conducted the present study to assess the correlation of the prostatic anatomical parameters, especially the ratio of peripheral zone thickness and transitional zone thickness, with clinical and uroflowmetry characteristics suggestive of benign prostate hyperplasia (BPH). A total of 468 consecutive patients with a detailed medical history were identified. All patients were evaluated by scoring subjective symptoms with the International Prostate Symptom Score (IPSS) and quality of life (QoL). The prostatic anatomical parameters were measured using transrectal ultrasonography, and postvoid residual urine and maximum flow rate (Q(max)) values were also determined. Pearson's correlation analysis revealed that both total prostate volume (TPV; r = 0.160, P < 0.001) and transitional zone volume (TZV; r = 0.104, P = 0.016) increased with patients' age; however, no correlations were observed of TPV, TZV, transitional zone index (TZI), and transitional zone thickness (TZT) with IPSS or QoL (all P > 0.05). Peripheral to transitional zone index (PTI) was found negatively correlated with total IPSS (r = −0.113, P = 0.024), storage IPSS (r = −0.103, P = 0.041), and voiding IPSS (r = −0.123, P = 0.014). As regards the uroflowmetry characteristics, PTI (r = 0.157, P = 0.007) was indicated to be positively correlated with Q(max) and negatively correlated with TZI (r = −0.119, P = 0.042) and TZT (r = −0.118, P = 0.045), but not correlated with TPV, TZV, or peripheral zone thickness (PZT) (all P > 0.05). Postvoid residual urine (PVR) had not correlated with all the prostatic anatomical variables (all P > 0.05). This is the first study that formally proposed the concept of PTI, which is an easy-to-measure prostate anatomical parameter which significantly correlates with total IPSS, storage IPSS, voiding IPSS, and Q(max), suggesting that PTI would be useful in evaluating and managing men with lower urinary tract symptoms (LUTS)/BPH. However, well-designed studies are mandatory to verify the clinical utility of PTI.