AB218. The size of seminal vesicles on ultrasound is related with premature ejaculation

OBJECTIVE: Myriad biological factors have been proposed to explain premature ejaculation (PE). However, data correlating PE with seminal vesicles (SV) are sparse. The study aimed to evaluate the relationship between the size of SV on ultrasound and PE and to explore the potential mechanism of the relationship. METHODS: A cross-sectional study was conducted that included 44 PE outpatients and another 44 male volunteers without PE. Self-estimated intravaginal ejaculatory latency time (IELT), the Premature Ejaculation Diagnostic Tool (PEDT), the International Index of Erectile Function-15 (IIEF) and the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) were used for assessment of symptoms. The size of SV and other ultrasound figures were compared between PE group and control group. Tandem mass tag (TMT) method followed by mass spectrometry analysis was used to compare the relative expression levels of seminal plasma proteins between PE group and control group. RESULTS: Compared to the control group, the PE group had significantly higher mean anterior-posterior diameter (APD) of SV. The optimal mean APD of SV cutoff level as identified by the maximal Youden index was 9.25 mm for PE. In the PE group, PEDT was also higher with mean APD of SV >9.25 mm compared with mean APD of SV <9.25 mm. PEDT was significantly correlated with mean APD of SV, even after adjusting for age, IIEF-15 erectile function score and NIH-CPSI pain domain and voiding domain score. Compared to the matched six control subjects, 102 proteins were at least 1.5-fold up- or down-regulated in seminal plasma of six PE patients. Among them, GGT1, LAMC1 and APP were significantly higher in the PE group. CONCLUSIONS: Our results indicated that men with larger mean APD of SV might have a higher PEDT score. Transrectal ultrasound of SV should be considered in the clinical evaluation of patients with PE. The changes of SV might be associated with the higher expressed GGT1, LAMC1 and APP, which might further result in PE.