Relationship between penile erection and the ratio of estradiol to testosterone: A retrospective study

Previous studies have found that the ratio of estradiol to testosterone (E2/T ratio) has a negative effect on sexual function, but the relationship between the E2/T ratio and erection of the penis is not clarified. We conducted a retrospective study of 183 patients with erectile dysfunction and 52 healthy men to investigate the relationship between penis base erection and tip erection. All participants underwent nocturnal penile tumescence tests and medical history checks and had relevant biochemical and endocrine indicators measured. The ratio of estradiol to testosterone was calculated. The relationship between E2/T ratio and erectile time of penile tip and penile base was determined by univariate analysis, multivariate analysis and stratification analysis. After adjusting for mixed factors, the results showed that the E2/T ratio had a more significant negative effect on the base of the penis compared with the tip of the penis (Hazard ratio: -4.34 95% CI: -6.52, -2.16 p = .0001). Moreover, when the effective erection time was ≥10 min, the negative effect of E2/T on penile root erection was more obvious (HR ratio: -4.46 95% CI: -6.50, -2.43 p < .0001). In summary, our study demonstrated a negative relationship between E2/T ratio and penile erection, particularly at the root of the penis.