Effect of estradiol on penile erection: a cross-sectional study.

Background: Past studies have shown that elevated estradiol levels could inhibit penile erection, but the relationship between estradiol and erection of the penile tip or base has not been extensively researched.

Methods: We therefore investigated estradiol's effects on the erection of the penile tip and base, with a cross-sectional study of 135 patients with erectile dysfunction (ED), based on scores of ≤21 according to the International Index of Erectile Function-5. All patients were tested for nocturnal penile tumescence, blood pressure (BP), serum glucose, total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin (PRL), progesterone (P), estradiol (E), and testosterone (T). Univariate and multivariate analyses were used to assess associations between estradiol levels and erection at the penile tip and base.

Results: We found no obvious relationship between erection time at penile tip and estradiol levels but did observe a negative correlation between base erection time and estradiol level [hazard ratio (HR): ‒0.11; 95% CI: ‒0.80-1.72]. With increasing estradiol concentration, multivariate analysis showed an obvious reduction in base erection time among patients with normal Rigiscan results (HR: ‒0.31; 95% CI: ‒1.63-1.29) (P<0.05) as estradiol concentration increased.

Conclusions: Our data indicate that estradiol inhibits penile erection, particularly at the penile base. Also, when the effective erection time of the penile base lasts longer than 10 min, estradiol has a more obvious inhibitory effect on penile base erection.