Ultrastructural Study of Clitoral Cavernous Tissue and Clitoral Blood Flow From Type 1 Diabetic Premenopausal Women on Phosphodiesterase-5 Inhibitor

Background: The effects of phosphodiesterase-type 5 (PDE5) inhibitors on the in vivo clitoral structure of women with diabetes have never been investigated. Aim: To study the in vivo structural and hemodynamic changes of the clitoris in premenopausal women with type 1 diabetes on PDE5 inhibitors. Methods: 38 premenopausal women with type 1 diabetes aged 36 -46 years. A randomized 1:1 study design was used: Study Group (group A) on Tadalafil 5 mg daily, and control group (group B). Blood samples were taken from each woman to measure HbA1c, testosterone, and Free Androgen Index. The women underwent microbiopsy of the clitoral body by means of semiautomatic gun during total anesthesia for surgery therapy of a benign gynecological pathology. The tissue removed was processed for electron microscopy. Translabial color Doppler ultrasound was used to measure the peak systolic velocity (PSV), the end diastolic velocity (EDV), and the pulsatility index (PI) of clitoral arteries. Main Outcome Measures: Micro-ultrastructure observation of clitoral tissue and color Doppler sonography of clitoral blood flow. Results: Of the 38 women, 13 (68.4%) of group A and 15 (78.9%) of group B completed the study. Group A showed a mean PSV and EDV increase, and a mean PI decrease with respect to baseline (P < .001). Group B did not show any change in both the parameters (P = NS). By a quantitative study in both groups a variable degree of ultrastructural abnormalities of smooth muscle cells (SMCs) was observed, consisting in increased glycogen and lipoic deposits, cytoplasmic vacuoles, and focal increase of electron density of SMCs. Moreover, the mean SMC thickness of group A (1.83 ± 0.68 µm) was larger than that of group B (1.3 ± 0.41 µm) (P = .02). Clinical Implications: PDE5 inhibitors could be used to treat diabetic women with genital arousal disorder. Strengths & Limitations: The study shows a clear effect of PDE5 inhibitors on clitoral SMCs. However, a limit was to not have investigated the sexual function/behavior of women of both groups, this was because of the short time of the study. Conclusion: This study could help to understand in what way PDE5 inhibitors act on the ultrastructural pathophysiological clitoral cavernous tissue of women with diabetes. It could support PDE5 inhibitor usage in women with genital sexual arousal disorder due to metabolic diseases. Caruso S, Cianci A, Cianci S, et al. Ultrastructural Study of Clitoral Cavernous Tissue and Clitoral Blood Flow From Type 1 Diabetic Premenopausal Women on Phosphodiesterase-5 Inhibitor. J Sex Med 2019;16:375–382