Evidence Hub

Folate Pathway Polymorphisms and Tadalafil Response in Men with Diabetes Mellitus and Erectile Dysfunction: An Exploratory Study

Boštjan Hostnik, A. Janež, K. Goričar, Tanja Blagus, Vita Dolžan, Andrej Kastrin, Jasna Klen

Journal of Clinical Medicine, 2026

78 participants

Abstract

Background/Objectives: Erectile dysfunction (ED) is a common complication of diabetes mellitus (DM), largely driven by endothelial dysfunction and impaired nitric oxide signaling. Although phosphodiesterase type 5 inhibitors (PDE5i) such as tadalafil are effective, treatment response varies considerably between individuals. Genetic variation in the folate–homocysteine pathway may influence endothelial function and contribute to this variability. To investigate the association of selected polymorphisms in folate–homocysteine pathway genes (MTHFR rs1801133 and rs1801131, MTR rs1805087 and MTRR rs1801394) with ED severity and response to tadalafil treatment in men with DM. Methods: In this prospective exploratory pharmacogenetic study, 78 men with DM and ED were treated with tadalafil 5 mg once daily for three months. ED was assessed using the International Index of Erectile Function (IIEF-5) questionnaire before and after treatment. The pre-specified primary endpoint was treatment response, defined as a ≥4-point increase in IIEF-5 score (based on the minimal clinically important difference for the IIEF erectile function domain). Genotyping was performed using competitive allele-specific PCR. Associations between genetic variants and treatment outcomes were evaluated using logistic regression. Results: Before treatment 24 patients (30.8%) had moderate or severe ED. No significant associations were observed between the investigated polymorphisms and baseline ED severity. IIEF-5…

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free