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

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.