Clinical Research Directory

Inclusion Criteria: Men aged 40 years or older Erectile dysfunction symptoms for at least 3 months International Index of Erectile Function-Erectile Function domain (IIEF-EF) score below 26 Predominantly vasculogenic erectile dysfunction based on medical history, focused physical examination, and baseline clinical assessment Suitable for tadalafil treatment Phosphodiesterase type 5 inhibitor-naive or no phosphodiesterase type 5 inhibitor use for at least 1 month before enrollment Provided written informed consent Exclusion Criteria: Contraindication to tadalafil, including nitrate use Major cardiovascular disease within the previous 6 months or other clinically unstable cardiovascular conditions Diagnosed hypogonadism or hormone replacement therapy Severe hepatic or renal insufficiency Predominantly psychogenic erectile dysfunction Erectile dysfunction primarily attributable to neurological, hormonal, or medication-related causes Previous radical pelvic surgery or major pelvic trauma Penile anatomical abnormalities, including Peyronie's disease Alcohol or substance dependence Poorly controlled diabetes mellitus, defined as glycated hemoglobin (HbA1c) of 8.0% or higher Use of medications affecting lipid metabolism, such as corticosteroids Initiation or dose modification of lipid-lowering therapy within the previous 3 months Uncontrolled thyroid dysfunction Active infection or inflammatory disease Active malignancy treatment