An observational study in Vasculogenic Erectile Dysfunction, sponsored by Al-Azhar University. Recruiting at 1 site in Egypt. Open to male participants aged 30 Years to 70 Years. Per ClinicalTrials.gov, last updated 2026-08-20.
Sponsored by Al-Azhar University · Observational
This prospective cohort study will recruit eligible men attending the Urology/Andrology outpatient clinic. Baseline assessment will include demographic and clinical data, cardiovascular risk assessment, erectile-function questionnaires, routine laboratory investigations, brachial artery flow-mediated dilatation, carotid intima-media thickness, and selected circulating endothelial biomarkers including endothelin-1, nitrite/nitrate, high-sensitivity C-reactive protein, soluble vascular cell adhesion molecule-1, and soluble intercellular adhesion molecule-1. All participants will receive tadalafil 5 mg once daily for 12 weeks. Erectile function, adherence, and adverse events will be assessed during follow-up. The primary outcome will be clinical response at 12 weeks, defined as an improvement of at least 4 points in the IIEF-EF domain together with a positive response to the Global Assessment Question.
Erectile dysfunction is a common male sexual disorder and is often associated with endothelial dysfunction, impaired nitric oxide bioavailability, inflammation, arterial stiffness, and subclinical atherosclerosis. Because penile arteries are relatively small, vasculogenic erectile dysfunction may appear before overt cardiovascular disease. Brachial artery flow-mediated dilatation reflects endothelial-dependent vasodilation, carotid intima-media thickness reflects structural vascular change, and circulating endothelial biomarkers may provide additional information about endothelial injury and inflammation.
This prospective observational cohort study will recruit men with predominantly vasculogenic erectile dysfunction attending the Urology/Andrology outpatient clinic. Baseline demographic, clinical, sexual, laboratory, vascular, and biomarker data will be collected before treatment. All participants will receive tadalafil 5 mg once daily for 12 weeks. Erectile function will be measured again at follow-up using the IIEF-EF domain, IIEF-5/SHIM, and the Global Assessment Question. The primary outcome is clinical response at 12 weeks, defined as an improvement of at least 4 points in IIEF-EF together with a positive Global Assessment Question response. The study will also evaluate whether baseline endothelial dysfunction markers improve prediction of tadalafil response beyond standard clinical variables.
701 studies on the registry are indexed under Erectile Dysfunction; 125 are open to participants now.
This study's planned enrollment of 120 is close to the median of 130 across 125 observational studies indexed under Erectile Dysfunction.
Browse Erectile Dysfunction studies →Al-Azhar University is the lead sponsor of 531 studies on the registry; 172 are open to participants now.
Of its 5 completed or terminated interventional studies of FDA-regulated products, 0 (0%) have results posted.
Counted across the registry records on this site, refreshed daily.
Consecutive adult men with predominantly vasculogenic erectile dysfunction presenting to the Urology/Andrology outpatient clinic at Al-Hussein and Sayed Galal Hospitals, Al-Azhar University, Cairo, Egypt, aged 30 to 70 years and eligible for tadalafil 5 mg once daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Participants must fulfill all of the following:
Exclusion Criteria:
Patients will be excluded if they have:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Adult men with predominantly vasculogenic erectile dysfunction who are eligible for tadalafil 5 mg once daily and enrolled in this prospective cohort study.
Drug: Tadalafil 5mg
All enrolled participants will receive tadalafil 5 mg orally once daily for 12 weeks as part of clinical management.
Also known as: PDE5 inhibitor
Clinical response to tadalafil at 12 weeks
Proportion of participants achieving clinical response, defined as an increase of at least 4 points in the IIEF-EF domain score from baseline together with a positive response to the Global Assessment Question. The IIEF-EF domain scores erectile function on a higher-is-better scale; higher scores indicate better erectile function.
Time frame: 12 weeks
Change in the International Index of Erectile Function erectile function score.
Change from baseline in the erectile function domain of the International Index of Erectile Function (IIEF-EF). The IIEF-EF domain is a validated erectile function score, with higher values indicating better erectile function.
Time frame: Baseline to 12 weeks
Change in Erection Hardness Score
Change from baseline in the Erection Hardness Score, a 4-point scale used to assess penile rigidity during erection. Higher scores indicate firmer erections.
Time frame: Baseline and12 weeks.
Brachial artery flow-mediated dilatation
Association between baseline brachial artery flow-mediated dilatation percentage and clinical response to tadalafil. Flow-mediated dilatation is a functional ultrasound-based measure of endothelial-dependent vasodilation; lower values indicate worse endothelial function. Baseline FMD will be evaluated as an independent predictor of treatment response.
Time frame: Baseline
Carotid intima-media thickness
Association between baseline mean carotid intima-media thickness and clinical response to tadalafil. Carotid intima-media thickness is a structural ultrasound marker of subclinical atherosclerosis; higher values indicate more advanced vascular wall thickening. Baseline CIMT will be evaluated as an independent predictor of treatment response.
Time frame: Baseline
Serum endothelin-1 level
Baseline biomarker levels will be evaluated as independent predictors of treatment response.
Time frame: Baseline
Serum nitrite/nitrate level
Baseline biomarker levels will be evaluated as independent predictors of treatment response.
Time frame: Baseline
Serum high-sensitivity C-reactive protein
Baseline biomarker levels will be evaluated as independent predictors of treatment response.
Time frame: Baseline
Adverse events during tadalafil treatment
Number and type of treatment-emergent adverse events occurring during 12 weeks of tadalafil 5 mg once-daily therapy.
Time frame: Throughout the 12-week treatment period.
Started Aug 2026 (actual). Primary completion is estimated for Aug 2028, 24 months after the start.
Of 40 observational studies under Erectile Dysfunction, half reached primary completion within 36 months of starting (the median), counting those still running; a quarter within 12 and three quarters within 77. This study's planned 24 months is below that.
How these figures are worked out, and which studies are left out of them.
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