An observational study in Varicocele, Male Infertility and Zonulin, sponsored by Süleyman Tümer Çalışkan. Completed at 1 site in Turkey (Türkiye). Open to male participants aged 18 Years to 50 Years. Per ClinicalTrials.gov, last updated 2026-08-05.
Sponsored by Süleyman Tümer Çalışkan · Observational
This prospective cross-sectional observational study was designed to evaluate serum and seminal plasma zonulin levels in infertile men with clinically diagnosed varicocele and compare them with those in infertile men without varicocele. The study also aimed to investigate the association between zonulin concentrations and conventional semen parameters.
A total of 119 men evaluated for infertility between December 2022 and May 2023 were included. Participants were classified into two groups according to the presence or absence of clinically diagnosed varicocele. Serum and seminal plasma zonulin concentrations were measured using enzyme-linked immunosorbent assay (ELISA). Conventional semen parameters, including semen volume, sperm concentration, total sperm count, progressive motility, total motility, and normal sperm morphology, were evaluated and compared between the study groups.
Varicocele is one of the most common causes of male infertility and is associated with impaired spermatogenesis through multiple mechanisms, including oxidative stress, inflammation, and disruption of testicular microcirculation. Zonulin, a physiological regulator of epithelial tight junctions, has been proposed as a biomarker of increased intestinal permeability and systemic inflammation. However, the relationship between serum and seminal plasma zonulin levels and varicocele in infertile men has not been fully investigated.
This prospective observational study was designed to evaluate serum and seminal plasma zonulin levels in infertile men with clinically diagnosed varicocele and compare them with those in infertile men without varicocele. The study was also designed to examine the association between zonulin concentrations and conventional semen parameters, including semen volume, sperm concentration, total sperm count, progressive motility, total motility, and normal sperm morphology.
A total of 119 infertile men presenting to the Urology outpatient clinic between December 2022 and May 2023 were enrolled. Participants were assigned to groups according to the presence or absence of clinically diagnosed varicocele. Patients with systemic diseases, active infections, tobacco or cannabis use, use of medications known to affect semen parameters, abnormal body mass index, or evidence of genital tract infection were excluded. Serum and seminal plasma samples were collected on the day of semen analysis, and zonulin concentrations were measured using enzyme-linked immunosorbent assay (ELISA).
The primary objective was to compare serum and seminal plasma zonulin levels between infertile men with and without varicocele. Secondary objectives were to evaluate the association between zonulin concentrations and conventional semen parameters.
53 studies on the registry are indexed under Varicocele; 15 are open to participants now.
This study's enrollment of 119 is close to the median of 119 across 17 observational studies indexed under Varicocele.
Browse Varicocele studies →This is the only study on the registry with Süleyman Tümer Çalışkan as lead sponsor.
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Patients who had presented for infertility assessment were included in the study. Participants were divided into two groups: men with varicocele-related infertility and men with infertility without varicocele
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.
Exclusion Criteria:
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.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
infertile men without varicocele
infertile men with varicocele
Serum and Seminal Zonulin Levels
Assessment and comparison of serum and seminal zonulin concentrations in infertile men with varicocele and infertile men without varicocele.
Time frame: 1 day
Comparison of Semen Parameters Between Groups
Assessment and comparison of semen parameters between infertile men with varicocele and infertile men without varicocele
Time frame: 1 day
Plan to share: No — Individual participant data will not be shared due to privacy and confidentiality concerns. Data access is restricted to the study investigators in accordance with institutional regulations.
This study is completed, as verified in Jul 2026. You cannot join it, but the record below documents what was studied.
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