Objective: To examine levels of sperm DNA damage and oxidative stress (OS) in infertile men with
varicocele.
Design: Prospective controlled study.
Setting: Male infertility clinic, Glickman Urological Institute, Cleveland Clinic Foundation, Cleveland, Ohio.
Patient(s): Thirty-one infertility patients and 16 fertile controls.
Intervention(s): Sperm DNA fragmentation index (DFI), levels of seminal reactive oxygen species (ROS),
and total antioxidant capacity (TAC) were assessed using the sperm chromatin structure assay, chemiluminescence
assay, and enhanced chemiluminescence assay, respectively. ROS-TAC score was calculated as a
measure of OS.
Main Outcome Measure(s): Median (interquartile range) DFI and ROS-TAC scores.
Result(s): Sixteen of the 31 patients had left varicocele [grade I (n _ 3), grade II (n _ 10), and grade III
(n _ 3)], and the remaining 15 had normal genital examination. Patients with varicoceles had significantly
higher percent DFI than controls (25%, range: 20%–35%; vs. 15%, range: 10%–22%). Patients with
varicoceles had significantly lower ROS-TAC scores (21, range: 9.5–31) than the infertile patients with normal
genital examination (34, range: 28–42) or the controls (40.3, range: 38–44).
Conclusion(s): Infertile men with varicoceles showed significantly increased spermatozoal DNA damage that
appears to be related to high levels of OS in semen.