Qi-ling Wang, Li-xin Tang, Shun-mei Deng, Yun-ge Tang and Li-xin Zheng
Objective: To investigate the oxidative DNA damage in the seminal plasma and spermatozoa of infertile men with varicocele and to evaluate the potential relationship between oxidative DNA damage and varicocele.
Methods: This case-control study recruited 180 infertile men with varicocele and 199 infertile men without varicocele and 168 fertile male control subjects. Semen parameters, seminal plasma 8-hydroxy-2-deoxyguanosine (8-OHdG) and sperm DNA Fragmentation Index (DFI) were assessed.
Results: Compared to the infertile men without varicocele and control subjects, infertile men with varicocele exhibited lower sperm concentration, lower progressive motility, lower vitality and lower percentage of normal morphology (all P=0.0001). The seminal content of 8-OHdG and sperm DFI were higher in infertile men with varicocele than in infertile men without varicocele and in the control group (all P<0.001). A positive correlation was observed between the 8-OHdG levels and DFI (P<0.001). However, There were negative correlations between seminal plasma 8-OHdG levels or sperm DFI with sperm concentration, progressive motility, vitality, and normal forms in the varicocele group (all P<0.001). Furthermore, the seminal plasma 8-OHdG content and sperm DFI was significantly higher in grades II and III than in grade I after controlling age, BMI, abstinence period and semen parameters.
Conclusions: Infertile men with varicocele have greater oxidative DNA damage in seminal plasma and spermatozoa than the subjects without varicocele. The degrees of varicocele and DNA damage were associated with decreased semen quality in infertile men with varicocele.