Sperm nuclear DNA fragmentation and mitochondrial activity in men with varicocele.
OBJECTIVE
To verify the impact of varicocele on semen quality and sperm function (DNA integrity and mitochondrial activity).


METHODS
Prospective study.


METHODS
Patients in an academic research environment.


METHODS
Seventeen patients with a clinical diagnosed varicocele of grade II or III and 20 men without a varicocele.


METHODS
Rate of sperm DNA fragmentation as assessed by the Comet assay and categorized as classes I (no DNA fragmentation), II (little DNA fragmentation), III (meaningful DNA fragmentation), and IV (high DNA fragmentation). Rate of mitochondrial activity as assessed by the diaminobenzidine (DAB) assay and categorized as grades I (all mitochondria active), II (most mitochondria active), III (most mitochondria inactive), and IV (all mitochondria inactive).


RESULTS
No statistically significant differences were found between the study and control groups with respect to age, ejaculatory abstinence, and round cell count. Men with varicocele had significantly higher ejaculate volume, concentration of immotile sperm, and neutrophil count and lower mean percentage of sperm concentration, progressive motility, and morphology than men in the control group. The study group presented a lower percentage of sperm with little DNA fragmentation (class II) and a higher percentage of sperm with DNA fragmentation (class IV). In addition, the study group presented a greater percentage of sperm with inactive mitochondria (class III).


CONCLUSIONS
Compared with men without varicocele, men with varicocele had a higher percentage of cells with DNA fragmentation and sperm with inactive mitochondria. Indeed, varicocele causes a decrease in motility, concentration, and morphology and an increase in volume and concentration of immotile sperm and neutrophils. The sperm functional evaluation (DNA fragmentation and mitochondrial activity) could be important factors in deciding treatment options for men with varicocele.
D000328:Adult; D016022:Case-Control Studies; D002467:Cell Nucleus / Q000378:metabolism* / Q000473:pathology; D048430:Cell Shape; D020552:Comet Assay; D053938:DNA Fragmentation; D006801:Humans; D007248:Infertility, Male / Q000209:etiology* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008297:Male; D008928:Mitochondria / Q000378:metabolism*; D009504:Neutrophils / Q000473:pathology; D011446:Prospective Studies; D012720:Severity of Illness Index; D013076:Sperm Count; D013081:Sperm Motility; D013094:Spermatozoa / Q000378:metabolism* / Q000473:pathology; D014646:Varicocele / Q000150:complications / Q000235:genetics / Q000378:metabolism* / Q000473:pathology