Relationship between creatine kinase levels and clinical diagnosis of infertility.

PURPOSE: The creatine kinase level indicates sperm maturity and correlates with the spermatozoal fertilizing potential. The relationship between creatine kinase levels in subfertile men and their clinical diagnosis was examined. METHODS: Patients with unexplained infertility (n = 34), varicocele (n = 20), postvasectomy reversal (n = 7), or cancer (n = 22) were included in this prospective clinical study. The control group consisted of healthy normal donors (n = 15). RESULTS: The median and interquartile range values of creatine kinase for each group were as follows: normal donors, 0.061 U/10(8) sperm (0.056 to 0.076 U/10(8) sperm); idiopathic male factor, 0.119 U/10(8) sperm (0.061 to 0.190 U/10(8) sperm); varicocele, 0.392 U/10(8) sperm (0.209 to 1.494 U/10(8) sperm); postvasectomy reversal, 0.589 U/10(8) sperm (0.425 to 4.043 U/10(8) sperm); and cancer, 0.068 U/10(8) sperm (0.047 to 0.168 U/10(8) sperm). Sperm creatine kinase levels were significantly higher in patients with varicocele compared to normal donors (P = 0.0001), cancer patients (P = 0.0002), and men with idiopathic infertility (P = 0.0009). Sperm concentration and creatine kinase level were inversely correlated in patients (r = -0.7, P < 0.001) but not in normal donors. CONCLUSIONS: Semen quality is poorer in subfertile patients with clinical varicocele and postvasectomy reversal than in cancer patients and patients with idiopathic male infertility. That the creatine kinase levels in cancer patients were similar to those of normal donors suggests that the final phase of spermatogenesis may not be altered in men with cancer; thus semen from these patients should be banked to ensure fertility after cancer treatment.