Relationship between creatine kinase activity and semen characteristics insubfertile men

Objective-Creatine kinase is an indicator of sperm maturity. We studied whe ther sperm creatine kinase levels differ between normal healthy donors and subfertile patients and determined the correlation between sperm creatine k inase level and semen quality in subfertile men. Material and Methods-Semen samples were obtained from 76 subfertile and 15 healthy normal donors afte r 48 to 72 hours of sexual abstinence. Sperm characteristics were assessed with a computer-assisted semen analyzer. Morphology was evaluated by Kruger 's strict criteria and World Health Organization methods. The thiobarbituri c acid assay was used to measure lipid peroxidation; sperm creatine kinase activity was measured using a commercial kit after detergent extraction (Tr iton X-100). Results-Creatine kinase levels were significantly higher (P < .001) in subfertile men (median = 0.197 U/10(8) sperm) compared with donors (median = 0.061 U/108 sperm). In subfertile men, creatine kinase levels co rrelated significantly with lipid peroxidation levels (r =.49; P = 0.03) an d sperm concentration (r = -.70; P < .001), and with normal sperm forms by Kruger's (r = -.30; P = 0.01) and WHO methods (r = -.32; P < .005). Creatin e kinase levels and spermatozoal characteristics did not correlate signific antly in donors. Compared with subfertile normospermic men, creatine kinase activity was significantly higher in oligospermic and asthenospermic men ( P < .001). Conclusions-The inverse relationship between creatine kinase lev el and sperm concentration and morphological forms suggests that creatine k inase levels can be a reliable marker for semen quality in subfertile men. An elevated creatine kinase level and its correlation with lipid peroxidati on levels may reflect biochemically immature spermatozoa.