OBJECTIVETo investigate the changes in seminal paraoxonase-1 (PON-1) activity in infertile male patients and assess the clinical value of seminal PON-1 examination in the diagnosis of male infertility.

METHODSSeminal PON-1 activity was detected by spectrophotometric method in the semen samples from 270 infertile male patients and 50 health fertile males (control), and the semen parameters were analyzed using a computer-assisted semen analysis system.

RESULTSIn the male infertility group, seminal PON-1 activity was 1.22∓0.76 U/L in the patients with normal semen parameters and 0.64∓0.54 in the patients with abnormal semen parameters, both significantly lower than that of the control group (3.17∓0.89 U/L, P<0.01). In patients with asthenospermia, the declined sperm motility was associated with decreased seminal PON-1 activity, which showed significant differences between patients with mild, moderate, and severe asthenospermia. Seminal PON-1 activity was positively correlated with the percentage of sperm viability (P<0.01), but inversely with the percentage of morphologically abnormal sperm (P<0.01). According to ROC curves, the area of seminal PON-1 activity under the curve was 0.907, showing a statistical significance (P<0.01).

CONCLUSIONThe detection of seminal PON-1 activity can provide a laboratory evidence for the diagnosis of male infertility.