Comparison of the resazurin test, adenosine triphosphate in semen, and various sperm parameters

The results of the resazurin test (RES) and adenosine triphosphate (ATP) concentration in semen, measured by two methods, were compared for their ability to predict sperm parameters of semen samples from 42 subfertile men as assessed by a semi-computerized system. The highest correlation of RES grade was with sperm concentration (r = 0.70, P < 0.001), concentration of motile spermatozoa, concentration of motile spermatozoa with normal morphology and the ATP concentration using the reference LKB method (all r = 0.65, P < 0.001). The RES test has a positive predictive value of 93% for a progressive motile sperm concentration of 20 x 10(6)/ml or more, and a negative predictive power of 90% for the same variable at a criterion value of 10 x 10(6)/ml. The results of ATP measurement using the reference LKB and FireZyme methods presented a strong correlation (r = 0.74, P < 0.001). The correlations between ATP measurements from the FireZyme method and sperm characteristics were better than those obtained using the reference LKB method for ATP determination. It is concluded that the RES test can be performed with a relatively small volume of semen; it is easy to perform and requires not technical equipment. The accuracy and predictive value of this test are similar to more sophisticated ATP measurements. In addition, the RES may identify a subgroup of subfertile men with a decreased reducing capacity of semen.