RESUMEN
<p><b>Objective</b>To explore the correlation of the sperm DNA fragmentation index (DFI) with age, sperm concentration and sperm motility in infertile men.</p><p><b>METHODS</b>We collected semen samples from 531 infertile males in our hospital from January 2016 to June 2017. We determined the semen parameters using the computer-assisted semen analysis system, measured the sperm DFI by sperm chromatin structure assay, and analyzed the correlation of the sperm DFI with the age, sperm concentration and sperm motility of the patients.</p><p><b>RESULTS</b>With the increase of age, the infertile males showed a significantly decreased proportion of the sperm with a DFI ≤15% and elevated proportion of the sperm with a DFI ≥25%, with a positive correlation between age and sperm DFI (r = 0.653, P < 0.01). With the increase of sperm concentration and motility, however, the proportion of the sperm with a DFI ≤15% was remarkably increased while that of the sperm with 15%<DFI<25% and ≥25% markedly reduced, both sperm concentration and motility negatively correlated with the sperm DFI (r = －0.246, P < 0.01 and r = －0.406, P < 0.01).</p><p><b>CONCLUSIONS</b>The sperm DFI is significantly correlated with age, sperm concentration and sperm motility, and therefore can be used as an important index for the evaluation of semen quality. A comprehensive analysis of the sperm DFI and semen parameters may contribute to an accurate assessment of male fertility.</p>