Detection of sperm DNA damage in male infertility patients and evaluation of Levocarnitine efficacy using sperm chromatin diffusion (SCD) and AI-DFI methods: a cross-sectional study

The objective of this study was to elucidate the relationship between sperm DNA damage and sperm parameters in male infertility patients and to assess the changes in sperm DNA fragmentation index before and after treatment with Levocarnitine in patients with asthenozoospermia and oligozoospermia. The results of 508 patients' semen samples tested between August 2021 and December 2022 in our Department of Urology and Reproductive Medicine were retrospectively analyzed. The 508 patients were divided into 3 groups: normal semen group (n = 181), asthenozoospermia group (n = 170), and oligozoospermia group (n = 157). Their sperm DNA integrity was evaluated using the sperm chromatin diffusion (SCD) method and an artificial Intelligence-based DNA fragmentation index (AI-DFI). The patients were divided into two groups based on the assessment of sperm DNA integrity: a sperm DNA damage group and a sperm DNA integrity group. The two groups were then compared in terms of sperm concentration, motility, viability, and the proportion of normal sperm morphology. Pearson's correlation coefficient analysis was employed to examine the relationship between sperm DNA damage and semen parameters. The results showed that sperm concentration, progressive motility, viability, and normal morphology rate were significantly lower in the DNA damaged group, and correlation analysis showed that the results of sperm DNA damage detection was negatively correlated with these semen parameters. And the DNA fragmentation index (DFI) was highest in the asthenozoospermia group, followed by the oligospermia group and the normal group, with significant differences between the groups (20.30 ± 2.85; 18.62 ± 2.42; 12.83 ± 2.13, P = 0.01). Treatment of patients in the group with sperm DNA damage with Levocarnitine oral solution was found to significantly improve sperm concentration, progressive motility, viability, normal morphology rate, and DFI results after its use (t = 7.265, 5.823, 7.750, 8.737, 8.355; P = 0.03, 0.02, 0.02, 0.03, 0.01). This study concludes that men with asthenozoospermia and oligozoospermia have a high DFI, and Levocarnitine is effective in reducing DNA damage and improving sperm quality, suggesting that Levocarnitine has potential for clinical use.