[The relationship between male semen parameters and sperm DNA fragment index with the age]

To investigate the relationship between male semen parameters and sperm DNA fragment index with age. Adopt cross-sectional sampling survey design, 3 203 male patients who visited the Department of Reproductive Andrology in the Third Affiliated Hospital of Zhengzhou University from January 2019 to June 2021 were selected as subjects. Age range is 18-57 years, with the median age of 30 years. Through quartile regression analysis, the correlation between age and different male semen parameters and DNA fragment index (DFI) was presented. The study population was divided into ≤30 years old group and >30 years old group, and the correlation between age and semen volume, sperm concentration, total sperm count, progressive motility, total motility, percentage of normal sperm and DFI level were compared and analyzed. The results showed that there were significant differences in progressive motility, total motility and DFI level among different age groups (χ-4.608, -4.604, -7.719,P all <0.05), but there was no significant difference in semen volume, sperm concentration, total sperm count and percentage of normal sperm (χ=-1.712, -1.203, -0.149, -0.175,P all >0.05). In the>30 years old age group, there was a very weak negative correlation between male age and semen volume, progressive motility and total motility (r=-0.137, -0.101 and -0.056, P all <0.05). There was a very weak positive correlation between male age and sperm concentration and sperm DFI level (r=0.061, 0.190, P all <0.05), while there was no correlation between male age and total sperm count and percentage of normal sperm (r=-0.018, -0.016,P all >0.05). In conclusion, with the increase of age, especially after the age of 30, semen volume, progressive motility and total motility decreased, while sperm concentration and DFI level increased, and semen quality decreased.