Sperm DNA fragmentation in men of different age

Abstract

The study objective is to analyze the content of spermatozoa with single and double-stranded DNA breaks in different age groups.Materials and methods. The level of DNA fragmentation was studied in 300 ejaculate samples obtained from 266 sub- or infertile men. The group 1 included 150 samples obtained from 131 patients under the age of 45 (21–44 years), the group 2 included 150 samples obtained from 135 patients above the age of 45 (45–68 years). Mean ages were 34.8 ± 3.9 and 48.6 ± 3.1 years, respectively. The number of sperm with fragmented DNA was evaluated using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method on ejaculate smears. The number of spermatozoa with >15 % of fragmented DNA was considered elevated. Standard semen analysis was performed in 117 and 97 men from the groups 1 and 2, respectively.Results. The number of sperm with fragmented DNA varied in ejaculated samples from 1.5 to 64.5 %. Mean number of sperm with DNA breaks in the group 1 (12.0 ± 6.0 %) was significantly lower than in the group 2 (16.1 ± 8.3 %, p <0.05). Mean sperm count in the ejaculate of the group 1 (267.0 ± 198.7 million) was significantly higher than in the group 2 (201.0 ± 162.9 million, p = 0.02).Conclusion. We revealed that in men over the age of 45 years, the percentage of spermatozoa with DNA fragmentation is higher than in men under 45 years of age, it may indirectly indicate an increased level of reactive oxygen species in the seminal plasma in older patients.