The higher risk for sperm DNA damage in infertile men

Objectives: Supplementary assays are needed for determination of relationships between sperm biomarkers and fertility potential. Therefore, our research was designed to determine the extent of sperm DNA fragmentation (SDF) and establish a discriminating threshold of SDF for fertility potential. Material and methods: Semen characteristics were evaluated according to World Health Organization recommendations, and SDF was assessed by sperm chromatin dispersion test on ejaculated spermatozoa from infertile and healthy normozoospermic men. Results: A higher proportion of SDF was noted in infertile men (median 23.00%) than normozoospermic (median 14.00%). Significantly less subjects (17.03%) with low SDF level (≤ 15%) and more (35.17%) with high SDF level ( > 30%) were found for the infertile group vs the normooospermic (57.90% and 5.26%, respectively). Infertile group had significantly lower odds ratio (OR) for having a low SDF level (OR: 0.1493) and higher OR for having a high SDF level (OR: 9.7627). Receiver operating characteristic analysis [area under curve (AUC) = 0.785] revealed that 20% SDF is predictive value for discriminating between infertile and normozoospermic subjects. SDF was negatively correlated with the sperm number, morphology, progressive motility and vitality but positively with the teratozoospermia index. Conclusions: Our study demonstrates: (1) a significant difference in the extent of SDF and in the risk for having damaged sperm DNA between infertile and normozoospermic men, (2) > 20% SDF has negative predictive value for fertility potential, (3) coexistence of abnormal standard sperm parameters with sperm chromatin damages. Therefore, SDF should be considered as a highly valuable indicator of male fertility potential

The impact of sedentary work on sperm nuclear DNA integrity

Introduction. Contemporary professional jobs that often enforce a sedentary lifestyle and are frequently associated with testicular overheat, deserve special attention with respect to male fertility potential. Interestingly, the harmful effect of testicular heat stress on sperm characteristics including nuclear DNA integrity was well characterized; however, the influence of sedentary work on sperm chromatin has not yet been documented. Therefore, our research was designed to examine the potential effects of sedentary work not only on conventional semen features but also on sperm nuclear DNA status.Materials and methods. The study was carried out on ejaculated sperm cells obtained from men who spent ≥ 50% of their time at work (≥ 17.5 h per week) in a sedentary position (n = 152) and from men who spent < 50% of their time at work in a sedentary position (n = 102). Standard semen characteristics were assessed according to the WHO 2010 recommendations, while sperm nuclear DNA fragmentation (SDF) was evaluated using the Halosperm test.Results. There were no significant differences in the standard semen parameters between the study groups. The groups differed only in SDF parameter. The men who spent at least 50% of their work time in a sedentary position had a higher proportion of SDF than the men who spent < 50% of their time at work in a sedentary position (median value 21.00% vs. 16.50%, respectively). The incidence of low SDF levels (related to 0–15% sperm cells with abnormal DNA dispersion) was significantly lower (27.63% vs. 45.10%), the percentage of men with high SDF levels (related to > 30%) was significantly higher (30.92% vs. 16.67%) in group of men who spent at least 50% of their work time in a sedentary positon. Furthermore, these men were more than twice as likely to have not a low SDF level (OR: 0.4648) and had more than twice the risk of having a high SDF level (OR: 2.2381) than the men in less sedentary occupations.Conclusions. Despite lack of association between sedentary work and conventional semen characteristics our study revealed detrimental effect of seated work on sperm nuclear DNA integrity. A sedentary job doubled the risk of high levels of sperm DNA damage. The pathomechanism could be related to testicular heat stress resulting in sperm chromatin remodelling failure during spermiogenesis. Therefore, it seems reasonable to simultaneously carry out routine seminological analyses and tests assessing sperm chromatin status while diagnosing male infertility

Evaluation of selected semen parameters and biomarkers of male infertility – preliminary study [version 1; peer review: 1 approved, 2 approved with reservations]

Background: Because the etiopathogenesis of male infertility is multifactorial our study was designed to clarify the relationship between standard semen parameters, testicular volume, levels of reproductive hormones and the fragmentation of sperm nuclear DNA (SDF). Methods: Patients (n = 130) were clustered as subjects: 1) with an abnormal volume (utrasonography) of at least one testis (30%), moderate (>15–30%) or low (≤15%) (sperm chromatin dispersion test). Results: In subjects with a decreased testicular volume and in subjects with abnormal levels of reproductive hormones, decreased basic semen parameters were found. Participants with abnormal testicular volume had a higher percentage of SDF and a higher level of FSH (Mann–Whitney U test). In turn, men with a high level of SDF had lower testicular volume and conventional sperm parameters than men with a low level of SDF (Kruskal–Wallis test). Conclusions: We showed that spermatogenesis disorders coexisted with decreased testicular volume and increased FSH levels. The disorders of spermatogenesis were manifested by reduced basic sperm characteristics and a high level of sperm nuclear DNA damage