Bio-Functional Sperm Parameters: Does Age Matter?

Abstract

The evaluation of biofunctional sperm parameters can explain some cases of idiopathic male infertility. Among these, sperm DNA fragmentation (fDNA) is the most studied biofunctional sperm parameter. Mitochondrial membrane potential (MMP) correlates positively with sperm motility, the evaluation of sperm apoptosis by flow cytometry allows us to identify a population of spermatozoa not recognizable at the optical microscopy and finally, lipid peroxidation (LP) and mitochondrial superoxide levels measurements are rational oxidative stress indices. Male age seems to affect sperm concentration and sperm fDNA. For these reasons, this study was undertaken to evaluate the correlation, if any, between male age and biofunctional sperm parameters evaluating their possible impact on fDNA. To accomplish this, MMP, degree of chromatin compactness, sperm apoptosis/vitality, fDNA, LP, and mitochondrial superoxide levels were evaluated by flow cytometry in a cohort of 874 men. A significant negative correlation was found between age and the percentage of alive spermatozoa (r = -0.75, p < 0.05). The percentage of spermatozoa with low MMP (L-MMP) correlated positively with the percentage of spermatozoa with abnormal chromatin compactness (r = 0.24, p < 0.05). Spermatozoa with abnormal chromatin compactness and L-MMP correlated negatively with the percentage of alive spermatozoa (r = 0.83, p < 0.05) and positively with spermatozoa with PS externalization (r = 0.13, p < 0.01). The percentage of alive spermatozoa correlated negatively with both the percentage of spermatozoa with PS externalization (r = 0.24, p < 0.01) and of the spermatozoa with fDNA (r = 0.10, p < 0.05). Spermatozoa with PS externalization correlated positively with the percentage of spermatozoa with fDNA (r = 0.09, p < 0.05). Spermatozoa with LP correlated positively with the percentage of spermatozoa with increased mitochondrial superoxide (r = 0.11, p < 0.01) In conclusion, these findings in a large number of men suggest that age, mitochondrial damage, and alteration of chromatin compactness could activate the apoptotic cascade which could result in an increased fDNA rate.

Retrospective Monocentric Clinical Study on Male Infertility: Comparison between Two Different Therapeutic Schemes Using Follicle-Stimulating Hormone

“…Therefore, these findings strongly suggest that FSH treatment improves the pregnancy rate in couples including men with idiopathic infertility by reducing sperm DNA fragmentation. Moreover, FSH may also be prescribed in patients with increased sperm DNA fragmentation resulting from several conditions, such as male age, elevated BMI, cigarette smoke, etc., especially when associated with increased oxidative stress in the seminal fluid [ 27 ].…”

Sperm Vitality and Necrozoospermia: Diagnosis, Management, and Results of a Global Survey of Clinical Practice

“…Advanced male age may also be accompanied by necrozoospermia. The mechanisms remain unknown at this time but may involve an alteration in accessory gland secretions [ 42 43 44 ]. However, after a complete andrological evaluation, some patients with necrozoospermia remain idiopathic.…”

Necrozoospermia: The tree that hides the forest

“…114,118 The mechanisms involved remain unknown but could involve seminal fluid regulatory enzymes (as previously described), an alteration of accessory glands secretions, an increase in oxidative stress as well as a decline in sperm DNA integrity. 35,114,115…”

“…There is a significant negative correlation between age and sperm vitality 35,114–117 . Studies report an increase in the prevalence of necrozoospermia from the age of 35–45 114,118 .…”