Fertility and Sperm Quality in the Aging Male

Abstract

Parenthood at an older age is becoming a trend among men, especially in the most developed societies. Aging has a significant impact on male fertility. Older men exhibit notable disturbances in the reproductive axis, with steroidogenesis being impacted much more than spermatogenesis. The endocrine changes, together with morphological and functional alternations of the aging testis, result in decreased testosterone production. Nonetheless, studies are needed to scrutinize the impact of age per se versus age-induced dysfunction of the reproductive axis. Furthermore, the multiple effects of aging on the acquisition of sperm motility, on sperm morphology and concentration indicate that the quality of spermatozoa declines over time, but few works have shed light on the molecular mechanisms that hamper sperm function in old men. In fact, this question is far from being completely answered and this is a subject of controversy. Hence, we will present an up-to-date review and discuss the molecular mechanisms involved in the alteration of the reproductive function in aging men. We will focus on the functioning of the reproductive axis and what are the major effects of aging in spermatogenesis. We will also discuss how aging affects sperm quality and possible causes underlying sperm dysfunction with special emphasis in oxidative stress.

Icariin Improves Age-Related Testicular Dysfunction by Alleviating Sertoli Cell Injury via Upregulation of the ERα/Nrf2-Signaling Pathway

“…sex hormones levels (Haji et al, 1994;Petersen et al, 2015;Li et al, 2017;Wang et al, 2017). Clinical studies have shown that testosterone concentration, sperm count and quality are declined, and the incidence of infertility is increased in aged men (Gunes et al, 2016;Almeida et al, 2017). In our study, we found icariin effectively ameliorated the age-related decline in testicular function by increasing testicular and epididymal weights and indices, sperm count and sperm viability, testicular testosterone concentrations, and seminiferous tubule diameters and heights.…”

Associations of sperm telomere length with semen parameters, clinical outcomes and lifestyle factors in human normozoospermic samples

“…61,62 As a confounding factor, ageing is linked to fertility issues, such as the decline in male hormones and sperm quality. 63 Therefore, an age threshold is required to investigate the effect of age on STL (such as < 30 years vs > 50 years, 0. 27,64 Herein, the age threshold has matched the age considered the start of the male fertility decline (35 years,.…”

Pathological and molecular examination findings in postmortem testis biopsies reveal spermatogenesis damages in COVID-19 patients

“…Nevertheless, this study has limitations, including the small number of cases from a 282 single-center, and the patients were older people, which may not represent the fecundity of 283 men in the golden age of childbearing. For example, the patients with COVID-19 were 284 examined in this study are all aging men and had comorbidities, which may compromise 285 spermatogenesis and male germ cell development (Almeida et al, 2017;Shiraishi and 286 Matsuyama, 2018). Nonetheless, our analysis suggests that this possibility is unlikely, 287 particularly since the degree of germ cell apoptosis in the patients with COVID-19 increased 288 significantly, whereas in the control patients (also aging men), it remained stable at a 289 significantly lower level.…”