Assisted reproductive technology outcomes in obese and diabetic men: lighting the darkness

Abstract

The prevalence of obesity and diabetes, two of the most prevalent metabolic disorders (MetDs) in the world, has been rising exponentially over the last two decades. In addition to other comorbidities, MetDs have a detrimental impact on reproductive features, leading to a boost of the use of assisted reproductive technologies (ARTs) to overcome fertility problems. Although ARTs help to improve MetD male reproductive outcomes, data show that the results are less successful compared with those of men without MetD. Currently, intracytoplasmic sperm injection is the election procedure to bypass infertility in men with MetD. Nevertheless, embryos obtained by intracytoplasmic sperm injection using spermatozoa of men with MetD have a lower probability to end in a live birth. This embryo development shutdown has been related to a higher rate of spermatozoa with fragmented DNA and with modifications on pathways that do not allow embryos to go further in the development process. This special detrimental feature of sperm from men with MetD indicates that advanced sperm selection techniques should be used in these patients to avoid sperm with fragmented DNA. Fortunately, sperm selection procedures are under constant development and eventually will allow physicians to select spermatozoa with higher quality and low DNA fragmentation to be used in further ART, increasing the outcome of those procedures. Future research should be performed to enlighten alterations in embryos derived from spermatozoa of men with MetD.

Obesity and reproduction

“…This study suggested that embryo morphokinetics may be disrupted by obesity-induced epigenetic alterations in sperm [26 ▪▪ ]. Men with metabolic disease produce embryos with poorer live birth rate potential, attributed to DNA fragmentation [22 ▪▪ ]. However, another recent prospective cohort study concluded that male obesity does not affect clinical outcomes, including fertilization, blastocyst formation, implantation or live birth rate [9 ▪▪ ].…”

“…An obesogenic environment significantly impairs male fertility in similar ways to that of the female. In men, obesity can negatively impact spermatogenesis and testosterone production through its effects on suppressing the hypothalamic pituitary axis [21,22 ▪▪ ,23]. In addition, infertile obese men often have a lower testosterone to oestradiol ratio due to an increase in aromatase activity.…”

“…The authors questioned if improved metabolic health translates to increased fecundity; however, there was an increased but not significant rate of first trimester loss in the intensive group [43 ▪ ]. In both human and animal studies, a reduction in daily calories has been correlated with normal sperm parameters [22 ▪▪ ]. Despite the discrepancies and heterogeneity among literature in obese men and women, clearly, lifestyle changes are important for long-term health.…”

“…The associated hyperinsulinemia with obesity can further metabolically inhibit spermatogenesis and cause mitochondrial DNA damage [23]. Compared with female obesity, male obesity also causes elevated proinflammatory markers, which produce reactive oxygen species leading to DNA damage [22 ▪▪ ,23]. In all, the testicular environment of obese men has a negative impact of spermatogenesis and DNA integrity.…”

Desarrollo y evaluación de la competencia gestión de la información en titulaciones técnicas: estudio de casos

“…Figura 1: Página de inicio catálogo en http://www.elementosconstructivos.codigotecnico.org En el diseño de la siguiente actividad (14) se pretenden objetivos específicos propios de la titulación tanto de Arquitectura como de Ingeniería de la Edificación, tal y como se ha definido en el párrafo anterior, como otros definidos para el desarrollo de la competencia de la gestión de la información. Dentro de estos últimos destacarán:…”