Effect of Bariatric Surgery on Male Infertility: An Updated Meta-Analysis and Literature Review

PURPOSE

We aimed to perform a meta-analysis to assess the evolution of sperm parameters and some sex hormones in obese males with idiopathic infertility who underwent bariatric surgery.

MATERIALS AND METHODS

We systematically searched MEDLINE and Embase databases for studies that documented sperm parameters and sex hormones before and after surgery.

RESULTS

Twelve studies have been included with a total of 285 patients. The heterogeneity was deemed moderate, with an I² value of 28%. The random effects model analysis indicated a statistically significant negative association between weight loss surgery and sperm concentration. The standardized mean difference (SMD) was -5.44, with a 95% confidence interval (CI) ranging from -7.65 to -3.22. The p-value was <0.0001. Twelve articles recorded the sperm volume before and after undergoing bariatric surgery. The analysis revealed no statistically significant alteration in sperm volume following surgery (SMD=-0.16, 95% CI -0.53-0.22; p=0.42). We assessed the total sperm count available in seven studies. The analysis did not prove any significant difference between groups (SMD=12.29, 95% CI -15.01-39.58; p=0.38). Evaluated in five studies, semen pH did not evolve significantly (SMD=-0.02, 95% CI -0.12-0.09; p=0.76). Also, total motility did not improve significantly (SMD=0.61, CI -2.86-4.09; p=0.73), and the included studies had a low heterogeneity (I²=29%). Following bariatric surgery, there was a significant increase in levels of both total testosterone and sex hormone-binding globulin (SHBG) (SMD=-6.40, 95% CI -9.12 to -3.67, p<0.00001 for total testosterone and -22.22, 95% CI -26.11 to -18.33, p<0.00001 for SHBG).

CONCLUSIONS

Our data suggests that bariatric surgery does not provide any benefits in terms of sperm parameters. Obesity likely affects fertility through processes that are not well understood.

Effect of laparoscopic sleeve gastrectomy on male reproductive function in Chinese men with obesity: a prospective cohort study

BACKGROUND

Obesity is a widely recognized global public health issue, and bariatric surgery has emerged as an effective intervention for alleviating obesity associated health complications. However, the impact of bariatric surgery on male reproductive function remains inconclusive in the literature. The current understanding of the impact of laparoscopic sleeve gastrectomy (LSG) on male reproductive function remains ambiguous, despite its status as the most commonly performed bariatric surgery. This prospective cohort study aimed to investigate the impact of LSG on erectile function and semen quality.

PATIENTS AND METHODS

A total of 34 obese patients were enrolled in this study and underwent LSG. Prior to the operation and at 3, 6, and 12 months postoperation, all participants were required to complete the International Index of Erectile Function-5 (IIEF-5) questionnaire and undergo a nocturnal erectile function test and semen quality analysis.

RESULTS

Within 12 months postoperation, BMI, blood lipids, and insulin resistance showed significant improvement. The IIEF-5 score increased significantly (18.88±5.97 vs. 23.78±3.19, P <0.05), and the frequency and duration of erections significantly improved compared to baseline. Sperm concentration, total motility, survival rate, and sperm morphology parameters exhibited a significant decline at 3 months but demonstrated a significant improvement at 6 and 12 months postoperation. At 12 months, sperm concentration was shown to be correlated with changes in zinc (r=0.25, P =0.033) as well as changes in testosterone (r=0.43, P =0.013).

CONCLUSIONS

LSG has beneficial effects on erectile function, despite a transient decline in semen quality at 3 months postoperatively, followed by a significant improvement at 12 months.

Di-(2-ethylhexyl) phthalate exacerbates abnormalities of testicular development in F1 males via inhibition the Wnt/β-catenin signaling pathway

The theory of "Developmental Origins of Health and Disease (DOHaD)" espouses that environmental exposures to toxicants during critical developmental stages can affect health outcomes in adulthood. Di (2-ethylhexyl) phthalate (DEHP) is a plasticizer that can be transferred to developing organisms via the placenta and breast milk as an environmental endocrine disruptor. We herein implemented a cross-fostering model to decipher the contributions of prenatal vs. postnatal exposure to low or high dose DEHP (30 or 500 mg/kg-bw•d) on reproductive outcomes in male offspring and the underlying mechanism of action. Unexpectedly, we observed that postnatal DEHP exposure programmed weight gain in a dose-dependent manner, in-utero exposure to high dose DEHP appeared to constitute a significant factor in the weight loss of male offspring. Moreover, in the low dose group, offspring of control that were suckled by DEHP dams (CC-DE) generated a considerable number of adverse reproductive outcomes compared with the offspring of DEHP that were suckled by control dams (DE-CC), based on histopathologic alterations in the testis, blockage of sex hormone secretion, and transcriptional inhibition of steroid-hormone-related factors in the hypothalamic-pituitary-testicular (HPT) axis. However, DE-CC group affected reproductive dysfunction in male offspring more so than CC-DE in the high dose group. Mechanistically, DEHP contributed to the inhibition of steroidogenesis by perturbing the Wnt/β-catenin-signaling pathway. These studies confirm the sensitivity window in which future reproductive outcomes in offspring are influenced following developmental exposure to DEHP at two different dosages, and reveals a critical role for the Wnt/β-catenin signaling pathway in DEHP-induced male reproductive disorders.

[Impact of lifestyle and environmental factors on male reproductive health]

The identification of potential environmental hazards is of clinical relevance for the diagnosis of male infertility. Knowledge about these factors will improve prevention of fertility disorders. Apart from drugs or factors related to lifestyle such as alcohol and tobacco smoke, various environmental and occupational agents, both chemical and physical, may impair male reproduction. Reproductive toxicity may evolve at the hypothalamic-pituitary, testicular, or posttesticular level; endpoints comprise deterioration of spermatogenesis and sperm function as well as endocrine disorders and sexual dysfunction. However, due to the complex regulation of the male reproductive system, information regarding single exogenous factors and their mechanisms of action in humans is limited. This is also due to the fact that extrapolation of results obtained from experimental animal or in vitro studies remains difficult. Nevertheless, the assessment of relevant exposures to reproductive toxicants should be carefully evaluated during diagnostic procedures of andrological patients.