Male gonadal dysfunction

Smoking and obesity negatively affect the favourable outcome of varicocelectomy in sub-fertile men

We assessed the effect of smoking and/or obesity on semen parameters and testosterone/oestradiol (T/E) ratio among sub-fertile men treated with sub-inguinal varicocelectomy. In this prospective, controlled, clinical study, 80 sub-fertile men with clinical varicocele who were subjected to sub-inguinal varicocelectomy were assigned into four equal groups (n = 20/each), group A: obese and smokers, group B: obese and nonsmokers, group C: smokers and nonobese and group D: nonsmokers and nonobese. Semen parameters, serum testosterone, oestradiol, follicle-stimulating hormone, luteinising hormone, prolactin and calculation of T/E ratio were assessed at baseline and 6 months post-varicocelectomy. The mean age ± SD of the study population was 26.1 ± 4.55. No statistical difference was detected among the study groups regarding age, residence, education, marital status and occupation (p > 0.05 for each). Post-operatively, significant improvements in semen parameters were detected in all groups. There was a significant difference between groups A and B versus C and D (obese versus nonobese groups) and between groups A and C versus B and D (smokers versus nonsmokers; p < 0.05 for each) regarding semen parameters, testosterone level and T/E ratio. Smoking and/or obesity negatively affect(s) the favourable outcome of varicocelectomy, specifically improvement of semen parameters and hormonal pattern in sub-fertile men with varicocele.

Reproductive Endocrinology of Nonalcoholic Fatty Liver Disease

The liver and the reproductive system interact in a multifaceted bidirectional fashion. Sex steroid signaling influences hepatic endobiotic and xenobiotic metabolism and contributes to the pathogenesis of functional and structural disorders of the liver. In turn, liver function affects the reproductive axis via modulating sex steroid metabolism and transport to tissues via sex hormone-binding globulin (SHBG). The liver senses the body's metabolic status and adapts its energy homeostasis in a sex-dependent fashion, a dimorphism signaled by the sex steroid milieu and possibly related to the metabolic costs of reproduction. Sex steroids impact the pathogenesis of nonalcoholic fatty liver disease, including development of hepatic steatosis, fibrosis, and carcinogenesis. Preclinical studies in male rodents demonstrate that androgens protect against hepatic steatosis and insulin resistance both via androgen receptor signaling and, following aromatization to estradiol, estrogen receptor signaling, through regulating genes involved in hepatic lipogenesis and glucose metabolism. In female rodents in contrast to males, androgens promote hepatic steatosis and dysglycemia, whereas estradiol is similarly protective against liver disease. In men, hepatic steatosis is associated with modest reductions in circulating testosterone, in part consequent to a reduction in circulating SHBG. Testosterone treatment has not been demonstrated to improve hepatic steatosis in randomized controlled clinical trials. Consistent with sex-dimorphic preclinical findings, androgens promote hepatic steatosis and dysglycemia in women, whereas endogenous estradiol appears protective in both men and women. In both sexes, androgens promote hepatic fibrosis and the development of hepatocellular carcinoma, whereas estradiol is protective.

Dietary trans and saturated fatty acids effects on semen quality, hormonal levels and expression of genes related to steroid metabolism in mouse adipose tissue

Our objectives were to assess sperm alteration and adipose tissue (AT) genes expression related to steroid metabolism subsequent to fatty acids consumption. Twenty-nine mature male mice were divided into: fat diet (FD; n = 15) and the control group (n = 14). FD group was fed with low level of trans and saturated fatty acids source for 60 days. Sperm parameters, levels of hormones and the mRNA abundance of the target genes in AT were assessed. The sperm concentration, total and progressive motilities were lower in FD group compared to that of control (p < 0.01). Blood estradiol levels increased in FD (p < 0.001), whereas no significant difference was observed in testosterone. The mRNA levels of StAR, CYP11A1, CYP17A1, 17βHSD7 and 17βHSD12 in AT of FD were higher than those of the control (p < 0.05). In contrast, mRNA level of Cyp19a1 in FD was significantly (p < 0.05) lower than that of control. 17βHSD12 and 17βHSD7 (as oestrogenic genes) increased, while 17βHSD5 and 17βHSD3 (as androgenic genes) remained unchanged, indicating that dietary trans/saturated fatty acids affect AT genes expression. Probably, sperm parameters were altered by increment of expression level of genes involved in oestrogenic metabolism rather than those engaged in androgenic metabolism after fatty acids consumption.

Hypogonadism and male obesity: Focus on unresolved questions

Obesity, increasing in prevalence globally, is the clinical condition most strongly associated with lowered testosterone concentrations in men and presents as one of the strongest predictors of receiving testosterone treatment. While low circulating total testosterone concentrations in modest obesity primarily reflect reduced concentrations of sex hormone binding globulin, more marked obesity can lead to genuine hypothalamic-pituitary-testicular axis (HPT) suppression. HPT axis suppression is likely mediated via pro-inflammatory cytokine and dysregulated leptin signalling and aggravated by associated comorbidities. Whether oestradiol-mediated negative hypothalamic-pituitary feedback plays a pathogenic role requires further study. Although the obesity-hypogonadism relationship is bidirectional, the effects of obesity on testosterone concentrations are more substantial than the effects of testosterone on adiposity. In markedly obese men submitted to bariatric surgery, substantial weight loss is very effective in reactivating the HPT axis. In contrast, lifestyle measures are less effective in reducing weight and generally only associated with modest increases in circulating testosterone. In randomized controlled clinical trials (RCTs), testosterone treatment does not reduce body weight, but modestly reduces fat mass and increases muscle mass. Short-term studies have shown that testosterone treatment in carefully selected obese men may have modest benefits on symptoms of androgen deficiency and body composition even additive to diet alone. However, longer term, larger RCTs designed for patient-important outcomes and potential risks are required. Until such trials are available, testosterone treatment cannot be routinely recommended for men with obesity-associated nonclassical hypogonadism. Lifestyle measures or where indicated bariatric surgery to achieve weight loss, and optimization of comorbidities remain first line.

Male obesity and subfertility, is it really about increased adiposity?

The prevalence of overweight and obesity in reproductive-aged men is increasing worldwide, with >70% of men >18 years classified as overweight or obese in some western nations. Male obesity is associated with male subfertility, impairing sex hormones, reducing sperm counts, increasing oxidative sperm DNA damage and changing the epigenetic status of sperm. These changes to sperm function as a result of obesity, are further associated with impaired embryo development, reduced live birth rates and increased miscarriage rates in humans. Animal models have suggested that these adverse reproductive effects can be transmitted to the offspring; suggesting that men's health at conception may affect the health of their children. In addition to higher adiposity, male obesity is associated with comorbidities, including metabolic syndrome, hypercholesterolemia, hyperleptinemia and a pro-inflammatory state, all which have independently been linked with male subfertility. Taken together, these findings suggest that the effects of male obesity on fertility are likely multifactorial, with associated comorbidities also influencing sperm, pregnancy and subsequent child health.

Impact of obesity on male fertility, sperm function and molecular composition

Male obesity in reproductive-age men has nearly tripled in the past 30 y and coincides with an increase in male infertility worldwide. There is now emerging evidence that male obesity impacts negatively on male reproductive potential not only reducing sperm quality, but in particular altering the physical and molecular structure of germ cells in the testes and ultimately mature sperm. Recent data has shown that male obesity also impairs offspring metabolic and reproductive health suggesting that paternal health cues are transmitted to the next generation with the mediator mostly likely occurring via the sperm. Interestingly the molecular profile of germ cells in the testes and sperm from obese males is altered with changes to epigenetic modifiers. The increasing prevalence of male obesity calls for better public health awareness at the time of conception, with a better understanding of the molecular mechanism involved during spermatogenesis required along with the potential of interventions in reversing these deleterious effects. This review will focus on how male obesity affects fertility and sperm quality with a focus on proposed mechanisms and the potential reversibility of these adverse effects.

Male sexual function and its disorders: physiology, pathophysiology, clinical investigation, and treatment

This review is designed to help the reproductive endocrinologist integrate his or her professional activity with those of other disciplines including urology, radiology, neurology, and psychology in order to successfully manage all of the inseparable aspects of male sexual and reproductive functioning. Significant advances in the field of male sexual physiology and pathophysiology and new methods of investigation and treatment of male sexual disorders are outlined. The review synthesizes available data on the following: norms of sexual organs, aging and sexuality, role of central and peripheral neurochemicals in each stage of the sexual cycle, role of corporeal smooth muscles in the hemodynamic control of erection and detumescence, influence of psychological factors, drugs, and disease on all aspects of sexual functioning, and use of nocturnal penile tumescence monitoring, imaging investigations, and neurophysiologic studies in the diagnostic workup of males with sexual dysfunction. Clinical algorithms are presented where appropriate. Extensive discussions on newly developed strategies in psychological and behavioral counseling, drug therapy, tissue engineering, nonsurgical devices, and surgical treatments for all forms of sexual disorders are also provided. Lastly, the effect of sexual dysfunction and its treatment on quality of life in affected men is addressed, along with recommendations for future research endeavors.

Evaluation of testicular function

The evaluation of testicular function is based primarily on a detailed medical history, a careful physical examination, basal measurements of FSH, LH and testosterone and a routine semen analysis. In a patient with androgen deficiency, the diagnosis can often be made with these basic tests. The clinician will then decide on other investigations to localize the organic lesion and to plan further treatment for the patient. Sperm function tests are often performed in patients presenting with infertility. These newer tests may help to delineate the abnormality of the spermatozoa at each stage during the achievement of fertilizing capacity such as adequate forward motility, penetration of cervical mucus, acrosome reaction, development of hyperactivated motility, binding to the zona pellucida, and fusion with the oocyte. Currently, many of these sperm function tests depend on cumbersome bioassays with many limiting factors contributing to their availability, accuracy and precision. The development of biochemical tests as markers of sperm function may allow more precise definition of sperm functional abnormalities. With the continued improvement of computer-aided sperm analysis, objective motion parameter measurements are possible and morphological assessment are being developed. These newer objective methods of semen analysis have to be shown to be valuable in the clinical assessment of patients with testicular dysfunction.

Sex hormone binding globulin: origin, function and clinical significance

Sex hormone binding globulin (SHBG) is a glycoprotein possessing high affinity binding for 17 beta-hydroxysteriod hormones such as testosterone and oestradiol. It is probably synthesized in the liver, plasma concentrations being regulated by, amongst other things, androgen/oestrogen balance, thyroid hormones, insulin and dietary factors, it is involved in transport of sex steroids in plasma and its concentration is a major factor regulating their distribution between the protein-bound and free states. Its detailed role in the delivery of hormones to target tissues is not yet clear. Plasma SHBG concentrations are affected by a number of different diseases, high values being found in hyperthyroidism, hypogonadism, androgen insensitivity and hepatic cirrhosis in men. Low concentrations are found in myxoedema, hyperprolactinaemia and syndromes of excessive androgen activity. Concentrations are also affected by drugs such as androgens, oestrogens, thyroid hormones and anti-convulsants. Measurement of SHBG is useful in the evaluation of mild disorders of androgen metabolism and enables identification of those women with hirsutism who are more likely to respond to oestrogen therapy. Testosterone:SHBG ratios correlate well with both measured and calculated values of free testosterone and help to discriminate subjects with excessive androgen activity from normal individuals.

Testicular atrophy in AIDS: a study of 57 autopsy cases

The pertinent clinical data and histologic features of the testes in 57 autopsied acquired immunodeficiency syndrome (AIDS) patients were analyzed and compared with those of 55 age-matched control patients without AIDS. The testes of the AIDS patients showed a significantly lower degree of spermatogenesis (determined by a testicular score count), as well as more prominent thickening of the basement membrane and interstitial fibrosis when compared with the controls. While the precise cause of testicular atrophy in AIDS patients remains to be determined, the chronicity of the disease, prolonged fever, malnutrition, testicular infection, and chemotherapy are all contributing factors. Since the vast majority of the studied AIDS patients were homosexual and most control patients were heterosexual, the observed testicular changes can be ascribed to AIDS and/or homosexuality. Because of a high prevalence of sexually transmitted diseases, antisperm antibodies, and possible zinc deficiency and endocrine disorders, homosexual men appear predisposed to tubular atrophy. Conversely, AIDS-related factors, such as a direct toxic effect of the human immunodeficiency virus on germinal epithelium or as yet undetermined endocrine imbalances might exert a detrimental effect on the testis independent of homosexuality.

Endocrine evaluation in the assessment of male reproductive hazards

Male reproductive function requires the integrated functioning of the hypothalamus, pituitary, and testis. The disturbance of endocrine function at any of these levels may result in hypogonadism and infertility. The clinical and laboratory evaluation of these disorders is reviewed here.