Clomiphene citrate effect in obese men with low serum testosterone treated with metformin due to dysmetabolic disorders: A randomized, double-blind, placebo-controlled study

Pharmacological management of testosterone deficiency in men current advances and future directions

INTRODUCTION

Testosterone deficiency (TD) is relatively common in aging men, affecting around 2% of the general population. Testosterone replacement therapy (TRT) represents the most common medical approach for subjects who are not interested in fathering.

AREAS COVERED

This review summarizes advances in TRT, including approved or non-approved pharmacological options to overcome TD. When possible, a meta-analytic approach was applied to minimize subjective and biased interpretations of the available data.

EXPERT OPINION

During the last decade, several new TRT formulations have been introduced on the market, including oral, transdermal, and parenteral formulations. Possible advantages and limitations have been discussed appropriately. Anti-estrogens, including selective estrogen modulators or aromatase inhibitors still represent further possible off-label options. However, long-term side effects on sexual function and bone parameters constitute major limitations. Glucagon-like peptide 1 analogues can be an alternative option in particular for massive obesity-associated TD. Weight loss obtained through lifestyle modifications including diet and physical exercise should be encouraged in all overweight and obese patients. A combination of TRT and lifestyle changes can be considered in those subjects in whom a reversal of the condition cannot be expected in a reasonable time frame.

Effect of oestrogen modulation on semen parameters in men with secondary hypogonadism: Systematic review and meta-analysis

BACKGROUND

Selective oestrogen receptor modulators and aromatase inhibitors stimulate endogenous gonadotrophins and testosterone in men with hypogonadism. There are no systematic reviews/meta-analyses assessing the effects of selective oestrogen receptor modulators/aromatase inhibitors on semen parameters in men with secondary hypogonadism.

OBJECTIVES

To assess the effect of monotherapy or a combination of selective oestrogen receptor modulators/aromatase inhibitors on sperm parameters and/or fertility in men with secondary hypogonadism.

MATERIALS AND METHODS

A systematic search was conducted in PubMed, MEDLINE, Cochrane Library and ClinicalTrials.gov. Study selection and data extraction were performed by two reviewers independently. Randomised controlled trials and non-randomised studies of interventions reporting effects of selective oestrogen receptor modulators and/or aromatase inhibitors on semen parameters or fertility in men with low testosterone with low/normal gonadotrophins were selected. The risk of bias was assessed using ROB-2 and ROBINS-I tools. The results of randomised controlled trials were summarised using vote counting while summarising effect estimates where available. Non-randomised studies of intervention meta-analysis were conducted using the random-effect model. The certainty of evidence was assessed using GRADE.

RESULTS

Five non-randomised studies of interventions (n = 105) of selective oestrogen receptor modulators showed an increase in sperm concentration (pooled mean difference 6.64 million/mL; 95% confidence interval 1.54, 11.74, I2  = 0%) and three non-randomised studies of interventions (n = 83) of selective oestrogen receptor modulators showed an increase in total motile sperm count (pooled mean difference 10.52; 95% confidence interval 1.46-19.59, I2  = 0%), with very low certainty of evidence. The mean body mass index of participants was >30 kg/m2 . Four randomised controlled trials (n = 591) comparing selective oestrogen receptor modulators to placebo showed a heterogeneous effect on sperm concentration. Three included men with overweight or obesity. The results were of very low certainty of evidence. Limited pregnancy or live birth data were available. No studies comparing aromatase inhibitors with placebo or testosterone were found.

DISCUSSION AND CONCLUSION

Current studies are of limited size and quality but suggest that selective oestrogen receptor modulators may improve semen parameters in those patients, particularly when associated with obesity.

Impact of GLP-1 Agonists on Male Reproductive Health-A Narrative Review

Background and objective-Obesity is a prevalent health concern that notably impairs male fertility through hormonal disruptions and other pathophysiological alterations. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) can significantly reduce weight. This narrative review synthesizes the existing literature discussing the impact of glucagon-like peptide-GLP-1 RAs on the male reproductive system, particularly on the hypothalamic-pituitary-gonadal axis and spermatogenesis, highlighting their potential impact on male fertility. Material and methods-PubMed database was used for the retrieval of English-language articles published up to November 2023. This non-systematic literature review predominantly concentrates on both pre-clinical and clinical studies pertaining to GLP-1 RAs, specifically exploring their impact on male reproductive hormones and sperm parameters. Results-GLP-1 receptors have been identified within the male reproductive system according to the existing literature. While the exact mechanisms are not well understood, they appear to be involved in glucose homeostasis and energy metabolism, both vital processes in spermatogenesis. Multiple clinical trials have demonstrated the efficacy of GLP-1 RAs for promoting weight loss. Recent studies show that the use of GLP-1 RAs in obese males may enhance sperm metabolism, motility, and insulin secretion in vitro, along with positive effects on the human Sertoli cells. Recent clinical trials discussed in this review demonstrate weight loss associated with GLP-1 RAs is correlated with improvements in sperm count, concentration, and motility. However, the direct impact of GLP-1 RAs on male reproductive hormones remains unclear, necessitating further research to confirm their potential role in treating male infertility. Conclusions-This narrative review summarizes the existing literature discussing the potential impact of GLP-1 RA on the male reproductive system, emphasizing their potential therapeutic role in addressing idiopathic infertility in obese men. Despite numerous studies exploring the influence of GLP-1 and GLP-1 RAs on reproductive hormones, testicular function, and spermatogenesis, further clinical trials are crucial to validate initial evidence. Longer follow-up periods are essential to address uncertainties regarding the long-term repercussions and outcomes of GLP-1 RA use. While this holds true, the current literature suggests that GLP-1RAs show promise as a potential therapeutic approach for improving sperm parameters in obese men.

Ketogenic state improves testosterone serum levels-results from a systematic review and meta-analysis

BACKGROUND

It is widely demonstrated that obesity and hypogonadism are bi-directionally correlated, since the hypogonadism prevalence is higher in obese population, while weight loss increases testosterone serum levels. Several approaches are available to contrast weight excess, from simple dietary regimens to more complex surgical procedures. Ketogenic diets (KD) fit in this context and their application is growing year after year, aiming to improve the metabolic and weight patterns in obese patients. However, KD influence on testosterone levels is still poorly investigated.

OBJECTIVES

To systematically evaluate the potential effect of KD on testosterone levels.

METHODS

A systematic literature search was performed until April 2022 including studies investigating testosterone levels before and after KD. Secondary endpoints were body weight, estradiol and sex-hormone binding globulin serum levels. Any kind of KD was considered eligible, and no specific criteria for study populations were provided.

RESULTS

Seven studies (including eight trials) were included in the analysis for a total of 230 patients, five using normocaloric KD and three very low calories KD (VLCKD). Only three studies enrolled overweight/obese men. A significant total testosterone increase was recorded after any kind of KD considering 111 patients (2.86 [0.95, 4.77], p = 0.003). This increase was more evident considering VLCKD compared to normocaloric KD (6.75 [3.31, 10.20], p < 0.001, versus 0.98 [0.08, 1.88], p = 0.030). Meta-regression analyses highlighted significant correlations between the post-KD testosterone raise with patients' age (R-squared 36.4, p < 0.001) and weight loss (R-squared 73.6, p < 0.001).

CONCLUSIONS

Comprehensively, KD improved testosterone levels depending on both patients' age and KD-induced weight loss. However, the lack of information in included studies on hormones of the hypothalamic-pituitary-gonadal axis prevents an exhaustive comprehension about mechanisms connecting ketosis and testosterone homeostasis.

Effects of treatment for diabetes mellitus on testosterone concentrations: A systematic review

BACKGROUND

Low testosterone levels are frequently present in men with obesity and insulin resistance. Currently available treatment options (testosterone replacement therapy or lifestyle changes) hold possible risks or are insufficient. Since low testosterone levels are closely related to obesity and type 2 diabetes, treatment modalities for these conditions could result into improvement of testosterone levels.

OBJECTIVES

To summarize the available evidence on the effects of traditional and recent treatment modalities for diabetes mellitus on testosterone levels and androgen-deficiency-related signs and symptoms.

MATERIALS AND METHODS

PubMed was searched from the year 2000 till present using MESH terms: "hypogonadism," "testosterone," "testosterone deficiency," "functional hypogonadism," and the different classes of medications. Studies with observational and experimental designs on humans that evaluated the effect of antidiabetic medications on gonadotropins and testosterone were eligible for inclusion.

RESULTS

Current available data show no or only limited improvement on testosterone levels with the classic antidiabetic drugs. Studies with GLP1-receptor analogues show beneficial effects on both body weight and testosterone levels in men with low testosterone levels and obesity with or without type 2 diabetes. However, data are limited to small and heterogeneous study groups and only few studies report data about impact on androgen-deficiency-related signs and symptoms.

DISCUSSION AND CONCLUSION

With the recent advances in the knowledge of the pathophysiological pathways in obesity, there is an enormous progress in the development of medications for obesity and type 2 diabetes. Newer incretin-based agents have a great potential for the treatment of functional hypogonadism due to obesity since they show promising weight reducing results. However, before the use of GLP1-receptor analogues can be suggested to treat functional hypogonadism, further studies are needed.

The role of the androgen receptor in the pathogenesis of obesity and its utility as a target for obesity treatments

Obesity is associated with hypothalamic-pituitary-testicular axis dysregulation in males. Here, we summarize recent evidence derived from clinical trials and studies in preclinical animal models regarding the role of androgen receptor (AR) signaling in the pathophysiology of males with obesity. We also discuss therapeutic strategies targeting the AR for the treatment of obesity and their limitations and provide insight into the future research necessary to advance this field.

Overall sexual function in dysmetabolic obese men with low testosterone levels treated with clomiphene citrate

BACKGROUND

Sexual disorders are the most common clinical manifestations of hypogonadism. Functional hypogonadism is the most frequent form, and clomiphene citrate (CC) has been recently introduced as a possible off-label therapeutic option for these patients.

OBJECTIVES

This study aims to evaluate the effects of CC on the overall sexual function in dysmetabolic obese men with low testosterone(T) levels.

METHODS

This was a sub-study of a randomized, double-blind, cross-over, placebo-controlled trial that included twenty-four obese or overweight subjects, with impaired glucose tolerance, or type 2 diabetes, and confirmed low total T (≤10.4 nmol/l) levels. Subjects were treated with CC or placebo (Plac) for 12 weeks, with an interval wash-out period of 6 weeks between treatments. All subjects were on metformin 2gr/day and a low-calorie diet. The between-treatment difference in the overall sexual function was assessed by IIEF-15 and a qADAM questionnaire.

RESULTS

IIEF-15 and qADAM questionnaire data were available for 18 individuals. In unadjusted analyses, CC was associated with lower IIEF-15 total, erectile function, and intercourse satisfaction domain scores than Plac. After adjustments for multiple variables, CC was associated with a higher IIEF-15 sexual desire domain score (+0.9 ± 0.8; p<.001) despite a lower qADAM score (-2.1 ± 0.9; p=.008) with respect to Plac. No differences were found for the other domains between groups.

DISCUSSION

The clinical significance of the absolute changes in IIEF-15 and qADAM scores during CC versus Plac is limited. However, CC has a reliable effect on sexual desire, and is also as safe as Plac. According to the sample size, duration of follow-up, and inclusion criteria defined for the main study, further studies are therefore needed to assess the long-term efficacy of CC.

CONCLUSION

Compared to Plac, CC was associated with a neutral effect on overall sexual function.

The Effects of Separate and Combined Treatment of Male Rats with Type 2 Diabetes with Metformin and Orthosteric and Allosteric Agonists of Luteinizing Hormone Receptor on Steroidogenesis and Spermatogenesis

In men with type 2 diabetes mellitus (T2DM), steroidogenesis and spermatogenesis are impaired. Metformin and the agonists of luteinizing hormone/human chorionic gonadotropin(hCG)-receptor (LH/hCG-R) (hCG, low-molecular-weight allosteric LH/hCG-R-agonists) can be used to restore them. The aim was to study effectiveness of separate and combined administration of metformin, hCG and 5-amino-N-tert-butyl-2-(methylsulfanyl)-4-(3-(nicotinamido)phenyl)thieno[2,3-d]pyrimidine-6-carboxamide (TP3) on steroidogenesis and spermatogenesis in male rats with T2DM. hCG (15 IU/rat/day) and TP3 (15 mg/kg/day) were injected in the last five days of five-week metformin treatment (120 mg/kg/day). Metformin improved testicular steroidogenesis and spermatogenesis and restored LH/hCG-R-expression. Compared to control, in T2DM, hCG stimulated steroidogenesis and StAR-gene expression less effectively and, after five-day administration, reduced LH/hCG-R-expression, while TP3 effects changed weaker. In co-administration of metformin and LH/hCG-R-agonists, on the first day, stimulating effects of LH/hCG-R-agonists on testosterone levels and hCG-stimulated expression of StAR- and CYP17A1-genes were increased, but on the 3-5th day, they disappeared. This was due to reduced LH/hCG-R-gene expression and increased aromatase-catalyzed estradiol production. With co-administration, LH/hCG-R-agonists did not contribute to improving spermatogenesis, induced by metformin. Thus, in T2DM, metformin and LH/hCG-R-agonists restore steroidogenesis and spermatogenesis, with metformin being more effective in restoring spermatogenesis, and their co-administration improves LH/hCG-R-agonist-stimulating testicular steroidogenesis in acute but not chronic administration.

Impact of Clomiphene Citrate on the Steroid Profile in Dysmetabolic Men with Low Testosterone Levels

Clomiphene citrate (CC) in male hypogonadism increases testosterone (T) and estrogen levels by stimulating pituitary gonadotropin release. Our group confirmed these hormonal changes in a randomized, cross-over, double-blind trial of CC versus placebo in addition to metformin, conducted in 21 obese dysmetabolic men with low T levels. However, we hypothesize that based on its mechanism of action, CC may directly or indirectly affect adrenal steroidogenesis. The aim of this sub-study was to better understand the changes in steroid levels and metabolism induced by CC treatment. We assessed 17α-hydroxypregnelone (17αOH-P5), dehydroepiandrosterone (DHEA), progesterone (P4), 17α-hydroxyprogesterone (17αOH-P4), androstenedione (A), T, dihydrotestosterone (DHT), estrone (E1), 17β-estradiol (E2), 11-deoxycortisol (11 S), cortisol (F), and cortisone (E) by LC-MS/MS, and corticosteroid binding globulin (CBG) by ELISA, before and after each treatment. In addition, free-F and steroid product/precursor ratios were calculated. We observed a significant change in serum levels induced by CC compared with placebo for 17αOH-P4, DHT, T, E2, E1, F, E, and CBG, but not free-F. In addition, compared to placebo, CC induced higher 17αOH-P4/P4, E2/E1, 17αOH-P4/17αOH-P5, A/17αOH-P4, T/A, E1/A, F/11 S, and F/E ratios. Therefore, besides the CC stimulating effect on testis steroidogenesis, our study showed increased F, E, but not free-F, levels, indicating changes in steroid metabolism rather than adrenal secretion stimulation. The steroid profiling also revealed the CC stimulation of the Δ5 rather than the Δ4 pathway, thus indicating considerable testicular involvement in the increased androgen secretion.

The Role of testosterone treatment in patients with metabolic disorders

INTRODUCTION

The specific role of testosterone [T] replacement therapy [TRT] on glycometabolic profile and body composition, particularly in patients with metabolic syndrome [MetS] and/or type 2 diabetes mellitus [T2DM], is still the object of an intense debate.

AREAS COVERED

To discuss available evidence on the association between T and metabolic diseases and on the possible effect of T administration on metabolic disorder-associated hypogonadism. Both preclinical and clinical data have been considered. In addition, a meta-analysis of the available placebo and non-placebo-controlled randomized clinical trials [RCTs] investigating the effects of TRT in T2DM or MetS in several outcomes has been also performed.

EXPERT OPINION

Data derived from preclinical and clinical studies suggest that T administration, by reducing fat mass, can improve body composition and ameliorate some aspects of glucose metabolism. The effects of TRT on sexual function in patients with established metabolic derangements are inconsistent, whereas better results were observed in preclinical conditions or in patients with newly diagnosed T2DM.

The ketogenic diet corrects metabolic hypogonadism and preserves pancreatic ß-cell function in overweight/obese men: a single-arm uncontrolled study

BACKGROUND

Overweight and obesity are increasingly spread in our society. Low testosterone levels are often present in these patients, the so-called metabolic hypogonadism, that further alters the metabolic balance in a sort of vicious cycle. Very low-calorie ketogenic diet (VLCKD) has been reported to efficiently reduce body weight, glycaemia, and the serum levels of insulin, glycated hemoglobin, but its effects on β-cell function and total testosterone (TT) levels are less clear.

AIM

To evaluate the effects of VLCKD on markers suggested to be predictive of β-cell dysfunction development, such as proinsulin or proinsulin/insulin ratio, and on TT values in a cohort of overweight or obese nondiabetic male patients with metabolic hypogonadism.

METHODS

Patients with overweight or obesity and metabolic hypogonadism underwent to VLCKD for 12 weeks. Anthropometric parameters, blood testing for the measurement of glycaemia, insulin, C-peptide, proinsulin, TT, calculation of body-mass index (BMI), and HOMA index were performed before VLCKD and after 12 weeks.

RESULTS

Twenty patients (mean age 49.3 ± 5.2 years) were enrolled. At enrollement all patients presented increased insulin, HOMA index, C-peptide, and proinsulin levels, whereas the proinsulin/insulin ratio was within the normal values. After VLCKD treatment, body weight and BMI significantly decreased, and 14.9 ± 3.9% loss of the initial body weight was achieved. Glycaemia, insulin, HOMA index, C-peptide, and proinsulin significantly decreased compared to pre-VLCKD levels. Serum glycaemia, insulin, C-peptide, and proinsulin levels returned within the normal range in all patients. No difference in the proinsulin/insulin ratio was observed after VLCKD treatment. A mean increase of 218.1 ± 53.9% in serum TT levels was achieved and none of the patients showed TT values falling in the hypogonadal range at the end of the VLCKD treatment.

CONCLUSIONS

This is the first study that evaluated the effects of VLCKD on proinsulin, proinsulin/insulin ratio, and TT levels. VLCKD could be safely used to improve β-cell secretory function and insulin-sensitivity, and to rescue overweight and obese patients from β-cell failure and metabolic hypogonadism.

Improvement Effect of Metformin on Female and Male Reproduction in Endocrine Pathologies and Its Mechanisms

Metformin (MF), a first-line drug to treat type 2 diabetes mellitus (T2DM), alone and in combination with other drugs, restores the ovarian function in women with polycystic ovary syndrome (PCOS) and improves fetal development, pregnancy outcomes and offspring health in gestational diabetes mellitus (GDM) and T2DM. MF treatment is demonstrated to improve the efficiency of in vitro fertilization and is considered a supplementary drug in assisted reproductive technologies. MF administration shows positive effect on steroidogenesis and spermatogenesis in men with metabolic disorders, thus MF treatment indicates prospective use for improvement of male reproductive functions and fertility. MF lacks teratogenic effects and has positive health effect in newborns. The review is focused on use of MF therapy for restoration of female and male reproductive functions and improvement of pregnancy outcomes in metabolic and endocrine disorders. The mechanisms of MF action are discussed, including normalization of metabolic and hormonal status in PCOS, GDM, T2DM and metabolic syndrome and restoration of functional activity and hormonal regulation of the gonadal axis.

Treatment of Men with Central Hypogonadism: Alternatives for Testosterone Replacement Therapy

Central hypogonadism is a clinical condition, characterized by sexual symptoms and low serum testosterone levels, due to an impaired function of the hypothalamus or pituitary gland. Testosterone replacement therapy (TRT) is the standard treatment for hypogonadism, but it has some disadvantages. TRT is not a good option in men wishing to preserve fertility, nor in men with (a high risk of) prostate cancer, polycythemia, thrombophilia and severe cardiovascular disease. In this review, we discuss alternative treatments for central hypogonadism. If reversible causes are present, non-pharmacological interventions can be therapeutic. Gonadotropins are a good alternative to TRT when fertility is desired in the near future though they require frequent injections. Clomiphene citrate and tamoxifen seem to be a safe alternative for the treatment of functional central hypogonadism in men, as several studies reported a significant increase in testosterone levels with these drugs. However, their use is off-label and data supporting the efficacy of clomiphene citrate and tamoxifen on hypogonadal symptoms are insufficient. For this reason, clomiphene citrate and tamoxifen should not be used in routine clinical practice to treat sexual symptoms in men with central hypogonadism.

Late-onset hypogonadism and lifestyle-related metabolic disorders

BACKGROUND

Late-onset hypogonadism (LOH) is a condition defined by low levels of testosterone (T), occurring in advanced age. LOH is promoted by senescence, which, in turn, has negative effects on male fertility. Interestingly, the impact of metabolic disorders on the male reproductive system has been the topic of several studies, but the association with LOH is still debatable.

OBJECTIVES

Herein, we discuss the hypothesis that the prevalence of metabolic abnormalities potentiates the effects of LOH on the male reproductive system, affecting the reproductive potential of those individuals.

MATERIAL AND METHODS

We analyzed the bibliography available, until June 2019, about LOH in relation to metabolic and hormonal dysregulation, sperm quality profiles and assisted-reproduction treatment outcomes.

RESULTS

LOH affects the hypothalamic-pituitary testis (HPT) axis. Additionally, metabolic disorders can also induce T deficiency, which is reflected in decreased male fertility, highlighting a possible connection. Indeed, T replacement therapy (TRT) is widely used to restore T levels. Although this therapy is unable to reverse all deleterious effects promoted by LOH on male reproductive function, it can improve metabolic and reproductive health.

DISCUSSION AND CONCLUSIONS

Emerging new evidence suggests that metabolic disorders may aggravate LOH effects on the fertility potential of males in reproductive age, by enhancing T deficiency. These results clearly show that metabolic disorders, such as obesity and diabetes, have a greater impact on causing hypogonadotropic hypogonadism than tissue senescence. Further, TRT and off-label alternatives capable of restoring T levels appear as suitable to improve LOH, while also counteracting comorbidities related with metabolic diseases.

Effect of clomiphene citrate treatment on the Sertoli cells of dysmetabolic obese men with low testosterone levels

BACKGROUND

Clomiphene citrate (CC) has been shown to restore the hypothalamic-pituitary-gonadal (HPG) axis by increasing testosterone (T) levels to physiological levels in patients with dysmetabolic conditions such as obesity, metabolic syndrome and type 2 diabetes mellitus (T2DM). However, the data are unclear regarding the effects on Sertoli cell (SC) function.

AIM

To study SC function by assessing Inhibin B (IB) and anti-Mullerian hormone (AMH) levels at baseline and after 3 months of CC treatment.

MATERIALS AND METHODS

This is an ancillary study of a cross-over, randomised, double-blind, placebo-controlled trial performed to evaluate androgen response to CC treatment in dysmetabolic obese subjects with low T levels treated with metformin. We evaluated SC function by assessing IB and AMH levels at baseline and after 3 months of each treatment in ten dysmetabolic obese subjects with low T levels. In all subjects, the influence of the clinical characteristics, metabolic and hormonal baseline parameters on SC and Leydig (LC) function, evaluated respectively with AMH, IB, follicle-stimulating hormone (FSH) and T levels, was tested.

RESULTS

No significant changes were observed for IB and AMH concentrations after each treatment period. Whereas T and oestradiol (E2) levels were shown to be significantly higher in the CC plus metformin phase (CC/Met) only. No clinical, metabolic or hormonal parameters showed significant effects on serum AMH at baseline or after treatments. However, baseline T, dihydrotestosterone (DHT) and E2 positively affected IB levels during CC/Met therapy (P = .003, P = .038 and P = .049, respectively). Baseline leptin and FSH had a negative (P = 031) and positive (P = .048) respectively role on T levels during CC/Met, as they were statistically significant compared to the placebo period (Plac/Met).

CONCLUSION

Unlike the LC activity, CC was unable to influence SC function, as shown by the lack of IB and AMH serum modifications, thus suggesting an intrinsic nonreversible defect of SC cells in patients with dysmetabolic conditions.

Is There Room for SERMs or SARMs as Alternative Therapies for Adult Male Hypogonadism?

Hypogonadotropic hypogonadism (HH) can be sustained by organic or functional alterations of the hypothalamic-pituitary-testicular axis. Functional HH is related to systemic alterations, such as obesity or chronic inflammatory diseases, but could contribute to a negative course of the illness. For such situation, according to results obtained in infertile women, the administration of selective estrogen receptor modulators (SERMs) has been proposed in males too, with positive results on both metabolic and sexual function. This class of medications increases gonadotropin levels via antagonism to the estrogenic receptor; similar biological effects are also exerted by aromatase inhibitors (AIs), despite different mechanism of action. After a brief review of trials regarding SERMs and AIs use in male HH, we describe the structure and function of the androgen receptor (AR) as a basis for clinical research about compounds able to bind to AR, in order to obtain specific effects (SARMs). The tissue selectivity and different metabolic fate in comparison to testosterone can potentiate anabolic versus androgenic effects; therefore, they might be a valid alternative to testosterone replacement therapy avoiding the negative effects of testosterone (i.e., on prostate, liver, and hematopoiesis). Trials are still at an early phase of investigation and, at the moment, the application seems to be more useful for chronic disease with catabolic status while the validation as replacement for hypogonadism requires further studies.

The Interplay Between Pituitary Health and Diabetes Mellitus - The Need for 'Hypophyseo-Vigilance'

The anterior and posterior hypophyseal hormones alter glucose metabolism in health and disease. Secondary diabetes may occur due to hypersecretion of anterior pituitary hormones like adrenocorticotrophic hormone in Cushing's disease and growth hormone in acromegaly. Other hormones like prolactin, gonadotropins, oxytocin and vasopressin, though not overtly associated with causation of diabetes, have important physiological role in maintaining glucose homeostasis. Hypoglycaemia is not an unusual occurrence in hypopituitarism. Many of the medications that are used for treatment of hypophyseal diseases alter glucose metabolism. Agents like pasireotide should be used with caution in the setting of diabetes, whereas pegvisomant should be given preference. Diabetes mellitus itself, on the other hand, can alter the functioning of hypothalamic pituitary axis; this is documented in both type 1 and type 2 diabetes. This review focuses on the clinically relevant interplay of hypophyseal hormones and glucose homeostasis. The authors define 'hypophyseo-vigilance' as an approach which keeps the bidirectional, multifaceted interactions between the pituitary and glucose metabolism in mind while managing diabetes and pituitary disease.

Aging and the Male Reproductive System

This narrative review presents an overview of current knowledge on fertility and reproductive hormone changes in aging men, the factors driving and modulating these changes, their clinical consequences, and the benefits and risks of testosterone (T) therapy. Aging is accompanied by moderate decline of gamete quality and fertility. Population mean levels show a mild total T decline, an SHBG increase, a steeper free T decline, and a moderate LH increase with important contribution of comorbidities (e.g., obesity) to these changes. Sexual symptoms and lower hematocrit are associated with low T and are partly responsive to T therapy. The relationship of serum T with body composition and metabolic health is bidirectional; limited beneficial effects of T therapy on body composition have only marginal effects on metabolic health and physical function. Skeletal changes are associated primarily with estradiol and SHBG. Cognitive decline is not consistently linked to low T and is not improved by T therapy. Although limited evidence links moderate androgen decline with depressive symptoms, T therapy has small beneficial effects on mood, depressive symptoms, and vitality in elderly patients with low T. Suboptimal T (and/or DHT) has been associated with increased risk of stroke, but not of ischemic heart disease, whereas an association with mortality probably reflects that low T is a marker of poor health. Globally, neither severity of clinical consequences attributable to low T nor the nature and magnitude of beneficial treatment effects justify the concept of some broadly applied "T replacement therapy" in older men with low T. Moreover, long-term safety of T therapy is not established.

Sex hormones, obesity and type 2 diabetes: is there a link?

An imbalance in sex hormones has an important impact on type 2 diabetes (T2DM) mainly through the involvement of visceral adipose tissue. Androgens have an interesting sex-dimorphic association with T2DM, since hyperandrogenism in females and hypogonadism in males are risk factors for T2DM. Thus, treatments aimed at correcting hyperandrogenism in females and hypogonadism in males may prevent the development of T2DM or help in its treatment.

Testosterone Is a Contraceptive and Should Not Be Used in Men Who Desire Fertility

Testosterone has a variety of functions and is commonly used in older men to treat symptoms of hypogonadism, such as decreased libido, decreased mood and erectile dysfunction. Despite its positive effects on sexual function, it has a negative effect on fertility. Exogenous testosterone therapy can negatively affect the hypothalamic-pituitary gonadal axis and inhibit the production of follicle stimulating hormone and luteinizing hormone. The purpose of this review is to discuss the contraceptive properties of testosterone therapy and to discuss strategies to increase testosterone in men with the desire to preserve fertility.

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.

Effects of clomiphene citrate on male obesity-associated hypogonadism: a randomized, double-blind, placebo-controlled study

BACKGROUND

Obesity causes secondary hypogonadism (HG) in men. Standard testosterone (T) replacement therapy improves metabolic parameters but leads to infertility.

OBJECTIVE

To evaluate clomiphene citrate (CC) treatment of adult men with male obesity-associated secondary hypogonadism (MOSH).

DESIGN

Single-center, randomized, double-blind, placebo-controlled trial.

PARTICIPANTS

Seventy-eight men aged 36.5 ± 7.8 years with a body mass index (BMI) > 30 kg/m², total testosterone (TT) ≤ 300 ng/dL, and symptoms in the ADAM questionnaire.

INTERVENTION

Random allocation to receive 50 mg CC or placebo (PLB) for 12 weeks.

OUTCOMES

(1) Clinical features: ADAM and sexual behavior questionnaires; (2) hormonal profile: serum TT, free T, estradiol (E2), luteinizing hormone (LH), follicle-stimulating hormone (FSH), and sex hormone-binding globulin (SHBG); (3) body composition: BMI, waist circumference, and bioelectric impedance analysis; (4) metabolic profile: blood pressure, fasting blood glucose, HbA1c, insulin, HOMA-IR, and lipid profile; (5) endothelial function: flow-mediated dilation of the brachial artery, quantitative assessment of endothelial progenitor cells and serum sICAM-1, sVCAM-1, and selectin-sE levels; (6) safety aspects: hematocrit, serum prostate-specific antigen, International Prostate Symptom Score, and self-reported adverse effects.

RESULTS

There was an improvement in one sexual complaint (weaker erections; P < 0.001); increases (P < 0.001) in TT, free T, E2, LH, FSH, and SHBG; and improvements in lean mass (P < 0.001), fat-free mass (P = 0.004), and muscle mass (P < 0.001) in the CC group. CC reduced HDL (P < 0.001). No statistically significant differences were seen in endothelial function.

CONCLUSIONS

CC appeared to effectively improve the hormonal profile and body composition. CC may be an alternative treatment for MOSH in adult men.