Therapeutics · Hormonal Agents
Foresta C, Caretta N, Rossato M, Garolla A, Ferlin A
Erectile response in mammals is centrally and peripherally regulated by androgens. Severe hypogonadism in men usually results in loss of libido and potency. The present studies were designed to evaluate the possible influence of circulating androgens in the regulation of sexual function.
A total of 15 men with severe hypogonadism (testosterone less than 2.0 ng/ml) were recruited. The control group consisted of 20 patients with psychogenic erectile dysfunction. All subjects underwent nocturnal penile tumescence (NPT) and rigidity monitoring during 2 consecutive nights, evaluation of cavernous artery flow using penile color duplex ultrasound (P-CDU), and real-time visually stimulated erection evaluation at baseline and after administration of 50 mg sildenafil or 3 mg apomorphine. NPT, P-CDU and visually stimulated erection were evaluated after 6 months of therapy with a 5 mg daily testosterone patch.
NPT analysis in subjects with severe hypogonadism showed a significant decrease in sleep related erections. P-CDU showed a partial erectile response with an alteration of the parameters analyzed, and the visually stimulated erections test was pathological. Administration of 3 mg apomorphine and 50 mg sildenafil has no influence on erectile function. Testosterone treatment for 6 months induced normalization of NPT and P-CDU parameters, and of visually stimulated erection effects with the restoration of a normal response to pharmacological stimulation with apomorphine or sildenafil.
Our results show that testosterone has a key role in the central and peripheral modulation of erectile function even if the accurate testosterone plasma level threshold that may influence these processes remains to be established.
Mazzilli R et al., 2026 · Journal of endocrinological investigation
Male factor could contribute, alone or in combination with female factor, to the inability to conceive in a couple in more than half of cases. The effect of male factor infertility (MFI) on embryological assisted reproductive technology (ART) outcomes remains an ongoing discussion. to evaluate the impact of MFI on embryo aneuploidy rates, to better understand the role and possible indication for Preimplantation genetic testing for aneuploidies (PGT-A), considering the role of sperm characteristics, paternal age, sperm DNA fragmentation and sperm aneuploidies. this narrative review included all available articles, published up to January 2026. Available evidence, often based on heterogeneous and old-fashioned methodologies, suggests that MFI may impair embryonic development, particularly in terms of fertilization rate and blastulation rate, more than embryo euploidy; however, a comprehensive evaluation of MFI should be integrated into clinical practice in the context of couple infertility, to also optimize the efficiency and outcomes of ART. Promising results emerged from sperm DNA fragmentation as a tool to predict embryo euploidy, but further investigations involving larger sample sizes and improved standardization are required.
Grande G et al., 2026 · The Journal of clinical endocrinology and metabolism · Free to read
Male factor infertility (MFI) is frequently labelled idiopathic when evaluation relies primarily on semen analysis, potentially overlooking endocrine and pathophysiological mechanisms relevant for targeted management. To phenotypically define MFI and develop a pathophysiology-based classification aimed at reducing idiopathic infertility following comprehensive evaluation. Prospective monocentric cohort study conducted at a tertiary referral academic centre. Eight hundred male partners of infertile couples evaluated between October 2024 and January 2026 after exclusion of isolated female factor infertility. Prevalence of MFI categories, hormonal patterns across phenotypes, and proportion of idiopathic infertility after comprehensive work-up. All patients underwent standardized clinical evaluation, hormonal assessment (total testosterone, FSH, LH), testicular ultrasound, and complete semen analysis. Microbiological testing, transrectal ultrasound, and genetic analyses were performed according to guidelines. Primary spermatogenic failure was the most prevalent category (56.0%), followed by infection/inflammation (22.4%) and hypogonadotropic hypogonadism (8.5%). Idiopathic infertility was identified in only 5.3% of cases. Distinct endocrine profiles were observed, with high-FSH spermatogenic failure representing the dominant phenotype. Comprehensive phenotyping markedly reduces the proportion of patients classified as having idiopathic infertility and identifies clinically relevant subgroups. This prospective study provides validation of a pathophysiology-based classification and supports a shift toward endocrine-integrated diagnostic strategies in male infertility, with potential implications for targeted management.
Ponce MR et al., 2026 · Andrology · Free full text on PubMed Central
Transgender individuals assigned male at birth (AMAB) may choose to preserve their fertility prior to starting gender-affirming hormone therapy (GAHT). However, limited data exist regarding the baseline reproductive and hormonal characteristics of this population before and after GAHT. To characterize semen quality and hormonal profiles in transgender AMAB individuals prior to GAHT and compare findings with cisgender men and with transgender individuals who discontinued GAHT for at least 3 months. This retrospective study included transgender AMAB individuals from two tertiary andrology centers who underwent sperm cryopreservation before GAHT initiation (treatment-naïve group). Clinical evaluation included anthropometric measures, testicular volume assessment, varicocele detection, and sex hormone measures. Semen parameters were analyzed according to WHO criteria and compared with those of cisgender men and previously treated transgender individuals. Thirty-two treatment-naïve transgender AMAB individuals were included. Hormonal parameters were generally within reference ranges. Only 46.9% of treatment-naïve individuals met WHO criteria for normozoospermia, compared with 75.5% of cisgender controls. Compared with nine previously treated individuals, estradiol levels were higher and seminal volume lower. A higher frequency of seminal abnormalities was observed, although not statistically significant. A substantial proportion of treatment-naïve transgender AMAB individuals exhibited impaired semen parameters prior to GAHT initiation. Prior GAHT exposure showed a trend toward poorer semen quality. These findings support early fertility counseling and preservation in transgender individuals prior to GAHT initiation.
Graziani A et al., 2026 · Andrology · Free to read
Besides gonadal involvement (hypogonadism, male factor infertility, and testicular hypotrophy), patients with Klinefelter syndrome (KS) may suffer from several extra-gonadic complications, including neoplastic events. The aim of this review is to summarize all major clinical evidence dealing with the association between KS and neoplastic diseases and provide practical suggestions for the management of patients with KS regarding neoplastic risk. This narrative review was conducted through a comprehensive search of the PubMed database, using combinations of the following keywords: "Klinefelter syndrome," "cancer," "neoplasm," "breast cancer," "germ cell tumor," "lymphoma," and "testosterone replacement therapy". KS is associated with a higher risk of breast cancer and mediastinal germ cell tumors and an apparent higher risk of hematological malignancies, in particular non-Hodgkin lymphoma and leukemia. Evidence on testicular cancer is limited, with no clear increase in risk attributable to KS, while prostate cancer has a lower risk and lower mortality rate. Given the complexity of the syndrome and the limited available evidence, regular clinical follow-up with targeted investigations when clinically indicated may facilitate early diagnosis and management of associated comorbidities.
Caretta N et al., 2005 · Journal of endocrinological investigation
Aging in men is accompanied by a decrease in libido and sexual activity. Recently, it has been demonstrated that a significant proportion of men >60 yr of age has biochemical hypogonadism. Hypoandrogenism, which is associated with other conditions that negatively influence erectile activity, may be an important cofactor in the induction of erectile dysfunction and in the response to phosphodiesterase type 5 (PDE5) inhibitors in aging. In these patients, administration of 50 mg sildenafil or 3 mg apomorphine has no influence on erectile function. Recently we showed that, in hypogonadal subjects, testosterone treatment might stimulate endothelial and neuronal production of vasoactive substances like nitric oxide (NO). Furthermore it can improve endothelial repair mechanisms by increasing bone marrow-derived endothelial progenitor cell (EPC) number in the peripheral circulation. Finally, the normal response to pharmacological stimulation with apomorphine or sildenafil, observed in hypogonadal men treated with testosterone, indicates a positive role of this hormone in the central and peripheral control of erection, confirming the possible positive influence on endothelial function and PDE5 expression. Therefore, we suggest measuring plasma testosterone levels in aged men with erectile dysfunction and recommend treating them barring clinical contraindications. Testosterone plus PDE5 inhibitors may be beneficial in improving erectile function in hypogonadal men with erectile dysfunction who were unresponsive to PDE5 inhibitors alone.
Grande G et al., 2023 · Frontiers in endocrinology · Free full text on PubMed Central
Metabolomics proposes to unveil the molecular machinery involved in each specific disease by the comprehensive analysis of low-molecular-weight metabolites in a biological sample. This narrative mini-review analyzes previous studies applying ultra-high-performance liquid chromatography-high-resolution mass spectrometry (HRMS)-based metabolomics to highlight different metabolic pathways involved in male hypogonadism and testosterone replacement therapy, both in the case of insulin-sensitive patients with primary hypogonadism and in the case of insulin-resistant patients with functional hypogonadism. In functional hypogonadism, metabolomics revealed that different biochemical pathways are affected. In detail, glycolysis is the most important biochemical process involved in these patients. Glucose metabolism is fueled by amino acid degradation, and gluconeogenesis is widely stimulated. Some important pathways, including glycerol, are compromised. Furthermore, mitochondrial electron transport is influenced, namely, by a decrease in ATP production. On the contrary, beta-oxidation of short- and medium-chain fatty acids does not represent an energy source in hypogonadal patients. Both lactate and acetyl-CoA are converted into ketone bodies, which increased immensely. However, carnosine and β-alanine are greatly reduced. These metabolic changes are associated with increased fatigue and mental confusion. After testosterone replacement therapy, a complete restoration is achieved for only a part of the metabolites. It is of note that only in patients with functional hypogonadism treated with testosterone are ketone bodies produced at high levels, so the symptoms sometimes reported by these patients after the beginning of the therapy (difficulty in concentrating, depressed mood, brain fog, and memory impairment) might represent a specific "keto flu-like" syndrome, related to the metabolic ketonic state.
Mancini A et al., 2008 · Journal of andrology
Oxidative stress is involved both in metabolic syndrome and male infertility. Hypogonadism is also associated with increased risk for cardiovascular disease. To investigate the role of gonadal steroids in systemic antioxidant regulation, we determined plasma CoenzymeQ(10) (CoQ(10)) and total antioxidant capacity (TAC) in postsurgical hypopituitaric patients. Twenty-six patients aged 28-55 years were studied 6-12 months after surgery. CoQ(10) levels were measured by high-performance liquid chromatography and TAC by spectroscopy with the use of the mioglobin-H(2)O(2) system, which, in interacting with chromogen 2,2(I)-azinobis-(3-ethylbenzothiazoline-6-sulfonate), generates a radical after a latency time (LAG) that is proportional to antioxidant content. Sixteen patients presented low testosterone values; in 10 patients hypogonadism was isolated, and in 6 patients hypothyroidism also was present. CoQ(10) levels were significantly lower in isolated hypogonadism than in normogonadism. Testosterone treatment, performed in those patients with isolated hypogonadism, induced a significant enhancement both in CoQ(10) level and LAG. CoQ(10) and LAG values correlated significantly, suggesting an interrelationship between different antioxidants. Our data suggest that hypogonadism could represent a condition of oxidative stress, in turn related with augmented cardiovascular risk.
Corona G et al., 2020 · Reviews in endocrine & metabolic disorders
The association between diabetes mellitus (and its micro- and macro-vascular complications) and erectile dysfunction is widely known and the presence of hypogonadism may further complicate sexual dysfunction and quality of life, given the association between hypogonadism and reduced libido, ejaculatory disorders, and depressive symptoms. However, the recent introduction of novel antidiabetic agents with a wide range of mechanism of action may have a significant impact both on male and female sexuality directly (by inducing side effects as urinary tract infections) and indirectly (improving metabolic status and reducing diabetes complications behind sexual dysfunctions). To date only few papers are reporting the sexual effects of these treatments and, often, these are not comparable in their results. Conversely, female sexual dysfunctions are somehow under-investigated. Data on prevalence is heterogeneous and specific pathogenic mechanisms, as well as the burden of psychological factors, are still heatedly debated. The aim of this narrative review is to summarize current knowledge and stressing out the need to diagnose male and female sexual dysfunctions also in light of the impact of treatments with novel antidiabetic agents. This would highlight the still unmet needs for sexual care in a diabetes care setting and could represent an incentive for future discussions, as well as a required theoretical starting point for studies on this subject.
