Therapeutics · Hormonal Agents
Abstract
Background
The role of testosterone (T) replacement therapy (TRT) in subjects with late onset hypogonadism is still the object of an intense debate.
Methods
All observational studies and placebo-controlled or -uncontrolled randomized trials (RCTs) comparing the effect of TRT on different bone parameters were considered.
Results
Out of 349 articles, 36 were considered, including 3103 individuals with a mean trial duration of 66.6 weeks. TRT improves areal bone mineral density (aBMD) at the spine and femoral neck levels in observational studies, whereas placebo-controlled RTCs showed a positive effect of TRT only at lumber spine and when trials included only hypogonadal patients at baseline (total testosterone < 12 nM). The effects on aBMD were more evident in subjects with lower T levels at baseline and increased as a function of trial duration and a higher prevalence of diabetic subjects. Either T or estradiol increase at endpoint contributed to aBMD improvement. TRT was associated with a significant reduction of bone resorption markers in observational but not in controlled studies.
Conclusion
TRT is able to inhibit bone resorption and increase bone mass, particularly at the lumbar spine level and when the duration is long enough to allow the anabolic effect of T and estrogens on bone metabolism to take place.
Topics
By this author
Semen Analysis · Sperm Function Testing
Preimplantation genetic testing for male factor infertility: lights and shadows
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.
Neoplastic Risk in Patients With Klinefelter Syndrome
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.
Evidence Synthesis · Systematic Reviews
Body composition in male hypogonadism: practical considerations to the use of dual-energy x-ray absorptiometry
Delbarba A et al., 2026 · Reviews in endocrine & metabolic disorders · Free full text on PubMed Central
Male hypogonadism is associated with significant alterations in body composition, including reduced lean body mass (LBM), increased fat body mass (FBM), particularly visceral adiposity, and impaired muscle function, contributing to frailty and cardiometabolic risk. These changes reflect the disruption of a complex endocrine crosstalk among bone, muscle, and adipose tissue, mediated by cytokines such as osteokines, myokines, and adipokines. This dysregulation promotes the development of osteosarcopenic obesity, a condition characterized by the coexistence of low bone mass, sarcopenia, and excess adiposity. Testosterone (T) plays a central role in maintaining body composition by stimulating muscle protein synthesis, inhibiting adipogenesis, and preserving bone health. Its deficiency, irrespective of etiology, leads to rapid impairment of anabolic pathways, resulting in decreased lean mass and increased fat accumulation. Evidence from clinical and experimental models demonstrates that these alterations are partially reversible with T replacement therapy (TRT), although variability exists depending on the underlying cause of hypogonadism. Dual-energy X-ray absorptiometry (DXA) represents the gold standard for assessing bone mineral density (BMD) and a key tool for evaluating body composition through a three-compartment model. It allows precise quantification of fat and lean mass, as well as their regional distribution, with minimal radiation exposure. In this review, we provide a comprehensive and clinically oriented overview of body composition alterations in male hypogonadism, focusing on underlying pathophysiological mechanisms and the practical application of DXA across different clinical scenarios. We discuss evidence from conditions such as Klinefelter syndrome, Kallmann syndrome, androgen deprivation therapy, HIV infection, and transgender care, aiming to offer a pragmatic framework for integrating body composition assessment into routine practice and improving patient management.
Bone Mineral Density · Measurement
Impact of reference gender on bone mineral density and fracture risk assessment in transgender adults
Scala A et al., 2026 · Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA · Free full text on PubMed Central
In transgender adults, reference-gender choice alters Z-scores and fracture-risk estimates. Z-scores differ by 0.4-0.6 SD, with male references identifying more individuals with low BMD for age, especially in those assigned male at birth. Dual-reference reporting is advisable until further evidence becomes available. Transgender individuals, especially those assigned male at birth (AMAB), exhibit lower bone mineral density (BMD) compared with the cisgender population. Interpretation of densitometric data is challenging, as the choice of reference gender can significantly influence Z-scores and fracture risk scores. This study aims to evaluate the impact of the gender reference database (male or female) on the assessment of BMD and fracture risk in transgender adults prior to gender-affirming hormone therapy (GAHT). We conducted a cross-sectional analysis of 249 transgender individuals (153 assigned female at birth - AFAB and 96 AMAB) aged 18-43 years, recruited in the Hospitals of Padua and Brescia (Italy). Z-scores were calculated using both male and female reference databases and FRAX scores were computed using both gender inputs. Associations with anthropometric, biochemical, and hormonal parameters were explored. Z-scores differed systematically depending on the reference gender, with mean ΔZ ranging 0.4-0.6 SD across skeletal sites. Switching reference databases frequently led to reclassification of BMD status. AMAB individuals showed a higher prevalence of low BMD for age, particularly when assessed against male references (27.1%), whereas AFAB participants generally maintained normal BMD. However, FRAX scores remained low. BMI and 25-OH vitamin D levels were independent predictors of BMD and Z-scores in AMAB individuals. The choice of reference gender significantly influences densitometric interpretation in young transgender adults. Until further evidence becomes available, calculating Z-scores using both male and female reference databases is advisable. Early preventive interventions remain essential to preserve bone health.
Related research
Hormonal Agents · Androgens and DHEA
Testosterone treatment in male patients with Klinefelter syndrome: a systematic review and meta-analysis
Pizzocaro A et al., 2020 · Journal of endocrinological investigation
Low testosterone (T) in Klinefelter's syndrome (KS) can contribute to typical features of the syndrome such as reduced bone mineral density, obesity, metabolic disturbances and increased cardiovascular risk. The aim of the present study is to review and meta-analyze all available information regarding possible differences in metabolic and bone homeostasis profile between T treated (TRT) or untreated KS and age-matched controls. We conducted a random effect meta-analysis considering all the available data from observational or randomized controlled studies comparing TRT-treated and untreated KS and age-matched controls. Data were derived from an extensive MEDLINE, Embase, and Cochrane search. Out of 799 retrieved articles, 21 observational and 22 interventional studies were included in the study. Retrieved trials included 1144 KS subjects and 1284 healthy controls. Not-treated KS patients showed worse metabolic profiles (including higher fasting glycemia and HOMA index as well as reduced HDL-cholesterol and higher LDL-cholesterol) and body composition (higher body mass index and waist circumference) and reduced bone mineral density (BMD) when compared to age-matched controls. TRT in hypogonadal KS subjects was able to improve body composition and BMD at spinal levels but it was ineffective in ameliorating lipid and glycemic profile. Accordingly, TRT-treated KS subjects still present worse metabolic parameters when compared to age-matched controls. TRT outcomes observed in KS regarding BMD, body composition and glyco-metabolic control, are similar to those observed in male with hypogonadism not related to KS. Moreover, body composition and BMD are better in treated than untreated hypogonadal KS. Larger and longer randomized placebo-controlled trials are advisable to better confirm the present data, mainly derived from observational studies.
Guidelines by Clinical Area · Bone and Endocrine Guidelines
Outcomes of androgen replacement therapy in adult male hypogonadism: recommendations from the Italian society of endocrinology
Isidori AM et al., 2015 · Journal of endocrinological investigation · Free full text on PubMed Central
We developed clinical practice guidelines to assess the individual risk-benefit profile of androgen replacement therapy in adult male hypogonadism (HG), defined by the presence of specific signs and symptoms and serum testosterone (T) below 12 nmol/L. The task force consisted of eight clinicians experienced in treating HG, selected by the Italian Society of Endocrinology (SIE). The authors received no corporate funding or remuneration. Consensus was guided by a systematic review of controlled trials conducted on men with a mean T < 12 nmol/L and by interactive discussions. The guidelines were reviewed and sequentially approved by the SIE Guidelines Commission and Executive Committee. We recommend T supplementation (TS) for adult men with severely reduced T levels (T < 8 nmol/L) to improve body composition and sexual function. We suggest that TS be offered to subjects with T < 12 nmol/L to improve glycaemic control, lipid profile, sexual function, bone mineral density, muscle mass and depressive symptoms, once major contraindications have been ruled out. We suggest that lifestyle changes and other available interventions (e.g. for erectile dysfunction) be suggested prior to TS. We suggest that TS should be combined with currently available treatments for individuals at high risk for complications, such as those with osteoporosis and/or metabolic disorders. We recommend against using TS to improve cardiac outcome and limited mobility. We recommend against using TS in men with prostate cancer, unstable cardiovascular conditions or elevated haematocrit. The task force places a high value on the timely treatment of younger and middle-aged subjects to prevent the long-term consequences of hypoandrogenism.
Guidelines by Clinical Area · Bone and Endocrine Guidelines
Adult- and late-onset male hypogonadism: the clinical practice guidelines of the Italian Society of Andrology and Sexual Medicine (SIAMS) and the Italian Society of Endocrinology (SIE)
Isidori AM et al., 2022 · Journal of endocrinological investigation · Free full text on PubMed Central
To provide the evidence-based recommendations on the role of testosterone (T) on age-related symptoms and signs remains. The Italian Society of Andrology and Sexual Medicine (SIAMS) and the and the Italian Society of Endocrinology (SIE) commissioned an expert task force to provide an updated guideline on adult-onset male hypogonadism. Derived recommendations were based on Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system. Clinical diagnosis of adult-onset hypogonadism should be based on a combination of clinical and biochemical parameters. Testosterone replacement therapy (TRT) should be offered to all symptomatic subjects with hypogonadism after the exclusion of possible contraindications. T gels and the long-acting injectable T are currently available preparations showing the best efficacy/safety profile. TRT can improve all aspects of sexual function, although its effect is limited in more complicated patients. Body composition (reducing fat mass and increasing lean mass) is improved after TRT, either in subjects with or without metabolic syndrome or type 2 diabetes. Conversely, the role of TRT in improving glycometabolic control is more conflicting. TRT can result in increasing bone mineral density, particularly at lumbar site, but no information on fracture risk is available. Limited data support the use of TRT for improving other outcomes, including mood frailty and mobility. TRT can improve sexual function and body composition particularly in less complicated adult and in aging subjects with hypogonadism. When hypogonadism is adequately diagnosed, T appropriately prescribed and subjects correctly followed up, no short-term increased risk of adverse events is observed. Longer and larger studies are advisable to better clarify TRT long-term efficacy/safety profile.
Bone Mineral Density · Peak Bone Mass
Age-dependent bone mineral density responses to gender-affirming hormone therapy in transgender individuals: a one-year prospective study
Ceolin C et al., 2025 · Journal of endocrinological investigation · Free full text on PubMed Central
Evidence on the skeletal effects of gender-affirming hormone therapy (GAHT) in transgender individuals remains limited, especially across age groups. Individuals assigned male at birth (AMAB) often show reduced bone mineral density (BMD) even before GAHT, whereas findings in those assigned female at birth (AFAB) are more variable. Given the key role of adolescence and early adulthood in peak bone mass, timely skeletal assessment is essential. This study compared BMD before and after one year (1-y) of GAHT to age-matched cisgender controls. Prospective observational study involving 269 adults (162 transgender and 107 cisgender controls) conducted at the University Hospital of Padua (January 2020-November 2024). Dual-energy X-ray absorptiometry (DXA) was performed at baseline and after 1-y of GAHT. After 1-y of GAHT, in AMAB individuals, lumbar spine BMD significantly increased (from 0.97 ± 0.16 to 1.02 ± 0.14 g/cm², p < 0.001), particularly in those under 20 years. AFAB individuals experienced a modest but significant reduction in femoral neck BMD (from 0.81 ± 0.12 to 0.79 ± 0.13, p < 0.05), especially in the 20–30-year age group. Age-stratified analyses revealed that younger participants showed greater BMD improvements, while those over 20 exhibited stable or declining values. Linear regression confirmed age as an independent predictor of BMD change, with older age associated with reduced skeletal responsiveness to GAHT at key femoral sites. GAHT has variable effects on bone health, influenced by age and sex assigned at birth. Early initiation may favor bone accrual, especially in AMAB individuals, while AFAB individuals may require closer monitoring for site-specific bone loss during testosterone therapy.
Therapeutics › Hormonal Agents › Androgens and DHEA · Bone Health › Hormones and Bone › Estrogen and Bone
PMID 35041193 35041193 DOI 10.1007/s40618-021-01702-5 10.1007/s40618-021-01702-5 Corona et al. 2022, Corona 2022