Testosterone Treatment and Cognitive Function in Older Men With Low Testosterone and Age-Associated Memory Impairment

Sex differences in the relationship between depression and Alzheimer's disease-mechanisms, genetics, and therapeutic opportunities

Depression and Alzheimer's disease (AD) are prevalent neuropsychiatric disorders with intriguing epidemiological overlaps. Their interrelation has recently garnered widespread attention. Empirical evidence indicates that depressive disorders significantly contribute to AD risk, and approximately a quarter of AD patients have comorbid major depressive disorder, which underscores the bidirectional link between AD and depression. A growing body of evidence substantiates pervasive sex differences in both AD and depression: both conditions exhibit a higher incidence among women than among men. However, the available literature on this topic is somewhat fragmented, with no comprehensive review that delineates sex disparities in the depression-AD correlation. In this review, we bridge these gaps by summarizing recent progress in understanding sex-based differences in mechanisms, genetics, and therapeutic prospects for depression and AD. Additionally, we outline key challenges in the field, holding potential for improving treatment precision and efficacy tailored to male and female patients' distinct needs.

In the land of not-unhappiness: On the state-of-the-art of targeting aging and age-related diseases by biomedical research

The concept of the Land of Not-Unhappiness refers to the potential achievement of eliminating the pathologies of the aging process. To inform of how close we are to settling in the land, we summarize and review the achievements of research on anti-aging interventions over the last hundred years with a specific focus on strategies that slow down metabolism, compensate for aging-related losses, and target a broad range of age-related diseases. We critically evaluate the existing interventions labeled as "anti-aging," such as calorie restriction, exercise, stem cell administration, and senolytics, to provide a down-to-earth evaluation of their current applicability in counteracting aging. Throughout the text, we have maintained a light tone to make it accessible to non-experts in biogerontology, and provide a broad overview for those considering conducting studies, research, or seeking to understand the scientific basis of anti-aging medicine.

Causal effects of genetically predicted testosterone on Alzheimer's disease: a two-sample mendelian randomization study

OBJECTIVE

Although several studies have reported that testosterone may protect against Alzheimer's disease, no evidence of a causal relationship has been demonstrated.

METHODS

A Mendelian randomization (MR) study was performed to determine the causal role of testosterone in Alzheimer's disease. The study utilized public databases obtained from separately published genome-wide associationstudies (GWAS). Single-nucleotide polymorphisms (SNPs) for testosterone were extracted from the most recent and largest published GWAS meta-analysis (178,782 participants), and SNPs for Alzheimer's disease were extracted from UK Biobank (954 AD cases and 487,331 controls). The odds ratio (OR) of the inverse variance weighting (IVW) approach was the primary outcome, and the weighted median and MR Egger regression were used for sensitivity analysis.

RESULTS

Through IVW, we observed a causal association between genetically predicted testosterone and the risk of Alzheimer's disease, with an OR of 0.99 (95% confidence interval [CI] = 0.998-0.999, p = 0.047). In the sensitivity analyses, the weighted median regression showed directionally similar estimates (OR = 0.99, 95% CI = 0.998-0.999, p = 0.048). The MR Egger regression showed similar estimates (OR = 0.99, 95% CI = 0.998-1.00, p = 0.35), but with lower precision. Funnel plots, MR Egger intercepts, and Mendelian randomization pleiotropy residual sum and outlier (MR-PRESSO) analysis indicated the absence of directional pleiotropy effects.

CONCLUSION

In conclusion, our MR study provides evidence of a causal relationship between testosterone levels and Alzheimer's disease; however, this relationship must be validated in future studies with larger sample sizes. Early testosterone monitoring may enable the prevention of Alzheimer's and related diseases.

The effect of estradiol add-back: a longitudinal MRI study in prostate cancer patients

We investigated the effect of estradiol add-back therapy (EAT) on brain activation related to cognitive function and affect in addition to putative changes in gray and white matter volume in testosterone depleted participants with prostate cancer. We conducted a randomized controlled, double-blinded trial in which 40 patients received 0.9 mg of transdermal estradiol per day for 6 months or matched placebo. Anatomical MRI and three functional MRI (fMRI) scans were obtained for the emotion recognition task, verbal memory task, and visuospatial memory task. Activation in corresponding cognitive and affective brain networks was demonstrated for all tasks. Longitudinally, there was no difference in brain activation, reaction time, or accuracy in response to the fMRI tasks between the EAT group and placebo group at 6 months. In addition, there was no detectable change in whole-brain gray or white matter volume or in hippocampal volume between the two groups after 6 months. This study supports earlier findings that EAT does not improve verbal memory or affect and has no immediate effect on hippocampal volume in testosterone depleted patients with prostate cancer.

Effects of testosterone enanthate on aggression, risk-taking, competition, mood, and other cognitive domains during 28 days of severe energy deprivation

RATIONALE

Behavioral effects of testosterone depend on dose, acute versus sustained formulation, duration of administration, personality, genetics, and endogenous levels of testosterone. There are also considerable differences between effects of endogenous and exogenous testosterone.

OBJECTIVES

This study was the secondary behavioral arm of a registered clinical trial designed to determine if testosterone protects against loss of lean body mass and lower-body muscle function induced by a severe energy deficit typical of sustained military operations.

METHODS

Behavioral effects of repeated doses of testosterone on healthy young men whose testosterone was reduced by severe energy deficit were examined. This was a double-blind, placebo-controlled, between-group study. Effects of four weekly intramuscular injections of testosterone enanthate (200 mg/week, N = 24) or matching placebo (N = 26) were evaluated. Determination of sample size was based on changes in lean body mass. Tasks assessing aggression, risk-taking, competition, social cognition, vigilance, memory, executive function, and mood were repeatedly administered.

RESULTS

During a period of artificially induced, low testosterone levels, consistent behavioral effects of administration of exogenous testosterone were not observed.

CONCLUSIONS

Exogeneous testosterone enanthate (200 mg/week) during severe energy restriction did not reliably alter the measures of cognition. Study limitations include the relatively small sample size compared to many studies of acute testosterone administration. The findings are specific to healthy males experiencing severe energy deficit and should not be generalized to effects of other doses, formulations, or acute administration of endogenous testosterone or studies conducted with larger samples using tests of cognitive function designed to detect specific effects of testosterone.

Testosterone replacement in men with sexual dysfunction

BACKGROUND

Clinical practice guidelines recommend testosterone replacement therapy (TRT) for men with sexual dysfunction and testosterone deficiency. However, TRT is commonly promoted in men without testosterone deficiency and existing trials often do not clearly report participants' testosterone levels or testosterone-related symptoms. This review assesses the potential benefits and harms of TRT in men presenting with complaints of sexual dysfunction.

OBJECTIVES

To assess the effects of testosterone replacement therapy compared to placebo or other medical treatments in men with sexual dysfunction.

SEARCH METHODS

We performed a comprehensive search of CENTRAL (the Cochrane Library), MEDLINE, EMBASE, and the trials registries ClinicalTrials.gov and World Health Organization International Clinical Trials Registry Platform, with no restrictions on language of publication or publication status, up to 29 August 2023.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) in men (40 years or over) with sexual dysfunction. We excluded men with primary or secondary hypogonadism. We compared testosterone or testosterone with phosphodiesterase-5 inhibitors (PDEI5I) to placebo or PDE5I alone.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the literature, assessed the risk of bias, extracted data, and rated the certainty of evidence (CoE) according to GRADE using a minimally contextualized approach. We performed statistical analyses using a random-effects model and interpreted them according to standard Cochrane methodology. Predefined primary outcomes were self-reported erectile dysfunction assessed by a validated instrument, sexual quality of life assessed by a validated instrument, and cardiovascular mortality. Secondary outcomes were treatment withdrawal due to adverse events, prostate-related events, and lower urinary tract symptoms (LUTS). We distinguished between short-term (up to 12 months) and long-term (> 12 months) outcomes.

MAIN RESULTS

We identified 43 studies with 11,419 randomized participants across three comparisons: testosterone versus placebo, testosterone versus PDE5I, and testosterone with PDE5I versus PDE5I alone. This abstract focuses on the most relevant comparison of testosterone versus placebo. Testosterone versus placebo (up to 12 months) Based on a predefined sensitivity analysis of studies at low risk of bias, and an analysis combing data from the similar International Index of Erectile Function (IIEF-EF) and IIEF-5 instruments, TRT likely results in little to no difference in erectile function assessed with the IIEF-EF (mean difference (MD) 2.37, 95% confidence interval (CI) 1.67 to 3.08; I² = 0%; 6 RCTs, 2016 participants; moderate CoE) on a scale from 6 to 30 with larger values reflecting better erectile function. We assumed a minimal clinically important difference (MCID) of greater than or equal to 4. TRT likely results in little to no change in sexual quality of life assessed with the Aging Males' Symptoms scale (MD -2.31, 95% CI -3.63 to -1.00; I² = 0%; 5 RCTs, 1030 participants; moderate CoE) on a scale from 17 to 85 with larger values reflecting worse sexual quality of life. We assumed a MCID of greater than or equal to 10. TRT also likely results in little to no difference in cardiovascular mortality (risk ratio (RR) 0.83, 95% CI 0.21 to 3.26; I² = 0%; 10 RCTs, 3525 participants; moderate CoE). Based on two cardiovascular deaths in the placebo group and an assumed MCID of 3%, this would correspond to no additional deaths per 1000 men (95% CI 1 fewer to 4 more). TRT also likely results in little to no difference in treatment withdrawal due to adverse events, prostate-related events, or LUTS. Testosterone versus placebo (later than 12 months) We are very uncertain about the longer-term effects of TRT on erectile dysfunction assessed with the IIEF-EF (MD 4.20, 95% CI -2.03 to 10.43; 1 study, 42 participants; very low CoE). We did not find studies reporting on sexual quality of life or cardiovascular mortality. We are very uncertain about the effect of testosterone on treatment withdrawal due to adverse events. We found no studies reporting on prostate-related events or LUTS.

AUTHORS' CONCLUSIONS

In the short term, TRT probably has little to no effect on erectile function, sexual quality of life, or cardiovascular mortality compared to a placebo. It likely results in little to no difference in treatment withdrawals due to adverse events, prostate-related events, or LUTS. In the long term, we are very uncertain about the effects of TRT on erectile function when compared to placebo; we did not find data on its effects on sexual quality of life or cardiovascular mortality. The certainty of evidence ranged from moderate (signaling that we are confident that the reported effect size is likely to be close to the true effect) to very low (indicating that the true effect is likely to be substantially different). The findings of this review should help to inform future guidelines and clinical decision-making at the point of care.

Androgen Deprivation Therapy for Prostate Cancer: Focus on Cognitive Function and Mood

Prostate cancer is the second leading cause of cancer death in men in the United States. Androgen deprivation therapy (ADT) is currently the primary treatment for metastatic prostate cancer, and some studies have shown that the use of anti-androgen drugs is related to a reduction in cognitive function, mood changes, diminished quality of life, dementia, and possibly Alzheimer's disease. ADT has potential physiological effects such as a reduction in white matter integrity and a negative impact on hypothalamic functions due to the lowering of testosterone levels or the blockade of downstream androgen receptor signaling by first- and second-generation anti-androgen drugs. A comparative analysis of prostate cancer patients undergoing ADT and Alzheimer patients identified over 30 shared genes, illustrating common ground for the mechanistic underpinning of the symptomatology. The purpose of this review was to investigate the effects of ADT on cognitive function, mood, and quality of life, as well as to analyze the relationship between ADT and Alzheimer's disease. The evaluation of prostate cancer patient cognitive ability via neurocognitive testing is described. Future studies should further explore the connection among cognitive deficits, mood disturbances, and the physiological changes that occur when hormonal balance is altered.

EMAS position statement: Testosterone replacement therapy in older men

INTRODUCTION

Late-onset hypogonadism is the clinical entity characterised by low testosterone concentrations associated with clinical symptoms in the absence of organic disease in ageing men. It has been associated with metabolic syndrome, reduced bone mineral density, and increased cardiovascular morbidity and mortality risk. Although testosterone replacement therapy (TRT) reverses most of these conditions in young hypogonadal men, the risk/benefit ratio of TRT in older men is debatable.

AIM

To update the 2015 EMAS statement on TRT in older men with new research on late-onset hypogonadism and TRT.

MATERIALS AND METHODS

Literature review and consensus of expert opinion.

SUMMARY RECOMMENDATIONS

TRT should be offered only to symptomatic older men with confirmed low testosterone concentrations after explaining the uncertainties regarding the long-term safety of this treatment. TRT may be offered to men with severe hypogonadism and erectile dysfunction to improve sexual desire, erectile, and orgasmic function. It should also be considered in hypogonadal men with severe insulin resistance or pre-diabetes mellitus. TRT may also be considered, in combination with proven treatment strategies, for osteoporosis, or for selected patients with persistent mild depressive symptoms and/or low self-perceived quality of life, combined with standard medical care for each condition. TRT is contraindicated in hypogonadal men actively seeking fertility treatment. Due to a lack of data, TRT should not be routinely used in older men to improve exercise capacity/physical function, improve cognitive function, or prevent cognitive decline. TRT must be avoided in older, frail men with known breast cancer or untreated prostate cancer and all men who have had myocardial infarction or stroke within the last four months, and those with severe or decompensated heart failure. The quality of evidence regarding patients with previous prostate cancer or cardiovascular disease is too low to draw definitive conclusions. Any limits on duration of use are arbitrary, and treatment should continue for as long as the man feels the benefits outweigh the risks for him, and decisions must be made on an individual basis. Withdrawal should be considered when hypogonadism is reversed after the resolution of underlying disorder. Short-acting transdermal preparations should be preferred for TRT initiation in older men, but injectable forms may be considered subsequently. Older men on TRT should be monitored at 3, 6, and 12 months after initiation and at least yearly thereafter, or earlier and more frequently if indicated. Evaluation should include assessment of the clinical response, and measurement of total testosterone, haematocrit, and prostate-specific antigen (PSA) concentrations. Bone density and/or quality should also be assessed. Obese and overweight patients should be encouraged to undergo lifestyle modifications, including exercise and weight loss, to increase endogenous testosterone.

Sex-based differences in effector cells of the adaptive immune system during Alzheimer's disease and related dementias

Neurological conditions such as Alzheimer's disease (AD) and related dementias (ADRD) present with many challenges due to the heterogeneity of the related disease(s), making it difficult to develop effective treatments. Additionally, the progression of ADRD-related pathologies presents differently between men and women. With two-thirds of the population affected with ADRD being women, ADRD has presented itself with a bias toward the female population. However, studies of ADRD generally do not incorporate sex-based differences in investigating the development and progression of the disease, which is detrimental to understanding and treating dementia. Additionally, recent implications for the adaptive immune system in the development of ADRD bring in new factors to be considered as part of the disease, including sex-based differences in immune response(s) during ADRD development. Here, we review the sex-based differences of pathological hallmarks of ADRD presentation and progression, sex-based differences in the adaptive immune system and how it changes with ADRD, and the importance of precision medicine in the development of a more targeted and personalized treatment for this devastating and prevalent neurodegenerative condition.

Male Reproduction and Aging

Recent publications of well-conducted population studies have informed us that the syndromic prevalence of age-related low testosterone, also known as late-onset hypogonadism, is quite low. Several well-conducted trials in middle-aged and older men with age-related decline in testosterone levels have revealed that efficacy of testosterone therapy is modest with improvement in sexual function, mood, volumetric bone density, and anemia. Although select older men might benefit from testosterone therapy, its effect on prostate cancer risk and major adverse cardiovascular events remains unclear. The results of the ongoing TRAVERSE trial will likely provide important insights into these risks.

The British Society for Sexual Medicine Guidelines on Male Adult Testosterone Deficiency, with Statements for Practice

Testosterone deficiency (TD) is an increasingly common problem with significant health implications, but its diagnosis and management can be challenging. A multi-disciplinary panel from BSSM reviewed the available literature on TD and provide evidence-based statements for clinical practice. Evidence was derived from Medline, EMBASE and Cochrane searches on hypogonadism, testosterone therapy (T Therapy) and cardiovascular safety from May 2017 to September 2022. This revealed 1,714 articles, including 52 clinical trials and 32 placebo-controlled randomised controlled trials. A total of twenty-five statements are provided, relating to five key areas: screening, diagnosis, initiating T Therapy, benefits and risks of T Therapy, and follow-up. Seven statements are supported by level 1 evidence, eight by level 2, five by level 3, and five by level 4. Recent studies have demonstrated that low levels of testosterone in men are associated with increased risk of incident type 2 diabetes mellitus, worse outcomes in chronic kidney disease and COVID 19 infection with increased all-cause mortality, along with significant quality of life implications. These guidelines should help practitioners to effectively diagnose and manage primary and age-related TD.

Causal effects of serum testosterone levels on brain volume: a sex-stratified Mendelian randomization study

PURPOSE

To assess the causal effects of serum testosterone and sex hormone-binding globulin levels on brain volumetric measurements in women and men.

METHODS

We performed a sex-stratified two-sample Mendelian randomization study using the random-effects inverse variance-weighted method as the primary analysis method. Sex-specific genetic instruments were obtained from a study with up to 194,453 men and 230,454 women. For testosterone, variants with dominant effects on both total and bioavailable testosterone but no aggregate effect on sex hormone-binding globulin were used as the main genetic instruments. Sex-specific summary-level data for magnetic resonance imaging brain volumetric measurements were obtained from a study with 11,624 women and 10,514 men.

RESULTS

Analyses showed per standard deviation (approximately 3.7 nmol/L) higher testosterone levels in men were suggestively associated with larger gray matter volume (beta = 0.208, 95% confidence interval = 0.067 to 0.349, p = 0.004). The association remained in sensitivity analyses and multivariable analyses. Further analyses showed the effect was mainly act on peripheral cortical gray matter, but not on subcortical gray matter. Testosterone in men was not associated with hippocampal volume. Testosterone in women and sex hormone binding globulin in both sexes had no effect on all outcomes.

CONCLUSION

Our findings overall support previous evidence that testosterone might have neuroprotective properties in elderly men. Future larger trials with long duration of intervention are warranted to assess the efficacy of testosterone for elderly men with cognitive impairment, especially in those with hypoandrogenism.

Testosterone, cognitive decline and dementia in ageing men

As men grow older, circulating testosterone concentrations decline, while prevalence of cognitive impairment and dementia increase. Epidemiological studies of middle-aged and older men have demonstrated associations of lower testosterone concentrations with higher prevalence and incidence of cognitive decline and dementia, including Alzheimer's disease. In observational studies, men with prostate cancer treated by androgen deprivation therapy had a higher risk of dementia. Small intervention studies of testosterone using different measures of cognitive function have provided inconsistent results, with some suggesting improvement. A randomised placebo-controlled trial of one year's testosterone treatment conducted in 788 men aged ≥ 65 years, baseline testosterone < 9.54 nmol/L, showed an improvement in sexual function, but no improvement in cognitive function. There is a known association between diabetes and dementia risk. A randomised placebo-controlled trial of two year's testosterone treatment in 1,007 men aged 50-74 years, waist circumference ≥ 95 cm, baseline testosterone ≤ 14 nmol/L, showed an effect of testosterone in reducing type 2 diabetes risk. There were no cognitive endpoints in that trial. Additional research is warranted but at this stage lower testosterone concentrations in ageing men should be regarded as a biomarker rather than a proven therapeutic target for risk reduction of cognitive decline and dementia, including Alzheimer's disease.

Randomised controlled trials for the prevention of cognitive decline or dementia: A systematic review

Dementia prevention research has progressed rapidly in recent years, with publication of several large lifestyle intervention trials, and renewed interest in pharmacological interventions, notably for individuals with Alzheimer's disease biomarkers, warranting an updated review of results and methodology. We identified 112 completed trials testing the efficacy of single-domain pharmacological (n = 33, 29%), nutritional (n = 27, 24%), physical activity (n = 18, 16%) and cognitive stimulation (n = 13, 12%), or multidomain (n = 22, 20%) interventions on incident dementia, or a relevant intermediate marker (e.g. cognitive function, biomarkers or dementia risk scores) in people without dementia. The earliest trials tested pharmacological interventions or nutritional supplements, but lifestyle interventions predominated in the last decade. In total, 21 (19%) trials demonstrated a clear beneficial effect on the pre-specified primary outcome (or all co-primary outcomes), but only two (10%) were large-scale (testing blood pressure lowering (Syst-Eur) or multidomain (FINGER) interventions on incident dementia and cognitive change in cognitive function, respectively). Of the 116 ongoing trials, 40% (n = 46) are testing multidomain interventions. Recent methodological shifts concern target populations, primary outcome measures, and intervention design, but study design remains constant (parallel group randomised controlled trial). Future trials may consider using adaptive trials or interventions, and more targeted approaches, since certain interventions may be more effective in certain subgroups of the population, and at specific times in the life-course. Efforts should also be made to increase the representativeness and diversity of prevention trial populations.

Effect of estradiol on cognition in men undergoing androgen deprivation therapy: A randomized placebo-controlled trial

OBJECTIVE

Roles for estradiol in modulating cognition in men remain uncertain. We assessed the isolated effects of estradiol on cognition in men in the absence of testosterone.

DESIGN

Randomized trial of transdermal estradiol 0.9 mg daily, or matched placebo, for 6 months, hypothesizing that estradiol would improve verbal learning, verbal memory, and spatial problem solving over time.

PATIENTS

Men receiving androgen deprivation therapy (ADT) for prostate cancer.

MEASUREMENTS

Cognition was assessed by a tablet-based cognitive battery (Cogstate) at baseline, Month 1, Month 3, and Month 6. Anxiety and depression symptoms were assessed using the Hospital Anxiety and Depression Scale.

RESULTS

Seventy-eight participants were randomized. Baseline mean scores were 21.0 (standard deviation [SD] 4.1) for the International Shopping List test (ISL), assessing verbal learning and memory (higher scores better), and 60.4 (SD 19.5) for the Groton Maze Learning test (GML), assessing spatial problem solving (lower scores better). There was no significant difference in performance over time for the estradiol group versus the placebo group for the ISL, mean adjusted difference (MAD) 0.7 (95% confidence interval [CI] -1.2 to 2.5), p = .36, or the GML, MAD -3.2 (95% CI -12.0 to 5.6), p = 0.53. There was no significant difference between groups over time in performance in any other cognitive domain, or on depression or anxiety scores.

CONCLUSIONS

We found no major effects of estradiol on cognition in men with castrate testosterone concentrations. Although the cognitive effects of ADT are debated, this study suggests that any such effects are unlikely to be prevented by the administration of estradiol.

Lower serum testosterone concentrations are associated with a higher incidence of dementia in men: The UK Biobank prospective cohort study

INTRODUCTION

The association of testosterone concentrations with dementia risk remains uncertain. We examined associations of serum testosterone and sex hormone-binding globulin (SHBG) with incidence of dementia and Alzheimer's disease.

METHODS

Serum total testosterone and SHBG were measured by immunoassay. The incidence of dementia and Alzheimer's disease (AD) was recorded. Cox proportional hazards regression was adjusted for age and other variables.

RESULTS

In 159,411 community-dwelling men (median age 61, followed for 7 years), 826 developed dementia, including 288 from AD. Lower total testosterone was associated with a higher incidence of dementia (overall trend: P = .001, lowest vs highest quintile: hazard ratio [HR] = 1.43, 95% confidence interval [CI] = 1.13-1.81), and AD (P = .017, HR = 1.80, CI = 1.21-2.66). Lower SHBG was associated with a lower incidence of dementia (P < .001, HR = 0.66, CI = 0.51-0.85) and AD (P = .012, HR = 0.53, CI = 0.34-0.84).

DISCUSSION

Lower total testosterone and higher SHBG are independently associated with incident dementia and AD in older men. Additional research is needed to determine causality.

Associations between cognitive function and endogenous levels of estradiol and testosterone in adults with type 2 diabetes

AIMS

To assess associations that endogenous estradiol and testosterone levels have with cognitive function in older adults with Type 2 diabetes mellitus (T2DM).

METHODS

We use data from the Look AHEAD clinical trial of behavioral weight loss. Endogenous estradiol and total testosterone levels were determined using stored serum from 996 individuals, mean age 69 years, at two times (averaging 4 years apart) during years 8-18 of follow-up. One to four standardized assessments of attention, executive function, memory, and verbal fluency were collected during this follow-up. Mixed effects models and multiple imputation were used to assess associations that estradiol and total testosterone levels had with body mass index and cognitive function.

RESULTS

Estradiol levels were not associated with cognitive function in either sex. Total testosterone levels were not associated with cognitive function in women, but greater total testosterone levels were associated with better verbal fluency in men (p < 0.001), most strongly among those carrying the APOE-e4 allele (interaction p = 0.02). The weight loss intervention left a legacy of relatively lower cognitive functioning among women, which was not mediated by current levels of sex hormones.

CONCLUSIONS

Behavioral weight loss intervention does not affect cognitive functioning through mechanisms related to estradiol or testosterone.

CLINICALTRIALS

gov Identifier: NCT00017953.

Aging, testosterone, and neuroplasticity: friend or foe?

Neuroplasticity or neural plasticity implicates the adaptive potential of the brain in response to extrinsic and intrinsic stimuli. The concept has been utilized in different contexts such as injury and neurological disease. Neuroplasticity mechanisms have been classified into neuroregenerative and function-restoring processes. In the context of injury, neuroplasticity has been defined in three post-injury epochs. Testosterone plays a key yet double-edged role in the regulation of several neuroplasticity alterations. Research has shown that testosterone levels are affected by numerous factors such as age, stress, surgical procedures on gonads, and pharmacological treatments. There is an ongoing debate for testosterone replacement therapy (TRT) in aging men; however, TRT is more useful in young individuals with testosterone deficit and more specific subgroups with cognitive dysfunction. Therefore, it is important to pay early attention to testosterone profile and precisely uncover its harms and benefits. In the present review, we discuss the influence of environmental factors, aging, and gender on testosterone-associated alterations in neuroplasticity, as well as the two-sided actions of testosterone in the nervous system. Finally, we provide practical insights for further study of pharmacological treatments for hormonal disorders focusing on restoring neuroplasticity.

Effects of membrane androgen receptor binding on synaptic plasticity in primary hippocampal neurons

Androgens play an important role in the regulation of hippocampal synaptic plasticity. While the classical molecular mechanism of androgen's genomic activity is their binding to intracellular androgen receptors (iARs), they can also induce rapid non-genomic effects through specific membrane androgen receptors (mARs). In this study, we aimed to localize and characterize these mARs in primary rat hippocampal neurons. Specific punctate fluorescent signals on the cell surface, observed by testosterone-fetal bovine serum albumin conjugated fluorescein isothiocyanate (T-BSA-FITC), indicated the presence of mARs in hippocampal neurons. T-BSA-FITC binding to the cell membrane was incompletely blocked by the iAR-antagonist flutamide, and mAR binding site was competitively bound by free testosterone (T). Most neurons expressing androgen membrane binding sites are glutamatergic (excitatory), although several are γ-aminobutyric acid (GABA)ergic (inhibitory). Confocal microscopy and live-cell imaging techniques were used to observe the real-time rapid effects of androgens on hippocampal dendritic spine morphology. Immunofluorescence cell staining was used to observe their effects on the postsynaptic density protein 95 (PSD95) and synapsin (SYN) synaptic markers. While androgens did not cause a short-term increase in dendritic spine density of rat primary hippocampal neurons, they promoted the transformation of dendritic spines from thin to mushroom, promoted dendritic spine maturation, increased dendritic spine surface area, and rapidly increased PSD95 and SYN expression in the primary hippocampal neurons. Hippocampal synaptosomes were prepared using the Optiprep and Percoll density gradient two-step centrifuge methods, and the gene expression profiles of the synaptosomes and hippocampus were compared using a gene chip; PSD95 mRNA expression was detected by reverse transcription-polymerase chain reaction. Several mRNAs were detected at the synaptic site, including PSD95. Finally, the Venus-PSD95 plasmid was constructed and transfected into HT22 cells, which is a mouse hippocampal neuronal cell line. The real-time effect of androgen on synaptic protein PSD95 was observed by fluorescence recovery after photobleaching experiments, which involved the translation process of PSD95 mRNA. In conclusion, our findings increased our understanding of how androgens exert the neuroprotective mechanisms on synaptic plasticity.

Ageing male (part 2): Management of functional hypogonadism in older men, a patient-centric holistic approach

The diagnosis of functional hypogonadism should prompt a thorough assessment and optimization of general health, including lifestyle changes, weight reduction, care of comorbidities and cessation of offending medications, some of which can lead to meaningful gains in endogenous testosterone (T) concentrations. Having excluded or addressed reversible causes and contra-indications, patients with functional hypogonadism can be offered a trial of testosterone replacement therapy (TRT) after full discussion on the anticipated benefits and potential risks. T treatment improves libido but may be less effective for erectile dysfunction (ED). T treatment can also have modest positive effects on insulin resistance, bone strength, some measures of physical strength, and mild depressive symptoms but the clinical significance of these relatively short-term improvements remain uncertain in terms of longer-term patient-important outcomes. Initiation of TRT is a joint decision between patient and clinician since longer-term benefits and risks have not been adequately defined.

Comparison of neuroprotective effects of dihydrotestosterone, 17β-estradiol, and Pueraria mirifica herb extract on cognitive impairment in androgen deficient male rats

This study investigated the neuroprotective effects of dihydrotestosterone (DHT), 17β-estradiol (E₂), and Pueraria mirifica herb extract (PME; an alternative source of natural estrogens) on the (i) learning and memory in androgen-deficient male rats, and on the hippocampus expression levels of (ii) mRNA of genes associated with synaptic transmission and structure, neurofibrillary tangles, and amyloid plaques, and (iii) total and phosphorylated tau proteins. The four-month-old male rats were sham-operated or orchidectomized (ODX). The ODX rats were divided into four groups, and orally treated for 2 months with either 1 mL/d of distilled water or 100 mg/kg/d of PME; or subcutaneously injected with 1 mg/kg/d of DHT or 80 μg/kg/d of E₂. The impairment of spatial learning behavior and memory capacity in the ODX rats was prevented by DHT, E_2, and PME. Recovery of the orchidectomy-induced deterioration of the synaptic plasticity in the hippocampus of rats was ranked as E₂ ≥ PME > DHT. Both DHT and PME mitigated the increased Tau3 and Tau4 mRNA levels, and Tau-5 and P-Tau Ser³⁹⁶ protein levels more than E₂ (DHT ≥ PME > E₂). Only DHT tended to decrease App mRNA expression level. In conclusion, DHT showed a stronger efficacy for mitigation of the impaired spatial learning behavior and memory capacity in androgen-deficient male rats compared to E₂ and PME, and their mechanisms of action are slightly different.

Identifying the outcomes important to men with hypogonadism: A qualitative evidence synthesis

OBJECTIVE

Men with male hypogonadism (MH) experience sexual dysfunction, which improves with testosterone replacement therapy (TRT). However, randomised controlled trials provide little consensus on functional and behavioural symptoms in hypogonadal men; these are often better captured by qualitative information from individual patient experience.

METHODS

We systematically searched major electronic databases to identify qualitative data from men with hypogonadism, with or without TRT. Two independent authors performed the selection, extraction, and thematic analysis of data. Quality of eligible studies was assessed using the Critical Appraisals Skills Programme and Grading of Recommendations Assessment, Development and Evaluation-Confidence in the Evidence from Reviews of Qualitative research tools.

RESULTS

We analysed data from five studies published in nine reports that assessed a total of 284 participants. Published data were only available within North America, with no ethnic minority or other underserved groups included. In addition to sexual dysfunction, men with MH experienced adverse changes in physical strength, perceptions of masculinity, cognitive function, and quality of life. The experience of MH appeared dependent on the source(s) of educational material.

DISCUSSION

We propose a patient-centred approach to clinician interactions rather than focusing on discreet MH symptoms. Current evidence about the experience of MH is limited to North America and predominantly white ethnicity, which may not be broadly applicable to other geographic regions. Broadening our understanding of the MH experience may improve the targeting of information to patients. In addition, a multidisciplinary approach may better address symptoms neither attributable to MH nor alleviated by TRT.

Synthesis, In Silico, and Biological Evaluation of a Borinic Tryptophan-Derivative That Induces Melatonin-like Amelioration of Cognitive Deficit in Male Rat

Preclinical and clinical evidence supports melatonin and its analogues as potential treatment for diseases involving cognitive deficit such as Alzheimer's disease. In this work, we evaluated by in silico studies a set of boron-containing melatonin analogues on MT1 and MT2 receptors. Then, we synthesized a compound (borolatonin) identified as potent agonist. After chemical characterization, its evaluation in a rat model with cognitive deficit showed that it induced ameliorative effects such as those induced by equimolar administration of melatonin in behavioral tests and in neuronal immunohistochemistry assays. Our results suggest the observed effects are by means of action on the melatonin system. Further studies are required to clarify the mechanism(s) of action, as the beneficial effects on disturbed memory by gonadectomy in male rats are attractive.

The Benefits and Risks of Testosterone Treatment in Older Hypogonadal Men

As men age, their serum testosterone concentrations decrease-the total testosterone very little but the free testosterone more. Testosterone treatment of older men whose serum testosterone concentrations are unequivocally low to bring their testosterone levels to normal for young men improves their sexual function, walking, mood, bone mineral density, and hemoglobin, but does not improve their sense of vitality or cognitive function. This treatment has also been suspected of increasing the risk of prostate cancer, benign prostatic hyperplasia, and heart disease, but these possible risks have neither been confirmed nor refuted.

Distinct and Convergent Beneficial Effects of Estrogen and Insulin on Cognitive Function in Healthy Young Men

CONTEXT

Systematic investigations into the cognitive impact of estradiol and insulin in male individuals are sparse, and it is unclear whether the 2 hormones interact to benefit specific cognitive functions in humans.

OBJECTIVE

We investigated the acute effect of estradiol and insulin and of their combined administration on divergent (creative) and convergent (arithmetical) thinking as well as short-term and working verbal memory in healthy young men.

METHODS

According to a 2 × 2 design, 2 groups of men (each n = 16) received a 3-day transdermal estradiol (100 µg/24 h) or placebo pretreatment and on 2 separate mornings were intranasally administered 160 IU regular human insulin and, respectively, placebo before completing a battery of cognitive tests; we also determined relevant blood parameters.

RESULTS

Estrogen compared with placebo treatment induced a 3.5-fold increase in serum estradiol and suppressed serum testosterone concentrations by 70%. Estrogen in comparison to placebo improved creative performance, that is, verbal fluency and flexibility, but not arithmetical thinking, as well as verbal short-term memory, but not visuospatial memory. The combination of estrogen and insulin enhanced recognition discriminability at delayed verbal memory recall; insulin alone remained without effect.

CONCLUSION

Estrogen specifically enhances core aspects of creativity and verbal memory in young male individuals; delayed recognition memory benefits from the combined administration of estradiol and insulin. Our results indicate that insulin's acute cognitive impact in young men is limited and not robustly potentiated by estradiol. Estradiol per se exerts a beneficial acute effect on creative and verbal performance in healthy young men.

Role of circulating molecules in age-related cardiovascular and metabolic disorders

Studies analyzing heterochronic parabiosis mice models showed that molecules in the blood of young mice rejuvenate aged mice. Therefore, blood-based therapies have become one of the therapeutic approaches to be considered for age-related diseases. Blood includes numerous biologically active molecules such as proteins, metabolites, hormones, miRNAs, etc. and accumulating evidence indicates some of these change their concentration with chronological aging or age-related disorders. The level of some circulating molecules showed a negative or positive correlation with all-cause mortality, cardiovascular events, or metabolic disorders. Through analyses of clinical/translation/basic research, some molecules were focused on as therapeutic targets. One approach is the supplementation of circulating anti-aging molecules. Favorable results in preclinical studies let some molecules to be tested in humans. These showed beneficial or neutral results, and some were inconsistent. Studies with rodents and humans indicate circulating molecules can be recognized as biomarkers or therapeutic targets mediating their pro-aging or anti-aging effects. Characterization of these molecules with aging, testing their biological effects, and finding mimetics of young systemic milieu continue to be an interesting and important research topic to be explored.

Impact of Testosterone on Alzheimer's Disease

Alzheimer’s disease (AD) is a neurodegenerative disease responsible for almost half of all dementia cases in the world and progressively increasing. The etiopathology includes heritability, genetic factors, aging, nutrition, but sex hormones play a relevant role. Animal models demonstrated that testosterone (T) exerted a neuroprotective effect reducing the production of amyloid-beta (Aβ), improving synaptic signaling, and counteracting neuronal death. This study aims to evaluate the impact of T deprivation and T administration in humans on the onset of dementia and AD. A search was conducted on MEDLINE and Scopus for the “androgen deprivation therapy” and “testosterone therapy” with “dementia” and “Alzheimer’s.” Studies lasting twenty years with low risk of bias, randomized clinical trial, and case-controlled studies were considered. Twelve articles on the effect of androgen deprivation therapy (ADT) and AD and seventeen on T therapy and AD were retrieved. Men with prostate cancer under ADT showed a higher incidence of dementia and AD. The effect of T administration in hypogonadal men with AD and cognitive impairment has evidenced some positive results. The majority of studies showed the T administration improved memory and cognition in AD while others did not find any benefit. Although some biases in the studies are evident, T therapy for AD patients may represent an essential clinical therapy to reduce dementia incidence and AD progression. However, more specific case-controlled trials on the effect of androgens therapy in men and women to reducing the onset of AD are necessary.

Neurodegenerative Disease: Roles for Sex, Hormones, and Oxidative Stress

Neurodegenerative diseases cause severe impairments in cognitive and motor function. With an increasing aging population and the onset of these diseases between 50 and 70 years, the consequences are bound to be devastating. While age and longevity are the main risk factors for neurodegenerative diseases, sex is also an important risk factor. The characteristic of sex is multifaceted, encompassing sex chromosome complement, sex hormones (estrogens and androgens), and sex hormone receptors. Sex hormone receptors can induce various signaling cascades, ranging from genomic transcription to intracellular signaling pathways that are dependent on the health of the cell. Oxidative stress, associated with aging, can impact the health of the cell. Sex hormones can be neuroprotective under low oxidative stress conditions but not in high oxidative stress conditions. An understudied sex hormone receptor that can induce activation of oxidative stress signaling is the membrane androgen receptor (mAR). mAR can mediate nicotinamide adenine dinucleotide-phosphate (NADPH) oxidase (NOX)-generated oxidative stress that is associated with several neurodegenerative diseases, such as Alzheimer disease. Further complicating this is that aging can alter sex hormone signaling. Prior to menopause, women experience more estrogens than androgens. During menopause, this sex hormone profile switches in women due to the dramatic ovarian loss of 17β-estradiol with maintained ovarian androgen (testosterone, androstenedione) production. Indeed, aging men have higher estrogens than aging women due to aromatization of androgens to estrogens. Therefore, higher activation of mAR-NOX signaling could occur in menopausal women compared with aged men, mediating the observed sex differences. Understanding of these signaling cascades could provide therapeutic targets for neurodegenerative diseases.

Improving clinical outcomes through attention to sex and hormones in research

Biological sex, fluctuations in sex steroid hormones throughout life and gender as a social construct all influence every aspect of health and disease. Yet, for decades, most basic and clinical studies have included only male individuals. As modern health care moves towards personalized medicine, it is clear that considering sex and hormonal status in basic and clinical studies will bring precision to the development of novel therapeutics and treatment paradigms. To this end, funding, regulatory and policy agencies now require inclusion of female animals and women in basic and clinical studies. However, inclusion of female animals and women often does not mean that information regarding potential hormonal interactions with pharmacological treatments or clinical outcomes is available. All sex steroid hormones can interact with receptors for drug targets, metabolism and transport. Genetic variation in receptors or in enzymatic function might contribute to sex differences in therapeutic efficacy and adverse drug reactions. Outcomes from clinical trials are often not reported by sex, and, if the data are available, they are not translated into clinical practice guidelines. This Review will provide a historical perspective for the current state of research related to hormone trials and provide concrete strategies that, if implemented, will improve the health of all people.

Systems Analysis Reveals Ageing-Related Perturbations in Retinoids and Sex Hormones in Alzheimer's and Parkinson's Diseases

Neurodegenerative diseases, including Alzheimer's (AD) and Parkinson's diseases (PD), are complex heterogeneous diseases with highly variable patient responses to treatment. Due to the growing evidence for ageing-related clinical and pathological commonalities between AD and PD, these diseases have recently been studied in tandem. In this study, we analysed transcriptomic data from AD and PD patients, and stratified these patients into three subclasses with distinct gene expression and metabolic profiles. Through integrating transcriptomic data with a genome-scale metabolic model and validating our findings by network exploration and co-analysis using a zebrafish ageing model, we identified retinoids as a key ageing-related feature in all subclasses of AD and PD. We also demonstrated that the dysregulation of androgen metabolism by three different independent mechanisms is a source of heterogeneity in AD and PD. Taken together, our work highlights the need for stratification of AD/PD patients and development of personalised and precision medicine approaches based on the detailed characterisation of these subclasses.

Optimizing the Diagnostic Accuracy and Treatment Decisions in Men with Testosterone Deficiency

OBJECTIVE

This narrative review offers a guideline-based approach to optimizing the diagnostic evaluation and treatment decision-making in men being evaluated for testosterone deficiency.

METHODS

A narrative review RESULTS: Testosterone deficiency is a clinical syndrome that results from the inability of the testes to produce normal amounts of testosterone, and is characterized by a constellation of symptoms and signs associated with consistently low testosterone concentrations. The diagnosis of testosterone deficiency is made by ascertainment of symptoms and signs; measurement of total and, if indicated, free testosterone levels, in early morning fasting samples on 2 or more days; measurement of LH and FSH to distinguish primary from secondary hypogonadism; and additional evaluation to ascertain the cause of testosterone deficiency. Non-specificity of symptoms and signs; variations in testosterone levels over time; inaccuracy in the measurement of total and free testosterone levels; variations in binding protein concentrations; and the suboptimal reference ranges contribute to diagnostic inaccuracy. Testosterone treatment is indicated for men with symptomatic testosterone deficiency. Testosterone treatment should be avoided in men with prostate or breast cancer, erythrocytosis, thrombophilia, increased risk of prostate cancer or severe lower urinary tract symptoms without prior urological evaluation, recent major adverse cardiovascular event, uncontrolled heart failure or severe untreated sleep apnea. Testosterone replacement therapy should be accompanied by a standardized monitoring plan.

CONCLUSION

The shared decision to treat should be guided by consideration of the burden of symptoms, potential benefits and risks, patient's values, and the cost and burden of long-term treatment and monitoring.

Anabolic-Androgenic Steroid Use in Sports, Health, and Society

This consensus statement is an update of the 1987 American College of Sports Medicine (ACSM) position stand on the use of anabolic-androgenic steroids (AAS). Substantial data have been collected since the previous position stand, and AAS use patterns have changed significantly. The ACSM acknowledges that lawful and ethical therapeutic use of AAS is now an accepted mainstream treatment for several clinical disorders; however, there is increased recognition that AAS are commonly used illicitly to enhance performance and appearance in several segments of the population, including competitive athletes. The illicit use of AAS by competitive athletes is contrary to the rules and ethics of many sport governing bodies. Thus, the ACSM deplores the illicit use of AAS for athletic and recreational purposes. This consensus statement provides a brief history of AAS use, an update on the science of how we now understand AAS to be working metabolically/biochemically, potential side effects, the prevalence of use among athletes, and the use of AAS in clinical scenarios.

Androgen Misuse and Abuse

Androgens are potent drugs requiring prescription for valid medical indications but are misused for invalid, unproven, or off-label reasons as well as being abused without prescription for illicit nonmedical application for performance or image enhancement. Following discovery and first clinical application of testosterone in the 1930s, commercialization of testosterone and synthetic androgens proliferated in the decades after World War II. It remains among the oldest marketed drugs in therapeutic use, yet after 8 decades of clinical use, the sole unequivocal indication for testosterone remains in replacement therapy for pathological hypogonadism, organic disorders of the male reproductive system. Nevertheless, wider claims assert unproven, unsafe, or implausible benefits for testosterone, mostly representing wishful thinking about rejuvenation. Over recent decades, this created an epidemic of testosterone misuse involving prescription as a revitalizing tonic for anti-aging, sexual dysfunction and/or obesity, where efficacy and safety remains unproven and doubtful. Androgen abuse originated during the Cold War as an epidemic of androgen doping among elite athletes for performance enhancement before the 1980s when it crossed over into the general community to become an endemic variant of drug abuse in sufficiently affluent communities that support an illicit drug industry geared to bodybuilding and aiming to create a hypermasculine body physique and image. This review focuses on the misuse of testosterone, defined as prescribing without valid clinical indications, and abuse of testosterone or synthetic androgens (androgen abuse), defined as the illicit use of androgens without prescription or valid indications, typically by athletes, bodybuilders and others for image-oriented, cosmetic, or occupational reasons.

D-chiro-inositol, an aromatase down-modulator, increases androgens and reduces estrogens in male volunteers: a pilot study

BACKGROUND

Androgen deficiency affects men in the adulthood, causing several harmful effects at the reproductive and behavioural levels. Since aromatase is an enzyme that catalyses the conversion of androgens to estrogens, and it is responsible for an adequate balance of both sex hormones in males and females, the administration of molecules acting as down modulators may contribute to restore an abnormal enzymatic activity. A prospective pilot study was carried out to investigate the effect of D-chiro-inositol, a putative aromatase down-modulator, on serum levels of testosterone, estradiol, estrone, dehydroepiandrosterone and epiandrosterone from a group of adult male volunteers. Glucose, insulin, follicle-stimulating hormone, luteinizing hormone, inhibin B, D-chiro-inositol and myo-inositol serum levels were also measured.

RESULTS

Male volunteers were selected according to age and body mass index. Subjects with altered glycemia and/or hormonal status, due to advanced age or abnormal weight, were enrolled in the study. Each of the 10 volunteers enrolled took oral D-chiro-inositol (1 g/day) for 1 month. Serum assays of selected markers were performed at baseline (control) and after treatment. D-chiro-inositol administration was associated to reduced serum levels of estrone (- 85.0%) and estradiol (- 14.4%), and increased serum levels of testosterone (+ 23.4%) and dehydroepiandrosterone (+ 13.8%). In addition, epiandrosterone levels were higher (+39%) after treatment. On the other hand, follicle-stimulating hormone, luteinizing hormone and inhibin B did not change. A trend toward a decrease of glycemia, insulinemia and Homeostatic Model Assessment index was observed after D-chiro-inositol treatment, although differences did not reach statistical significance. D-chiro-inositol treatment did not cause any noticeable adverse effect.

CONCLUSIONS

Increased androgens and decreased estrogens seem to confirm that D-chiro-inositol acts as an aromatase down-modulator, but with a still unknown mechanism of action. This pilot study opens up new perspectives of research and therapeutic applications for D-chiro-inositol at different dosages and length of treatment. Authorization number 005/2020 released by the Local Ethics Committee of Alma Res Fertility Center, Rome.

TRIAL REGISTRATION NUMBER

NCT04615767 (registry: ClinicalTrials.gov) Date of registration: November 3, 2020.

Immune profiling of pituitary tumors reveals variations in immune infiltration and checkpoint molecule expression

PURPOSE

Pituitary tumors are the second most common primary brain tumors. Functional tumors demonstrate increased PD-L1 expression, but expression of other checkpoint regulators has not been characterized. We sought to characterize the immune microenvironment of human pituitary tumors to identify new treatment opportunities.

METHODS

72 pituitary tumors were evaluated for expression of the immune regulatory markers programmed death ligand 1 (PD-L1), programmed death ligand 2 (PD-L2), V-domain Ig suppressor of T cell activation (VISTA), lymphocyte activation gene 3 (LAG3) and tumor necrosis factor receptor superfamily member 4 (OX40) by immunohistochemistry (IHC). Lymphocyte infiltration, macrophage infiltration, and angiogenesis were analyzed using IHC. Expression of pituitary tumor initiating cell marker CD15 and mismatch repair proteins MutS protein homolog 2 (MSH2) and MutS protein homolog 6 (MSH6) was also assessed.

RESULTS

Pituitary tumors were infiltrated by macrophages and T cells, and they expressed varying levels of PD-L1, PD-L2, VISTA, LAG3, and OX40. Functional tumors and tumors with high expression of tumor stem cell markers had higher immune cell infiltration and greater expression of immunosuppressive checkpoint regulators. Increased PD-L1 and LAG3 and reduced VISTA were observed in primary tumors compared to recurrent tumors.

CONCLUSION

Immune cell infiltration and checkpoint regulator expression vary depending on functional status and presence of pituitary tumor initiating cells. Functional tumors may have a particularly immunosuppressive microenvironment. Further studies of immune checkpoint blockade of pituitary tumors, particularly functional tumors, are warranted, though combination therapy may be required.

Testosterone Therapy for the Treatment of Age-Related Hypogonadism: Risks with Uncertain Benefits

Testosterone replacement therapy has been approved in the United States since the 1950s for men with “classical” hypogonadism. These men have specific and well-recognized hypothalamic, pituitary, or testicular conditions leading to deficient or absent endogenous testosterone. A more controversial treatment population is aging men, many with comorbidities, who have low serum testosterone concentrations compared with young healthy men and who do not have the well-recognized medical conditions that cause “classical” hypogonadism. Testosterone continues to be widely used in these men with “age-related hypogonadism” even though the benefits of testosterone for this use are uncertain and there are important risks, including a potential risk of major adverse cardiac events for the testosterone class, and two testosterone products with increases in blood pressure that can increase the risk of myocardial infarction and stroke. Given the uncertain clinical benefit of testosterone in men with “age-related hypogonadism” in the face of known and potential adverse outcomes, none of the testosterone products is FDA approved for such use.

Androgen receptor CAG repeat length as a moderator of the relationship between free testosterone levels and cognition

Age-related decrease in testosterone levels is a potential risk factor for cognitive decline in older men. However, observational studies and clinical trials have reported inconsistent results on the effects of testosterone on individual cognitive domains. Null findings may be attributed to factors that studies have yet to consider. In particular, individual variations in polyglutamine (CAG) length in the androgen receptor (AR) gene could alter androgenic activity in brain regions associated with cognitive processes including memory and executive functions. However, the role of AR CAG repeat length as a moderator of the relationship between testosterone levels and cognition has not been investigated. Therefore, we aimed to examine the relationship between baseline calculated free testosterone (cFT) levels, change in cFT levels over 18 months and CAG repeat length on cognitive performance in memory, executive function, language, attention and processing speed domains. These relationships were examined in 304 cognitively normal older male participants of the Australian Imaging, Biomarkers and Lifestyle (AIBL) Study of Ageing. In the attention and processing speed domain, a short CAG repeat length appears to exacerbate the effects of low baseline cFT levels that are also lower than expected at follow-up. These results highlight that individual variations in AR CAG repeat length should be considered in future studies and clinical trials that examine the complex relationship between testosterone and cognition.

Hormonal and Metabolic Changes of Aging and the Influence of Lifestyle Modifications

Increased life expectancy combined with the aging baby boomer generation has resulted in an unprecedented global expansion of the elderly population. The growing population of older adults and increased rate of age-related chronic illness has caused a substantial socioeconomic burden. The gradual and progressive age-related decline in hormone production and action has a detrimental impact on human health by increasing risk for chronic disease and reducing life span. This article reviews the age-related decline in hormone production, as well as age-related biochemical and body composition changes that reduce the bioavailability and actions of some hormones. The impact of hormonal changes on various chronic conditions including frailty, diabetes, cardiovascular disease, and dementia are also discussed. Hormone replacement therapy has been attempted in many clinical trials to reverse and/or prevent the hormonal decline in aging to combat the progression of age-related diseases. Unfortunately, hormone replacement therapy is not a panacea, as it often results in various adverse events that outweigh its potential health benefits. Therefore, except in some specific individual cases, hormone replacement is not recommended. Rather, positive lifestyle modifications such as regular aerobic and resistance exercise programs and/or healthy calorically restricted diet can favorably affect endocrine and metabolic functions and act as countermeasures to various age-related diseases. We provide a critical review of the available data and offer recommendations that hopefully will form the groundwork for physicians/scientists to develop and optimize new endocrine-targeted therapies and lifestyle modifications that can better address age-related decline in heath.

Sex hormones and cognition in aging

Hormones of the hypothalamic-pituitary-gonadal axis that regulate reproductive function are also potent neurosteriods that have multiple effects on the development, maintenance and function of the brain. There is a growing body of evidence linking sex hormones to cognitive functioning across the lifespan. Both subjective and objective cognitive changes can occur with aging. For women, cognitive complains are commonly associated with the menopause transition-a time of significant hormone flux. Sex differences in neurodegenerative conditions associated with cognitive dysfunction, such as Alzheimer's disease and Parkinson's disease, suggest a potential link between sex hormones and cognitive decline. Evidence for the effects of hormone therapy on cognition is growing, but remains inconclusive. This chapter provides an overview of sex hormones and cognition in association with healthy aging, including a focus on the menopause transition, as well as reviewing findings linking sex hormones to cognitive decline associated with Alzheimer's disease and Parkinson's disease. An overview of hormone therapy and cognition is also provided.

Sex differences of oxytocin and vasopressin in social behaviors

The neuropeptides oxytocin (OT) and vasopressin (VP) are known to mediate social cognition and behaviors in a sex-dependent manner. This chapter reviews the sex-dependent influence of OT and VP on social behaviors, focusing on (1) partner preference and sexual orientation, (2) memory modulation, (3) emotion regulation, and (4) trust-related behaviors. Most studies suggest that OT promotes familiar (opposite-sex) partner preference, strengthens memory, relieves anxiety, and increases trust. However, VP-regulated social cognition has been studied less than OT. VP facilitates familiar (opposite-sex) partner preference, enhances memory, induces anxiety, and influences happiness/anger perception. Detailed sex differences of these effects are reviewed. There is a male preponderance in the use of animal models and many study results are too complex to draw firm conclusions. Clarifying the complex interplay between the OT/VP system and sex hormones in the regulation of social behaviors is needed.

Preserving Well-being in Patients With Advanced and Late Prostate Cancer

Androgen deprivation therapy, alone or in combination with androgen signaling inhibitors, is a treatment option for patients with advanced prostate cancer (PC). When making treatment decisions, health care providers must consider the long-term effects of treatment on the patient's overall health and well-being. Herein, we review the effects of these treatments on the musculoskeletal and cardiovascular systems, cognition, and fall risk, and provide management approaches for each. We also include an algorithm to help health care providers implement best clinical practices and interdisciplinary care for preserving the overall well-being of PC patients.

Association of Androgens and Gonadotropins with Amnestic Mild Cognitive Impairment and Probable Alzheimer’s Disease in Chinese Elderly Men

Background: Age-related hormone changes play important roles in cognitive decline in older men, and apolipoprotein E ɛ4 (APOE ɛ4) is a risk factor for Alzheimer’s disease (AD). Objective: This study aimed to investigate the interactive role of androgen decline and APOE ɛ4 genotype in the pathogenesis of amnestic mild cognitive impairment (aMCI) and AD. Methods: In total, 576 elderly men over 65 years old from communities in Shijiazhuang were enrolled in this study, including 243 with normal cognition (NC), 271 with aMCI, and 62 with probable AD. Cognitive function was evaluated with a battery of neuropsychological tests. The serum levels of androgen and gonadotropin were detected by ELISA and chemiluminescence immunoassay. Results: The levels of free testosterone (FT) and dihydrotestosterone (DHT) were lower in the aMCI group (p < 0.05), and even lower in the AD group (p < 0.001), but the levels of follicle stimulating hormone (FSH) and luteinizing hormone (LH) were higher in AD group (p < 0.01), comparing with that in NC or aMCI group. The interaction of lower FT or DHT levels with APOE ɛ4 had a risk role in global cognitive impairment (p < 0.05). The area under the curve (AUC) of the ROC curve for predicting aMCI by serum FT levels was 0.745. Conclusion: These results indicated that the interaction of androgen decline and APOE ɛ4 genotype play a role in aMCI and AD. Serum FT levels have a predictive value for aMCI and might be a potential biomarker for prodromal AD.

Age-Related Male Hypogonadism and Cognitive Impairment in the Elderly: Focus on the Effects of Testosterone Replacement Therapy on Cognition

BACKGROUND

Epidemiological data report that male hypogonadism may play a role in cognitive impairment in elderly. However, the effect of testosterone replacement therapy (TRT) on cognitive abilities in this cluster of patients has not been well established. Methods. PubMed/MEDLINE, Google Scholar, Cochrane Library, and Web of Science were searched by using free text words and medical subject headings terms related with "male hypogonadism", "late-onset hypogonadism", elderly, cognition, "mild cognitive impairment", memory, "testosterone replacement therapy" used in various combinations according to the specific clinical questions. Original articles, reviews, and randomized controlled trials written in English were selected. Results. A long-term TRT could improve specific cognitive functions, such as verbal and spatial memory, cognitive flexibility, and physical vitality. However, randomized controlled trials do not provide positive results, and in most of the cases TRT might not induce beneficial effects on cognitive function in elderly men. Discussion and conclusions. Since the lengthening of life expectancy, the prevalence rate of cognitive decline in elderly men is expected to increase remarkably over the next decade with considerable healthcare and economical concerns. Therefore, this remains a relevant clinical topic and further investigations are needed for clarifying the role of TRT especially in elderly men with hypogonadism.

Low Testosterone on Social Media: Application of Natural Language Processing to Understand Patients' Perceptions of Hypogonadism and Its Treatment

BACKGROUND

Despite the results of the Testosterone Trials, physicians remain uncomfortable treating men with hypogonadism. Discouraged, men increasingly turn to social media to discuss medical concerns.

OBJECTIVE

The goal of the research was to apply natural language processing (NLP) techniques to social media posts for identification of themes of discussion regarding low testosterone and testosterone replacement therapy (TRT) in order to inform how physicians may better evaluate and counsel patients.

METHODS

We retrospectively extracted posts from the Reddit community r/Testosterone from December 2015 through May 2019. We applied an NLP technique called the meaning extraction method with principal component analysis (MEM/PCA) to computationally derive discussion themes. We then performed a prospective analysis of Twitter data (tweets) that contained the terms low testosterone, low T, and testosterone replacement from June through September 2019.

RESULTS

A total of 199,335 Reddit posts and 6659 tweets were analyzed. MEM/PCA revealed dominant themes of discussion: symptoms of hypogonadism, seeing a doctor, results of laboratory tests, derogatory comments and insults, TRT medications, and cardiovascular risk. More than 25% of Reddit posts contained the term doctor, and more than 5% urologist.

CONCLUSIONS

This study represents the first NLP evaluation of the social media landscape surrounding hypogonadism and TRT. Although physicians traditionally limit their practices to within their clinic walls, the ubiquity of social media demands that physicians understand what patients discuss online. Physicians may do well to bring up online discussions during clinic consultations for low testosterone to pull back the curtain and dispel myths.