Cardiovascular and cancer safety of testosterone in women

Androgen-based therapies in women

Androgens play a key biological role in libido and sexual arousal in women, and knowledge about their complex role in other systems remains ambiguous and incomplete. This narrative review examines the role of endogenous androgens in women's health throughout the life span before focusing on evidence surrounding the use of androgen-based therapies to treat postmenopausal women. The role of testosterone as a therapeutic agent in women continues to attract controversy as approved preparations are rare, and use of off-label and compounded formulations is widespread. Despite this androgen therapy has been used for decades in oral, injectable, and transdermal formulations. Responses to androgen therapy have been demonstrated to improve aspects of female sexual dysfunction, notably hypoactive sexual desire disorder, in a dose related manner. Substantial research has also been conducted into the role of androgens in treating aspects of the genitourinary syndrome of menopause (GSM). Evidence for benefits beyond these is mixed and more research is required regarding long-term safety. However, It remains biologically plausible that androgens will be effective in treating hypoestrogenic symptoms related to menopause, either through direct physiological effects or following aromatization to estradiol throughout the body.

Cardiovascular Safety and Benefits of Testosterone Implant Therapy in Postmenopausal Women: Where Are We?

We discuss the CV safety and efficacy data for subcutaneous testosterone therapy (STT) in postmenopausal women. We also highlight new directions and applications of correct dosages performed in a specialized center. To recommend STT, we propose innovative criteria (IDEALSTT) according to total testosterone (T) level, carotid artery intima-media thickness, and calculated SCORE for a 10-year risk of fatal cardiovascular disease (CVD). Despite all the controversies, hormone replacement therapy (HRT) with T has gained prominence in treating pre and postmenopausal women in the last decades. HRT with silastic and bioabsorbable testosterone hormone implants has gained prominence recently due to its practicality and effectiveness in treating menopausal symptoms and hypoactive sexual desire disorder. A recent publication on the complications of STT, looking at a large cohort of patients over seven years, demonstrated its long-term safety. However, the cardiovascular (CV) risk and safety of STT in women are still controversial.

Individual Benefits and Risks of Intravaginal Estrogen and Systemic Testosterone in the Management of Women in the Menopause, With a Discussion of Any Associated Risks for Cancer Development

ABSTRACT

Several formulations of intravaginal oestrogen are available for the treatment of genitourinary syndrome of menopause (GSM). These are safe and effective treatments for the symptoms of GSM. Licensed doses of intravaginal oestrogen do not elevate systemic estradiol levels above the normal postmenopausal range with long term use and there is no evidence of an increased risk of coronary heart disease, stroke, thromboembolism, colorectal cancer, endometrial cancer, breast cancer or breast cancer recurrence with their use. This should reassure both women and their healthcare professionals and should lead to more women receiving these localised, vaginally administered hormonal treatments. Available evidence also suggests a positive safety profile for transdermal testosterone treatment when delivered at physiological concentrations.

Androgen therapy for women after menopause

Androgens are essential hormones in women. Yet, androgen therapy is understudied and underutilized despite showing improvement in postmenopausal hypoactive sexual desire disorder (HSDD) and the genitourinary syndrome of menopause (GSM). Additionally, regulatory concerns have left a significant gap in commercially available testosterone preparations, formulated specifically for women, in most countries. This has led to off-label use of male formulations and compounded therapies which are under-regulated. Beyond HSDD and GSM, testosterone likely influences the brain, breast, cardiovascular and musculoskeletal systems. These effects are not well studied, and therefore it is difficult to counsel patients on testosterone therapy when used for these endpoints. Ultimately, further study is needed to elucidate these effects, create a fuller picture of the risks and benefits, and encourage product development specifically designed for women.

The testosterone prescribing practice of BMS menopause specialists

The NICE Guidelines published in 2015 state that testosterone supplementation can be considered for menopausal women with low sexual desire if hormone replacement therapy alone is not effective. There is however, no detail on what to prescribe, how much to prescribe or whether monitoring is required. At the time of conception of this project, there was no national guideline or official advice from the British Menopause Society. We decided to ask menopause experts from around the UK to see if a consensus could be reached about good prescribing practice. The method and results as discussed below may be helpful in future recommendations and guidance.

Risks of Testosterone for Postmenopausal Women

Transdermal testosterone therapy, dosed within premenopausal physiologic testosterone ranges, used alone or with menopausal hormone therapy for postmenopausal hypoactive sexual desire disorder, has shown short-term efficacy, with few androgenic side effects. After natural or surgical menopause, meaningful improvements include an additional satisfying sexual episode per month; improvement in desire, arousal, orgasm, pleasure, and responsiveness; and a reduction in distress. Long-term data on cardiovascular, cancer, and cognitive safety are lacking. No approved testosterone preparation is available for women. Compounded testosterone creams or reduced dosing of male-approved therapies represent off-label use. Injections or pellets cause supraphysiological testosterone levels and are not recommended.

Sex-Specific Associations of Testosterone and Genetic Factors With Health Span

BACKGROUND

Previous studies have suggested associations between testosterone, genetic factors, and a series of complex diseases, but the associations with the lifespan phenotype, such as health span, remain unclear.

METHODS

In this prospective cohort study, we analyzed 145,481 men and 147,733 women aged 38-73 years old from UK Biobank (UKB) to investigate the sex-specific associations of total testosterone (TT), free testosterone (FT), or polygenic risk score (PRS) with health span termination (HST) risk. At baseline, serum testosterone levels were measured. HST was defined by eight events strongly associated with longevity. PRS, an efficient tool combining the effect of common genetic variants to discriminate genetic risk of complex phenotypes, was constructed by 12 single-nucleotide polymorphisms related to health span from UKB (P ≤ 5.0 × 10^-8). We used multivariable Cox regression models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

With a median follow-up time of 7.70 years, 26,748 (18.39%) men and 18,963 (12.84%) women had HST. TT was negatively associated with HST in men [HR per standard deviation (SD) increment of log-TT: 0.92, 95% CI: 0.88-0.97]. Inversely, both TT (HR per SD increment of log-TT: 1.05, 95% CI: 1.02-1.08) and FT (HR per SD increment of log-FT: 1.08, 95% CI: 1.05-1.11) presented an increased risk of HST in women. PRS was positively associated with HST risk (quintile 5 versus quintile 1, men, HR: 1.19, 95% CI: 1.15-1.24; women, HR: 1.21, 95% CI: 1.16-1.27). Moreover, men with high TT and low genetic risk showed the lowest HST risk (HR: 0.80, 95% CI: 0.73-0.88), whereas HST risk for women with both high TT and genetic risk increased obviously (HR: 1.32, 95% CI: 1.19-1.46). Similar joint effects were observed for FT in both genders.

CONCLUSIONS

We observed sex-specific associations that testosterone was negatively associated with HST risk in men and positively associated with HST risk in women. Genetic factors increased the HST risk, suggesting that participants with both high genetic risk and abnormal testosterone levels (high level in women or low level in men) should be the target for early intervention. Although our findings highlight the associations between testosterone and health span, further mechanistic studies and prospective trials are warranted to explore the causation behind.

Thrombotic issues in transgender medicine: A review

Clinicians, including hematologists, are more frequently encountering transgender individuals in practice; however, most lack training on the management and complications of transgender medicine. Hormonal therapy forms the backbone of medical interventions for patients undergoing gender transition. While supplementing an individual's intrinsic sex hormone is associated with a variety of hematologic complications including increased rates of venous thrombosis, cardiovascular events, erthyrocytosis, and malignancy, the risks of supplementing with opposing sex hormones are not well understood. Data on the hematologic complications of these therapies are accumulating but remain limited, and clinicians have little experience with their management. This review highlights the current interventions available in transgender medicine and related potential hematologic complications, and it suggests simple, evidence-based management going forward. Am. J. Hematol. 92:204-208, 2017. © 2016 Wiley Periodicals, Inc.

Androgens and Female Sexual Function and Dysfunction--Findings From the Fourth International Consultation of Sexual Medicine

INTRODUCTION

Androgens have been implicated as important for female sexual function and dysfunction.

AIM

To review the role of androgens in the physiology and pathophysiology of female sexual functioning and the evidence for efficacy of androgen therapy for female sexual dysfunction (FSD).

METHODS

We searched the literature using online databases for studies pertaining to androgens and female sexual function. Major reviews were included and their findings were summarized to avoid replicating their content.

MAIN OUTCOME MEASURES

Quality of data published in the literature and recommendations were based on the GRADES system.

RESULTS

The literature supports an important role for androgens in female sexual function. There is no blood androgen level below which women can be classified as having androgen deficiency. Clinical trials have consistently demonstrated that transdermal testosterone (T) therapy improves sexual function and sexual satisfaction in women who have been assessed as having hypoactive sexual desire disorder. The use of T therapy is limited by the lack of approved formulations for women and long-term safety data. Most studies do not support the use of systemic dehydroepiandrosterone therapy for the treatment of FSD in women with normally functioning adrenals or adrenal insufficiency. Studies evaluating the efficacy and safety of vaginal testosterone and dehydroepiandrosterone for the treatment of vulvovaginal atrophy are ongoing.

CONCLUSION

Available data support an important role of androgens in female sexual function and dysfunction and efficacy of transdermal T therapy for the treatment of some women with FSD. Approved T formulations for women are generally unavailable. In consequence, the prescribing of T mostly involves off-label use of T products formulated for men and individually compounded T formulations. Long-term studies to determine the safety of T therapy for women and possible benefits beyond that of sexual function are greatly needed.

Hypoactive Sexual Desire Disorder: A Review of Epidemiology, Biopsychology, Diagnosis, and Treatment

INTRODUCTION

Hypoactive Sexual Desire Disorder (HSDD) is defined in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Revised (DSM-IV-TR) as persistent deficient sexual fantasies and desire for sexual activity that causes marked distress or interpersonal difficulty. In the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), HSDD has been subsumed by Female Sexual Interest/Arousal Disorder. However, decades of research based on DSM-IV-TR HSDD criteria form the foundation of our understanding of the essential symptom of distressing low sexual desire, its epidemiology, clinical management, and treatment.

AIM

This publication reviews the state of knowledge about HSDD.

METHODS

A literature search was performed using terms HSDD and female sexual dysfunction (FSD).

MAIN OUTCOME MEASURES

Physicians acknowledge that FSD is common and distressing; however, they infrequently address it, citing low confidence, time constraints, and lack of treatment as barriers.

RESULTS

HSDD is present in 8.9% of women ages 18 to 44, 12.3% ages 45 to 64, and 7.4% over 65. Although low sexual desire increases with age, distress decreases; so prevalence of HSDD remains relatively constant across age. HSDD is associated with lower health-related quality of life; lower general happiness and satisfaction with partners; and more frequent negative emotional states. HSDD is underdetected and undertreated. Less than half of patients with sexual problems seek help from or initiate discussions with physicians. Patients are inhibited by fear of embarrassing physicians and believe that physicians should initiate discussions. The Decreased Sexual Desire Screener, a tool for detecting and diagnosing HSDD, is validated for use in general practice.

CONCLUSION

Women can benefit from intervention in primary care, behavioral health and sexual medicine settings. Psychotherapeutic and pharmacological interventions aim to enhance sexual excitatory process and decrease inhibitory processes. Flibanserin, the first centrally acting daily medication for HSDD, was recently approved in the US for premenopausal women.

Testosterone in women--the clinical significance

Testosterone is an essential hormone for women, with physiological actions mediated directly or via aromatisation to oestradiol throughout the body. Despite the crucial role of testosterone and the high circulating concentrations of this hormone relative to oestradiol in women, studies of its action and the effects of testosterone deficiency and replacement in women are scarce. The primary indication for the prescription of testosterone for women is loss of sexual desire, which causes affected women substantial concern. That no formulation has been approved for this purpose has not impeded the widespread use of testosterone by women--either off-label or as compounded therapy. Observational studies indicate that testosterone has favourable cardiovascular effects measured by surrogate outcomes; however, associations between endogenous testosterone and the risk of cardiovascular disease and total mortality, particularly in older women, are yet to be established. Adverse cardiovascular effects have not been seen in studies of transdermal testosterone therapy in women. Clinical trials suggest that exogenous testosterone enhances cognitive performance and improves musculoskeletal health in postmenopausal women. Unmet needs include the availability of approved testosterone formulations for women and studies to elucidate the contribution of testosterone to cardiovascular, cognitive, and musculoskeletal health and the risk of cancer.

Menopause

Menopause is an inevitable component of ageing and encompasses the loss of ovarian reproductive function, either occurring spontaneously or secondary to other conditions. It is not yet possible to accurately predict the onset of menopause, especially early menopause, to give women improved control of their fertility. The decline in ovarian oestrogen production at menopause can cause physical symptoms that may be debilitating, including hot flushes and night sweats, urogenital atrophy, sexual dysfunction, mood changes, bone loss, and metabolic changes that predispose to cardiovascular disease and diabetes. The individual experience of the menopause transition varies widely. Important influential factors include the age at which menopause occurs, personal health and wellbeing, and each woman's environment and culture. Management options range from lifestyle assessment and intervention through to hormonal and non-hormonal pharmacotherapy, each of which has specific benefits and risks. Decisions about therapy for perimenopausal and postmenopausal women depend on symptomatology, health status, immediate and long-term health risks, personal life expectations, and the availability and cost of therapies. More effective and safe therapies for the management of menopausal symptoms need to be developed, particularly for women who have absolute contraindications to hormone therapy. For an illustrated summary of this Primer, visit: http://go.nature.com/BjvJVX.

Transdermal testosterone improves verbal learning and memory in postmenopausal women not on oestrogen therapy

OBJECTIVE

The aim of this study was to examine the effects of testosterone on verbal learning and memory in postmenopausal women.

DESIGN

Randomized, placebo-controlled trial in which participants were randomized (1:1) to transdermal testosterone gel 300 mcg/day, or identical placebo, for 26 weeks.

PATIENTS

Ninety-two postmenopausal women aged 55-65 years, on no systemic sex hormone therapy.

MEASUREMENTS

The primary outcome was the score for the International Shopping List Task (ISLT) of CogState. Secondary outcomes included other CogState domains, the Psychological General Well-Being Index (PGWB) and safety variables.

RESULTS

Eighty-nine women, median age 60 years, were included in the primary analysis. Testosterone treatment resulted in statistically significantly better performance for the ISLT (improved verbal learning and memory) compared with placebo, adjusted for age and baseline score (mean difference 1·57; 95%CI 0·13, 3·01) P = 0·03). There were no significant differences for other CogState domains or the PGWB scores. At 26 weeks, the median total testosterone was 1·7 nm (interquartile range (IQR) 1·1, 2·4) in the testosterone group and 0·4 nm (IQR 0·3, 0·5) in the placebo group.

CONCLUSIONS

The small but statistically significant effect of testosterone treatment on verbal learning and memory in postmenopausal women provides the basis for further clinical trials.

The safety of testosterone therapy in women

Hypoactive sexual desire disorder (HSDD), a subset of female sexual dysfunction, causes personal distress for surgically and naturally postmenopausal and premenopausal women. HSDD has a multi-factorial etiology, including psychosocial factors such as relationship issues and medical factors such as medications, chronic illnesses, and hormonal effects. Although no androgen therapies for female sexual dysfunction are currently approved for use in Canada, clinical trials support the efficacy and short-term safety of testosterone therapy for HSDD. We review the scientific evidence for the safety of testosterone therapy for HSDD.

Androgens for postmenopausal women's health?

Obesity, metabolic syndrome, and diabetes are becoming a leading health concern in the developed Countries, due to their link to cardiovascular disease. These conditions are common in women in the post-menopausal period. Unfortunately, actual lifestyle change strategy fail to prevent cardiovascular events for several reasons, thus specific medications are needed. In addition, it was showed an increased cardiovascular diseases and breast cancer risk in postmenopausal women taking estrogens alone or with progestin, thus the optimal therapy for the prevention of chronic disease in women is still lacking. Androgens exert different actions on organs like adipose tissue, brain, bone, and on cardiovascular system. However, a debate still exists on the positive role of androgens on human health, especially in women. Furthermore, the vascular effects of androgens remain poorly understood and have been controversial for a long time. Sex hormones are important determinants of body composition. Aging is, often, accompanied by a decrease in free testosterone levels, a concomitant reduction in muscle mass and an increase in fat mass. Furthermore, numerous studies showed that total serum testosterone levels were inversely related to the atherosclerosis disease incidence in postmenopausal women. New therapeutic targets may, therefore, arise understanding how androgen could influence the fat distribution, the metabolic disease onset, the vascular reactivity and cardiovascular risk, in both sex.

The contribution of SHBG to the variation in HOMA-IR is not dependent on endogenous oestrogen or androgen levels in postmenopausal women

OBJECTIVE

Sex hormone-binding globulin (SHBG) is a robust predictor of insulin resistance. Whether this is independent of circulating sex steroid levels remains uncertain. The aim of this study was to investigate the determinants of SHBG in postmenopausal women and whether the relationship between SHBG and insulin resistance is independent of oestrogen and androgen levels.

DESIGN

A cross-sectional study of naturally and surgically menopausal women.

PARTICIPANTS

Seven hundred and sixty three postmenopausal women not using any systemic hormone therapy, mean age 54·4 ± 5·8 years, recruited in the US, Canada, Australia, UK and Sweden between July 2004 and February 2005.

MEASUREMENTS

Relationships between log-transformed (ln) SHBG and ln homoeostasis model assessment for insulin resistance (HOMA-IR) were explored, taking into account age, body mass index (BMI), blood pressure (BP) and circulating oestradiol, oestrone, testosterone and dihydrotestosterone.

RESULTS

Taking into account age, race, years since menopause, menopause type, BMI, BP, prior postmenopausal hormone use and the sex steroids measured, 34·4% of the variation in SHBG could be explained by the model that included negative contributions by HOMA-IR, BMI and diastolic BP, and a positive contribution by total testosterone (P < 0·001). None of the sex steroids made independent contributions to HOMA-IR, which was best explained by the model that included BMI, SHBG, systolic BP and surgical menopause, with each variable being positively related to HOMA-IR (r(2) = 0·3152, P = 0·03).

CONCLUSIONS

The relationship between SHBG and HOMA-IR, as an estimate of insulin resistance, is not explained by endogenous oestrogen and androgen levels and is, at least in part, independent of BMI in postmenopausal women.

Long-term cross-sex hormone treatment is safe in transsexual subjects

The European Journal of Endocrinology recently published a paper (Asscheman et al.) presenting mortality data from more than a thousand transsexuals followed for a median time of 18 years and who had undergone previous or were currently on long term cross-sex hormonal treatment. Transsexualism is a rare condition and in scientific literature there are few reports on the long-term safety of different treatment protocols and on the physical and psychological outcomes of medical treatments. The safety of long-term high doses oestrogen or testosterone in subjects of the opposite sex has been debated and data on long term effects are scant at best. The Asscherman paper therefore represents a very important and reassuring reference for professionals working in this field suggesting that mortality is increased among transsexuals although due to causes unrelated to cross sex replacement therapy. These results will benefit the care and treatment of these subjects.