Changes in bone mineral density after orchidectomy and hormone replacement therapy in individuals with androgen insensitivity syndrome

Dilemmas in management of osteoporosis in patients with complete androgen insensitivity syndrome

Complete androgen insensitivity syndrome (CAIS)-resulting in 46,XY karyotype, but female phenotype-is a disorder of sex development and primary amenorrhea, but its effect on bone mineral density (BMD) is singular and difficult to manage. Androgens are an important modulator of bone remodeling and health, and the androgen receptor (AR) is pivotal for signaling within the bone cells. CAIS results in a severely disrupted AR throughout the body, causing an elevated risk of early osteoporosis. Timing of gonadectomy and hormone replacement therapy protocols are not established, creating a wide variety of treatment plans and BMD profiles. Our objective is to report a patient with CAIS status post prepubertal orchiectomy that developed early osteoporosis and to describe the lack of optimal strategies and consensus available to improve bone health in this population. Additionally, our case illustrates the fact there are no guidelines advocating the use of newer drugs for osteoporosis in this population.

Case Report: Low Bone and Normal Lean Mass in Adolescents With Complete Androgen Insensitivity Syndrome

INTRODUCTION

Osteopenia and osteoporosis have been reported in adults with Complete Androgen Insensitivity Syndrome (CAIS). Little is known about changes in bone mineral density (BMD) in adolescents with CAIS and whether it is affected by early gonadectomy. Body composition data have not been reported.

METHODS

Single-center, retrospective study of CAIS adolescents who underwent dual-energy x-ray absorptiometry (DXA) (Hologic, Horizon A). Body composition is presented as lean and fat mass indices (LMI, FMI). Z-scores for lumbar spine areal BMD (LBMD), total body less head (TBLH), bone mineral content (BMC), LMI, and FMI were calculated using female normative data. Results are expressed as median and min, max.

RESULTS

Six females with genetically confirmed CAIS were identified-one with intact gonads and five with history of gonadectomy at 2-11 months. In the subject with intact gonads, LBMD-Z and TBLH BMC-Z were -1.56 and -1.26, respectively, at age 16 years. Among those with gonadectomy, LBMD-Z was -1.8 (-3.59 to 0.49) at age 15.6 years (12-16.8) and decreased in all three subjects who had longitudinal follow-up despite hormone replacement therapy (HRT). Adherence to HRT was intermittent. LMI-Z and FMI-Z were 0.1 (-1.39 to 0.7) and 1.0 (0.22 to 1.49), respectively.

CONCLUSIONS

These limited data indicate that adolescents with CAIS have bone mass deficit. Further studies are needed to understand the extent of BMD abnormalities and the effect of gonadectomy, especially early in childhood, and to establish the optimal HRT regimen for bone accrual. Data on lean mass are reassuring.

Long-term consequences of androgen insensitivity syndrome

Androgen insensitivity syndrome (AIS) is one of the most common sexual developmental disorders. According to the grade of the remaining androgen receptor (AR) function, AIS is classified as complete (CAIS), partial (PAIS) or mild (MAIS). In CAIS, the prevalence of germ cell tumours is increased compared with the general population. Although patients with CAIS used to undergo gonadectomy before puberty, nowadays a gonadectomy is recommended after spontaneous puberty, and up to 15% of patients retain their gonads. Nevertheless, the risk of germ cell tumour increases gradually after puberty. Annual follow-up with ultrasound or magnetic resonance imaging (MRI) is recommended. Unfortunately, these imaging methods are not sensitive enough for the diagnosis of an in situ germ cell tumour. In PAIS, the risk of germ cell tumour is higher than in CAIS; therefore, an early gonadectomy or an orchidopexy is indicated. Optimal hormone replacement therapy (HRT) is necessary for long-term health. The risks of osteopenia and of regimen osteoporosis are higher, ESPECIALLY in patients with early gonadectomy. Infertility is the rule in CAIS and PAIS. A few mutations do not affect fertility detrimentally, and these are responsible for MAIS. In PAIS leading to a predominantly male phenotype or ambiguous genitalia, multiple surgical procedures for gynaecomastia and/or hypospadias are required. Some small studies have found a higher risk of obesity, hyperlipidaemia and impaired insulin sensitivity. Psychological support is essential, as the prevalence of psychiatric disorders is increased. In conclusion, the diagnosis of AIS has long-term consequences for which shared decision-making (physicians, patients, parents) is appropriate.

Hormone replacement treatment choices in complete androgen insensitivity syndrome: an audit of an adult clinic

OBJECTIVE

To review the treatment choices of women with complete androgen insensitivity syndrome (CAIS) at a single tertiary centre.

DESIGN

Retrospective review.

PATIENTS

Women with CAIS identified from our database.

RESULTS

The study group comprised 141 women with CAIS. Eleven percent (16/141) of women had gonads in situ, 3 of whom were under workup for gonadectomy. The age of gonadectomy in the remainder 125 women was 17 (0.1-53) years. The most common form of HRT was oral oestrogen or transdermal oestrogen in 80% (113/141). 13/141 (9%) women used vaginal oestrogens alone or together with other forms of HRT. Testosterone preparations had been used by 17% (24/141) of women and were currently used in 10% (14/141). Of those who had used testosterone, 42% (10/24) had chosen not to continue after a therapeutic trial.

CONCLUSIONS

In a clinic offering individualised multidisciplinary care for women with CAIS, we found that the majority of women chose oestrogen-based treatment while a significant minority used testosterone.

Response to hormonal treatment of young females with primary or very premature ovarian failure

The aim of this study was to evaluate the impact of hormone treatment (HT) on several endocrinologic, metabolic and bone parameters in young women with primary or very premature ovarian failure. The study included 40 phenotypically females of 14-20 years old with primary or secondary amenorrhoea and female external genitalia. Study subjects were categorised in three groups: Group A included 12 subjects with Turner syndrome, Group B included 19 subjects with Swyer syndrome and Group C included 9 subjects with very premature ovarian failure. HT was administered for 24 months and included conjugated oestrogens and medroxyprogesterone acetate. In all groups, HT provided a beneficial hormonal profile and resulted in safe and adequate serum oestrogens levels. In Group A, no adverse effects on metabolic or coagulation parameters were noted; significant increases in high-density lipoprotein cholesterol (HDL) levels and bone density were observed. Similar positive effects of HT were observed in Group B. Finally, in Group C, no adverse effects of HT were noted, but the favourable increase in HDL was absent; bone density kept significantly increasing until the 12-month evaluation. In conclusion, the administration of HT is remarkably beneficial for young women with primary or very premature ovarian failure.

Disorders of sexual development

Disorders of sex development are medical conditions in which the development of chromosomal, gonadal, or anatomic sex varies from normal and may be incongruent with each other. This article primarily addresses the medical conditions where infants may be born with ambiguous genitalia leading to decisions with regard to gender assignment. The approach to investigations and diagnosis in the newborn period will be stressed within an interprofessional team. Policies with regard to surgery have developed, with techniques evolving and data emerging from long-term outcome studies. Current medical and surgical management are reviewed. Finally, a developmental approach to disclosure is presented.

Androgens and bone

Testosterone is the major gonadal sex steroid produced by the testes in men. Testosterone is also produced in smaller amounts by the ovaries in women. The adrenal glands produce the weaker androgens dehydroepiandrosterone, dehydroepiandrosterone sulfate, and androstenedione. These androgens collectively affect skeletal homeostasis throughout life in both men and women, particularly at puberty and during adult life. Because testosterone can be metabolized to estradiol by the aromatase enzyme, there has been controversy as to which gonadal sex steroid has the greater skeletal effect. The current evidence suggests that estradiol plays a greater role in maintenance of skeletal health than testosterone, but that androgens also have direct beneficial effects on bone. Supraphysiological levels of testosterone likely have similar effects on bone as lower levels via direct interaction with androgen receptors, as well as effects mediated by estrogen receptors after aromatization to estradiol. Whether high doses of synthetic, non-aromatizable androgens may, in fact, be detrimental to bone due to suppression of endogenous testosterone (and estrogen) levels is a potential concern that warrants further study.

Disorders of sex development: hormonal management in adolescence

Hormonal treatment represents the principal aspect of clinical management of people with disorders of sex development (DSD) from adolescence onwards. In fact, individuals with DSD may require sex steroid replacement to induce secondary sex characteristics, to optimize bone mass accrual, and to promote physical and social well-being. Testosterone is the main hormone for treatment in males and estrogens in females. The optimal regimens for sex steroid substitutive therapy in subjects with DSD should be better defined in multi-center prospective studies. Bone health remains a crucial aspect in the management of these persons, but few sound data are available to guide clinical practice.

Height and bone mineral density in androgen insensitivity syndrome with mutations in the androgen receptor gene

INTRODUCTION AND HYPOTHESIS

Androgen insensitivity syndrome (AIS) constitutes a natural model to study effects of androgens and estrogens on growth and bone density. We evaluated height and bone density in patients with AIS with mutations in the androgen receptor (AR) gene.

METHODS

A retrospective analysis was conducted of eight subjects with complete AIS (CAIS) and four with partial AIS (PAIS) submitted to gonadectomy followed by estrogen replacement, and three with PAIS who did not undergo gonadectomy. Standing height and bone mineral apparent density (BMAD) by DXA were measured and compared with male (z (m)) and female (z (f)) reference populations. The z-scores were compared with a value of zero using the one-sample t-test.

RESULTS

Final heights of patients with CAIS and PAIS were intermediate between those predicted for females and males. BMAD of the lumbar spine in CAIS and PAIS after gonadectomy and estrogen replacement (z (f) = - 1.56 +/- 1.04, P = 0.006, and z (m) = - 0.75 +/- 0.89, P = 0.04) indicated vertebral bone deficit, whereas BMAD at the femoral neck was normal. No patient reported fractures.

CONCLUSION

Subjects with AIS had mean final height intermediate between mean normal male and female, and decreased bone mineral density in the lumbar spine. These data suggest an important role for androgens in normal male growth and bone density not replaced by estrogens.

Bone mineral density in the complete androgen insensitivity and 5alpha-reductase-2 deficiency syndromes

CONTEXT

Subjects with complete androgen insensitivity (CAI) and 5alpha-reductase-2 deficiency (5alphaRD-2) are natural human models to study the direct effect of androgens on bone mineral density (BMD).

OBJECTIVE

The objective of this study was to test the hypothesis that androgens have a direct effect on BMD in men.

DESIGN

This was a prospective, observational study (1989-1999) using dual energy x-ray absorptiometry.

SETTING

The study was set in an outpatient specialty referral center.

PATIENTS OR OTHER PARTICIPANTS

All known subjects with these conditions (12 CAI and 16 5alphaRD-2) from diverse sociodemographic backgrounds were recruited for the study.

INTERVENTIONS

There were no interventions.

MAIN OUTCOME MEASURE

Mean Z score and weight-matched Z score at lumbar spine and femoral neck for CAI and 5alphaRD-2 subjects were determined.

RESULTS

Twelve CAI subjects had mean Z score at L2-L4 of -2.84 (+/-0.97, P < 0.001) and a mean weight-matched Z score of -2.52 (+/-0.94, P < 0.001). The mean Z score at the femoral neck was -1.33 (+/-0.91, P < 0.001) and the mean weight-matched Z score was -1.10 (+/-0.82, P = 0.001). Sixteen 5alphaRD-2 subjects had a mean Z score at L2-L4 of -0.84 (+/-1.29, P = 0.02) and a mean weight-matched Z score for 15 of 16 patients of -0.44 (+/-1.08, P = 0.14). The mean Z score at the femoral neck was 0.14 (+/-1.02, P = 0.58) and the mean weight-matched Z score for 15 of 16 patients was 0.49 (+/-0.94, P = 0.06). Therefore, in CAI subjects, BMD was significantly decreased in the spine and hip. 5alphaRD-2 subjects had normal BMD values.

CONCLUSIONS

1) Androgens are of direct importance in the development and/or maintenance of BMD; and 2) testosterone and/or low levels of dihydrotestosterone appear to be sufficient for BMD development and/or maintenance.

Hormonal therapies for individuals with intersex conditions: protocol for use

Hormonal therapy forms part of the treatment of every intersex condition. For some conditions, such as salt-wasting congenital adrenal hyperplasia, hormonal replacement therapy is life saving because hormones necessary for survival (cortisol and aldosterone) are replaced. In contrast, other hormones such as androgens or mineralocorticoids are secreted in excessive amounts in congenital adrenal hyperplasia due to an enzyme imbalance, and the role of hormonal therapy is to suppress the unwanted hormone excess by exerting negative feedback. For patients with one of the many causes of hypogonadism, sex hormone replacement therapy may be prescribed to stimulate sexual development: growth of a hypoplastic penis in a young boy, pubertal changes (male or female), psychosexual development, and adult sexual behavior. It has equally important and highly beneficial effects on bone mineral density. Hormonal therapy is also used to treat the unborn child. For the last 20 years, prenatal dexamethasone treatment administered to the pregnant woman has been used to prevent the development of ambiguous genitalia in females with 21-hydroxylase deficiency. Outcome studies show this treatment to be well tolerated and, in general, efficacious. Intersex conditions are, however, difficult to treat because they may intrinsically perturb complex aspects of the person's gender identity, gender-role behavior, sexual orientation, sexual functioning, and psychologic adjustment. Furthermore, decisions made about the sex of an infant by doctors and parents do not always turn out to be correct; the person may grow up feeling uncertain about his or her gender identity, or worse still, harbor a sense of outrage about their life and treatment experiences. Such a person will have definite views about hormonal therapy when the time comes and skillful counseling will be needed. A vigorous debate about ethical aspects of current medical practices relating to intersex conditions has been waged for the last 7 years between certain patient advocacy organizations and the medical profession, and is expected to continue for some time. The quality of the debate will be improved by evidence. The results of a number of long-term follow-up studies have been published, and more are expected. The published studies show mixed, but mainly encouraging, results.

Androgens and bone

Loss of estrogens or androgens increases the rate of bone remodeling by removing restraining effects on osteoblastogenesis and osteoclastogenesis, and also causes a focal imbalance between resorption and formation by prolonging the lifespan of osteoclasts and shortening the lifespan of osteoblasts. Conversely, androgens, as well as estrogens, maintain cancellous bone mass and integrity, regardless of age or sex. Although androgens, via the androgen receptor (AR), and estrogens, via the estrogen receptors (ERs), can exert these effects, their relative contribution remains uncertain. Recent studies suggest that androgen action on cancellous bone depends on (local) aromatization of androgens into estrogens. However, at least in rodents, androgen action on cancellous bone can be directly mediated via AR activation, even in the absence of ERs. Androgens also increase cortical bone size via stimulation of both longitudinal and radial growth. First, androgens, like estrogens, have a biphasic effect on endochondral bone formation: at the start of puberty, sex steroids stimulate endochondral bone formation, whereas they induce epiphyseal closure at the end of puberty. Androgen action on the growth plate is, however, clearly mediated via aromatization in estrogens and interaction with ERalpha. Androgens increase radial growth, whereas estrogens decrease periosteal bone formation. This effect of androgens may be important because bone strength in males seems to be determined by relatively higher periosteal bone formation and, therefore, greater bone dimensions, relative to muscle mass at older age. Experiments in mice again suggest that both the AR and ERalpha pathways are involved in androgen action on radial bone growth. ERbeta may mediate growth-limiting effects of estrogens in the female but does not seem to be involved in the regulation of bone size in males. In conclusion, androgens may protect men against osteoporosis via maintenance of cancellous bone mass and expansion of cortical bone. Such androgen action on bone is mediated by the AR and ERalpha.

Relation of sex hormones to bone mineral density in middle-aged men during a 4 year exercise intervention trial

Recent studies have emphasized the symbiotic role of estradiol and testosterone on bone metabolism. Several anthropomorphic-, lifestyle-, and dual-energy X-ray (DXA)-derived parameters were measured with respect to estradiol (E(2)), testosterone (T), free T (fT), and sex hormone-binding globulin (SHBG) in 140 men (aged 53-62 years) participating in a controlled, randomized exercise intervention trial. After 4 years of intervention, 132 (94.3%) men remained as participants. During the period of study, aerobic threshold increased significantly in the exercise intervention group compared with the reference group (13.4% vs. -1.9%: p < 0.023). Serum E(2) and fT were not convincingly related to bone mineral density (BMD) or BMD change. Aerobic threshold or the change in aerobic threshold were not associated with sex hormone or SHBG levels. Body mass index was a significant determinant of T (beta = -0.337), fT (beta = -0.293), and SHBG (beta = -0.306), and smoking predicted T (beta = 0.231) and fT (beta = 0.245). Alcohol intake was a significant determinant of E(2) (beta = 0.213). Ultimately there was no convincing relation between sex hormone levels and BMD or BMD change in middle-aged men.