Gradually increasing ethinyl estradiol for Turner syndrome may produce good final height but not ideal BMD

Hormone Therapy During Infancy or Early Childhood for Patients with Hypogonadotropic Hypogonadism, Klinefelter or Turner Syndrome: Has the Time Come?

Managing patients unable to produce sex steroids using gonadotropins to mimic minipuberty in hypogonadotropic hypogonadism, or sex steroids in patients with Klinefelter or Turner syndrome, is promising. There is a need to pursue research in this area, with large prospective cohorts and long-term data before these treatments can be routinely considered.

Pubertal induction in Turner syndrome without gonadal function: A possibility of earlier, lower-dose estrogen therapy

Delayed and absent puberty and infertility in Turner syndrome (TS) are caused by primary hypogonadism. A majority of patients with TS who are followed at hospitals during childhood will not experience regular menstruation. In fact, almost all patients with TS need estrogen replacement therapy (ERT) before they are young adults. ERT in TS is administered empirically. However, some practical issues concerning puberty induction in TS require clarification, such as how early to start ERT. The present monograph aims to review current pubertal induction therapies for TS without endogenous estrogen production and suggests a new therapeutic approach using a transdermal estradiol patch that mimics incremental increases in circulating, physiological estradiol. Although evidence supporting this approach is still scarce, pubertal induction with earlier, lower-dose estrogen therapy more closely approximates endogenous estradiol secretion.

The Changing Face of Turner Syndrome

Turner syndrome (TS) is a condition in females missing the second sex chromosome (45,X) or parts thereof. It is considered a rare genetic condition and is associated with a wide range of clinical stigmata, such as short stature, ovarian dysgenesis, delayed puberty and infertility, congenital malformations, endocrine disorders, including a range of autoimmune conditions and type 2 diabetes, and neurocognitive deficits. Morbidity and mortality are clearly increased compared with the general population and the average age at diagnosis is quite delayed. During recent years it has become clear that a multidisciplinary approach is necessary toward the patient with TS. A number of clinical advances has been implemented, and these are reviewed. Our understanding of the genomic architecture of TS is advancing rapidly, and these latest developments are reviewed and discussed. Several candidate genes, genomic pathways and mechanisms, including an altered transcriptome and epigenome, are also presented.

Skeletal Characteristics of Children and Adolescents with Turner Syndrome

Turner syndrome (TS) is a chromosomal disorder characterized by a short stature and gonadal dysgenesis, the latter of which requires estrogen replacement therapy (ERT) to induce and maintain secondary sexual characteristics. Insufficient ERT is associated with compromised skeletal health, including bone fragility, in adults with TS. In particular, estrogen insufficiency during adolescence is critical because the acquisition of a defective bone mass during this period results in impaired bone strength later in the life. In addition to bone mass, bone geometry is also a crucial factor influencing bone strength; therefore, a more detailed understanding of the skeletal characteristics of both bone mass and geometry during childhood and adolescence and their relationships with the estrogen status is needed to prevent compromised skeletal health during adulthood in TS. Although a delay in the initiation of ERT is associated with a lower bone mineral density during adulthood, limited information is currently available on the effects of ERT during adolescence on bone geometry. Herein, we summarize the current knowledge on skeletal characteristics in children and adolescents with TS and their relationships with estrogen sufficiency, and discuss the potential limitations of the current protocol for ERT during adolescence in order to achieve better skeletal health in adulthood.

Pubertal induction and transition to adult sex hormone replacement in patients with congenital pituitary or gonadal reproductive hormone deficiency: an Endo-ERN clinical practice guideline

An Endo-European Reference Network guideline initiative was launched including 16 clinicians experienced in endocrinology, pediatric and adult and 2 patient representatives. The guideline was endorsed by the European Society for Pediatric Endocrinology, the European Society for Endocrinology and the European Academy of Andrology. The aim was to create practice guidelines for clinical assessment and puberty induction in individuals with congenital pituitary or gonadal hormone deficiency. A systematic literature search was conducted, and the evidence was graded according to the Grading of Recommendations, Assessment, Development and Evaluation system. If the evidence was insufficient or lacking, then the conclusions were based on expert opinion. The guideline includes recommendations for puberty induction with oestrogen or testosterone. Publications on the induction of puberty with follicle-stimulation hormone and human chorionic gonadotrophin in hypogonadotropic hypogonadism are reviewed. Specific issues in individuals with Klinefelter syndrome or androgen insensitivity syndrome are considered. The expert panel recommends that pubertal induction or sex hormone replacement to sustain puberty should be cared for by a multidisciplinary team. Children with a known condition should be followed from the age of 8 years for girls and 9 years for boys. Puberty induction should be individualised but considered at 11 years in girls and 12 years in boys. Psychological aspects of puberty and fertility issues are especially important to address in individuals with sex development disorders or congenital pituitary deficiencies. The transition of these young adults highlights the importance of a multidisciplinary approach, to discuss both medical issues and social and psychological issues that arise in the context of these chronic conditions.

Fracture risk, underlying pathophysiology, and bone quality assessment in patients with Turner syndrome

Turner syndrome (TS), the most common type of X chromosomal disorder, has various, clinical manifestations. Among these, primary hypogonadism, which may lead to osteoporosis, is a life-long health issue. A high prevalence of fractures associated with osteoporosis is a major problem in patients with TS, where it may be 1.4-2.2 times higher than in healthy individuals and increases with age. Among the risk factors associated with fractures in TS, hypogonadism is arguably the most important. Estrogen deficiency due to hypogonadism leads to low bone mineral density (BMD), resulting in a high prevalence of bone fractures. Estrogen replacement therapy (ERT) in patients with TS reportedly improved their BMD. However, other causes of low BMD may exist, given that this condition begins in the prepubertal period in patients with TS. Most previous studies have reported low BMD in patients with TS using dual-energy X-ray absorptiometry (DXA), but this method has some limitations. Areal BMD values assessed by DXA were influenced by bone size and short stature, resulting in an underestimation of BMD. Currently, volumetric BMD values may be accurately obtained using peripheral quantitative computed tomography (pQCT). pQCT, high-resolution pQCT, and the trabecular bone score can also be used to evaluate bone quality, including bone geometry and microarchitecture, in TS. The present review discusses the high fracture risk, role of estrogen deficiency in low BMD, advantages and disadvantages of various bone assessment methods, and characteristics of bone quality in TS.

Growth in girls with Turner syndrome

Turner syndrome (TS) is a chromosomal disorder affecting females characterized by short stature and gonadal dysgenesis. Untreated girls with TS reportedly are approximately 20-cm shorter than normal girls within their respective populations. The growth patterns of girls with TS also differ from those of the general population. They are born a little smaller than the normal population possibly due to a mild developmental delay in the uterus. After birth, their growth velocity declines sharply until 2 years of age, then continues to decline gradually until the pubertal age of normal children and then drops drastically around the pubertal period of normal children because of the lack of a pubertal spurt. After puberty, their growth velocity increases a little because of the lack of epiphyseal closure. A secular trend in height growth has been observed in girls with TS so growth in excess of the secular trend should be used wherever available in evaluating the growth in these girls. Growth hormone (GH) has been used to accelerate growth and is known to increase adult height. Estrogen replacement treatment is also necessary for most girls with TS because of hypergonadotropic hypogonadism. Therefore, both GH therapy and estrogen replacement treatment are essential in girls with TS. An optimal treatment should be determined considering both GH treatment and age-appropriate induction of puberty. In this review, we discuss the growth in girls with TS, including overall growth, pubertal growth, the secular trend, growth-promoting treatment, and sex hormone replacement treatment.

Starting age of oestrogen-progestin therapy is negatively associated with bone mineral density in young adults with Turner syndrome independent of age and body mass index

OBJECTIVE

Osteoporosis is an important health issue in patients with Turner syndrome (TS), and oestrogen sufficiency has been implicated in increased bone mineral density (BMD); however, the impact of the starting age of hormone replacement therapy (HRT) on bone mineral density remains unclear, particularly during young adulthood.

DESIGN

A retrospective study from three tertiary care hospitals in Japan.

PATIENTS

One hundred and three patients with TS aged between 18 and 30 years of age who underwent dual-energy X-ray absorptiometry.

MEASUREMENTS

Anthropometric parameters, lumbar bone mineral density (L-BMD), including areal BMD (aBMD) and volumetric BMD (vBMD), karyotypes, the presence of spontaneous menarche, the starting ages of oestrogen replacement therapy (ERT) and oestrogen-progestin therapy (EPT), and the duration between starting ages of oestrogen replacement therapy and oestrogen-progestin therapy were investigated. vBMD was calculated based on the Kröger method.

RESULTS

aBMD was lower in young adults with TS than in an age-matched reference population. L-BMD positively correlated with weight and body mass index (BMI). L-BMD was higher in subjects with spontaneous menarche (N = 22) than in those without. A dose escalation regimen of oestrogen replacement therapy was used in 84% of subjects without spontaneous menarche (N = 81). The starting age of oestrogen replacement therapy and the duration between the starting ages of oestrogen replacement therapy and oestrogen-progestin therapy negatively and independently correlated with aBMD, but not with vBMD, after adjustment with age and BMI. The starting age of oestrogen-progestin therapy negatively correlated with L-BMD independent of age and BMI.

CONCLUSIONS

Early introduction of hormone replacement therapy, particularly oestrogen-progestin therapy, is important to accrue better L-BMD in young adults with TS.

Monitoring and maintaining bone health in patients with Turner syndrome

INTRODUCTION

Subjects affected with Turner Syndrome (TS) suffer low bone mineral density and high risk of fracture from a young age. Estrogen deficiency is considered the main risk factor but other factors, such as intrinsic bone abnormalities, enhanced osteoclastogenesis, vitamin D deficiency and other comorbidities may contribute to the exalted bone fragility.

AREAS COVERED

The authors performed a literature search in PubMed and EMBASE, using selected key words. They focused their search on pathogenetic mechanisms of osteoporosis in TS and updated the diagnosis, prevention and therapeutic interventions.

EXPERT OPINION

Bone health is a concern in subjects with TS, and strategies to prevent osteoporosis and fractures should be considered from childhood. Advice on how to live a healthy lifestyle, including physical activity and correct nutrition, should be given during childhood in order to prevent bone impairment later in life. The screening for vitamin D deficiency should be performed between the ages of 9 and 11, and every 2-3 years thereafter. Early initiation of estrogen replacement therapy (ERT) between 11-12 years of age, prompt titration to the adult dose after 2 years, and long-term follow-up to guarantee compliance with ERT, are the key points of osteoporosis prevention in women with TS.

A retrospective multicenter study of bone mineral density in adolescents and adults with Turner syndrome in Japan

Osteoporosis is one of the clinical features of women with Turner syndrome (TS). The reasons for low bone mineral density (BMD) and increased bone fragility are multifactorial, including estrogen deficiency, X-chromosome abnormalities, and environmental factors. Few, large-scale studies on bone mineral density in either adolescents or adults with TS have been done in Japan. The goal of the present study was to investigate spinal BMD in women with TS, assess its relationship with clinical parameters, especially estrogen replacement therapy, and investigate its longitudinal changes. The spinal BMD and clinical data of 149 Japanese women with TS aged 15 to 49 years who were followed at the four participating hospitals were retrospectively analyzed. The BMD Z-scores of the women with TS ranged from -5.30 to +1.89. Women with TS aged 15-39 years had lower BMD than healthy Japanese women (p < 0.01) while women with spontaneous menstruation had a significantly higher BMD Z-score than those without spontaneous menstruation (-0.73 ± 1.11 vs. -1.67 ± 1.18, p < 0.01). In women without spontaneous menstruation, BMD Z-scores correlated with the duration of their estrogen therapy (r = 0.167, p < 0.01). Women aged 15-39 years with TS had low BMD, which was associated with primary amenorrhea and short estrogen replacement therapy duration.

Perspectives on growth promoting treatment for patients with Turner syndrome in Japan

In Japan, anabolic steroid hormone (ASH) treatment for Turner syndrome (TS) to promote growth had been provided before GH therapy for TS was approved. ASH effectively improved the adult height (AH) of TS patients without spontaneous puberty but decreased the AH of TS patients with spontaneous puberty. Although GH therapy for TS was approved in 1991, the approved dosage remained 0.5 IU/kg/wk for GH-deficient TS patients and improved AH by approximately 7 cm. However, AH did not reach -2 standard deviations in healthy girls. In 1999, the requirement of GH deficiency was removed and a dose of 1.0 IU/kg/wk was approved. Although an increase in AH was expected, no reports showed significant improvements in AH at a high dose of GH. GH + ASH combination therapy was reevaluated and recommended for TS patients with gonadal failure and an extremely short stature or those who respond poorly to GH therapy. Although early estrogen replacement therapy is recommended to improve psychological quality of life and prevent osteoporosis, it lowered AH even at a low dose of ethinyl estradiol (25 ng/kg/d). The initiation of ethynyl estradiol at an extremely low dose (1-5 ng/kg/d) at a relatively young age successfully improved AH.

Ultra-low-dose estrogen therapy for female hypogonadism

In females, endogenous estrogen secretion increases gradually before pubertal development. The benefits of low-dose estrogen therapy in patients with Turner syndrome were originally discussed by Ross et al. and Quigley et al. These seminal studies used ethinyl estradiol (EE2), starting at a dose of 25 ng/kg/d. We hypothesized that the initial dosage of estrogen could be titrated to more closely mimic physiological increments of endogenous estrogen. Therefore, our recent study initiated EE2 treatment at a dosage of 1–2 ng/kg/d, an ultra-low-dose estrogen therapy in pediatric patients with Turner syndrome. The ultra-low-dose estrogen therapy in this syndrome produced a good final height outcome but achieved suboptimal bone mineral density (BMD). In the present review, we have explained our findings to clarify the merits and demerits of this new therapy and to promote further discussion and research. This type of ultra-low-dose estrogen therapy, initiated at an early age, could be ideal for estrogen replacement in female patients with hypogonadism, such as Turner syndrome.

Turner syndrome and osteoporosis

Turner syndrome is one of the most common sex chromosomal anomalies, characterized by the complete or partial loss of one X chromosome. Females with Turner syndrome are characterized by skeletal abnormalities, short stature and primary ovarian insufficiency. The aim of this narrative review was to identify the underlying mechanisms of osteoporosis in Turner syndrome, summarize its clinical manifestations and provide suggestions regarding the management of osteoporosis. Girls and women with Turner syndrome have lower bone mineral density and a higher fracture rate than healthy individuals. The most important risk factors for osteoporosis are inadequately treated primary ovarian insufficiency, followed by intrinsic bone abnormalities. Comorbidities that further increase the risk of osteoporosis include vitamin D deficiency, celiac disease and inflammatory bowel disease. In addition, hearing problems can predispose to falls. Early initiation of hormone replacement therapy (HRT) at the age of 11-13 years, prompt titration to the adult dose after 2 years and long-term follow-up to ensure compliance with HRT are the cornerstones of osteoporosis prevention in women with Turner syndrome.

Prevalence of diverse complications and its association with karyotypes in Japanese adult women with Turner syndrome-a questionnaire survey by the Foundation for Growth Science

The reported prevalence of complications in Turner Syndrome (TS) was highly variable because of the rarity and the limited numbers analyzed. Again, possible presence of other complications that are not described as specific for TS, is also speculated. To resolve these issues, a questionnaire survey was conducted in hGH treated 492 patients with adult TS (17-42 years). The possible association with these complications and karyotypes were also analyzed. The complications and their prevalence were as follows: chronic thyroiditis (25.2%), inflammatory bowel disease (1.8%), congenital cardiovascular anomaly (11.8%), urinary tract malformation (11.8%), low bone mineral density (BMD) (42.9%), scoliosis (8.4%), hearing loss (6.2%), epilepsy (2.8%) and schizophrenia (0.9%). The majority of prevalence of these diseases in TS was higher than in the general population. In distribution, the most frequent karyotype was 45,X monosomy (28.9%), followed by 45,X/46,X,Xi (16.9%), 46,X,Xi (9.1%), and 45,X/46,XX (6.3%), while other mosaic 45,X was noted in 29.9%. Regarding the karyotype, cardiovascular anomaly was more frequent in the 45,X group and less in the 46,X,Xi group. Urinary tract malformation and epilepsy were frequently associated with the chromosome 45,X. The prevalence of low BMD was noticed more in the chromosome 46,X,Xi and 45,X/46,X,Xi, and less in other mosaic 45,X. In conclusion, the more exact prevalence of diverse complications was clarified and it exceeded the prevalence of the majority of complications in general population. As novel findings, it was observed that the prevalence of epilepsy was significantly high, and epilepsy and low BMD were frequently associated with the specific karyotypes.