Gonadal dysgenesis and bone metabolism

The complications of male hypogonadism: is it just a matter of low testosterone?

The history of diagnosing hypogonadism and hypotestosteronemia shows us the many steps that were necessary to achieve our current knowledge and the ability to improve these patients' well-being. Moreover, so far, criteria for diagnosing hypotestosteronemia varies according to the underlying condition, and according to the consensus or guideline adopted. Furthermore, besides the many signs and symptoms, there are several complications associated with low testosterone levels such as osteoporosis, metabolic alterations, as well as cardiovascular disorders. However, data are often conflicting regarding the severity, timing or even the real clinical relevance of these complications, although these studies often lack essential information such as gonadotropin levels or the underlying cause of hypogonadism. The present review focus on the complications of male hypogonadism according to the cause of testosterone deficiency, highlighting the lack of information found in many studies investigating its effects. We thereby stress the necessity to always perform a complete evaluation of the type of hypogonadism (including at least gonadotropins and secondary causes) when investigating the effects of low testosterone levels.

Beyond Human Perception: Sexual Dimorphism in Hand and Wrist Radiographs Is Discernible by a Deep Learning Model

Despite the well-established impact of sex and sex hormones on bone structure and density, there has been limited description of sexual dimorphism in the hand and wrist in the literature. We developed a deep convolutional neural network (CNN) model to predict sex based on hand radiographs of children and adults aged between 5 and 70 years. Of the 1531 radiographs tested, the algorithm predicted sex correctly in 95.9% (κ = 0.92) of the cases. Two human radiologists achieved 58% (κ = 0.15) and 46% (κ = − 0.07) accuracy. The class activation maps (CAM) showed that the model mostly focused on the 2nd and 3rd metacarpal base or thumb sesamoid in women, and distal radioulnar joint, distal radial physis and epiphysis, or 3rd metacarpophalangeal joint in men. The radiologists reviewed 70 cases (35 females and 35 males) labeled with sex along with heat maps generated by CAM, but they could not find any patterns that distinguish the two sexes. A small sample of patients (n = 44) with sexual developmental disorders or transgender identity was selected for a preliminary exploration of application of the model. The model prediction agreed with phenotypic sex in only 77.8% (κ = 0.54) of these cases. To the best of our knowledge, this is the first study that demonstrated a machine learning model to perform a task in which human experts could not fulfill.

Androgens and Androgen Receptor Actions on Bone Health and Disease: From Androgen Deficiency to Androgen Therapy

Androgens are not only essential for bone development but for the maintenance of bone mass. Therefore, conditions with androgen deficiency, such as male hypogonadism, androgen-insensitive syndromes, and prostate cancer with androgen deprivation therapy are strongly associated with bone loss and increased fracture risk. Here we summarize the skeletal effects of androgens—androgen receptors (AR) actions based on in vitro and in vivo studies from animals and humans, and discuss bone loss due to androgens/AR deficiency to clarify the molecular basis for the anabolic action of androgens and AR in bone homeostasis and unravel the functions of androgen/AR signaling in healthy and disease states. Moreover, we provide evidence for the skeletal benefits of androgen therapy and elucidate why androgens are more beneficial than male sexual hormones, highlighting their therapeutic potential as osteoanabolic steroids in improving bone fracture repair. Finally, the application of selective androgen receptor modulators may provide new approaches for the treatment of osteoporosis and fractures as well as building stronger bones in diseases dependent on androgens/AR status.

Extracellular vesicles in bone: "dogrobbers" in the "eternal battle field"

Throughout human life, bone is constantly in a delicate dynamic equilibrium of synthesis and resorption, hosting finely-tuned bone mineral metabolic processes for bone homeostasis by collaboration or symphony among several cell types including osteoclasts (OCs), osteoblasts (OBs), osteocytes (OYs), vascular endothelial cells (ECs) and their precursors. Beyond these connections, a substantial level of communication seems to occur between bone and other tissues, and together, they form an organic unit linked to human health and disease. However, the current hypothesis, which includes growth factors, hormones and specific protein secretion, incompletely explains the close connections among bone cells or between bone and other tissues. Extracellular vesicles (EVs) are widely-distributed membrane structures consisting of lipid bilayers, membrane proteins and intravesicular cargo (including proteins and nucleic acids), ranging from 30 nm to 1000 nm in diameter, and their characters have been highly conserved throughout evolution. EVs have targeting abilities and the potential to transmit multidimensional, abundant and complicated information, as powerful and substantial "dogrobbers" mediating intercellular communications. As research has progressed, EVs have gradually become thought of as "dogrobbers" in bone tissue-the "eternal battle field" -in a delicate dynamic balance of destruction and reconstruction. In the current review, we give a brief description of the major constituent cells in bone tissues and explore the progress of current research on bone-derived EVs. In addition, this review also discusses in depth not only potential directions for future research to breakthrough in this area but also problems existing in current research that need to be solved for a better understanding of bone tissues.

Klinefelter syndrome: more than hypogonadism

Klinefelter syndrome (KS) is the most frequent chromosome disorder in males (1:650 newborn males), defined by 47,XXY karyotype. The classical phenotype is that of a tall male with relatively long legs, small, firm testes and gynecomastia. Azoospermia and infertility are almost inevitably present, but may be overcome by TESE and ICSI. Nevertheless, a broad spectrum of phenotypes has been described and more than 70% of the actually existing KS men may remain undiagnosed throughout their lifespan. Accordingly, hypogonadism is usually not evident until early adulthood and progresses with ageing. KS patients present a series of comorbidities that increase morbidity and mortality by 40%. Such disturbances are the impaired metabolic profile (obesity, dyslipidemia, insulin resistance) and a tendency to thrombosis, which all favor cardiovascular disease. They also present susceptibility for specific neoplasias (breast cancer, extragonadal germ cell tumors), autoimmune diseases as well as osteoporosis and bone fractures. Moreover, KS has been associated with verbal processing and attention deficits as well as social skill impairments, leading KS individuals to academic and professional achievements inferior to those of their peers of comparable socio-economic status. Nevertheless, the majority fall within the average range regarding their intellectual abilities and adaptive functioning. Testosterone replacement therapy (TRT) is the mainstay of treatment in hypogonadal KS patients; however, randomized trials are needed to determine optimal therapeutic regimens and follow-up schedules.

Long-term effect of testosterone replacement therapy on bone in hypogonadal men with Klinefelter Syndrome

PURPOSE

To assess different aspects of bone damage in untreated adult patients with Klinefelter Syndrome (KS) before and during testosterone replacement therapy (TRT).

METHODS

Fifteen untreated hypogonadal men with KS and 26 control subjects (C) matched for age and BMI were recruited. Sex hormone levels were measured in all subjects. Lumbar spine (LS) and femoral (neck: FN and total hip: TH) bone mineral density (BMD), trabecular bone score (TBS), hip structure analysis (HSA) and fat measures (percentage of fat mass, android/gynoid ratio and visceral adipose tissue) were evaluated by DEXA. In KS patients, blood analysis and DEXA measurements were assessed at baseline and repeated yearly for three years during TRT.

RESULTS

Fat measures were significantly higher in KS than C (p < 0.01). In contrast, mean LS, FN and TH BMD were significantly reduced in KS compared to C (p < 0.01), while there was no difference in TBS. HSA revealed a significantly lower cortical thickness and significantly higher buckling ratio in KS compared to C at all femoral sites (p < 0.01). In KS patients, TRT significantly increased BMD at LS only, but did not improve TBS and HSA parameters. Fat measures were inversely associated with TBS values, and TRT did not influence this relationship.

CONCLUSIONS

In untreated hypogonadal men with KS, lumbar and femoral BMD was reduced, and femoral bone quality was impaired. Adiposity seemed to have a detrimental effect on lumbar bone microarchitecture, as indirectly evaluated by TBS. However, TRT failed to remedy these negative effects on bone.

Bone Mineral Density in Adolescent Girls with Hypogonadotropic and Hypergonadotropic Hypogonadism

OBJECTIVE

Deficiency of sex steroids has a negative impact on bone mineral content. In studies conducted on postmenopausal women and animal studies, elevated follicle-stimulating hormone (FSH) levels were found to be correlated with a decrease in bone mineralization and osteoporosis. The aim of the present study was to evaluate bone mineral density (BMD) in adolescent girls with hypogonadotropic and hypergonadotropic hypogonadism and also to investigate the correlation between FSH level and BMD.

METHODS

The study group included 33 adolescent girls with hypogonadism (14 with hypogonadotropic hypogonadism and 19 with hypergonadotropic hypogonadism). FSH, luteinizing hormone, estradiol levels, and BMD (using dual energy x-ray absorptiometry) were measured.

RESULTS

There were no statistically significant differences between the chronological age and bone age of the two patient groups, namely, with hypogonadotropic and hypergonadotropic hypogonadism. There was also no significant difference between BMD z-score values obtained from measurements from the spine and the femur neck of patients in the two groups (p-values were 0.841 and 0.281, respectively). In the hypergonadotropic group, a moderately negative correlation was detected between FSH level and BMD z-score measured from the femur neck (ρ=-0.69, p=0.001), whilst no correlation was observed between FSH levels and height adjusted BMD-z scores measured from the spine (ρ=0.17, p=0.493). FSH level was not found to be an independent variable affecting BMD z-score.

CONCLUSION

BMD z-scores were detected to be similar in adolescent girls with hypogonadotropic and hypergonadotropic hypogonadism, and FSH levels were not found to have a clinically relevant impact on BMD.

Role of vitamin D levels and vitamin D supplementation on bone mineral density in Klinefelter syndrome

This manuscript describes the role of low vitamin D in bone metabolism of Klinefelter subjects. Low vitamin D is frequent in this condition and seems to be more important than testosterone in inducing low bone mineral density (BMD) and osteoporosis. Supplementation with vitamin D restores BMD after 2 years of treatment, whereas testosterone alone seems to be ineffective.

INTRODUCTION

Decreased bone mineral density (BMD) in Klinefelter syndrome (KS) is frequent, and it has been traditionally related to low testosterone (T) levels. However, low BMD can be observed also in patients with normal T levels and T replacement therapy does not necessarily increase bone mass in these patients. Nothing is known about vitamin D levels and supplementation in KS. In this study, we determine vitamin D status and bone mass in KS subjects and compare the efficacy of T therapy and vitamin D supplementation on BMD.

METHODS

A total of 127 non-mosaic KS patients and 60 age-matched male controls were evaluated with reproductive hormones, 25-hydroxyvitamin D, PTH, and bone densitometry by dual-energy X-ray absorptiometry (DEXA). Patients with hypogonadism and/or 25-hydroxyvitamin D deficiency were treated with T-gel 2% and/or calcifediol and re-evaluated after 24 months of treatment.

RESULTS

25-hydroxyvitamin D levels were significantly lower in KS patients with respect to controls, and they had significantly lower lumbar and femoral BMD. The percentage of osteopenia/osteoporosis in subjects with 25-hydroxyvitamin D deficiency was higher with respect to subjects with normal 25-hydroxyvitamin D and was not related to the presence/absence of low T levels. Subjects treated with calcifediol or T + calcifediol had a significant increase in lumbar BMD after treatment. No difference was found in T-treated group.

CONCLUSIONS

These data highlight that low 25-hydroxyvitamin D levels seem to have a more critical role than low T levels in inducing low BMD in KS subjects. Furthermore, vitamin D supplementation seems to be more effective than T replacement therapy alone in increasing BMD.

A review of osteocyte function and the emerging importance of sclerostin

➤ Osteocytes, derived from osteoblasts, reside within bone and communicate extensively with other bone cell populations to regulate bone metabolism. The mature osteocyte expresses the protein sclerostin, a negative regulator of bone mass.➤ In normal physiologic states, the protein sclerostin acts on osteoblasts at the surface of bone and is differentially expressed in response to mechanical loading, inflammatory molecules such as prostaglandin E2, and hormones such as parathyroid hormone and estrogen.➤ Pathologically, sclerostin dysregulation has been observed in osteoporosis-related fractures, failure of implant osseous integration, metastatic bone disease, and select genetic diseases of bone mass.➤ An antibody that targets sclerostin, decreasing endogenous levels of sclerostin while increasing bone mineral density, is currently in phase-III clinical trials.➤ The osteocyte has emerged as a versatile, indispensable bone cell. Its location within bone, extensive dendritic network, and close communication with systemic circulation and other bone cells produce many opportunities to treat a variety of orthopaedic conditions.

Management of Turner's syndrome in adult life: case-series and systematic review

OBJECTIVE

To assess the symptoms and outcomes of clinical management in adult patients with Turner's Syndrome.

DESIGN

Retrospective case-series and systematic review of the literature.

SETTING

Gynaecological Endocrinology Unit in a teaching hospital.

PATIENTS

Patients followed in the Gynaecological Endocrinology Unit.

INTERVENTIONS

Review of medical records and a computer search via several databases to identify journals relevant to the subject were performed.

MAIN OUTCOME MEASURES

Final height, weight, previous treatments with growth hormone, cardiac or renal malformations, metabolic profile, and additional treatment for osteoporosis.

RESULTS

Thirty-one patients were analysed. Differences in final height were found between groups with monosomy and other karyotypes. Four patients bore congenital cardiac malformations, and six, renal congenital malformations. Nine patients had a previous diagnosis of hypercholesterolemia. The most abnormal hepatic parameter was GGT, with fifteen patients having values over the normality limit. Ten patients were receiving treatment for osteopenia or osteoporosis.

CONCLUSIONS

This case-series provides recommendations for the management of adult patients with Turner's syndrome and insight into the different medical complaints of this syndrome. A link between karyotypes and clinical features suggests a novel hypothesis to explain the different phenotypes and clinical abnormalities of these patients.

[Clinical practice guidelines for evaluation and treatment of osteoporosis associated to endocrine and nutritional conditions. Bone Metabolism Working Group of the Spanish Society of Endocrinology]

OBJECTIVE

To provide practical recommendations for evaluation and treatment of osteoporosis associated to endocrine diseases and nutritional conditions.

PARTICIPANTS

Members of the Bone Metabolism Working Group of the Spanish Society of Endocrinology, a methodologist, and a documentalist.

METHODS

Recommendations were formulated according to the GRADE system (Grading of Recommendations, Assessment, Development, and Evaluation) to describe both the strength of recommendations and the quality of evidence. A systematic search was made in MEDLINE (Pubmed), using the following terms associated to the name of each condition: AND "osteoporosis", "fractures", "bone mineral density", and "treatment". Papers in English with publication date before 18 October 2011 were included. Current evidence for each disease was reviewed by two group members, and doubts related to the review process or development of recommendations were resolved by the methodologist. Finally, recommendations were discussed in a meeting of the Working Group.

CONCLUSIONS

The document provides evidence-based practical recommendations for evaluation and management of endocrine and nutritional diseases associated to low bone mass or an increased risk of fracture. For each disease, the associated risk of low bone mass and fragility fractures is given, recommendations for bone mass assessment are provided, and treatment options that have shown to be effective for increasing bone mass and/or to decreasing fragility fractures are listed.

Bone density and risk of osteoporosis in Klinefelter syndrome

Different mechanisms in Klinefelter syndrome contribute to reduced bone mass and osteoporosis, which have a precocious onset and are detected in up to 40% of patients, irrespectively of testosterone levels. Androgen receptor, X chromosome inactivation and INSL3 levels are hypothesized to cooperate with and modulate the effect of testosterone on the bone.

CONCLUSION

New perspectives on genetic topics are opening exciting areas of research on the pathophysiology of reduced bone mass in Klinefelter patients.

Bone mass in subjects with Klinefelter syndrome: role of testosterone levels and androgen receptor gene CAG polymorphism

CONTEXT

Klinefelter syndrome (KS) is a chromosomal alteration characterized by supernumerary X-chromosome(s), primary hypogonadism, decreased pubertal peak bone mineral density (BMD), and accelerated bone loss during adulthood. Decreased bone mass has been traditionally related to low testosterone levels. However, testosterone replacement therapy does not necessarily increase bone mass in these patients, and low BMD can be observed also in patients with normal testosterone levels. The androgen receptor (AR) gene CAG polymorphism seems to modulate the sensitivity to testosterone and previous studies have related it to some clinical aspects of KS, to include BMD, gynecomastia, testes and prostate volume, and hemoglobin concentration.

OBJECTIVE

To analyze the relation between bone mass, testosterone, and AR CAG polymorphism in men with KS.

DESIGN

Cross-sectional cohort study.

SETTING

University department.

PATIENTS

One hundred twelve consecutive treatment-naïve 47,XXY Klinefelter patients (mean age 33.5 ± 4.7 yr) and 51 age-matched normal male controls.

MAIN OUTCOME MEASURES

Dual-energy x-ray absorptiometry, CAG repeat length polymorphism, X-chromosome inactivation, and testosterone levels.

RESULTS

Forty-nine of 112 KS subjects (42.5%) had low bone mass (osteopenia or osteoporosis). Lumbar and/or femoral T-scores were lower in KS patients compared with controls. No significant relationship was observed between testosterone levels and bone parameters, and the prevalence of osteopenia/osteoporosis was similar in subjects with normal and low testosterone levels (43.7% and 40.5%, respectively). The mean CAG repeat length calculated after X-chromosome inactivation analysis showed no differences between patients with normal and low bone mass.

CONCLUSIONS

Testosterone levels and AR CAG polymorphism are not associated with bone mass phenotype in KS.

Consensus statement on diagnosis and clinical management of Klinefelter syndrome

Nearly 70 years after its description, Klinefelter syndrome (KS) remains a largely undiagnosed condition. As its clinical presentation may be subtle, many of those affected may be unaware or diagnosed only during evaluation for hypogonadism and/or infertility. In February 2010 an interdisciplinary panel of specialists met in Abano Terme (Padua, Italy) in a workshop on "Klinefelter Syndrome: diagnosis and clinical management". The main aim of this meeting was to discuss several aspects related to the epidemiology, pathogenesis, and evaluation of KS and to develop a consensus defining its early diagnosis and treatment. In the present consensus we have highlighted the features that may prompt the physicians to look after patients with KS both for the syndrome and correlated diseases. We have provided evidences that, during the different phases of life, there might be some advantages in establishing the diagnosis and starting proper follow-up and treatment. The workshop was carried out under the auspices of the Italian Society of andrology and Sexual Medicine (SIAMS).

Strategies and advantages of early diagnosis in Klinefelter's syndrome

Nearly 70 years after its description, Klinefelter's syndrome (KS) remains a largely undiagnosed condition. In addition to its typical characteristics of increased follicle-stimulating hormone secretion and small and firm testes, the syndrome presents an extremely wide spectrum of phenotypes. This could be explained by the possible presence of chromosomal mosaicism, androgen receptor polymorphisms and related heterogeneous endocrine abnormalities. The varied but relatively mild physical abnormalities also explain why many patients do not receive clinical attention until adulthood, when they seek medical advice on small testes or infertility. Diagnosis is also hindered by the low awareness of the disease among health professionals. This paper aims to review the possible signs of KS at different stages of life that could help achieve an early (or at least earlier) diagnosis. It has been demonstrated that the early diagnosis of KS improves patients' quality of life and enables better medical treatment. To achieve this, it is crucial to increase both medical and general awareness of the disease, including through use of the media and patients' associations.

Healthcare for adolescents with Turner syndrome

This review paper highlights important healthcare issues for adolescents with Turner Syndrome. Turner Syndrome potentially affects multiple organ systems including: cardiovascular, renal, endocrine, neurologic, gastrointestinal, skin, skeletal, auditory, and reproductive systems. Congenital and acquired cardiac defects remain the most significant health problem faced by women with Turner Syndrome.

Osteoporosis in children and adolescents: etiology and management

Bone mass increases progressively during childhood, but mainly during adolescence when approximately 40% of total bone mass is accumulated. Peak bone mass is reached in late adolescence, and is a well recognised risk factor for osteoporosis later in life. Thus, increasing peak bone mass can prevent osteoporosis. The critical interpretation of bone mass measurements is a crucial factor for the diagnosis of osteopenia/osteoporosis in children and adolescents. To date, there are insufficient data to formally define osteopenia/osteoporosis in this patient group, and the guidelines used for adult patients are not applicable. In males and females aged <20 years the terminology 'low bone density for chronologic age' may be used if the Z-score is less than -2. For children and adolescents, this terminology is more appropriate than osteopenia/osteoporosis. Moreover, the T-score should not be used in children and adolescents. Many disorders, by various mechanisms, may affect the acquisition of bone mass during childhood and adolescence. Indeed, the number of disorders that have been identified as affecting bone mass in this age group is increasing as a consequence of the wide use of bone mass measurements. The increased survival of children and adolescents with chronic diseases or malignancies, as well as the use of some treatment regimens has resulted in an increase in the incidence of reduced bone mass in this age group. Experience in treating the various disorders associated with osteoporosis in childhood is limited at present. The first approach to osteoporosis management in children and adolescents should be aimed at treating the underlying disease. The use of bisphosphonates in children and adolescents with osteoporosis is increasing and their positive effect in improving bone mineral density is encouraging. Osteoporosis prevention is a key factor and it should begin in childhood. Pediatricians should have a fundamental role in the prevention of osteoporosis, suggesting strategies to achieve an optimal peak bone mass.

Adequacy of androgen replacement influences bone density response to testosterone in androgen-deficient men

OBJECTIVE

Androgen deficiency (AD) leads to bone loss and contributes to osteoporotic fractures in men. Although low bone mineral density (BMD) in AD men is improved by testosterone replacement, the responses vary between individuals but the determinants of this variability are not well defined.

DESIGN AND METHODS

Retrospective review of dual energy X-ray absorptiometry (DEXA) of the lumbar spine and proximal femur in men with established AD requiring regular androgen replacement therapy (ART). After a DEXA scan all men were treated with testosterone implants (800 mg, approximately 6 month intervals). Patients were classified as having a congenital, childhood, or post-pubertal onset, as well as according to the adequacy of treatment prior to their first DEXA scan as untreated, partially treated or well treated.

RESULTS

Men with AD requiring regular ART (n = 169, aged 46.3+/-1.1 years, range 22-84 years) underwent a DEXA scan prior to being treated with testosterone implants (800 mg, approximately 6 month intervals). In cross-sectional analysis at the time of the first DEXA scan untreated men (n = 24) had significantly reduced age-adjusted BMD at all four sites (L1-L4, femoral neck, Ward's triangle and trochanter). Well-treated men (n = 77) had significantly better age-adjusted BMD at all four sites compared with those who were partially treated (n = 66) or untreated (n = 24) with their age-adjusted BMD being normalized. In a longitudinal assessment of men (n = 60) who had two or more serial DEXA scans, at the second DEXA scan after a median of 3 years, men who were previously partially treated (n = 19) or untreated (n = 11) had proportionately greater improvements in BMD, significantly for Ward's triangle (P = 0.025) and the trochanter (P = 0.044) compared with men (n = 30) previously well treated.

CONCLUSIONS

The present study demonstrates a positive relationship between adequacy of testosterone replacement and BMD in men with overt organic AD. Additionally, the BMD of well-treated AD men approximates that of age-matched non-AD controls. The greatest BMD gains are made by those who have been either untreated or partially treated, and optimal treatment over time (median 3 years) normalizes BMD to the level expected for healthy men of the same age.

High risk of hypogonadism after traumatic brain injury: clinical implications

Several recent studies have convincingly documented a close association between traumatic brain injury (TBI) and pituitary dysfunction. Post-traumatic hypogonadism is very common in the acute post-TBI phase, though most cases recover within six to twelve months following trauma. The functional significance of early hypogonadism, which may reflect adaptation to acute illness, is not known. Hypogonadism persists, however, in 10-17% of long-term survivors. Sex steroid deficiency has implications beyond psychosexual function and fertility for survivors of TBI. Muscle weakness may impair functional recovery from trauma and osteoporosis may be exacerbated by immobility secondary to trauma. Identification and appropriate and timely management of post-traumatic hypogonadism is important in order to optimise patient recovery from head trauma, improve quality of life and avoid the long-term adverse consequences of untreated sex steroid deficiency.

Klinefelter's syndrome

Klinefelter's syndrome is the most common genetic cause of human male infertility, but many cases remain undiagnosed because of substantial variation in clinical presentation and insufficient professional awareness of the syndrome itself. Early recognition and hormonal treatment of the disorder can substantially improve quality of life and prevent serious consequences. Testosterone replacement corrects symptoms of androgen deficiency but has no positive effect on infertility. However, nowadays patients with Klinefelter's syndrome, including the non-mosaic type, need no longer be considered irrevocably infertile, because intracytoplasmic sperm injection offers an opportunity for procreation even when there are no spermatozoa in the ejaculate. In a substantial number of azoospermic patients, spermatozoa can be extracted from testicular biopsy samples, and pregnancies and livebirths have been achieved. The frequency of sex chromosomal hyperploidy and autosomal aneuploidies is higher in spermatozoa from patients with Klinefelter's syndrome than in those from normal men. Thus, chromosomal errors might in some cases be transmitted to the offspring of men with this syndrome. The genetic implications of the fertilisation procedures, including pretransfer or prenatal genetic assessment, must be explained to patients and their partners.

The impact and management of Turner's syndrome in adult life

Turner's syndrome (TS), caused by an absent or structurally abnormal X chromosome, affects 1 in 2500 live female births. Most medical attention has focused on the attainment of final height in childhood and, when this has been achieved, many women are discharged to primary care. It has become increasingly evident that adults with Turner's syndrome are susceptible to a range of disorders such as osteoporosis, hypothyroidism and diabetes. Because of these, and because of the need for long-term oestrogen replacement, it seems most practical for adult health surveillance in TS to come under the remit of the endocrinologist. It must be accepted, however, that the reduced life expectancy in women with TS is largely accounted for by cardiovascular disease. Also, the commonly observed social isolation in adults with TS can be linked to deafness that is increasingly prevalent in an ageing group. Co-ordination of all these issues requires a dedicated multidisciplinary clinic along the lines of those in place in diabetes.

Factors associated with the reduction of bone density in patients with gonadal dysgenesis

OBJECTIVE

To correlate bone mineral density (BMD) in women with primary hypoestrogenism caused by 46,XX pure gonadal dysgenesis or Turner's syndrome with age, age at estrogen therapy initiation, length of estrogen use, and body mass index (BMI).

DESIGN

Cross-sectional study.

SETTING

Academic tertiary-care hospital.

PATIENT(S)

Thirty-eight women, aged 16 to 35 years (mean, 24.6 years), affected by these genetic disorders.

INTERVENTION(S)

Measurement of lumbar spine and femoral neck BMD using double x-ray absorptiometry. The results were correlated with the control variables by using Pearson's coefficient of correlation. Variables associated with BMD were evaluated by multiple linear regression analysis.

MAIN OUTCOME MEASURE(S)

Bone mineral density.

RESULT(S)

Bone mineral density of the lumbar spine showed that 90% of the women presented osteopenia or osteoporosis. The femoral neck was affected in 55% of these women. The length of estrogen therapy and the BMI showed a positive association with BMD at the lumbar spine and femoral neck, respectively.

CONCLUSION(S)

Women affected by pure gonadal dysgenesis or Turner's syndrome presented a marked decrease in BMD of the lumbar spine and femoral neck. Medical attention for their diagnosis and early hormone replacement therapy are advised.