The influence of testosterone substitution on bone mineral density in patients with Klinefelter's syndrome

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.

Cortical Bone Mass is Low in Boys with Klinefelter Syndrome and Improves with Oxandrolone

Context

Klinefelter syndrome (KS) is the most common sex aneuploidy in men. Affected males have hypogonadism, and, as a result, face an increased risk for osteoporosis and fractures. Androgen therapy is standard in adolescents and adults with KS but has not been used earlier in childhood.

Objective

To determine the effects of androgen treatment on bone mass in children with KS.

Methods

Randomized, double-blind, placebo-controlled clinical trial of oxandrolone (OX; 0.06 mg/kg daily; n = 38) versus placebo (PL; n = 40) for 2 years in boys with KS (ages 4-12 years). Changes in bone mass were examined by digital x-ray radiogrammetry, which determines the Bone Health Index (BHI) and standard deviation score (SDS).

Results

BHI SDS was similar between groups at baseline (–0.46 ± 1.1 vs –0.34 ± 1.0 OX vs PL, P > .05) and higher in the OX group at 2 years (–0.1 ± 1.3 vs –0.53 ± 0.9, OX vs PL, P < .01). At baseline, BHI SDS values of all subjects were not normally distributed with 25.7% of subjects plotted below –1 SDS (P < .001), suggesting a deficit in bone mass. In total, 13.5% of subjects had sustained a fracture and their BHI SDS was lower than those with no fractures (–1.6 ± 1.3 vs –0.3 ± 1.0, P = .004).

Conclusion

Bone mass using BHI SDS is reduced in some children with KS and improves with OX. Since these individuals are at risk for osteoporosis, age-appropriate androgen replacement and future studies on bone health in children with KS should be further explored.

Clinical manifestation, diagnosis, and treatment of Klinefelter syndrome

Klinefelter syndrome is the most common congenital chromosomal syndrome in men. Clinical manifestations of Klinefelter syndrome vary greatly depending on the level of expression of the added X chromosome, the sensitivity of the androgen receptor, and the testosterone level. On average, the likelihood of a lifetime diagnosis of Klinefelter syndrome patients is less than 40%, and more than 60% of patients are unaware of their condition. Klinefelter syndrome patients in infancy sometimes have speech impairment; however, there are more cases without symptoms. In the early stages of puberty, there are many normal puberty development cases, but after mid-puberty, secondary sexual characteristics stop progressing. In adulthood, it is often diagnosed as a non-obstructive azoospermia disease. After middle-age, an increase in various metabolic disorders due to testosterone reduction appears as the main symptom. Testosterone treatment can promote the development of secondary sexual characteristics from puberty. Diagnosing a patient with Klinefelter syndrome due to infertility in adulthood may cause a psychological shock; therefore, a psychotherapeutic approach is also essential. Klinefelter syndrome is a disease that requires lifelong management, and in most cases the quality of life of patients and their families can be improved with appropriate therapeutic intervention. Because there are many cases without symptoms, it is important to screen suspected patients through active chromosomal testing.

The epidemiology of sex chromosome abnormalities

Sex chromosome abnormalities (SCAs) are characterized by gain or loss of entire sex chromosomes or parts of sex chromosomes with the best-known syndromes being Turner syndrome, Klinefelter syndrome, 47,XXX syndrome, and 47,XYY syndrome. Since these syndromes were first described more than 60 years ago, several papers have reported on diseases and health related problems, neurocognitive deficits, and social challenges among affected persons. However, the generally increased comorbidity burden with specific comorbidity patterns within and across syndromes as well as early death of affected persons was not recognized until the last couple of decades, where population-based epidemiological studies were undertaken. Moreover, these epidemiological studies provided knowledge of an association between SCAs and a negatively reduced socioeconomic status in terms of education, income, retirement, cohabitation with a partner and parenthood. This review is on the aspects of epidemiology in Turner, Klinefelter, 47,XXX and 47,XYY syndrome.

Morbidity in Klinefelter syndrome and the effect of testosterone treatment

Klinefelter syndrome (KS; 47,XXY) is the most common sex chromosome abnormality in males (150 per 100,000 males). The condition leads to hypergonadotropic hypogonadism and ever since the condition was described approximately 80 years ago, testosterone treatment has been the cornerstone in care for individuals with KS. However, KS is associated with an array of health-related and socioeconomic challenges and it is becoming progressively clear that proper care for boys and men with KS reaches far beyond simply supplementing with testosterone. There are no widely implemented guidelines for KS care, and studies investigating crucial aspects of testosterone treatment in individuals with KS, including both beneficial and potentially adverse effects, have only begun to emerge during the last decades. For this descriptive review, we present an overview of literature describing health-related outcomes of testosterone treatment in KS and outline the clinical applications of testosterone treatment in KS. Collectively, beneficial effects of testosterone treatment on overall health in KS are described with few apparent adverse effects. However, larger randomized studies in adult and pediatric patients are warranted to elucidate key aspects of treatment. We stress the implementation of centralized multidisciplinary clinics and the need for a dedicated international guideline to ensure optimal care of boys and men with KS.

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.

Effects of the Timing of Sex-Steroid Exposure in Adolescence on Adult Health Outcomes

CONTEXT

Variation in pubertal timing is associated with a wide range of adult risks and outcomes, but it is unclear whether these associations are causal, and it is largely unknown whether these associations can be modified by treatment.

EVIDENCE ACQUISITION

We conducted PubMed searches to identify Mendelian randomization (MR) studies on the influence of pubertal timing on adult health and studies on sex-steroid treatment of the following conditions associated with reduced reproductive endocrine function in adolescence: constitutional delay, Turner syndrome, and Klinefelter syndrome.

EVIDENCE SYNTHESIS

Results of MR studies suggest that earlier pubertal timing increases body mass index; increases risk for breast, ovarian, endometrial, and prostate cancers; elevates fasting glucose levels and blood pressure; impairs lung capacity and increases risk for asthma; leads to earlier sexual intercourse and first birth; decreases time spent in education; and increases depressive symptoms in adolescence. Later pubertal timing appears to lower bone mineral density (BMD). Although studies of constitutional delay have not shown that sex-steroid treatment alters adult height or BMD, studies of girls with Turner syndrome and boys with Klinefelter syndrome suggest that earlier initiation of sex-steroid treatment improves physical and neurocognitive outcomes.

CONCLUSIONS

Despite having some limitations, MR studies suggest that pubertal timing causally influences many adult conditions and disease risks. Studies of Turner syndrome and Klinefelter syndrome suggest that earlier sex-steroid exposure may have short- and long-term benefits. The mechanisms underlying these findings and the effects of trends and treatments affecting pubertal timing remain to be determined.

Klinefelter syndrome: From pediatrics to geriatrics

BACKGROUND

Klinefelter syndrome (KS) is one of the major causes of nonobstructive azoospermia (NOA). Microdissection testicular sperm extraction (micro-TESE) is often performed to retrieve sperm. Infertility specialists have to care for KS patients on a lifelong basis.

METHODS

Based on a literature review and our own experience, male infertility treatment and KS pathophysiology were considered on a lifelong basis.

MAIN FINDINGS

Patients diagnosed early often have an increased number of aberrant X chromosomes. Cryptorchidism and hypospadias are often found, and surgical correction is required. Cryopreservation of testicular sperm during adolescence is an issue of debate because the sperm retrieval rate (SRR) in KS patients decreases with age. The SRR in adult KS patients is higher than that in other patients with NOA; however, low testosterone levels after micro-TESE will lower the general health and quality of life. KS men face a number of comorbidities, such as malignancies, metabolic syndrome, diabetes, cardiovascular disease, bone disease, and immune diseases, which ultimately results in increased mortality rates.

CONCLUSION

A deeper understanding of the pathophysiology of KS and the histories of KS patients before they seek infertility treatment, during which discussions with multidisciplinary teams are sometimes needed, will help to properly treat these patients.

Type 1 Diabetes Mellitus and Klinefelter Syndrome

A 60-year-old male patient with type 1 diabetes mellitus (T1DM) was admitted for glycemic control. The patient exhibited abdominal adiposity, osteoporosis, and high insulin requirement (>100 U), and we suspected hypogonadism. A physical examination revealed small testes and thin pubic hair, laboratory examination found high luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels and low testosterone levels, and a chromosome analysis (47, XXY) indicated hypogonadism due to Klinefelter syndrome (KS). KS is associated with autoimmune diseases and patients positive for diabetes related auto-antibodies. In male patients with T1DM and abdominal adiposity, the concurrence of KS should be taken into consideration.

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.

Anatomical and clinical aspects of Klinefelter's syndrome

Klinefelter's syndrome, the most common sex disorder associated with chromosomal aberrations, is characterized by a plethora of clinical features. Parameters for diagnosis of the syndrome are constantly expanding as new anatomical and hormonal abnormalities are noted, yet Klinefelter's remains underdiagnosed and underreported. This review outlines the key anatomical characteristics associated with the syndrome, which are currently used for clinical diagnosis, or may provide means for improving diagnosis in the future. Clin. Anat. 29:606-619, 2016. © 2016 Wiley Periodicals, Inc.

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.

Bone geometry, volumetric density, microarchitecture, and estimated bone strength assessed by HR-pQCT in Klinefelter syndrome

Although the expected skeletal manifestations of testosterone deficiency in Klinefelter's syndrome (KS) are osteopenia and osteoporosis, the structural basis for this is unclear. The aim of this study was to assess bone geometry, volumetric bone mineral density (vBMD), microarchitecture, and estimated bone strength using high-resolution peripheral quantitative computed tomography (HR-pQCT) in patients with KS. Thirty-one patients with KS confirmed by lymphocyte chromosome karyotyping aged 35.8 ± 8.2 years were recruited consecutively from a KS outpatient clinic and matched with respect to age and height with 31 healthy subjects aged 35.9 ± 8.2 years. Dual-energy X-ray absorptiometry (DXA) and HR-pQCT were performed in all participants, and blood samples were analyzed for hormonal status and bone biomarkers in KS patients. Twenty-one KS patients were on long-term testosterone-replacement therapy. In weight-adjusted models, HR-pQCT revealed a significantly lower cortical area (p < 0.01), total and trabecular vBMD (p = 0.02 and p = 0.04), trabecular bone volume fraction (p = 0.04), trabecular number (p = 0.05), and estimates of bone strength, whereas trabecular spacing was higher (p = 0.03) at the tibia in KS patients. In addition, cortical thickness was significantly reduced, both at the radius and tibia (both p < 0.01). There were no significant differences in indices of bone structure, estimated bone strength, or bone biomarkers in KS patients with and without testosterone therapy. This study showed that KS patients had lower total vBMD and a compromised trabecular compartment with a reduced trabecular density and bone volume fraction at the tibia. The compromised trabecular network integrity attributable to a lower trabecular number with relative preservation of trabecular thickness is similar to the picture found in women with aging. KS patients also displayed a reduced cortical area and thickness at the tibia, which in combination with the trabecular deficits, compromised estimated bone strength at this site.

The role of hypogonadism in Klinefelter syndrome

Klinefelter syndrome (KS) (47, XXY) is the most abundant sex-chromosome disorder, and is a common cause of infertility and hypogonadism in men. Most men with KS go through life without knowing the diagnosis, as only 25% are diagnosed and only a few of these before puberty. Apart from hypogonadism and azoospermia, most men with KS suffer from some degree of learning disability and may have various kinds of psychiatric problems. The effects of long-term hypogonadism may be diffi cult to discern from the gene dose effect of the extra X-chromosome. Whatever the cause, alterations in body composition, with more fat and less muscle mass and diminished bone mineral mass, as well as increased risk of metabolic consequences, such as type 2 diabetes and the metabolic syndrome are all common in KS. These findings should be a concern as they are not simply laboratory findings; epidemiological studies in KS populations show an increased risk of both hospitalization and death from various diseases. Testosterone treatment should be offered to KS patients from early puberty, to secure a proper masculine development, nonetheless the evidence is weak or nonexisting, since no randomized controlled trials have ever been published. Here, we will review the current knowledge of hypogonadism in KS and the rationale for testosterone treatment and try to give our best recommendations for surveillance of this rather common, but often ignored, syndrome.

Prostate volume and growth during testosterone replacement therapy is related to visceral obesity in Klinefelter syndrome

OBJECTIVE

Klinefelter syndrome (KS) is a chromosomal alteration characterized by increased risk of metabolic syndrome, mainly caused by visceral obesity. In the last years, obesity has been studied as a potential risk factor for prostate disease and recently a link has been demonstrated between visceral adiposity with prostate volume. The aim of this study was to analyze the relationship between obesity and prostate volume and growth during testosterone therapy in KS subjects.

DESIGN AND METHODS

We evaluated reproductive hormones, metabolic parameters, anthropometric measures, PSA, and prostate volume in 121 naïve non-mosaic KS patients and 60 age-matched healthy male controls. Fifty-six KS hypogonadic subjects were treated with testosterone-gel 2% and reevaluated after 18 months of treatment.

RESULTS

Prostate volume in KS was positively related to waist circumference (WC). The KS group with WC ≥94 cm had significantly higher prostate volume, BMI, insulin plasma levels, homeostasis model assessment index, total cholesterol, triglycerides, and glycemia with respect to the KS group with WC <94 cm. After testosterone replacement therapy, only hypogonadic KS men with WC ≥94 cm had a statistically significant increase in prostate volume. Furthermore, in untreated KS subjects, prostate volume showed a statistically significant increase after 18 months of follow-up only in subjects with WC ≥94 cm.

CONCLUSIONS

This study showed that visceral obesity, insulin resistance, and lipid and glucose metabolism alterations are associated with prostate volume and growth during testosterone replacement therapy in KS, independently from androgen or estrogen levels. These latter findings might provide the basis for a better management and follow-up of KS subjects.

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.

Postnatal screening for Klinefelter syndrome: is there a rationale?

Diagnosis of Klinefelter syndrome (KS) allows for timely beneficial interventions across the lifespan. Most cases currently remain undiagnosed because of low awareness of KS amongst health professionals, the hesitancy of men to seek medical attention and its variable clinical presentation. Given these barriers, population-based genetic screening provides an approach to comprehensive and early detection. We examine current evidence regarding risks and benefits of diagnosing KS at different ages.

CONCLUSION

There is a lack of evidence regarding the influence of age at diagnosis on adult outcomes that can only be obtained through a pilot screening programme.

Bone mineral density in Klinefelter syndrome is reduced and primarily determined by muscle strength and resorptive markers, but not directly by testosterone

SUMMARY

Klinefelter syndrome (KS) patients have lower bone mineral density (BMD) at the spine, hip and forearm compared to healthy subjects, but frank osteoporosis is not common. Muscle strength and bone markers predicted BMD but KS itself and serum testosterone did not. Low vitamin D and high PTH were frequent among KS.

INTRODUCTION

The long-term consequence of KS on bone health is not well described. The objective of this study is to investigate the regional BMD and its determinants in KS.

METHODS

This is a cross-sectional study. BMD at the spine, hip and forearm are measured by DXA and correlated to biochemical markers of bone turnover, vitamin D metabolites, PTH, sex hormones, growth factors as well as muscle strength and anthropometric measures. The setting is at a university clinical research centre. The study involves 70 adult KS patients and 71 age-matched healthy subjects.

RESULTS

In KS, BMD was universally lowered in all regions. Markers of bone formation or bone resorption were not altered in KS, but 25-OH-Dvitamin was lower (55 vs. 82 nmol/L, p < 0.0001) than in healthy subjects. Significantly more KS patients had low BMD (Z-scores below -2) at the forearm (15 KS vs. two healthy subjects, p = 0.001) but not at the spine or hip. Muscle strength (bicep and quadriceps) was lower among KS patients. Multivariate analysis revealed that muscle strength, treatment with testosterone (ever/never), age at diagnosis, SHBG, bone-specific alkaline phosphatase and 1CTP were all independent predictors of BMD, but androgens was not.

CONCLUSIONS

KS patients had lower BMD at the spine, hip and forearm compared to age-matched healthy subjects, but frank osteoporosis was not common. Muscle strength, previous history of testosterone treatment, age at diagnosis and bone markers were predictors of BMD, but testosterone was not. Signs of secondary hyperparathyroidism were present among KS. Dietary intake of vitamin D or sun exposure may be lower in KS 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.

Spermatogenesis in Klinefelter syndrome

BACKGROUND

Klinefelter syndrome (KS) (47,XXY) is the most common sex chromosomal disorder, and it is a frequent form of male hypogonadism and infertility. Although the majority of these patients are azoospermic, they might have severe oligozoospermia or residual single-residual foci with spermatogenesis in the testis.

AIM

We report our experience on sperm retrieval in the ejaculate and testis, and evaluate the frequency of chromosome abnormalities in sperm of KS.

SUBJECTS AND METHODS

Eighty-four 47,XXY KS were evaluated with seminal analysis, body hair distribution, reproductive hormones, ultrasonographic scanning of the testis and prostate, bilateral testicular sperm extraction (TESE), sperm or testicular cells sex chromosomes aneuploidies.

RESULTS

Out of 84 patients, 7 (7/84; 8.3%) had sperm in the ejaculate. Out of the 77 azoospermic patients, 24 underwent TESE and 9 (9/24; 37.5%) had successful sperm recovery. The comparison of reproductive hormones, age and testicular volume did not show significant differences between patients with and without successful sperm recovery in semen or TESE . Patients without successful sperm recovery in semen analysis or TESE had signs of hypoandrogenism more evident than patients with successful sperm recovery. Patients with KS produced a higher number of sperm aneuploidy with respect to normozoospermic fertile controls and non-genetic severely oligozoospermic men.

CONCLUSIONS

Men with KS are not always sterile. In some of these patients sperm can be found in semen or in the testis, but the proportion of sperm aneuploidy is high. Signs of hypoandrogenism seem to be associated with low sperm recovery rate.

Klinefelter syndrome presenting as behavioral problems in a young adult

BACKGROUND

An 18-year-old Somali man presented to a primary care clinic to investigate a potential pathophysiological reason for behavioral problems at school that had arisen in the past 1-2 years. A previous physical examination at school revealed the patient to have small, firm testicles which prompted further testing.

INVESTIGATION

Thyroid function and levels of prolactin, total testosterone, follicle-stimulating hormone and luteinizing hormone were determined. Testes were measured. Chromosome analysis testing was performed to determine the patient's karyotype.

DIAGNOSIS

Klinefelter syndrome with a 47,XXY karyotype.

MANAGEMENT

Testosterone replacement therapy was recommended, but the patient declined treatment.

The clinical significance of bone mineral density and testosterone levels in Korean men with non-mosaic Klinefelter's syndrome

OBJECTIVE

To measure bone mineral density (BMD) and testosterone levels in patients with non-mosaic Klinefelter's syndrome (KS), as a low BMD is common in hypogonadal men, but little is known about the relationship between BMD and serum testosterone levels in men with KS.

PATIENTS, SUBJECTS AND METHODS

The study included 40 patients with KS and 20 healthy fertile men recruited as controls. Serum testosterone, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels were measured by radioimmunoassay. The BMD was obtained at the lumbar spine (L2-4), femoral neck and Ward's triangle, by dual-energy X-ray absorptiometry.

RESULTS

The serum testosterone level was lower, while FSH and LH were higher, in patients with KS than in the control group (P < 0.001). Patients with KS had a significantly lower mean (sd) BMD at the lumbar spine, femoral neck and Ward's triangle, than the controls, at 0.88 (0.13) vs 1.09 (0.10) (P < 0.001), 0.78 (0.12) vs 0.87 (0.10) (P = 0.006) and 0.65 (0.12) vs 0.76 (0.11) g/cm(2) = 0.001), respectively. There was a linear correlation between all BMD values and serum testosterone levels in men with KS who had a low serum testosterone level.

CONCLUSIONS

There was a relationship between a lower BMD and testosterone levels in patients with KS. These findings suggest that low testosterone levels cause inadequate bone development and a low BMD in men with KS; therefore, testosterone replacement might be necessary to prevent bone mineral deficiency and future risk of fractures in men with KS who also have low serum testosterone levels.

Primary testicular failure in Klinefelter's syndrome: the use of bivariate luteinizing hormone-testosterone reference charts

BACKGROUND

The diagnosis of androgen deficiency is based on clinical features and confirmatory low serum testosterone levels. In early primary testicular failure, a rise in serum LH levels suggests inadequate androgen action for the individual's physiological requirements despite a serum testosterone level within the normal range. The combined evaluation of serum LH and testosterone levels in the evaluation of testicular failure has not been widely advocated.

PATIENTS

Seven hundred and six healthy males and 39 patients with known primary hypogonadism due to Klinefelter's syndrome and SRY-positive 46,XX karyotypes were included in the study.

DESIGN

Testosterone, oestradiol and LH serum concentrations were measured in all individuals. Based on the 706 healthy males two-dimensional bivariate LH-testosterone reference charts were constructed.

RESULTS

Despite a median serum total and free testosterone and oestradiol levels being reduced (P < 0.001) and LH levels elevated (P < 0.001) in Klinefelter's syndrome and 46,XX-males, many subjects (69%) had total testosterone within the reference range. However, using the bivariate charts all subjects lay outside the 97.5 percentile.

CONCLUSION

Bivariate LH and testosterone charts are useful in the evaluation of men with known primary testicular failure due to sex chromosomal aneuploidy in whom evaluation based on testosterone measurement in isolation underestimates the prevalence of hypogonadism. It is, however, important to emphasize that isolated use of the bivariate evaluation should not form the basis for androgen substitution therapy. Further studies are needed in order to evaluate the use of bivariate LH and testosterone charts in the assessment of any younger man with possible primary testicular failure.

Natural history of seminiferous tubule degeneration in Klinefelter syndrome

Klinefelter syndrome (47,XXY) is characterized by small, firm testis, gynaecomastia, azoospermia and hypergonadotropic hypogonadism. Degeneration of the seminiferous tubules in 47,XXY males is a well-described phenomenon. It begins in the fetus, progresses through infancy and accelerates dramatically at the time of puberty with complete hyalinization of the seminiferous tubules, although a few tubules with spermatogenesis may be present in adult life. Activation of the pituitary-gonadal axis at 3 months of age is seen in Klinefelter boys similar to healthy boys. However, the level of testosterone in Klinefelter boys is significantly lower than in controls. After this 'minipuberty', the hormone levels decline to normal prepubertal levels until puberty. In puberty, an initial rise in testosterone, inhibin B, LH and FSH occurs in Klinefelter boys. However, the rise in testosterone levels off and ends at a low-normal level in young adults. Likewise, serum concentration of inhibin B exhibits a dramatic decline to a low, often undetectable level, concomitantly with a rise in FSH, reflecting the degeneration of the seminiferous tubules. Many hypotheses about the underlying mechanism of the depletion of the germ cells in Klinefelter males have been reported and include insufficient supranumerary X-chromosome inactivation, Leydig cell insufficiency and disturbed regulation of apoptosis of Sertoli and Leydig cells. However, at present, the exact mechanism remains unclear. In this article, we summarize current knowledge on the development of the classical endocrinological and histological features of 47,XXY males from fetus to adulthood and review the literature concerning the degeneration of the seminiferous tubules in this syndrome.

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.

Male hypogonadism in the primary care clinic

Hypogonadism is common in clinical practice but is frequently unrecognized and underdiagnosed. The common causes of male hypogonadism vary with the age of presentation. The overall prevalence of male hypogonadism based upon low serum total testosterone levels is high and increases with age. There are many pitfalls in making the diagnosis of male hypogonadism. First, male hypogonadism is sometimes difficult to recognize because the signs and symptoms are often nonspecific and overlap with other common syndromes. Second, the biochemical diagnosis of male hypogonadism is not straightforward because it might not be clear which testosterone assay to select from the many that are available. Finally, even after the diagnosis of male hypogonadism is made, the patient and clinician must weigh the potential benefits and risks of androgen replacement therapy. However, new diagnostic tools and therapies are making decisions easier.

Bone mineral density outcomes following long-term treatment with subcutaneous testosterone pellet implants in male hypogonadism

BACKGROUND

Osteoporosis is a common complication of untreated male hypogonadism. Even mild hypogonadism due to suboptimal testosterone replacement may result in decreased bone mineralization and osteoporosis.

OBJECTIVE

To assess bone mineral density in hypogonadal men following long-term long-acting subcutaneous testosterone pellet implants as replacement therapy.

PATIENTS

A cross-sectional study of 37 patients with primary or secondary hypogonadism receiving long-term (mean 6.6 years) subcutaneous testosterone pellet implants as replacement therapy.

MEASUREMENTS

Bone mineral density was measured in all patients using dual energy X-ray absorptiometry. Serum testosterone 3-4 months after insertion of pellets was measured in all patients to assess adequacy of replacement therapy.

RESULTS

Mean areal bone mineral density were 1.02 (SD 0.14) g/cm2 with a mean Z score of -0.64 (SD 1.3) and 0.87 (SD 0.13) g/cm2 with a mean Z score of -0.72 (SD 1.2) at lumbar spine and neck of femur, respectively. Mean serum testosterone 3-4 months after pellets insertion was 15.45 nmol/l (SD 4.2 nmol/l). There was no significant correlation between bone mineral density and patient's age at start or duration of testosterone therapy.

CONCLUSIONS

Bone mineral density in long-term regularly treated hypogonadal men was not different from the age-matched reference range for normal men. Long-acting subcutaneous testosterone pellet implants as replacement therapy in male hypogonadism are safe, acceptable to the patient, result in adequate bone mass accumulation and maintenance of normal bone mineral density. By provision of sustained physiological levels of testosterone they may contribute to increased androgen effect at the receptor level.

Klinefelter syndrome is a common cause for mental retardation of unknown etiology among prepubertal males

Klinefelter syndrome (KS) has not typically been associated with mental retardation (MR), however, in recent years a growing body of evidence suggested that KS boys often experience language deficits and academic difficulties. In this study, we screened DNA samples from 1205 patients originally referred for fragile X syndrome (FRAX) testing, because of MR of unknown etiology and detected 8 KS patients. A similar number of males in the same age group were found to have FRAX; 3 of them had a family history of FRAX. Based on these findings, KS might be the most common cause of MR of unknown etiology among prepubertal males. Because of the significant benefits of early recognition and treatment of KS, we emphasize the importance of cytogenetic testing of all prepubertal males with cognitive impairment even without dysmorphic features.

Gonadal dysgenesis and bone metabolism

Gonadal dysgenesis is defined as congenital hypogonadism related to abnormalities of the sex chromosomes. Because sex steroids play a central role in the acquisition and maintenance of bone mass, studies have been done to investigate bone status in patients with gonadal dysgenesis, particularly Turner's syndrome and Klinefelter's syndrome, which are the two most common types. The severe estrogen deficiency characteristic of Turner's syndrome (44, X0) is associated with a significant bone mass decrease ascribable to increased bone turnover, as shown by histological studies and assays of bone turnover markers. Estrogen therapy is followed by a significant bone mass gain and a return to normal of bone turnover markers, suggesting that it is the estrogen deficiency rather than the chromosomal abnormality that causes the bone mass deficiency, although abnormalities in the renal metabolism of vitamin D have been reported. Combined therapy with estrogens and growth hormone seems beneficial during the prepubertal period. In Klinefelter's syndrome (47XXY), serum testosterone levels are at the lower end of the normal range and dihydrotestosterone levels are low. Histological studies show depressed osteoblast function and a decrease in 5-alpha-reductase activity responsible for partial tissue resistance to androgens. Assays of bone turnover markers show evidence of increased bone turnover. The bone deficiency is most marked at the femoral neck and seems correlated with serum testosterone and estradiol levels. Androgen therapy has favorable effects on the bone only if it is started before puberty. Recent data suggest that estrogens may contribute to the development of demineralization in KS and that bisphosphonate therapy may be beneficial.

Diagnosis and treatment of Klinefelter syndrome

Many physicians underestimate the prevalence of Klinefelter syndrome and so fail to recognize its more obvious features. Increased awareness of its effects on physical, psychological, and social development should help to dispel persistent misconceptions about the condition and enable earlier diagnosis and more effective treatment.

Bones and Crohn's: problems and solutions

Inflammatory bowel disease may manifest in various extra intestinal manifestations. Osteopenia and various arthropathies may be debilitating. These may be related to the disease itself, patient genetics, lifestyle, or disease treatment. Calcium and vitamin D malabsorption, vitamin K deficiency, malnutrition, corticosteroid and other immunosuppressive medications, smoking, lack of exercise and postmenopausal state may all play important roles. Treatment may be undertaken to correct nutrient deficiencies, inhibit bone resorption and increase bone formation.

Testosterone replacement therapy

The benefits conferred by testosterone replacement therapy are substantial, both in the short term for the eradication of symptoms of androgen deficiency, and in the long term for the prevention of osteoporosis. As with any long-term treatment there are risks that must be considered, but overall the benefits achieved far outweigh potential risk. Ideally, androgen replacement therapy should provide physiological serum testosterone levels, as well as DHT and estradiol levels, and correct the clinical symptoms of androgen deficiency in hypogonadal men. This goal is difficult to achieve because the dose dependency of androgen-dependent physiological processes is not known. Androgen preparations that are currently available do not fulfill all criteria for an ideal androgen replacement therapy. Parenteral testosterone esters are effective, safe, practical, and inexpensive. The transdermal testosterone systems provide an alternative to testosterone esters in selected patients but these preparations are expensive. Ongoing studies are showing the benefits of testosterone replacement therapy in aging men, but there is concern about side effects on cardiovascular system and prostate. Thus, clinical decision regarding testosterone therapy in older men should be better defined.

Thrombophilia in a man with long-standing hypogonadism

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New aspects in the diagnosis and treatment of pubertal disorders

Recent developments in biochemistry, genetics, and clinical research have produced a profound effect on the understanding of normal and abnormal puberty. This article is intended to point out selected new developments that affect the understanding of puberty and clinical practice in disorders of puberty.

Bone mass and mineral metabolism in Klinefelter's syndrome

A reduced bone mineral density (BMD) is frequently observed in hypogonadal males; however, very little is known on bone and mineral metabolism in Klinefelter's syndrome (KS). In this study 32 XXY KS patients and 24 healthy age-matched male controls were examined. Serum total and free testosterone (TT and FT) were significantly lower in patients than in controls (TT in KS, 15.1 +/- 7.8 nmol/l; controls, 30.4 +/- 9.1; p < 0.001. FT in KS, 81.8 +/- 24.9 pmol/l; controls, 135.7 +/- 16.4; p < 0.001). 17 beta-Estradiol was slightly higher in KS patients (KS, 49.0 +/- 27.1 pg/ml; controls, 39.3 +/- 16.4 pg/ml), but the difference was not significant. BMD, measured at the spine (L2-4) and at the proximal epiphysis of the left femur, was similar in patients and in the control group (spine: KS, 1.016 +/- 0.142; controls, 1.085 +/- 0.144 g/cm2; p = not significant. Femoral neck: KS, 0.926 +/- 0.149; controls, 0.926 +/- 0.122 g/cm2; p = not significant). Bone GLA protein (BGP) was significantly higher in the KS group (12.7 +/- 4.8 vs 8.9 +/- 5.2 ng/ml; p < 0.02), while serum calcium, serum phosphate, calciotrophic hormones and the fasting urinary hydroxyproline/creatinine ratio (OHP/Creat) were similar in the two groups. A positive relationship between FT and both spine and femoral BMD was found in KS patients. Furthermore, OHP/Creat ratio was inversely related to BMD at the femur, and positively related to BGP in KS patients, but not in normal subjects. These findings suggest that (1) KS patients have normal bone mass, most probably because the hypogonadism is moderate; and (2) patients with lower bone mass appear to have higher bone turnover.