Reduction of bone density: an effect of gonadotropin releasing hormone analogue treatment in central precocious puberty

The effect of gonadotropin-releasing hormone analog treatment on the endocrine system in central precocious puberty patients: a meta-analysis

OBJECTIVES

Gonadotropin-releasing hormone (GnRHa) is the first choice for the treatment of patients with central precocious puberty (CPP). However, the effects of GnRHa on the endocrine system of CPP patients, including insulin sensitivity, lipid level, thyroid function, bone mineral density (BMD), and testosterone (T) level, are currently contradictory. Therefore, the long-term safety of GnRHa therapy remains controversial.

CONTENT

A systematic literature search was performed using PubMed, Embase, Cochrane Library, and CNKI databases. The changes in HOMA-IR, TG, LDL-C, HDL-C, TSH, FT3, FT4, T, and BMD in CPP patients before and after GnRHa treatment were compared by meta-analysis. As the heterogeneity between studies, we estimated standard deviation mean differences (SMDs) and 95 % confidence intervals (CIs) using a random-effects model. Egger's test was used to assess publication bias.

SUMMARY

A total of 22 studies were included in our meta-analysis. Compared with before GnRHa treatment, there were no statistically significant differences in endocrine indicators including HOMA-IR, TG, LDL-C, HDL-C, TSH, FT4, FT3, T, and BMD of CPP patients treated with GnRHa.

OUTLOOK

Treatment with GnRHa for central precocious puberty will not increase the adverse effect on the endocrine system.

Exploring Hormone Therapy Effects on Reproduction and Health in Transgender Individuals

Transgender individuals often face elevated mental health challenges due to gender dysphoria, but gender-affirming treatments such as surgery and hormone therapy have been linked to significant improvements in mental well-being. The potential influence of time and circadian rhythms on these treatments is prevalent. The intricate interplay between hormones, clock genes, and fertility is profound, acknowledging the complexity of reproductive health in transgender individuals. Furthermore, risks associated with gender-affirming hormonal therapy and potential complications of puberty suppression emphasize the importance of ongoing surveillance for these patients and the need of fertility preservation and family-building options for transgender individuals. This narrative review delves into the intricate landscape of hormone therapy for transgender individuals, shedding light on its impact on bone, cardiovascular, and overall health. It explores how hormone therapy affects bone maintenance and cardiovascular risk factors, outlining the complex interplay of testosterone and estrogen. It also underscores the necessity for further research, especially regarding the long-term effects of transgender hormones. This project emphasizes the critical role of healthcare providers, particularly obstetricians and gynecologists, in providing affirming care, calling for comprehensive understanding and integration of transgender treatments. This review will contribute to a better understanding of the impact of hormone therapy on reproductive health and overall well-being in transgender individuals. It will provide valuable insights for healthcare providers, policymakers, and transgender individuals themselves, informing decision-making regarding hormone therapy and fertility preservation options. Additionally, by identifying research gaps, this review will guide future studies to address the evolving healthcare needs of transgender individuals. This project represents a critical step toward addressing the complex healthcare needs of this population. By synthesizing existing knowledge and highlighting areas for further investigation, this review aims to improve the quality of care and support provided to transgender individuals, ultimately enhancing their reproductive health and overall well-being.

Gender Dysphoria in Young People: A Model of Chronic Stress

BACKGROUND

Gender dysphoria (GD) refers to the distress that may accompany gender incongruence, often heightened at the onset of puberty, with the development of secondary sex characteristics. Children and adolescents may be especially vulnerable to severe stressors, including GD, with potentially irreversible effects if these exposures occur during critical periods of development and brain maturation.

SUMMARY

We describe the evidence for GD as a chronic stressor, drawing parallels to other established models of stress, activating both innate psychological and biological stress responses. As well as being an inherently distressing experience, a person who experiences GD may also experience minority stress. Minority stress has been demonstrated in young people who experience GD with higher rates of social rejection and internalized stigma and shame. The biological stress response in young people with GD is illustrated through the activation of the hypothalamic-pituitary-adrenal axis, autonomic nervous system, and pro-inflammatory response. The number of young people who report experiencing GD has increased exponentially worldwide in the past decade, demanding a change in the clinic infrastructure. Paediatric endocrinologists and specialists in mental health work together to both support psychosocial well-being and offer individualized treatment to align the phenotype with gender identity with the aim of alleviating the distress of GD. Medical interventions may include puberty suppression and gender-affirming hormones. Ongoing monitoring is required prior to initiation and during treatment to ensure that the goals of treatment are being achieved.

International Consensus Guideline on Small for Gestational Age (SGA): Etiology and Management from Infancy to Early Adulthood

This International Consensus Guideline was developed by experts in the field of SGA of 10 pediatric endocrine societies worldwide. A consensus meeting was held and 1300 articles formed the basis for discussions. All experts voted about the strengths of the recommendations. The guideline gives new and clinically relevant insights into the etiology of short stature after SGA birth, including novel knowledge about (epi)genetic causes. Besides, it presents long-term consequences of SGA birth and new treatment options, including treatment with gonadotropin-releasing hormone agonist (GnRHa) in addition to growth hormone (GH) treatment, and the metabolic and cardiovascular health of young adults born SGA after cessation of childhood-GH-treatment in comparison with appropriate control groups. To diagnose SGA, accurate anthropometry and use of national growth charts are recommended. Follow-up in early life is warranted and neurodevelopment evaluation in those at risk. Excessive postnatal weight gain should be avoided, as this is associated with an unfavorable cardio-metabolic health profile in adulthood. Children born SGA with persistent short stature < -2.5 SDS at age 2 years or < -2 SDS at age of 3-4 years, should be referred for diagnostic work-up. In case of dysmorphic features, major malformations, microcephaly, developmental delay, intellectual disability and/or signs of skeletal dysplasia, genetic testing should be considered. Treatment with 0.033-0.067 mg GH/kg/day is recommended in case of persistent short stature at age of 3-4 years. Adding GnRHa treatment could be considered when short adult height is expected at pubertal onset. All young adults born SGA require counseling to adopt a healthy lifestyle.

How Do Drugs Affect the Skeleton? Implications for Forensic Anthropology

Simple Summary

Forensic anthropologists analyze human remains to assist in the identification of the deceased, predominantly by assessing age-at-death, sex, stature, ancestry and any unique identifying features. Whilst methods have been established to create this biological profile of the skeleton, these may be influenced by a number of factors. This paper, for the first time, provides an overview from a reading of the clinical and pharmacological literature to explore whether the intake of drugs can affect the skeleton and whether these may have implications for forensic anthropology casework. In effect, drugs such as tobacco, heroin, and prescription medications can alter bone mineral density, can increase the risk of fractures, destroy bone and changes to the dentition. By considering how drugs can affect the skeleton, forensic anthropologists can be aware of this when attempting to identify the deceased.

Abstract

Forensic anthropologists rely on a number of parameters when analyzing human skeletal remains to assist in the identification of the deceased, predominantly age-at-death, sex, stature, ancestry or population affinity, and any unique identifying features. During the examination of human remains, it is important to be aware that the skeletal features considered when applying anthropological methods may be influenced and modified by a number of factors, and particular to this article, prescription drugs (including medical and non-medical use) and other commonly used drugs. In view of this, this paper aims to review the medical, clinical and pharmacological literature to enable an assessment of those drug groups that as side effects have the potential to have an adverse effect on the skeleton, and explore whether or not they can influence the estimation of age-at-death, sex and other indicators of the biological profile. Moreover, it may be that the observation of certain alterations or inconsistencies in the skeleton may relate to the use of drugs or medication, and this in turn may help narrow down the list of missing persons to which a set of human remains could belong. The information gathered from the clinical and medical literature has been extracted with a forensic anthropological perspective and provides an awareness on how several drugs, such as opioids, cocaine, corticosteroids, non-steroidal anti-inflammatory drugs, alcohol, tobacco and others have notable effects on bone. Through different mechanisms, drugs can alter bone mineral density, causing osteopenia, osteoporosis, increase the risk of fractures, osteonecrosis, and oral changes. Not much has been written on the influence of drugs on the skeleton from the forensic anthropological practitioner perspective; and this review, in spite of its limitations and the requirement of further research, aims to investigate the current knowledge of the possible effects of both prescription and recreational drugs on bones, contributing to providing a better awareness in forensic anthropological practice and assisting in the identification process of the deceased.

Body composition in sexual precocity

PURPOSE OF REVIEW

In this review, we have summarized the current data on the effect of sexual precocity and treatment with gonadotropin-releasing hormone analogues (GnRHa) on body composition.

RECENT FINDINGS

Higher body weight and weight gain in infancy and childhood may increase the risk of early puberty in girls. The relation between BMI and pubertal onset in boys is controversial. Current studies draw attention to the fact that a similar relationship may exist in boys too. Obesity prevalence is high among girls with central precocious puberty (CPP) and treatment with GnRHa has a different effect on BMI according to baseline body composition. Although BMI values of normal weight girls tend to increase under treatment, they return to normal following treatment. The few studies that have followed up body composition longitudinally in girls show a gradual increase in adiposity, decrease in muscle mass and bone mineral density during GnRHa treatment, whereas bone mass was preserved after treatment. Adequate data are not available in boys to determine the effect of GnRHa therapy on body composition.

SUMMARY

Body composition and fat distribution should be monitored longitudinally in patients with CPP treated with GnRHa to ascertain the long-term effects of therapy.

Longitudinal Study on Metabolic Health in Adults SGA During 5 Years After GH With or Without 2 Years of GnRHa Treatment

BACKGROUND

In children born small for gestational age (SGA) with persistent short stature, 2 years of gonadotropin-releasing hormone analogue (GnRHa), in addition to long-term growth hormone (GH) treatment, can improve adult height. We assessed safety on metabolic and bone health of GnRHa/GH treatment during 5 years after cessation of GH.

METHODS

A total of 363 young adults born SGA, previously treated with combined GnRHa/GH or GH-only, were followed for 5 years after attainment of adult height at GH cessation and 2 and 5 years thereafter. Data at 5 years after GH cessation, at age 21 years, were also compared with 145 age-matched adults born appropriate for gestational age (AGA). Frequently sampled intravenous glucose tolerance (FSIGT) tests were used to assess insulin sensitivity, acute insulin response, and β-cell function. Body composition and bone mineral density (BMD) was determined by dual-energy x-ray absorptiometry (DXA) scans.

FINDINGS

In the GnRHa/GH and GH-only groups, fat mass increased during the 5 years after GH cessation, but the changes in FSIGT results, body composition, blood pressure, serum lipid levels, and BMD were similar in both groups. At age 21 years, the GnRHa/GH group had similar fat mass, FSIGT results, blood pressure, serum lipid levels and BMD-total body as the GH-only group and the AGA control group, a higher BMD-lumbar spine and lower lean body mass than the AGA control group.

INTERPRETATION

This study during 5 years after GH cessation shows that addition of 2 years of GnRHa treatment to long-term GH treatment of children short in stature born SGA has no unfavorable effects on metabolic and bone health in early adulthood.

CLINICAL TRIAL REGISTRATION

ISRCTN96883876, ISRCTN65230311 and ISRCTN18062389.

Long-term effects and significant Adverse Drug Reactions (ADRs) associated with the use of Gonadotropin-Releasing Hormone analogs (GnRHa) for central precocious puberty: a brief review of literature

Central precocious puberty (CPP) is defined as an early pubertal development that occurs before the age of 9 years in boys and 8 years in girls. It results from premature activation of the hypothalamic-pituitary-gonadal axis. Gonadotropin-releasing hormone agonists (GnRHa) have been the gold standard therapy for CPP for more than 30 years. These compounds have a high affinity for the pituitary LHRH receptor and are resistant to enzymatic degradation. Through continuous stimulation, GnRHa inhibit the pulsatile secretion of gonadotropin, resulting in hormonal suppression, cessation of pubertal development, and normalization of growth and skeletal maturation rates. The goal of therapy is to halt pubertal progression and delay epiphyseal maturation that leads to improvement of final adult height. There are no widely accepted guidelines for how long to continue treatment with a GnRHa for CPP, and individual practice varies widely. Furthermore, conflicting results have been published on the long-term effects of GnRHa therapy in patients with CPP. Therefore, we reviewed the current literature focusing our attention on the long-term effects and the significant adverse drug reactions (ADRs) observed during treatment with GnRHa in patients with CPP. Our review may provide the necessary data to enable clinicians to administer GnRHa in the safest and most appropriate way. Further studies are necessary to identify the mechanisms of development of potential adverse drug reactions related to GnRHa therapy in CPP.

Gender affirming medical care of transgender youth

The number of gender diverse and transgender youth presenting for treatment are increasing. This is a vulnerable population with unique medical needs; it is essential that all pediatricians attain an adequate level of knowledge and comfort caring for these youth so that their health outcomes may be improved. There are several organizations which provide clinical practice guidelines for the treatment of transgender youth including the WPATH and the Endocrine Society and they recommend that certain eligibility criteria should be met prior to initiation of gender affirming hormones. Medical intervention for transgender youth can be broken down into stages based on pubertal development: pre-pubertal, pubertal and post-pubertal. Pre-pubertally no medical intervention is recommended. Once puberty has commenced, youth are eligible for puberty blockers; and post-pubertally, youth are eligible for feminizing and masculinizing hormone regimens. Treatment with gonadotropin releasing hormone agonists are used to block puberty. Their function is many-fold: to pause puberty so that the youth may explore their gender identity, to delay the development of (irreversible) secondary sex characteristics, and to obviate the need for future gender affirmation surgeries. Masculinizing hormone regimens consists of testosterone and feminizing hormone regimens consist of both estradiol as well as spironolactone. In short term studies gender affirming hormone treatment with both estradiol and testosterone has been found to be safe and improve mental health and quality of life outcomes; additional long term studies are needed to further elucidate the implications of gender affirming hormones on physical and mental health in transgender patients. There are a variety of surgeries that transgender individuals may desire in order to affirm their gender identity; it is important for providers to understand that desire for medical interventions is variable among persons and that a discussion about individual desires for surgical options is recommended.

Transgender medicine - puberty suppression

Puberty suppression is the reversible first step of endocrine medical treatment in transgender youth, and allows for two very important aspects of transgender management. Firstly, it buys the patient, family and their medical team time to fully evaluate the presence and persistence of gender dysphoria. Secondly, it successfully prevents the development of cis-gender unwanted secondary sexual characteristics. The latter, when present, almost certainly increase the burden of psychological co-morbidity for any transgender person. This management is modelled from treatment of gonadotropin-dependent precious puberty, with use of GnRH agonists at its core. With the increasing number of transgender youth treated, and the changing demographics of patients seeking medical care, providers are faced with the decision to start puberty blockade at younger ages than previous decades. This article will review the rationale behind puberty blockade for transgender children, the providers' options for achieving this goal, the emerging literature for potential adverse effects on such an approach, as well as identify directions of potential future research.

Endocrine Treatment of Gender-Dysphoric/Gender-Incongruent Persons: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

To update the "Endocrine Treatment of Transsexual Persons: An Endocrine Society Clinical Practice Guideline," published by the Endocrine Society in 2009.

PARTICIPANTS

The participants include an Endocrine Society-appointed task force of nine experts, a methodologist, and a medical writer.

EVIDENCE

This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation approach to describe the strength of recommendations and the quality of evidence. The task force commissioned two systematic reviews and used the best available evidence from other published systematic reviews and individual studies.

CONSENSUS PROCESS

Group meetings, conference calls, and e-mail communications enabled consensus. Endocrine Society committees, members and cosponsoring organizations reviewed and commented on preliminary drafts of the guidelines.

CONCLUSION

Gender affirmation is multidisciplinary treatment in which endocrinologists play an important role. Gender-dysphoric/gender-incongruent persons seek and/or are referred to endocrinologists to develop the physical characteristics of the affirmed gender. They require a safe and effective hormone regimen that will (1) suppress endogenous sex hormone secretion determined by the person's genetic/gonadal sex and (2) maintain sex hormone levels within the normal range for the person's affirmed gender. Hormone treatment is not recommended for prepubertal gender-dysphoric/gender-incongruent persons. Those clinicians who recommend gender-affirming endocrine treatments-appropriately trained diagnosing clinicians (required), a mental health provider for adolescents (required) and mental health professional for adults (recommended)-should be knowledgeable about the diagnostic criteria and criteria for gender-affirming treatment, have sufficient training and experience in assessing psychopathology, and be willing to participate in the ongoing care throughout the endocrine transition. We recommend treating gender-dysphoric/gender-incongruent adolescents who have entered puberty at Tanner Stage G2/B2 by suppression with gonadotropin-releasing hormone agonists. Clinicians may add gender-affirming hormones after a multidisciplinary team has confirmed the persistence of gender dysphoria/gender incongruence and sufficient mental capacity to give informed consent to this partially irreversible treatment. Most adolescents have this capacity by age 16 years old. We recognize that there may be compelling reasons to initiate sex hormone treatment prior to age 16 years, although there is minimal published experience treating prior to 13.5 to 14 years of age. For the care of peripubertal youths and older adolescents, we recommend that an expert multidisciplinary team comprised of medical professionals and mental health professionals manage this treatment. The treating physician must confirm the criteria for treatment used by the referring mental health practitioner and collaborate with them in decisions about gender-affirming surgery in older adolescents. For adult gender-dysphoric/gender-incongruent persons, the treating clinicians (collectively) should have expertise in transgender-specific diagnostic criteria, mental health, primary care, hormone treatment, and surgery, as needed by the patient. We suggest maintaining physiologic levels of gender-appropriate hormones and monitoring for known risks and complications. When high doses of sex steroids are required to suppress endogenous sex steroids and/or in advanced age, clinicians may consider surgically removing natal gonads along with reducing sex steroid treatment. Clinicians should monitor both transgender males (female to male) and transgender females (male to female) for reproductive organ cancer risk when surgical removal is incomplete. Additionally, clinicians should persistently monitor adverse effects of sex steroids. For gender-affirming surgeries in adults, the treating physician must collaborate with and confirm the criteria for treatment used by the referring physician. Clinicians should avoid harming individuals (via hormone treatment) who have conditions other than gender dysphoria/gender incongruence and who may not benefit from the physical changes associated with this treatment.

Metabolic Outcomes, Bone Health, and Risk of Polycystic Ovary Syndrome in Girls with Idiopathic Central Precocious Puberty Treated with Gonadotropin-Releasing Hormone Analogues

BACKGROUND/AIMS

Gonadotropin-releasing hormone analogues (GnRHa) represent the gold standard treatment for central precocious puberty (CPP). We aimed to assess the effects of GnRHa treatment on metabolic outcomes, bone status, and polycystic ovary syndrome (PCOS) prevalence in young girls with idiopathic CPP (ICPP).

METHODS

We enrolled 94 ICPP girls who were at least 2 years after menarche and had already attained adult height at the time of the study: 56 previously treated with depot triptorelin (3.4 ± 0.6 years) and 38 untreated. Auxological parameters, lipid profile, homeostatic model assessment of insulin resistance (HOMA-IR), bone state, and prevalence of PCOS were assessed.

RESULTS

The 2 groups were similar for body mass index (BMI) and waist circumference. HOMA-IR, dehydroepi-androsterone sulfate, and Δ4-androstenedione were higher in the treated than in the untreated subjects (p < 0.001). Significant differences were found for amplitude-dependent speed of sound (p < 0.03) and bone transmission time z-scores (p < 0.01). The prevalence of PCOS was higher in the treated than in the untreated subjects (p < 0.04).

CONCLUSION

GnRHa therapy is associated with hyperandrogenism and an increase in insulin resistance and PCOS prevalence, but not with increased BMI or lipid profile alterations. Long-term evaluations at the time of expected peak bone mass achievement are needed to understand the persistent or transient nature of subtle bone abnormalities.

Fractures in spina bifida from childhood to young adulthood

This study assessed the prevalence and types of fractures in spina bifida and examined risk factors for fracture. Fracture prevalence was highest in childhood and reduced in adolescence and young adulthood. The importance of maintaining mobility is highlighted by the increased risk of fracture in those who are non-ambulatory.

INTRODUCTION

The aims of this study are to study the prevalence and types of fractures according to age group in spina bifida and examine risk factors associated with fracture.

METHODS

This is a retrospective cohort study of 146 individuals with spina bifida aged 2 years or older who attended the paediatric or adult spina bifida multidisciplinary clinic at a single tertiary hospital.

RESULTS

Median age at which first fracture occurred was 7 years (interquartile range 4-13 years). Fracture rates in children (ages 2-10), adolescents (ages 11-18) and adults (age > 18) were 10.9/1000 (95 % confidence interval 5.9-18.3), 5.4/1000 (95 % CI 1.5-13.8) and 2.9/1000 (95 % CI 0.6-8.1) patient years respectively. Childhood fractures predominantly involved the distal femur and femoral shaft; these fractures were rarely seen in adulthood. Non-ambulatory status was associated with a 9.8 times higher risk of fracture compared with ambulatory patients (odds ratio 9.8, p = 0.016, 95 % CI 1.5-63.0). Relative risk of re-fracture was 3.1 (95 % CI 1.4-6.8). Urological intervention with intestinal segments was associated with renal calculi (p = 0.037) but neither was associated with fracture.

CONCLUSIONS

The risk of fracture is lower in adults compared with children with spina bifida. The predominant childhood fracture affects the distal femur, and immobility is the most significant risk factor for fracture. Clinical factors contributing to fracture risk need to be elucidated to enable selection of patients who require investigation and treatment of osteoporosis.

Gonadotropin-releasing hormone analog therapy for central precocious puberty and other childhood disorders affecting growth and puberty

Gonadotropin-releasing hormone (GnRH) analog therapy relies primarily on the ability of these compounds to bind to and modulate GnRH-receptor activity. GnRH analogs have been used in pediatric patients where endogenous gonadotropin release is undesirable or potentially harmful, such as in: (i) patients with central precocious puberty (CPP); (ii) healthy short children where pubertal delay would provide an opportunity to supplement pre-pubertal linear growth; and (iii) children with malignancies and other disorders where treatment requires the use of gonadotoxic compounds. In the first two groups of patients, GnRH agonists may be used alone or in conjunction with somatropin (growth hormone [GH]) to prevent early skeletal maturation and increase the subsequent adult height, while in the latter case, GnRH agonists are used alone or in conjunction with GnRH antagonists in an attempt to preserve gonadal function.In children and adolescents with CPP, timely use of GnRH agonists alone can result in an adult height within the genetic potential of the individual (target height); however, minimal height is gained when GnRH agonist therapy is commenced after a marked advancement of skeletal age. This provides the rationale for combined therapy with GnRH agonists and somatropin in such patients, and studies have shown improved growth with this approach compared with GnRH agonists alone. Combination therapy with GnRH agonists and somatropin has also been shown to increase adult heights to a greater extent than GnRH agonists alone in pediatric patients with concomitant CPP and GH deficiency, those with idiopathic short stature, and those born small for gestational age; however, such combination therapy has shown no increased benefit over somatropin alone in pediatric patients with GH deficiency. Limited results in children and adolescents with congenital adrenal hyperplasia and chronic primary hypothyroidism have also shown increased growth rates, while no growth benefit was seen in pediatric renal transplant recipients.GnRH analogs also have potential as gonadoprotective agents; studies of GnRH agonists used alone and in combination with GnRH antagonists in women undergoing cytotoxic therapy have shown increased preservation of reproductive potential in patients who were receiving GnRH analog therapy versus those who were not.The adverse effects of GnRH analogs mainly consist of menopausal-like complaints. Increases in bodyweight and body mass index in children receiving GnRH agonist therapy have been shown; however, these increases do not persist after discontinuation of therapy. Adult bone mineral density and fertility are also not adversely affected by childhood GnRH agonist therapy.GnRH analog therapy appears to be both well tolerated and effective in pediatric patients, as it allows the preservation or improvement of adult height, and shows no longstanding negative effects on body composition, bone density, reproductive function, or endocrine physiology. These agents may also be useful for preservation of gonadal function in children and adolescents undergoing cytotoxic therapy.

An Examination of the Effects of Leuprolide Acetate Used in the Treatment of Central Precocious Puberty on Bone Mineral Density and 25-Hydroxy Vitamin D

AIM

Leuprolide acetate is a gonadotropin-releasing hormone (GnRH) analogue frequently used in the treatment of central precocious puberty. Research is currently taking place into its effects on endocrine systems. The aim of this study is to investigate the effect of leuprolide acetate on vitamin D and bone mineral density.

METHODS

Twenty-three children diagnosed with central precocious puberty and receiving leuprolide acetate therapy for at least 12 months, and a control group of 17 healthy children were enrolled. In the study group, calcium, phosphorus, alkaline phosphatase, parathormone and 25-hydroxy vitamin D levels and bone mineral density were measured. The results were compared with those of the control group.

RESULTS

25-Hydroxy vitamin D levels in the study and control groups were 15.17 ± 7 mg/dL and 22.2 ± 6.1 mg/dL, respectively (p < 0.05). In terms of bone mineral density, osteopenia was determined in 13 (56.5%) patients in the study group and osteoporosis in one (4.3%), while osteopenia was identified in seven patients in the control group, with no osteoporosis being identified (p > 0.05).

CONCLUSION

Gonadotropin-releasing hormone agonists may have an adverse effect on bone health. They may exhibit these effects by impacting on vitamin D levels. These levels should be periodically monitored in patients receiving treatment, and vitamin D support should be given in cases where the deficiency is identified.

Long-term effects of gonadotropin-releasing hormone analogs in girls with central precocious puberty

Gonadotropin-releasing hormone analogs (GnRHa) are widely used to treat central precocious puberty (CPP). The efficacy and safety of GnRHa treatment are known, but concerns regarding long-term complications are increasing. Follow-up observation results after GnRHa treatment cessation in female CPP patients up to adulthood showed that treatment (especially <6 years) was beneficial for final adult height relative to that of pretreated or untreated patients. Puberty was recovered within 1 year after GnRHa treatment discontinuation, and there were no abnormalities in reproductive function. CPP patients had a relatively high body mass index (BMI) at the time of CPP diagnosis, but BMI standard deviation score maintenance during GnRHa treatment seemed to prevent the aggravation of obesity in many cases. Bone mineral density decreases during GnRHa treatment but recovers to normal afterwards, and peak bone mass formation through bone mineral accretion during puberty is not affected. Recent studies reported a high prevalence of polycystic ovarian syndrome in CPP patients after GnRHa treatment, but it remains unclear whether the cause is the reproductive mechanism of CPP or GnRHa treatment itself. Studies of the psychosocial effects on CPP patients after GnRHa treatment are very limited. Some studies have reported decreases in psychosocial problems after GnRHa treatment. Overall, GnRHa seems effective and safe for CPP patients, based on long-term follow-up studies. There have been only a few long-term studies on GnRHa treatment in CPP patients in Korea; therefore, additional long-term follow-up investigations are needed to establish the efficacy and safety of GnRHa in the Korean population.

The effect of gonadotrophin-releasing hormone agonist treatment over 3 years on bone mineral density and body composition in girls with central precocious puberty

OBJECTIVE

Puberty is a period characterized by growth spurt and rapid change in body composition. The effect of GnRH agonist therapy for central precocious puberty on bone mineral density is unclear. We demonstrated changes in bone mineral density in subjects with central precocious puberty, who were treated with GnRH agonist for more than 3 years.

DESIGN

The changes in bone mineral density and body compositions were tested with analysis of variance with repeated measures to identify statistical significance over the treatment period.

PATIENTS

One hundred ninety-five Korean girls with central precocious puberty were treated with GnRH agonist, and among these subjects, 39 patients were treated for more than 3 years.

MEASUREMENTS

Dual-energy X-ray absorptiometry was performed on the subjects at the initial evaluation and once yearly thereafter while on the treatment.

RESULTS

The bone mineral density parameters for chronological age tended to decrease near the mean for the treatment period; however, they increased significantly for bone age excluding bone mineral apparent density. An increment of the BMI was not significant for the chronological age.

CONCLUSIONS

Three-year treatment with GnRH agonist in central precocious puberty patients did not impair bone maturation. GnRH agonist could be effectively commenced in girls with precocious puberty from an early age.

Bone mineral density and body composition in girls with idiopathic central precocious puberty before and after treatment with a gonadotropin-releasing hormone agonist

OBJECTIVES

Idiopathic central precocious puberty and its postponement with a (gonadotropin-releasing hormone) GnRH agonist are complex conditions, the final effects of which on bone mass are difficult to define. We evaluated bone mass, body composition, and bone remodeling in two groups of girls with idiopathic central precocious puberty, namely one group that was assessed at diagnosis and a second group that was assessed three years after GnRH agonist treatment.

METHODS

The precocious puberty diagnosis and precocious puberty treatment groups consisted of 12 girls matched for age and weight to corresponding control groups of 12 (CD) and 14 (CT) girls, respectively. Bone mineral density and body composition were assessed by dual X-ray absorptiometry. Lumbar spine bone mineral density was estimated after correction for bone age and the mathematical calculation of volumetric bone mineral density. CONEP: CAAE-0311.0.004.000-06.

RESULTS

Lumbar spine bone mineral density was slightly increased in individuals diagnosed with precocious puberty compared with controls; however, after correction for bone age, this tendency disappeared (CD = -0.74 + 0.9 vs. precocious puberty diagnosis = -1.73 + 1.2). The bone mineral density values of girls in the precocious puberty treatment group did not differ from those observed in the CT group.

CONCLUSION

There is an increase in bone mineral density in girls diagnosed with idiopathic central precocious puberty. Our data indicate that the increase in bone mineral density in girls with idiopathic central precocious puberty is insufficient to compensate for the marked advancement in bone age observed at diagnosis. GnRH agonist treatment seems to have no detrimental effect on bone mineral density.

Evaluation of bone density in girls with precocious and early puberty during treatment with GnRH agonist

BACKGROUND

Major changes in bone status occur during puberty. Most longitudinal studies have shown no impairment in bone mineral density (BMD) in girls with precocious (PP) and early puberty (EP) during and after GnRH agonist therapy.

METHODS

In the present study we evaluated BMD, bone strength (BS) and bone metabolism in 26 girls with PP and with EP before and during treatment with GnRH agonist. BMD was measured by dual energy X-ray absorptiometry and BS was measured using the quantitative high frequency ultrasound technique at baseline, after 6 and 12 months from onset of therapy. Variables were compared with age- and sex-matched values of the same population. Biochemical markers of bone turnover were measured at the same intervals.

RESULTS

Mean lumbar spine (LS) and femoral neck (FN) BMD were significantly lower at baseline (LS: p < 0.0001, FN: p < 0.0017) compared with age-matched reference values. Bone strength was significantly lower at the radius (p < 0.0001) and normal at the tibia. A non-significant increase in BMD and a significant increase in BS were observed throughout the first year of therapy with GnRH agonist. Serum bone specific alkaline phosphatase measurements were normal at baseline and remained stable. Urinary deoxypyridinoline\creatinine measurements were significantly higher (p < 0.0001) at baseline and decreased significantly (p < 0.001) during treatment.

CONCLUSIONS

Girls with central idiopathic PP and EP have lower BMD and BS for chronological age and increased bone resorption markers. These parameters show a trend of normalization during the first year of therapy with GnRH agonist.

Bone density in children treated with gonadotropin-releasing hormone analogs for central precocious puberty

Estrogens, growth hormones and IGFs are essential in the development and growth of the skeleton and for the maintenance of bone mass and density. Treatment of precocious puberty with gonadotropin-releasing hormone analogs (GnRHa), leads to a situation of hypoestrogenism by reducing sex-steroid levels, which, theoretically, may have a detrimental effect on bone mass during pubertal development. A reduction in bone mineral density during GnRHa treatment has been shown, but GnRHa treatment in patients with central precocious puberty does not seem to impair the achievement of normal peak bone mass at adult height. However, calcium supplementation is effective in improving bone densitometric levels and may promote better peak bone mass achievement.

Gonadotropin-releasing hormone-1 (GnRH-1) is involved in tooth maturation and biomineralization

Gonadotropin releasing-hormone-1 (GnRH-1) is expressed in mouse incisors during development. In this report, we identify (1) cell type(s) that express GnRH-1 throughout tooth development, (2) the GnRH-1 receptor, and (3) the role of GnRH-1/GnRH-1 receptor signaling in tooth maturation. Results show that GnRH-1-positive cells in dental epithelium differentiate and populate multiple tooth structures including ameloblast and papillary layers that are involved in enamel formation and mineralization. The GnRH-1 receptor was present, and in vitro a GnRH-1 antagonist attenuated incisor GnRH-1 cell expression. In vivo, in mice lacking GnRH-1 (-/-), the incisors were discolored, longer, and more curved compared to wildtype. Elemental analysis of calcium, phosphorus, and iron revealed changes in -/- incisors consistent with GnRH-1 affecting movement of minerals into the dental matrix. In sum, in tooth development a signal transduction pathway exists for GnRH-1 via the GnRH-1 receptor and disruption of such signaling affects incisor growth and biomineralization.

Long-term observation of 87 girls with idiopathic central precocious puberty treated with gonadotropin-releasing hormone analogs: impact on adult height, body mass index, bone mineral content, and reproductive function

OBJECTIVE

We assessed in a retrospective unicenter study the impact of treatment with GnRH analogs (GnRHa) on adult height (AH), body mass index (BMI), bone mineral density (BMD), and reproductive function in girls with idiopathic central precocious puberty (ICPP).

PATIENTS

Eighty-seven ICPP patients were treated with GnRHa for 4.2 +/- 1.6 yr (range 3-7.9) and observed for 9.9 +/- 2.0 yr (range 4-10.6 yr) after discontinuation of treatment; to estimate the efficacy better, 32 comparable ICPP untreated girls were analyzed.

RESULTS

AH was 159.8 +/- 5.3 cm, significantly higher than pretreatment predicted AH (PAH) either for accelerated or for average tables of Bayley and Pinneau. The gain in centimeters between pretreatment PAH and AH was 5.1 +/- 4.5 and 9.5 +/- 4.6 cm, respectively. Hormonal values and ovarian and uterine dimensions, reduced during treatment, increased to normal after 1 yr without therapy. Age of menarche was 13.6 +/- 1.1 yr with an interval of 0.9 +/- 0.4 yr after therapy. Menstrual pattern was normal. Six girls became pregnant and delivered normal offspring. BMI sd score for chronological age increased, but not significantly, before, during, and after therapy. BMD at discontinuation of treatment was significantly lower and increased to control values after gonadal activity resumption.

CONCLUSIONS

GnRHa treatment in ICPP is safe for the reproductive system, BMD, and BMI and helpful in reaching AH close to target height; however, the variability of individual responses suggests that one choose more parameters than increment in height, especially in girls with pubertal onset over 8 yr of age.

Treatment of central precocious puberty

The problems of central precocious puberty (CPP) are serious enough to the patient to deserve treatment. There is a general consensus among paediatric endocrinologists that the treatment of true CPP (i.e., in children young enough to have a formal diagnosis) is indicated in many cases. In children with modestly early puberty who are not fulfilling the diagnostic criteria, this is not the case. The treatment of choice is a gonadotropin-releasing hormone (GnRH) analogue. Prolonged analogues are more effective than short-acting ones and, most importantly, independent of patient compliance. Data on agonists have accumulated over two decades and evidence of effects is rich in girls but sparse in boys. GnRH agonists are generally effective and safe drugs; the suppression of puberty is reversible and there is much information on GnRH agonists for the treatment of CPP showing very few adverse effects and the effects on final height are well documented in girls < 6 years of age. There is some (but not highly convincing) evidence for their effect on final height for those of 6 - 8 years of age and there is no evidence for an increase in final height after the age of 8 years in girls. If a decision to have treatment is taken, treatment should start immediately as a possible benefit is less probable if the start of treatment is delayed. When treatment should be stopped is a matter of controversy. Combination with growth hormone increases final height, but the clinical relevance can be discussed as well as the health economy aspects. The limits of indications are still to be defined.

Central precocious puberty: current treatment options

Central precocious puberty (CPP) is characterized by early pubertal changes, acceleration of growth velocity, and rapid bone maturation that often result in reduced adult height. An onset of pubertal signs before the age of 8 years in girls and 9 years in boys should always be evaluated. A combination of clinical signs, bone age, pelvic echography in girls, and hormonal data are required to diagnose CPP and make a judgment concerning progression and prognosis. Not all children with apparently true CPP require medical intervention. The main reasons for treatment are to prevent compromised adult height and to avoid psychosocial or behavioral problems. The need for treatment for auxologic reasons is based on estimation of predicted adult height, with the finding of a reduced height potential, which may require a follow-up. Indication for treatment on the basis of psychologic and behavioral anomalies has to be determined on an individual basis. The main short-term aims of therapy are to stop the progression of secondary sex characteristics and menses (in girls) and to treat the underlying cause, when known. Long-term goals are to increase final adult height and to promote psychosocial well-being. Once it has been decided that treatment is appropriate, it should be initiated immediately with depot gonadotropin-releasing hormone (GnRH) agonists. The effective suppression of pituitary gonadal function is achieved with these compounds in practically all CPP patients. Long-term data are now available from 2 decades of GnRH agonist treatment for patients with CPP. Treatment preserves height potential in the majority of patients (especially in younger patients) and improves the final adult height of children with rapidly progressing CPP, with a complete recovery of the hypothalamic-pituitary-gonadal axis after treatment. GnRH agonist treatment using depot preparations is useful and has a good safety profile, with minimal adverse effects and no severe long-term consequences. Although further data are need, there may be a role in the future for combining somatropin (growth hormone) and GnRH agonist treatment for some patients with significantly impaired growth velocity. The introduction of GnRH antagonists is likely to improve the treatment options for CPP.

Effects on bone mineral density of gonadotropin releasing hormone analogs used in the treatment of central precocious puberty

The aim of this study was to compare vertebral bone mass values of patients with central precocious puberty (CPP) with healthy age and puberty matched controls and to determine the effect of gonadotropin releasing hormone (GnRH) analogs on bone mass in patients who had been treated at least for 1 year. Girls with idiopathic CPP, 11 pretreatment, 14 post-treatment, and 19 pubertal girls as controls were enrolled in the study. The mean ages of the controls and the patients with CPP pre- and post-treatment were 10.25 +/- 1.06, 8.23 +/- 1.11, and 10.36 +/- 1.82 years, respectively. Leuprolide acetate (Lucrin) 3.75 mg was administered s.c. monthly. Bone measurements were performed by dual energy X-ray absorptiometry (DEXA) (Norland) at the anterior-posterior vertebrae (L2-L4). The post-treatment group's mean BMD value was 0.66 +/- 0.12; Z scores according to CA and BA were 0.32 +/- 10 and 0.30 +/- 1.1, respectively. In the study group, BMD values compared to the control group were normal. No significant change in BMD values was observed after treatment. Neither osteopenia nor osteoporosis was observed in patients taking GnRH analog.

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.

End results in central precocious puberty with GnRH analog treatment: the data of the Italian Study Group for Physiopathology of Puberty

We report some end results with GnRH agonist (GnRHa) treatment in central precocious puberty (CPP), in terms of final height (FH), ovarian function, peak bone mass, body composition and psychological problems. The two studies reported (Study I and II) are part of the activity of the Italian Study Group for Physiopathology of Puberty. Study L Growth data were analyzed of three groups of patients: treated with i.n. spray buserelin, i.m. triptorelin and untreated. Both GnRHa administration modes were effective in arresting pubertal development and all girls had complete recovery of the reproductive axis after therapy. Treated patients showed an improvement in final height in comparison with untreated patients and compared to predicted height at the start of treatment with both agonist treatments. However, patients treated with the long-acting slow release preparation had a better improvement in adult height and reached or exceeded the genetic height potential. Study II. In a retrospective evaluation of the outcome in 71 girls with idiopathic CPP treated with triptorelin, we found that FH fell within the population norm and the target range in 87.3% and 90% of the patients respectively. The tallest FH was recorded in the patients who started therapy at less than 6 years of age and in those who discontinued treatment at a bone age of 12.0-12.5 yr. Finally, we and other groups have recently found normal values of bone mineral density in girls at the end of GnRHa treatment in the great majority of patients.

Side effects of GnRH analogue treatment in childhood

There are a few reports of side-effects of LHRHa treatment in childhood, the mechanisms of which remain little understood. Such effects can be local reactions: erythema, induration, wheal and sterile abscess formation, which can be possible causes of therapy failure. There are negative effects on growth velocity and final height requiring rhGH therapy or a suppressive treatment when bone age >13 years. Excessive weight gain can occur by various mechanisms: menopausal-like phenomena, or LHRHa influence on hypothalamic and/or leptin-mediated control of body weight. Other possible adverse effects involve increased ovarian volume with possible POS development; however, there is no evidence correlating LHRHa, hyperandrogenism and POS. The latter appears related to CPP onset with pre-existing hyperandrogenism, although lengthier follow-up is necessary to confirm this. Bone density decreases during therapy, but final peak bone mass is in the normal range. Frequent transitory side-effects include headaches, hot flushes, depression and irregular menses.

Estrogen agonist (zeranol) treatment in a castrated male lamb model: effects on growth and bone mineral accretion

The mechanism of estrogen's action on bone mineralization in children has received little attention. Our objective was to determine the effect of time (developmentally) and duration of exposure to an estrogen agonist (zeranol) on bone growth and mineralization using a castrated male lamb model. At birth, 40 male lambs were castrated and within 14 days of birth (day = 0) they were assigned (n = 10 per group) to age-matched control lambs (C-AGE) or to receive a 12.5-mg zeranol implant as follows: E-0, implanted on days 0, 45, 90, and 135; E-90, implanted on days 90 and 135; and E-0, 90, implanted on days 0, 90, and 135. Lambs were studied for 163 days. Serum was collected on days 28, 73, 118, 135, and 163 and analyzed for minerals (Ca, P, and Mg), markers of bone remodeling (bone alkaline phosphatase [ALP] and tartrate resistant acid phosphatase [TRAP]), 1,25-dihydroxyvitamin D [1,25(OH)2D], growth hormone (GH), and insulin-like growth factor I (IGF-I). Whole-body bone mineral content (BMC), bone mineral density (BMD), fat mass, and lean mass were determined by dual energy X-ray absorptiometry (DEXA) on days 28, 73, 118, and 163. There was a linear increase in growth at all time points. Whole-body BMC, weight, and lean mass of C-AGE and E-90 lambs were less than E-0, and E-0, 90 lambs at all time points. Whole-body BMD of C-AGE and E-90 lambs was less than E-0 and E-0, 90 lambs at 28 days and 73 days; however, after implantation at day 90 whole-body BMD of E-90 lambs was similar to E-0 and E-0, 90 lambs at day 118 and day 163 and all three were greater than C-AGE lambs. There was no effect of treatment on calcium absorption, serum minerals, hormones, or markers of bone remodeling. We conclude from these data that treatment of growing castrated lambs with an estrogen agonist from birth augments growth, whereas delaying estrogen agonist treatment does not facilitate growth but appears to augment bone mineral accretion. We suggest these observations may have clinical relevance, and deserve consideration when treating children with delays in growth and bone mineral accretion.

Central precocious puberty. An overview of diagnosis, treatment, and outcome

Central precocious puberty (CPP) is physiologically normal puberty beginning early. It is the consequence of early increased regulation of gonadotropin releasing hormone (GnRH) stimulation of pituitary gonadotropin release causing pubertal changes and accelerated growth. GnRH stimulation testing is the definitive diagnostic test--pubertal gonadotropin responses being indicative of CPP. Among patients with progressive CPP, GnRH analogue therapy is effective by decreased regulation of gonadotropin secretion. Pubertal progression is stopped, and accelerated growth rate and compromised adult height are precluded or alleviated. Outcome data have not identified unusual sequelae.

Chronic glucocorticoid therapy-induced osteoporosis in patients with obstructive lung disease

Long-term glucocorticoid (GC) therapy has been instrumental in decreasing morbidity and mortality in a variety of chronic inflammatory diseases, including persistent asthma. Long-term GC therapy is also widely prescribed for COPD. One of the important and often unrecognized side effects of chronic GC therapy is secondary osteoporosis. The risk of GC-induced bone loss is roughly correlated with daily dose, duration, and total cumulative lifetime dose of GC treatment. Oral prednisone increases the risk of bone loss and fracture. High doses of inhaled GCs may also increase the risk of osteopenia/osteoporosis, but the risk appears to be less than that associated with oral GCs. Hormone replacement therapy, oral and parenteral bisphosphonates, supplemental calcium and vitamin D, calcitonin, and fluoride compounds have been used, experimentally, in the management of GC-induced bone loss. Asthma and COPD specialists are key prescribers of oral and inhaled steroids and are likely to encounter patients with significant bone loss. Despite known risk factors and the availability of reliable diagnostic tools to recognize bone loss, the opportunity to slow, reverse, and treat bone loss is often missed. We present a review of the current literature regarding the incidence, treatment, and prevention of osteopenia/osteoporosis secondary to chronic GC therapy in adult asthma and COPD patients. Guidelines are presented regarding the identification of patients at risk for developing GC-induced secondary bone loss, and therapeutic alternatives are discussed.

Prevention of bone demineralization by calcium supplementation in precocious puberty during gonadotropin-releasing hormone agonist treatment

We have previously demonstrated a negative impact on peak bone mass in girls with precocious puberty treated with GnRH agonist (GnRHa). Several studies have shown that a high calcium intake positively influences bone mass in prepubertal girls and leads to a higher peak bone mass. The aim of this study was to evaluate the effect of calcium supplementation in girls with precocious puberty during GnRHa treatment. Forty girls affected by true central precocious puberty and treated with the GnRHa triptorelin were studied for 2 yr. After diagnosis, the patients were randomly assigned to three groups: group A, treated only with GnRHa; group B, treated for 12 months solely with GnRHa and then supplemented with calcium gluconolactate/carbonate (1 g calcium/day in two doses) for 12 months; and group C, treated from the beginning with combined GnRHa and calcium. Bone mineral density (BMD) at the lumbar spine was measured by dual energy x-ray absorptiometry at the beginning of the study and after 12 and 24 months and was expressed as the calculated true volumetric density (BMDv) in milligrams per cm3. Group A showed a decrease in absolute BMDv levels, in SD score for chronological age (CA), and even more in SD score for bone age (BA). Group B showed the same behavior during the first year, but this trend was reversed in the second year, when calcium supplementation was added to GnRHa treatment. Group C showed an increase in absolute BMDv levels and in SD score for CA and BA. BMDv variations (expressed as absolute values, SD score for CA, and SD score for BA) became statistically significant at 24 months between groups C and A (P = 0.036, P = 0.032, and P = 0.025, respectively). The behavior of the lumbar spine BMDv in the three groups is consistent with a positive effect of calcium supplementation during GnRHa treatment. In calcium-supplemented patients, the normal process of bone mass accretion at puberty is preserved despite GnRHa treatment. Therefore, the reduction in BMD during GnRHa treatment in girls with precocious puberty is at least completely reversible and preventable if calcium supplementation is associated from the beginning.

Effect of central precocious puberty and gonadotropin-releasing hormone analogue treatment on peak bone mass and final height in females

To evaluate the effect of central precocious puberty (CPP) and its treatment with gonadotropin-releasing hormone (GnRH) analogues on final height and peak bone mass (PBM), we measured lumbar bone mineral density (BMD) in 23 girls at final height. Patients were distributed in two groups. Group 1: 14 patients with progressive CPP were treated with GnRH analogues; seven patients received buserelin (1600 microg/daily), subsequently switched to depot triptorelin (60 microg/kg/26-28 days); seven patients were treated with depot triptorelin (60 microg/kg/26-28 days); mean age of treatment was 6.2 years (range 2.7-7.8 years); the treatment was discontinued at the mean age of 10.1 years (range 8.7-11.3 years); final height was reached at the mean age 13.4 years (range 12.0-14.9 years). Group 2: 9 patients (mean age 6.5 years, range 4.8-7.7 years) with a slowly progressing variant of CPP were followed without treatment; final height was reached at the mean age 13.6 years (range 12.5-14.8 years). Lumbar BMD (L2-L4 by dual energy X-ray absorptiometry) was measured in all patients at final height. In group 1, final height (158.9+/-5.4 cm) was significantly greater than the pre-treatment predicted height (153.5+/-7.2 cm, P < 0.001), but significantly lower than mid-parental height (163.2+/-6.2 cm, P < 0.005). Subdividing the girls of group 1 according to the bone age at discontinuation of therapy (i.e. < or =11.5 years, n=5, or > or =12.0 years, n=9), the former patients had a final height significantly higher than the latter (163.7+/-3.9 cm vs 156.5+/-4.6 cm, P < 0.02). In group 2, final height (161.8+/-4.6 cm) was similar to the pre-treatment predicted height (163.1+/-6.2 cm, P=NS) and was not significantly different from mid-parental height (161.0+/-5.9 cm). BMD values (group 1: 1.11+/-0.14 g/cm2, group 2: 1.22+/-0.08 g/cm2) were not significantly different from those of a control group (1.18+/-0.10 g/cm; n=20, age 16.3-20.5 years) and the patients' mothers (group 1: 1.16+/-0.07 g/cm2, n=11, age 32.9-45.1 years; group 2: 1.20+/-0.08 g/cm2, n=7, age 33.5-46.5 years). In group 1, the girls who stopped therapy at a bone age < or =11.5 years had significantly higher BMD (1.22+/-0.10 g/cm2) compared to those who discontinued therapy at a bone age > or =12.0 years (1.04+/-0.12 g/ cm2, P < 0.05).

CONCLUSION

In girls with progressive CPP, long-term treatment with GnRH analogues improves final height. A subset of patients with CPP does not require treatment because good statural outcome (slowly progressing variant). In CPP, the abnormal onset of puberty and the long-term GnRH analogue treatment do not impair the achievement of PBM. In GnRH treated patients, the discontinuation of therapy at an appropriate bone age for pubertal onset may improve both final height and PBM.

Bone mineral density and body composition before and during treatment with gonadotropin-releasing hormone agonist in children with central precocious and early puberty

Major changes in bone mineral density (BMD) and body composition occur during puberty. In the present longitudinal study, we evaluated BMD and calculated volumetric BMD [bone mineral apparent density (BMAD)], bone metabolism, and body composition of children (32 girls and 2 boys) with central precocious and early puberty before and during treatment with GnRH agonist (GnRH). Patients were studied at baseline and during treatment for 6 months (n = 34), 1 yr (n = 33), and 2 yr (n = 16). Lumbar spine and total body BMD and body composition were measured with dual-energy x-ray absorptiometry. The variables were compared with age- and sex-matched reference values of the same population and expressed as SD score (SDS). Bone age was assessed. Serum calcium, phosphate, alkaline phosphatase, osteocalcin, the carboxyterminal propeptide of type I collagen (PICP), cross-linked telopeptide of collagen I (ICTP), 1,25 dihydroxyvitamin D and urinary hydroxyproline/creatinine, and calcium/ creatinine ratios were measured. Mean lumbar spine BMD SDS was significantly higher than zero at baseline (P < 0.02) and did not differ from normal, after 2 yr of treatment. Mean spinal BMAD SDS and total body BMD SDS were not significantly different from zero at baseline and had not changed significantly after 2 yr of treatment. During therapy, fat mass and percentage body fat SDS increased, whereas lean tissue mass SDS decreased. Mean lumbar spine BMD and BMAD and total body BMD SDS, calculated for bone age, were all lower than zero at baseline (BMD P < 0.001 and BMAD P < 0.05) and also after 2 yr treatment (respectively, P < 0.001, P < 0.05, and P < 0.01). Biochemical bone parameters were significantly higher than prepubertal values at baseline, and they decreased during treatment. In conclusion, patients with central precocious and early puberty had normal BMD for chronological age but low BMD for bone age, after 2 yr of treatment with GnRH. Bone turnover decreased during treatment. Changes in body composition resembled those seen in patients with GH deficiency.

Final height in girls with slowly progressive untreated central precocious puberty

A group of six girls with slowly progressive idiopathic precocious puberty (IPP) and a good initial height prognosis was followed without treatment. At first observation the girls had a bone age advance over chronological age of no more than 18 months, a delta height age (delta HA): delta bone age (delta BA) ratio higher than 0.9 and height prognosis was unimpaired after 6 months. During the first two years of follow-up the girls maintained an acceptable height potential. The delta HA:delta BA ratio remained constant at greater than 0.9. Predicted height showed a slight increase or decrease (+/- 4 cm). The girls were reevaluated after the age of 14 years and followed-up until they reached their final height (FH). The mean FH (155.4 +/- 2.8 cm) was below the mean target height (159.3 +/- 4.2 cm) by 3.9 cm (range -2.1 to -6.7 cm); this difference was not statistically significant. The FH was more than 5 cm below the target height in only one case; this girl had the most precocious onset of puberty, at 6 years of age. In three cases FH was between the 3rd and 10th centiles. These three girls had a target height below 158 cm (< 25th centile). Girls with slowly progressive IPP and a good initial height prognosis preserved height potential with an acceptable final height without therapy.

Growth hormones and sex steroid interactions at puberty

Puberty is a period of dynamic changes mediated by GH and the gonadal steroid hormones. Although these substances exert important independent effects, their interaction is vital to normal pubertal growth and development. This is supported by observations of blunted growth and diminished levels of GH and IGF-1 during adolescence in individuals with panhypopituitarism in whom adequate replacement with both hormones had not been achieved. The independent roles of androgens and estrogens in mediating the rise in GH secretion at puberty have been studied in individuals with complete androgen insensitivity and through the administration of nonaromatizable androgens and the use of selective androgen- or estrogen-receptor blockade. The preponderance of evidence from studies of nonaromatizable (pure) androgens suggests that GH secretion is not enhanced as it is under the influence of testosterone. In addition, studies have shown increased GH secretion following androgen-receptor blockade and diminished GH release after estrogen-receptor blockade. Together these studies suggest a facilitory role of estrogen receptor-mediated processes on GH secretion and IGF-1 production. If androgens influence the GH/IGF-1 axis, it is most likely by an inhibitory mechanism. Observations of delayed skeletal maturation and deficient bone mineralization in individuals with estrogen receptor defects or mutations of the aromatase gene demonstrate the essential role of estrogen in promoting normal bone maturation, the accrual and maintenance of BMD, and control of the rate of bone turnover.

Bone mineral content in girls with precocious puberty treated with gonadotropin-releasing hormone analog

In order to evaluate the effects of gonadotropin-releasing hormone (GnRH) analogs on calcium metabolism, we studied 12 girls with central precocious puberty (CPP) who were treated with the GnRH agonist D-Trp6-GnRH every 28 days. The patients' mean age +/- SD was 5.9 +/- 2.1 years. The patients were studied before commencement and after 6 and 12 months of treatment. We also studied 12 age-matched healthy girls who served as controls. Bone mineral content was measured by dual-photon densitometry with 125I, in the distal third of the left radius. We evaluated the serum levels of calcium, phosphate, magnesium, parathyroid hormone, calcitonin, 25-hydroxy-vitamin D and the 24-h urinary excretion of calcium, phosphate and magnesium. All of these parameters were found to be normal before and during the treatment in both groups. At the beginning of the study, the patients with CPP had significantly higher bone mineral content than controls (0.51 +/- 0.12 g/cm2 vs. 0.39 +/- 0.09, p < 0.001); after 6 months contents were 0.42 +/- 0.11 vs. 0.41 +/- 0.05, p < 0.01; and after 12 months 0.44 +/- 0.11 vs. 0.44 +/- 0.05, NS, for treatment and control groups, respectively. This difference remained after 6 months of treatment, while after 12 months no significant difference between patients and controls was found. Our study shows that girls with CPP have an increased bone mineral content and that GnRH analogs modify bone density with a consequent reduction, it seems, that is not related to any of the calcium parameters studied.

Bone mineral density during treatment of central precocious puberty

Treatment of adults with gonadotropin releasing hormone analogs has resulted in rapid loss in bone mineral density (BMD). We measured lumbar and femoral neck BMD by dual-energy x-ray absorptiometry during 2 years of depot leuprolide therapy in 13 girls (mean age, 7.5 years; mean bone age, 10.9 years). At baseline, BMD was elevated for age and concordant with the advanced skeletal age. During therapy with gonadotropin releasing hormone analog, BMD values increased and BMD standard deviation scores for age and skeletal age did not change.