Treatment of hypogonadism in males

The treatment of adolescent males with hypogonadism using testosterone is dependent on the underlying diagnosis as well as the patient's and family's preferences. Those with testicular failure, always a pathologic condition, begin lifelong therapy, while short-term therapy is often begun for those who have a delayed puberty. There is a wide variety of testosterone formulations available, with differences in adverse events sometimes associated with the method of administration. The goals of treatment involve stimulating physical puberty, including achievement of virilization, a normal muscle mass and bone mineral density for age, and improvement in psychosocial wellbeing. While androgen therapy results in physical changes of puberty, the potential for fertility must be considered for those with permanent gonadotropin deficiency. in this population, therapy with gonadotropins or gonadotropin releasing hormone may be effective. For those with testicular failure, fertility may be possible but requires assisted reproductive procedures.

A comprehensive approach to the spectrum of abnormal pubertal development

Puberty is the biological transition from childhood to adulthood. The process involves the coordination of hormonal, physical, psychosocial, and cognitive systems to result in physiologic change. Precocious puberty is defined as pubertal development beginning earlier than expected based on normal standards. Gonadotropin dependent precocious puberty is caused by premature activation of the hypothalamus resulting in pulsatile secretion of GnRH. Gonadotropin independent precocious puberty is caused by excess sex hormones from peripheral or external sources. Treatment with GnRH agonists should be offered to prevent early fusion of the epiphyseal plates to avoid unnecessary short stature and should not be based on perceived psychosocial consequences of early puberty. Delayed puberty is the absence of or incomplete development of secondary sexual characteristics. Hypergonadotropic hypogonadism or primary hypogonadism may result from genetic mutation syndromes or can be acquired from antiovarian antibodies, exposure to radiation or chemotherapy, inflammatory insult, or surgical removal of the gonads. Hypogonadotropic hypogonadism or secondary hypogonadism is due to hypothalamic dysfunction resulting in impaired secretion of GnRH. The long-term goal for patients with inadequate estrogen stimulation is to maintain the serum concentration of sex steroids within the normal adult range to promote the development of secondary sexual characteristics, prevent premature bone loss, and ultimately to induce fertility when indicated.

Role of basal and provocative serum prolactin in differentiating idiopathic hypogonadotropic hypogonadism and constitutional delayed puberty--a diagnostic dilemma

BACKGROUND

The prevalence of Idiopathic Hypogonadotropic Hypogonadism (IHH) is approximately 1 in 10,000 men. Objectives of this study were to evaluate the role of basal and stimulated serum prolactin in differentiating Constitutional Delayed Puberty (CDP) from IHH.

METHODS

This cross-sectional study was carried out at the Department of Diabetes and Endocrinology, Military Hospital, Rawalpindi. A total of 20 male patients presenting with provisional diagnosis of IHH/CDP were enrolled in the study. Patients with known diseases were excluded from the study. Baseline FSH, LH, testosterone, and prolactin were estimated and the patients were subjected to provocative prolactin stimulation by Thyrotropin releasing hormone stimulation (TRH) test and chlorpromazine challenge. At each 6 monthly follow-up visit for 4 years, the patients were evaluated for adrenarche, pubarche and other secondary sexual characters. Tanner scale was taken as standards for comparing stage of puberty at a particular age. No treatment was given to both groups for 2 years. At the end of 2 years IHH patients with failed puberty or progression of puberty and CDP who lagged behind by more than 2 years by Tanner scale or 4 years per bone age with compelling psychosocial or psychosexual reasons at school or at home were given short courses of 50 mg injection testosterone in an attempt to expedite the onset or progression of puberty. Patients from either group with failed puberty after low dose testosterone were managed with high dose testosterone therapy to induce secondary sexual characters.

RESULTS

Twenty patients enrolled in the study were provisionally divided into 2 groups called IHH (n = 9), and CDP (n = 11) based on high basal and provocative serum prolactin levels in CDP group. Two patients from CDP group were lost in the follow-up leaving 9 patients in each group. A total of 10 (56%) patients, 3 (17%) from IHH group and 7 (39%) from CDP group achieved grade 4 puberty without any treatment. Remaining 8 (44%) patients, 6 (67%) from IHH group and 2 (22%) from CDP group were induced secondary sexual characters with full dose of 100 mg testosterone given parenterally at 4 weeks intervals.

CONCLUSION

Differentiation between IHH and CDP on the basis of basal and post-TRH and Chorpromazine challenge reported earlier could not be substantiated by our study.

Priapism in teenage boys following depot testosterone

Priapism is rare in children and may result in erectile dysfunction and sexual aversion behaviours. Testosterone therapy is commonly regarded as safe in children and is widely used in constitutional delay of growth and puberty, hypogonadism, hypospadias and micropenis. We report two cases of priapism in teenage boys with constitutional delay of growth and puberty after a change in the formulation of depot testosterone. One case required surgical intervention and the other was preceded by stuttering priapism. These cases illustrate the importance of patient and/or parent counselling before testosterone administration and consideration of lower doses in at-risk patients.

How do you initiate oestrogen therapy in a girl who has not undergone puberty?

The physiology of puberty needs to be taken into consideration in the induction of puberty. Puberty is a relatively slow process and replacement therapy should mimic this. Long-term maintenance requires careful monitoring and long-term assessment of risk-benefit. This has not been appreciably defined in the adolescent population. Options for fertility need careful consideration and may depend on the adequacy of pubertal induction in terms of uterine development. A number of regimens are available for pubertal induction but the lack of comparisons makes it difficult to advocate for a particular regimen. There remain a number of areas of uncertainty, and future studies need to consider these issues and whether there are cardiovascular risk factor advantages to certain preparations. The long-term risks of breast and gynaecological malignancy remain uncertain. Long-term cohort studies are required to address these issues.

Androgen therapy for delayed male puberty

PURPOSE OF REVIEW

Delayed puberty in men is a commonly presenting problem to paediatricians and an understanding of the available evidence on cause, treatments and outcomes is important to guide practice.

RECENT FINDINGS

Understanding of the regulation of the onset of puberty is gradually unfolding, although the genetic factors that dictate the timing of puberty in individuals and families remain poorly elucidated. Mutations and polymorphisms in candidate genes are being actively studied and it is likely that there is significant overlap between traditional diagnostic categories. Also, environmental endocrine disruptors may interact with the genetic regulation of puberty. Delayed puberty may not always be a benign condition, with increased risks of failing to achieve target height, adverse psychological and educational consequences, delayed sexual and psychosocial integration into society and effects on skeletal proportions and bone mass reported. Appropriate evaluation and follow-up is needed to guide clinical practice, particularly to distinguish constitutional delay in growth and puberty from that associated with other medical disease or permanent disorders.

SUMMARY

In milder cases of delayed puberty, treatment is often not required; however, considerable evidence exists for the efficacy and safety of short courses of low-dose testosterone therapy for appropriately selected individuals. This treatment is associated with high levels of patient satisfaction. There is not yet sufficient evidence for the routine use of other therapies (e.g. growth hormone, aromatase inhibitors) for constitutional delay in growth and puberty and better characterization of cause may lead to more targeted individual therapy.

Inducing puberty

Puberty is the result of increasing pulsatile secretion of the hypothalamic gonadotropin releasing hormone (GnRH), which stimulates the release of gonadotropins and in turn gonadal activity. In general in females, development of secondary sex characteristics due to the activity of the gonadal axis, i.e., the growth of breasts, is the result of exposure to estrogens, while in boys testicular growth is dependent on gonadotropins and virilization on androgens. Hypogonadotropic hypogonadism is a rare disease. More common is the clinical picture of delayed puberty, often associated with a delay of growth and more often familial occurring. Especially, boys are referred because of the delay of growth and puberty. A short course (3-6 months) of androgens may help these boys to overcome the psychosocial repercussions, and during this period an increase in the velocity of height growth and some virilization will occur. Hypogonadotropic hypogonadism may present in a congenital form caused by developmental disorders, some of which are related to a genetic disorder, or secondary to hypothalamic-pituitary dysfunction due to, among others, a cerebral tumor. In hypogonadotropic hypogonadism puberty can be initiated by the use of pulsatile GnRH, gonadotropins, and sex steroids. Sex steroids will induce development of the secondary sex characteristics alone, while combined administration of gonadotropins and GnRH may induce gonadal development including fertility.

[Pubertal delay]

Puberty is the phenomenon that conducts to reproductive maturation. Delayed puberty is defined in girls by the absence of breast development beyond 13-years-old or primary amenorrhea beyond 15-years-old, and in boys by the absence of testicular development beyond 14-years-old. Most delayed puberties are functional. Congenital hypogonadotrophic hypogonadism are rare. Turner syndrome is the most frequent hypergonadotrophic hypogonadism in girls. The delayed puberty treatment is hormonal replacement. Delayed puberty clearly has a genetic component, and new advances in genetic research may provide tools to aid our understanding of the factors that regulate the timing of puberty.

Adult height in children with short stature and idiopathic delayed puberty after different management

By retrospectively collecting data from nine Italian centres of pediatric endocrinology, we assessed the different management and final outcome of children with short stature and idiopathic delayed puberty. Data were obtained in 77 patients (54 males, 23 females) diagnosed and followed-up in the various centres during the last 15 years. Inclusion criteria were short stature at initial observation and idiopathic delayed puberty diagnosed during follow-up. At first observation, age was 13.8 +/- 1.0 years and height standard deviation score (SDS) was -2.6 +/- 0.6 in males. In females age was 13.1 +/- 0.9 years and height SDS -2.6 +/- 0.4. Local diagnostic and therapeutic protocols included testing for growth-hormone deficiency (six centres) and treatment in case of deficiency or, in the remaining centres, testosterone or no treatment in males, and no treatment in females. At diagnosis, both in males and in females, the auxological features (height SDS, target height SDS and bone age delay) were similar in the patients treated with growth hormone, testosterone or not treated. Overall 32 patients received growth hormone (25 males, 7 females), 33 no treatment (17 males, 16 females) and 12 testosterone. There was no difference in the adult height of males and females in the different treatment groups. In males there were no differences between adult and target height SDSs (growth hormone-treated 0.31 +/- 0.79, untreated 0.10 +/- 0.82, testosterone-treated 0.05 +/- 0.95), between adult and initial height SDSs (growth hormone-treated 1.70 +/- 0.93, untreated 1.55 +/- 0.92, testosterone-treated 1.53 +/- 1.43) and percentage of subjects with adult height above target height. In females, there were no differences between adult and target height SDSs (growth hormone-treated -0.49 +/- 1.13; untreated 0.10 +/- 0.97) and between adult and initial height SDSs (growth hormone-treated 1.76 +/- 0.92; untreated 1.77 +/- 0.98), whereas a significantly higher percentage of patients remained below target height in the growth hormone-treated group (6/7, 85.7% vs 5/11, 31.3%) (P = 0.02). In conclusion, the diagnostic and therapeutic management of the patients with short stature and delayed puberty is different among Italian pediatric endocrinologists. Our data do not support the usefulness of growth-hormone therapy in improving adult height in subjects with short stature and delayed puberty, particularly in the female sex.

Beneficial effects of propylthiouracil plus L-thyroxine treatment in a patient with a mutation in MCT8

CONTEXT

Mutations of the monocarboxylate transporter 8 (MCT8) gene determine a distinct X-linked phenotype of severe psychomotor retardation and consistently elevated T(3) levels. Lack of MCT8 transport of T(3) in neurons could explain the neurological phenotype.

OBJECTIVE

Our objective was to determine whether the high T(3) levels could also contribute to some critical features observed in these patients.

RESULTS

A 16-yr-old boy with severe psychomotor retardation and hypotonia was hospitalized for malnutrition (body weight = 25 kg) and delayed puberty. He had tachycardia (104 beats/min), high SHBG level (261 nmol/liter), and elevated serum free T(3) (FT(3)) level (11.3 pmol/liter), without FT(4) and TSH abnormalities. A missense mutation of the MCT8 gene was present. Oral overfeeding was unsuccessful. The therapeutic effect of propylthiouracil (PTU) and then PTU plus levothyroxine (LT(4)) was tested. After PTU (200 mg/d), serum FT(4) was undetectable, FT(3) was reduced (3.1 pmol/liter) with high TSH levels (50.1 mU/liter). Serum SHBG levels were reduced (72 nmol/liter). While PTU prescription was continued, high LT(4) doses (100 microg/d) were needed to normalize serum TSH levels (3.18 mU/liter). At that time, serum FT(4) was normal (16.4 pmol/liter), and FT(3) was slightly high (6.6 pmol/liter). Tachycardia was abated (84 beats/min), weight gain was 3 kg in 1 yr, and SHBG was 102 nmol/liter.

CONCLUSIONS

1) When thyroid hormone production was reduced by PTU, high doses of LT(4) (3.7 microg/kg.d) were needed to normalize serum TSH, confirming that mutation of MCT8 is a cause of resistance to thyroid hormone. 2) High T(3) levels might exhibit some deleterious effects on adipose, hepatic, and cardiac levels. 3) PTU plus LT(4) could be an effective therapy to reduce general adverse features, unfortunately without benefit on the psychomotor retardation.

Pharmacological management of children with short stature: the role of aromatase inhibitors

OBJECTIVE

To review the use of aromatase inhibitors, a novel treatment strategy for patients with short stature, which aims at delaying bone age advancement. Skeletal maturation is estrogen-dependent even in male children.

SOURCES

We performed a MEDLINE search of studies published in the last 10 years, including aromatase, short stature, and early puberty as keywords. The most informative articles on indications, dosages, treatment schedules, and side effects of aromatase inhibitors were included in the review.

SUMMARY OF THE FINDINGS

It has become increasingly clear that bone age advancement depends on the production of estrogen and its effect on the growth plate. In boys, testosterone is converted to estradiol by the cytochrome P450 enzyme aromatase. The use of aromatase inhibitors has been shown to be effective in prolonging the length of the growth phase in children with idiopathic short stature, constitutional growth delay, delayed puberty, as well as in children with growth hormone deficiency, in which bone age advancement jeopardizes the results of hormonal replacement therapy with growth hormones. As yet, significant adverse effects have not been reported, and results are encouraging in terms of effective increase in height, whenever the indication for the drug is appropriate.

CONCLUSIONS

Among the pharmacological treatments for short stature, aromatase inhibitors are indicated in cases in which bone age advancement may constitute an obstacle for reaching a final height that is in keeping with the family's target height.

[Diagnosis of delayed puberty]

Puberty is the phenomenon that conducts once to reproductive maturation. Delayed puberty (DP) is defined by the absence of testicular development in boys beyond 14 years old (or a testicular volume lower than 4 ml) and by the absence of breast development in girls beyond 13 years old. DP occurs in approximatively 3% of cases. Most cases are functional DP, with a large amount of constitutional delay of puberty. Others etiologies are hypogonadotrophic hypogonadism like Kallmann syndrome, or hypergonadotrophic hypogonadism. Turner syndrome is a diagnostic one should not forget by its frequency. Treatment is hormonal replacement therapy and of the etiology. During the last decade, many genes have been identified and elucidated the etiological diagnosis of some hypogonadotrophic hypogonadism syndrome. Further studies are required in collaboration with molecular biologists to better understand the mechanism of hypothalamic pituitary gonadal axis abnormalities and of the neuroendocrine physiology of the onset of puberty.

Male pubertal development and the role of androgen therapy

In boys, the hormonal changes that accompany normal puberty are well defined, as are the physical signs of pubertal development and the kinetics of the growth spurt. Most androgens are derived from the testes, although adrenal androgens may also contribute; testosterone can also be aromatized to estrogen to exert important effects during puberty. Androgens, but especially their conversion to estrogens by aromatase, have a major role in the dramatic changes in linear growth, secondary sexual characteristics, and changes to bone, muscle and fat distribution that occur during puberty. Androgen therapy for delayed puberty should permit full normal pubertal development and thereby also address some of the associated psychosocial problems. Adolescent boys with conditions of permanent hypogonadism (hypogonadotropic or hypergonadotropic) or transient hypogonadotropic hypogonadism (constitutional delay of growth and puberty) can benefit from testosterone therapy. Long-term testosterone therapy should be given for hypothalamic or pituitary gonadotropin deficiency, or for primary hypogonadism such as for adolescents with Klinefelter syndrome, if endogenous testosterone levels drop or levels of luteinizing hormone rise. Intramuscular administration every few weeks is effective, but newer cutaneous forms, for example, gels or patches, also show promise in permitting adolescent males to reach adult body composition.

Progressive reduction of relative height in childhood predicts adult stature below target height in boys with constitutional delay of growth and puberty

BACKGROUND/AIMS

In some adolescents with constitutional delay of growth and puberty (CDGP), the reduction in relative height (height SDs) starts already in childhood, before puberty. Some subjects with CDGP do not reach their target height (TH). We investigated whether early height SD reduction or testosterone treatment in low doses (1-2 mg/kg/month) influence final height (FH).

METHODS

The growth of 70 adult men with a history of CDGP was investigated. 31 subjects (13 treated with testosterone) had progressive height SD reduction between 3 and 9 years, and in 39 (17 treated with testosterone) no such reduction was seen.

RESULTS

In untreated subjects without early height SD reduction, FH was closer to TH than in those with such reduction (FH - TH 0.05 +/- 0.94 vs. -0.63 +/- 0.50 SD, p = 0.009). FH - TH did not differ between the testosterone-treated and untreated subjects in the group with early height SD reduction (FH - TH -0.36 +/- 0.48 vs. -0.63 +/- 0.50 SD, p = 0.15), nor in the group without such reduction (FH - TH -0.08 +/- 0.70 vs. 0.05 +/- 0.94 SD, p = 0.64).

CONCLUSION

Subjects with early height SD reduction do not attain FH consistent with their genetic height potential, whereas those without such reduction do. Treatment with low doses of testosterone does not adversely affect FH.

Treatment with the aromatase inhibitor letrozole during adolescence increases near-final height in boys with constitutional delay of puberty

OBJECTIVE

We investigated whether inhibition of oestrogen biosynthesis with the aromatase inhibitor, letrozole, during adolescence improves near-final height in boys with constitutional delay of puberty.

PATIENTS AND METHODS

Seventeen boys with constitutional delay of puberty were randomized to receive testosterone (T) enanthate (1 mg/kg i.m.) every 4 weeks for 6 months in combination with placebo (Pl, n = 8), or the aromatase inhibitor letrozole (Lz, 2.5 mg/day orally) (n = 9), for 12 months. After treatment, patients were followed up until near-final height. Height discrepancy was calculated as near-final height minus mid-parental target height.

MEASUREMENTS

The primary end point was the difference in near-final height between the groups treated either with T + Pl or T + Lz. Secondarily, height discrepancy and gain in height standard deviation score (SDS) were analysed in both groups.

RESULTS

Boys treated with T + Lz reached a higher mean near-final height than did boys on T + Pl (175.8 vs. 169.1 cm, respectively, P = 0.04). In T + Lz-treated boys, mean near-final height did not differ from their mid-parental target height (175.8 vs. 177.1 cm, P = 0.38), whereas in T + Pl-treated boys, mean near-final height was lower than mid-parental target height (169.1 vs. 173.9 cm, P = 0.007). T + Lz-treated boys had a greater increment in height SDS over the pretreatment height SDS than T + Pl-treated boys (+1.4 SDS vs.+0.8 SDS, P = 0.03).

CONCLUSIONS

Our findings indicate that in adolescent boys an increase in adult height can be attained by use of aromatase inhibitors.

New facets of androgen replacement therapy during childhood and adolescence

The goals of androgen therapy for adolescents are to promote linear growth and secondary sexual characteristics, at the same time as permitting the normal accrual of muscle mass and bone mineral content. Secondary goals are mainly in the psychosocial sphere, in which pubertally delayed boys feel that they look too young, are not considered a 'peer' in their age group and have difficulty competing in athletic endeavours. These goals are irrespective of the causes of delayed pubertal development: constitutional delay of growth and puberty (CDGP), a transient but very common form of pubertal delay and, much less commonly, primary or secondary permanent hypogonadism. Not all boys with CDGP require testosterone therapy, but those that come to a referral practice are likely candidates, as the watchful waiting period has finished. Although a range of androgen preparations is available for adults (injectable, oral, implantable and cutaneous patches and gels), most are drug delivery devices that are appropriate for full adult androgen replacement. These doses are too large for the induction of puberty. Therefore, at present, the injectable form is the only one that is easily adaptable for the increasing amounts of androgen necessary for the various stages of pubertal development. All preparations deliver testosterone that is readily converted to dihydrotestosterone by 5-alpha reductase. The author's practice is to begin with injecting 50-75 mg of one of the long-acting esters (enanthate or cypionate) per month, and gradually escalate to 100-150 mg/month, before changing to twice monthly dosage. As most adolescents have delayed puberty, the therapy is needed for 6-18 months before the hypothalamic-pituitary-gonadal axis functions at the late adolescent/adult level in those with CDGP. Those with permanent hypogonadism will require lifelong therapy. Once adequate virilisation is induced, and virtually full adult height is reached, any of the therapies noted above can be used in those permanently hypogonadal, whether primarily or secondarily.

Are short boys with constitutional delay of growth and puberty candidates for rGH therapy according to FDA recommendations?

BACKGROUND/AIMS

According to FDA-approved guidelines, boys whose height predictions fall to 160 cm or less are considered for treatment with recombinant growth hormone (rGH). The aim of this study was to analyze the value of different height prediction methods by accurately identifying those boys with constitutional delay of growth and puberty (CDGP) in whom final height (FH) prognosis was poor (<or=160 cm) and who might therefore be candidates for this treatment modality.

METHODS

In 69 boys with CDGP diagnosed at a mean age of 14.9 +/-1.2 years, FH prediction was calculated by means of Bayley-Pinneau (BP), Roche-Wainer-Tissen (RWT), Tanner-Whitehouse II (TWII) and target height (TH) methods. At the age of 22.6 +/- 3.5 years their height was remeasured and the accuracy of height prediction was analyzed.

RESULTS

In 6 men (8.7%) measured FH was <or=160 cm. Depending on the prediction method, different individual patients within the 14- to 16-year age range would have been candidates for rGH treatment. The BP method would have recruited 8 subjects of whom only 3 had FH <or=160 cm (sensitivity 50%, specificity 92%). The RWT and TW II methods identified only one recruit, and this patient did achieve FH <or=160 cm (sensitivity 17%, specificity 100%). None of the 8 subjects with FH <or=160 cm would have qualified for GH treatment using the TH method. In three boys none of the four methods predicted their final height <or=160 cm.

CONCLUSION

Although some boys with CDGP may be considered the candidates for rGH treatment according to FDA recommendations, none of the available methods of prediction are sufficiently sensitive to reliably recruit 14- to 16-year-old boys whose final height will fall at or below 160 cm.

Growth hormone normalizes pubertal onset in children with cystic fibrosis

Children with cystic fibrosis (CF) have a high incidence of delayed puberty and poor growth. We retrospectively reviewed pubertal maturation data from 105 children with CF who had participated in studies on growth hormone (GH). As part of the GH study, participants were randomized into two cohorts, one of which was treated with GH for 1 year, and then followed off GH, and the other group was first followed off GH, and then treated with GH for 1 year. Pubertal staging was obtained throughout these studies and we have retrospectively analyzed the data.

RESULTS

In prepubertal females, GH treatment resulted in a normalized onset of breast development as compared to delayed onset in non-treated females. Females treated during puberty had a normal tempo of breast development. In prepubertal males, GH treatment resulted in a normalized onset of testicular volume compared to non-treated males. Testicular size progression was not accelerated in pubertal boys treated with GH.

CONCLUSION

GH treatment normalizes pubertal onset in prepubertal children with CF.

A workshop on pubertal hormone replacement options in the United States

BACKGROUND

The optimal pubertal hormone replacement therapy in females and males is unclear.

OBJECTIVE

To review hormone replacement options for hypogonadal teenagers and to determine the relevant attitudes and practices of pediatric endocrinologists in the United States.

DESIGN/METHODS

A workshop on pubertal hormone replacement options was held during the Lawson Wilkins Pediatric Endocrine Society meeting in 2004. A questionnaire was distributed to investigate the audience's attitudes and practices in inducing puberty.

RESULTS

The majority of respondents used conjugated estrogens to treat hypogonadal girls with the primary aim of treatment being attainment of maximal adult height. The majority of respondents used depot testosterone to treat hypogonadal boys with the primary aim of treatment being pubertal development and virilization.

CONCLUSIONS

The use of physiological sex hormone replacement to optimize the induction of puberty in hypogonadal adolescents was recommended. The workshop revealed striking differences between US and European pediatric endocrinologists regarding their practices and attitudes regarding the induction of puberty in hypogonadal females. Detailed studies are necessary to develop more uniform guidelines.

Evaluation of the buserelin stimulation test in diagnosing gonadotropin deficiency in males with delayed puberty

OBJECTIVE

To assess the efficacy of the gonadotropin-releasing hormone (GnRH) agonist buserelin in a stimulated gonadotropin test for the investigation of delayed puberty in males.

STUDY DESIGN

Prepubertal males (n = 31; age range, 10.3 to 17.2 years) were studied; buserelin (100 microg) was administered subcutaneously, with blood sampling at 0 and 4 hours for serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH). At follow-up (mean, 4.2 years), 8/31 (26%) failed to progress into puberty, constituting hypogonadotropic hypogonadism (HH), but 23/31 (74%) had testicular enlargement (> or =8 mL) consistent with a normal hypothalamic-pituitary-gonadal (HPG) axis.

RESULTS

Stimulated serum LH response to buserelin was lower in males with HH (mean +/- standard error under the mean for HH, 1.4 +/- 0.5 U/L, compared with a normal HPG axis of 17.4 +/- 2.0 U/L; P < .0001). Stimulated serum FSH response was nondiscriminatory (HH, 7.7 +/- 2.2 U/L; normal HPG axis, 11.5 +/- 1.6 U/L; P = .27). All males with HH had a stimulated serum LH level <5 U/L, whereas only 1/23 with a normal HPG axis had a stimulated serum LH below this level. Using this value as the criterion for diagnosing HH, the buserelin stimulation test yielded a sensitivity of 100%, specificity of 96%, and positive predictive value of 89%.

CONCLUSIONS

The buserelin stimulation test is a highly specific and sensitive GnRH agonist test for the investigation of males with delayed puberty.