Are Klinefelter boys hypogonadal?

Male hypogonadism implies decreased function of one or more testicular cell population, i.e. germ, Leydig and/or Sertoli cells. In the normal prepubertal boy, Sertoli cells are very active, as indicated by high anti-Müllerian hormone (AMH) and inhibin B secretion, whereas the functional activity of Leydig cells is minimal, as evidenced by low testosterone production, and germ cells do not undergo the full spermatogenic process. Klinefelter syndrome is the most frequent cause of hypogonadism in the adult male. In this review, we discuss whether the gonadal failure is already established during infancy and childhood. In Klinefelter syndrome, there is increased germ cells degeneration from mid-foetal life - resulting in a decreased number at birth - which persists during infancy and childhood and becomes dramatic during puberty. Controversial results exist in the literature regarding Leydig cell function in Klinefelter boys: while some authors have found normal to low testosterone levels in infancy and childhood, others have reported normal to high values. Sertoli cell products AMH and inhibin B are normal in prepubertal boys and only decline during mid- to late puberty. CONCLUSION: Klinefelter syndrome is a primary hypogonadism affecting all testicular cell populations. Germ cells are affected from foetal life, and a severe depletion occurs at puberty. Leydig cell function may be normal or mildly affected in foetal and early postnatal life. Sertoli cell function is not impaired until mid- to late puberty, as reflected by normal AMH and inhibin B in Klinefelter boys.     

Decreased serum inhibin B/FSH ratio as a marker of Sertoli cell function in male survivors after chemotherapy in childhood and adolescence

OBJECTIVE: Inhibin B produced by Sertoli cells may be an important marker of seminiferous tubule function in patients treated with chemotherapy (CT). The aim of this study was to evaluate the inhibin B/FSH ratio to detect male gonadal dysfunction in cancer survivors treated in childhood and adolescence. PATIENTS: Twenty-one male patients (group A) treated with 6-10 courses of CT for Hodgkin's disease during childhood and adolescence were examined 3-11 years after the conclusion of treatment. Twenty healthy young men (18-23 years old) were used as controls (group B). METHODS: Serum samples for the determination of inhibin B, follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone (T), sex hormone-binding globulin (SHBG) and semen for analysis were collected. RESULTS: The median testicular volume of patients of group A was lower than those of group B (p = 0.001) and a positive correlation was found between testicular size and sperm count (r = -0.5, p = 0.01). Semen analysis revealed azoospermia in 11 patients, severe oligospermia in four and normal sperm count in three. No significant difference was found in the median of T, LH, SHBG, inhibin B concentrations and T/LH ratio between the groups. Serum inhibin B was correlated with the serum FSH levels (r = -0.5, p = 0.02). Median FSH was significantly higher (p = 0.0001), and median inhibin B/FSH ratio was significantly lower in group A than in controls (p = 0.0002), but the inhibin B/FSH ratio was higher in the patients with normal sperm count than in those with oligospermia (p = 0.00004). CONCLUSIONS: These results show that the cytotoxic effects of CT cause severe damage to the germinal epithelium with subtle effects on Sertoli cells. To assess Sertoli cell function in men with primary testicular damage after treatment with CT in childhood and adolescence, the inhibin B level needs to be interpreted in the context of the circulating FSH, especially when normal FSH levels are observed.     

How to evaluate gonadal function in the cryptorchid boy. Lessons from new testicular markers

In normal clinical practice, testicular evaluation in boys has relied on palpation and testosterone determination after hCG stimulation, which reflects the activity of interstitial Leydig cells. However, the most active compartment of the testis before puberty is the seminiferous tubule compartment, in which Sertoli cells proliferate and secrete anti-Müllerian hormone (AMH) and inhibin B. The recent development of commercially available assays for these two peptides has provided the pediatrician with excellent tools to assess the existence of functional testicular tissue in boys with no need for hCG stimulation. Serum AMH determination is also useful to assess testicular tissue mass and function in patients with intersex disorders. The determination of testosterone, its precursors and dihydrotestosterone, after hCG stimulation, should be reserved for situations in which Leydig cell function needs to be specifically assessed.     

Inverse relationship between serum inhibin B and FSH levels in prepubertal boys with cryptorchidism.

To investigate the gonadal control of FSH secretion in prepuberty, we studied the relationship between circulating inhibin B and FSH levels in 16 prepubertal boys with cryptorchidism (age range, 1-8 y). The effect of Leydig cell stimulation on the secretion of inhibin B, sex steroids, and FSH was investigated in nine boys who were given human chorionic gonadotropin (hCG) treatment. In these boys, serum inhibin B, testosterone, estradiol, and gonadotropin levels were measured before and on the fourth day of the last (third) hCG injection, given at 1-wk intervals. Except for one boy with both high inhibin B and FSH concentrations, basal serum levels of these hormones correlated negatively (r(s) = -0.79, n = 15, p < 0.005). This inverse relationship remained significant in the subgroup of boys younger than 2 y of age (r(s) = -0.84, n = 11, p = 0.008) who also had greater variance of serum FSH concentrations than 14 control boys of similar age with normally located testes (p < 0.01). hCG stimulation increased serum testosterone and suppressed serum FSH concentrations in each boy (n = 9, p < 0.005). In the four oldest subjects, the serum inhibin B level increased from the mean of 91 to 135 pg/mL (p < 0.05). These findings suggest that inhibin B regulates FSH secretion in early childhood. Moreover, the hCG-induced suppression of FSH secretion was probably mediated by sex steroids rather than by inhibin B. Finally, the increase in serum inhibin B concentration during the hCG treatment was likely to be indirect via Leydig cell-Sertoli cell or Sertoli cell-germ cell interaction(s).     

Gonadal function in low birth weight infants: a pilot study

OBJECTIVE: To evaluate gonadal function and anti-Müllerian hormone (AMH) serum concentrations during the first 3 months of life in low birth weight (low-BW) and normal birth weight (normal-BW) infants. INFANTS: Twenty low-BW and 29 normal-BW infants were studied. METHODS: The pituitary-gonadal axis was evaluated by a GnRH agonist test (leuprolide acetate, 10 microg/kg s.c.). Circulating concentrations of gonadotropins, steroid hormones, sex hormone binding globulin, inhibin B and AMH were determined by specific assays. RESULTS: In both sexes, basal concentrations of gonadotropins, sex steroids, sex hormone binding globulin and inhibin B were similar between low-BW and normal-BW infants. However, AMH concentrations were significantly higher in low-BW compared to normal-BW females (p = 0.004). This was not observed in males. After leuprolide administration, estradiol concentrations were higher in low-BW compared to normal-BW females (p = 0.043). In males, post-stimulated sex steroid concentrations were similar in both groups except for 17-OHP, which was significantly higher after leuprolide in the low-BW group (p = 0.023). CONCLUSIONS: An increase in AMH and post-stimulated estradiol serum concentrations suggests altered follicular development in low-BW girls. In contrast, the normal circulating levels of AMH and inhibin B seem to indicate that Sertoli cell function is normal in low-BW boys. We suggest that ovarian function seems to be more vulnerable than testicular function in infants with intrauterine growth restriction.     

Evaluation of the tubular and interstitial functions of the testis in 46,XY patients with ambiguous genitalia

Investigation of the origin of sexual ambiguity is complex. Although testicular function has traditionally been assessed only by examining the steroidogenic capacity of Leydig cells and spermatogenesis, it has recently been shown that the measurement of serum anti-Müllerian hormone (AMH) as a marker of Sertoli cell function may also help clinicians. The aim of this study was to evaluate both Leydig and Sertoli cell functions in 46,XY patients with intersex states in order to establish biochemical patterns that would help to reach an etiologic diagnosis. We measured serum androgens, AMH and gonadotropins in 24 patients with sexual ambiguity and XY karyotype: 8 with gonadal dysgenesis (GD), 3 with 3beta-hydroxysteroid dehydrogenase deficiency (3betaHSD), 5 with androgen insensitivity syndrome (AIS), 4 with 5alpha-reductase 2 (SRD5A2) deficiency, and 4 were of unknown origin or idiopathic. Our results showed that while testosterone was low and gonadotropins elevated in patients with either GD or 3betaHSD, AMH was low in the former and high in the latter. Serum AMH and gonadotropins were normal or high in patients with 3betaHSD or AIS, but these could be distinguished by testosterone levels. Serum testosterone and gonadotropins were normal or high in AIS and SRD5A2 deficiency patients; however, while AMH was elevated in AIS, it was not the case in SRD5A2 deficiency patients, indicating that testosterone is sufficient to inhibit AMH within the testis. In idiopathic cases gonadotropins and testosterone were normal, and AMH was normal or low. We conclude that the combined measurement of androgens, AMH and gonadotropins helps to establish the diagnosis in intersex patients.     

The relation of germ cells per tubule in testes,serum inhibin B and FSH in cryptorchid boys

At bilateral orchiopexy bilateral biopsies may be indicated to determine fertility potential. It is currently unknown if the serum inhibin B levels at time of orchiopexy reflect the testicular status of the bilaterally cryptorchid child. The aim of this study was to relate the results of inhibin B and FSH measurements with testicular biopsy parameters in bilateral cryptorchid boys. Included were 25 boys with bilateral cryptorchidism, median 2.5 years (9 months to 5.5 years) at surgery for bilateral cryptorchidism with simultaneous testicular biopsies, and blood sample for inhibin B and FSH. The number of spermatogonia and gonocytes was measured in 100 tubular transverse sections, the S/T and the mean-S/T of the patient was found, and expressed as percent of lowest normal value. Inhibin B and FSH were measured and related to age-specific values. Forty percent (10/25) of the patients had very low mean-S/T (mean-S/T < 10% of lowest normal-value). Inhibin B was decreased in 24% (6/25) of the patients, all with decreased mean-S/T, predominantly with a mean-S/T < 10% of lowest normal-value (p < 0.05). There was a negative correlation between inhibin B and FSH (p < 0.05). In cases of mean-S/T<10% of lowest normal-value and decreased inhibin B, we found increased FSH in 9% (2/22) of the patients and hypergonadotropic hypogonadism was suspected. Low FSH was found in 5% (1/22) of the patients and hypogonadotropic hypogonadism was suspected. Low inhibin B predicts a serious condition in respect of infertility. Low FSH and inhibin B indicates examination for hypogonadotropic hypogonadism. In bilateral cryptorchid boys inhibin B levels correlated negatively to FSH.     

Role of inhibins in childhood and puberty

Inhibins, produced mainly in the gonads, suppress FSH synthesis. The bioactive dimeric forms of inhibin (A and B) have been proposed as peripheral markers of Sertoli and granulosa cell function. The determination of serum dimeric inhibins from birth through adulthood reflects a distinct pattern of both inhibins in males and females. Concomitantly with the gonadotrophin surge, an important production of inhibin B is observed during the first months of life. In males, inhibin B levels are higher than in females and persist elevated up to childhood, whereas in females they decrease up to prepubertal levels by 6 months of age. In girls, high serum levels of inhibin A are observed during the first two months of life; thereafter, they are undetectable until puberty. An active secretion of inhibin B persists in both males and females in the period of maximal LHRH pulse generator restraint; however, the possible gonadotrophin dependence of this production remains controversial. At puberty, a progressive rise in serum inhibin B occurs concomitantly with the increased production of sex steroids in both males and females. A similar secretion pattern of inhibin A is observed in girls. This increment is mainly exerted by gonadotrophins and modulated by multiple paracrine/autocrine mechanisms within the ovary and the testis that regulate the dimerization of the inhibin subunits throughout pubertal maturation. The differences observed in males and females between circulating dimeric inhibins in relation to gonadotrophins and sex steroid concentrations from birth through puberty has opened a new perspective for research in human reproduction. These new markers may contribute to a better knowledge of the regulation of the hypothalamic-pituitary-gonadal axis function and the physiopathology of the mechanisms involved in sexual differentiation and/or fertility disorders.     

Testicular anti-Müllerian hormone: history, genetics, regulation and clinical applications

Anti-Müllerian hormone (AMH), also called MUllerian inhibiting substance (MIS) is a product of supporting gonadal Sertoli and granulosa cells. Its main physiological role is the induction of regression of Müllerian ducts in male fetuses but it also plays a role in Leydig cell steroidogenesis and in follicular development. It is a member of the transforming growth factor B family and signals through two serine/threonine kinase receptors, only one of whom, type II, is specific. Type I receptors and the intracytoplasmic signaling molecules are shared with the bone morphogenetic family. AMH is positively regulated by SF1, SOX9 and FSH. Testosterone is a powerful downregulator. Males lacking functional AMH or AMH receptor genes do not undergo regression of MUllerian derivatives during fetal life. AMH is an excellent marker of prepubertal testicular function and has gained recognition as a valuable marker of follicular reserve in adult women.     

Congenital gonadotropin deficiency in boys: management during childhood

OBJECTIVE: To analyze the features of boys with congenital gonadotropin deficiency (CGD), and to determine the value of plasma inhibin B and anti-Müllerian hormone (AMH) for predicting testicular function and the effect of testosterone treatment. PATIENTS: We followed 19 boys for CGD, including five with Kallmann syndrome. RESULTS: The boys were seen before 14 years of age for micropenis (9 boys) or later for delayed puberty (10 boys). No testis was palpable in the scrotum in 13 patients, bilaterally in seven of them. Luteinizing hormone (LH) peak after a gonadotropin releasing hormone (GnRH) test was between 0.5 and 5.6 U/l. Plasma inhibin B was low in the four patients evaluated at less than 1 year old. AMH was low in one of them and normal in four others. Of the older patients, three lad low plasma inhibin B and four had normal concentrations; plasma AMH was low in three of them and increased in four. Testosterone treatment restored penis length to normal in all patients. CONCLUSIONS: Low plasma inhibin B and AMH concentrations may indicate testicular damage in boys with CGD.     

Low serum inhibin B levels as a marker of testicular damage after treatment for a childhood malignancy

The aim of this study was to evaluate the role of inhibin B and the determination of its concentration to diagnose testicular damage after treatment for a childhood malignancy. Thirty-seven males treated for Hodgkin disease (n=11) or non-Hodgkin lymphoma (n=26) were examined at a mean age of 16.9 ± 2.9 years. Mean age at the stop of therapy was 11.3 ± 3.0 years and in most cases the chemotherapy regimen included gonadal damaging alkylating agents. Thirty-three normal males (mean age 17.9 ± 4.1 years) were examined as controls. Serum samples were collected for determination of inhibin B, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone. Median inhibin values were significantly lower in patients than in controls (96.0 vs 225.0 pg/ml, P < 0.0001) and a strong negative correlation was found between inhibin B and FSH (r=−0.86, P < 0.0001), a weak correlation with LH (r = −0.32, P < 0.05) and no correlation with testosterone. In post-pubertal patients (i.e., over 16 years) a positive correlation was found between testicular size and inhibin level (r=0.53, P < 0.05), but not between testicular size and testosterone level. Pathological low levels (values that differed by more than 2 SD from the mean value of control subjects) were found in 20 patients for inhibin B and 8 for testosterone (P < 0.01) and pathological high values in 19 patients for FSH and 3 for LH. Conclusion This study confirms the role that inhibin B plays in the regulation of FSH secretion and provides further evidence of the utility of its evaluation as a direct indicator of male gonadal dysfunction. Received: 21 April 1999 / Accepted: 27 September 1999     

Testicular torsion: Orchiectomy or orchiopexy?

ObjectiveTo evaluate the impact on testicular function of the surgical approach used to treat testicular torsion.Patients and methodsSeventeen males operated on for testicular torsion at a median age of 14 years were investigated. Serum follicle-stimulating hormone (FSH), testosterone and inhibin B as well as testicular volume were measured early (median 36 days) and/or late (median 1.1 years) after operation.ResultsOrchiectomy was performed in six, and testicular detorsion and orchiopexy in 11 patients. The duration of the preoperative symptoms in the detorsion group was 15 h (range 6–168) and in the orchiectomy group 42 h (range 24–96) (P = 0.03). Preoperative colour Doppler ultrasonography showed some circulation in 40% of the patients. At 1 month the median serum inhibin B level was significantly higher after preserving surgery (P = 0.01). At 1 year postoperatively, the median serum FSH level tended to be lower after testicular preservation (P = 0.09). Abnormal inhibin B or FSH values were observed in 35% of the patients.ConclusionsTesticular function is often compromised in patients with testicular torsion. Testis-preserving surgery yields better testicular function than orchiectomy in the short term if the testis is not obviously necrotic. Testicular torsion does not necessarily cause the circulation to cease completely, and preserving surgery can also sometimes be attempted after delayed diagnosis.     

隐睾患者血清抑制素B水平的变化特征及其诊断意义的研究进展

隐睾是男性最常见的泌尿生殖系统发育异常,以单侧或双侧睾丸下降至阴囊过程发生障碍为主要特征。血清促卵泡刺激素和血清抑制素B是两种常见的用以评估睾丸支持细胞/曲细精管功能是否异常的内分泌指标。很多针对隐睾症开展的研究显示,睾丸支持细胞/曲细精管功能(精子发生)均受累,但睾丸间质细胞(Leydig cell)的功能几乎没有受到影响。由此可见,隐睾患者在青春期前睾丸功能的评估重点是睾丸支持细胞的受损程度,而血清抑制素B是睾丸支持细胞的典型内分泌标志物,也是评估隐睾下降固定术后睾丸功能的一种安全、方便、间接的途径。本文将针对隐睾患者血清抑制素B水平的变化特征及其诊断意义的研究进展进行综述。     

Male reproductive health after childhood cancer

AIM: Twenty-five male patients were investigated to elucidate the correlation of semen parameters and other related parameters in the assessment of spermatogenesis after childhood cancer treatment. METHODS: Evaluation of given cancer treatment, anthropometric and testicular size measurements, semen analysis, and measurement of gonadotrophins, testosterone, sex hormone-binding globulin (SHBG), and inhibin B were performed according to a protocol. RESULTS: Median (range) sperm concentration (SC) was 35.5 (0-273)x10(6)/mL, and percentage of motile sperm 56 (0-86)%. Testicular size (r=0.73, p<0.001) and the level of inhibin B (r=0.66, p<0.001) correlated strongly to SC. SC correlated negatively to FSH (r=0.46, p=0.03). Only testicular size predicted SC significantly (p=0.03). Inhibin B showed highest area under ROC curve (0.83, 95%CI 0.67-0.99) in showing SC<20x10(6)/mL. Body mass index (BMI) did not correlate with SC, but negative correlation between BMI and SHBG was found (r=-0.41, p=0.04). CONCLUSION: Although semen analysis is a useful instrument for fertility assessment in men, it is often difficult to get these samples from childhood cancer survivors. Thus, indirect methods are needed in prediction of possible sperm count impairment in postpubertal adolescents after cancer treatment. When combined with the data on testicular size and follicle-stimulating hormone (FSH) level, inhibin B gives valuable addition to the estimations of spermatogenesis.     

Influence of open testicular biopsy in prepubertal rats on rats' adulthood fertility with correlation to serum levels of inhibin B and follicle stimulating hormone

ObjectiveOpen testicular biopsy (OTB) is one of the options to accurately assess fertility potential of the undescended testis. The aim of the study was to investigate consequences of OTB in prepubertal rats on their adulthood fertility.MethodsThirty-eight prepubertal male rats were divided into three groups depending on day 20 procedure. The first group was the control group, the second sham operated and the third has left OTB. Bilateral orchiectomy was performed on day 70 to all groups, with determination of serum inhibin B and follicle stimulating hormone (FSH). Removed testes were compared according to the weight, volume, spermatogenesis, histological and apoptotic changes in both testes with differences in serum levels of inhibin B and FSH.ResultsIpsilateral testicular weight, volume, and spermatogenesis reduction with a reduction of tubular number, diameter and germinative epithelium was found in OTB group. Significant increase in apoptotic index was found in biopsied testis without compensatory hypertrophy of contralateral testis. Differences of inhibin B and FSH were not statistically significant among three groups.ConclusionOTB in prepubertal rats has detrimental effects on fertility in adulthood. It does not cause compensatory hypertrophy of the contralateral testis nor does it disturb serum levels of inhibin B and FSH.     

Diagnosis of 5alpha-reductase type 2 deficiency: contribution of anti-Müllerian hormone evaluation

AIM: To evaluate anti-Müllerian hormone (AMH) levels in patients with clinical and molecular diagnosis of 5alpha-reductase 2 deficiency. PATIENTS AND METHODS: Data from 14 patients whose age ranged from 21 days to 29 years were analyzed according to age and pubertal stage. Sexual ambiguity was rated as Prader III in 11 patients. LH, FSH, testosterone (T), dihydrotestosterone (DHT) and AMH serum levels were measured in all but two patients, who had been previously submitted to gonadectomy; T and DHT were also measured in 20 age-matched controls. RESULTS: Gonadotropin levels were normal in all but one patient who retained gonads (six of whom had reached puberty) and T/DHT ratio was elevated in all patients when compared to controls. All prepubertal patients had AMH levels < -1 SD for age, while most pubertal patients had AMH levels compatible with pubertal stage. CONCLUSIONS: Prepubertal patients with 5alpha-reductase 2 deficiency have AMH values in the lower part of the normal range. These data indicate that T does not need to be converted to DHT to inhibit AMH secretion by Sertoli cells.     

Serum levels of immunoreactive inhibin, FSH, and LH in human infants at preterm and term birth.

Serum levels of immunoreactive inhibin, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were determined in 112 fetal cord blood samples obtained at birth between 26 and 40 weeks of gestation. High levels of inhibin immunoreactivity were detected in all samples. Between the gestational age of 26 and 28 weeks, the levels (mean +/- SE) were higher (p less than 0.05) in male (21.6 +/- 1.0 U/ml; n = 12) than in female (12.8 +/- 0.2 U/ml; n = 12) fetuses. With ongoing gestation, the serum inhibin immunoreactivity decreased and was found to be similar in male (12.1 +/- 0.3 U/ml; n = 13) and female (9.1 +/- 0.7 U/ml; n = 8) fetuses at term. Serum FSH and LH levels were elevated at the beginning of the 3rd trimester of pregnancy and decreased with ongoing gestation to undetectable values at term birth. Between 26 and 32 weeks of gestation, the FSH levels were higher in females (p less than 0.02), whereas the LH levels were higher in males (p less than 0.01). These observations suggest that in the human fetus the pituitary-gonadal axis is active and presents sexual dimorphism; both characteristics are pronounced early during the 3rd trimester of gestation and decrease towards term.     

Gonadotropin-releasing hormone (LH-RH) and human chorionic gonadotropin in the treatment of two boys with hypogonadotrophic hypogonadism.

Two brothers, 16 and 14 years of age, with hypogonadotrophic hypogonadism and anosmia were treated with subcutaneous injections of 200 microng gonadotropin-releasing hormone at 8-hour intervals for 4 weeks. Serum FSH increased to the range of normal adult men, but serum LH and serum testosterone showed little change and no clinical signs of pubertal development occurred. Thereafter the 2 patients were given HCG for 11 months and a combination of HCG and HMG for a further 3 months. In response to this treatment, the serum testosterone levels increased to the range of normal adult men and marked development of the secondary sex characteristics was seen.     

Low birth weight for gestational age and subsequent male gonadal function

OBJECTIVE: To verify whether a reduced birth weight for gestational age was associated with a testicular dysfunction in postpubertal boys.Study design: Boys born small for gestational age (SGA) (n = 25) were compared to 24 born with an appropriate weight. All subjects were postpubertal (mean age 17.5 +/- 1.3 and 17.6 +/- 2.0 years, respectively). The following clinical and endocrinologic variables were evaluated: final height, target height, body mass index, testicular volume, follicle-stimulating hormone, luteinizing hormone, testosterone, and inhibin B. RESULTS: The SGA group had reduced testicular size (16.3 +/- 2.7 mL vs 22.8 +/- 3.2 mL; P <.0001) with a lower testosterone level (3.76 +/- 1.35 ng/mL vs 4.77 +/- 1.55 ng/mL; P <.05) and a higher LH value (4.41 +/- 1.61 IU/L vs 3.44 +/- 1.29 IU/L; P <.05). Among the SGA group, 54% had a mean testicular volume >2 SD below the control mean (ie, <16 mL) and in these subjects, the inhibin B level was low (143 +/- 46 pg/mL vs 229 +/- 76 pg/mL; P <.0001). SGA patients with smaller testes had lower final height relative to target height(P <.05 vs patients with larger testes) and for the SGA group, inhibin B correlated with testicular size (P <.0001). Positive correlations also were found between the reduction of final height relative to target height and testicular volume (P <.005) and inhibin B values (P <.05). CONCLUSIONS: SGA subjects have pituitary-gonadal axis function that tends toward hypogonadism. There is a disruption of the exocrine function in subjects with smaller testicular size who failed to show a complete height catch-up growth. This study supports a link between low birth weight and lower fertility in adult males.     

GONADOTROPIN-RELEASING HORMONE (LH-RH) AND HUMAN CHORIONIC GONADOTROPIN IN THE TREATMENT OF TWO BOYS WITH HYPOGONADOTROPHIC HYPOGONADISM

Abstract. Two brothers, 16 and 14 years of age, with hypogonadotrophic hypogonadism and anosmia were treated with subcutaneous injections of 200μg gonadotropin-releasing hormone at 8-hour intervals for 4 weeks. Serum FSH increased to the range of normal adult men, but serum LH and serum testosterone showed little change and no clinical signs of pubertal development occurred. Thereafter the 2 patients were given HCG for 11 months and a combination of HCG and HMG for a further 3 months. In response to this treatment, the serum testosterone levels increased to the range of normal adult men and a marked development of the secondary sex characteristics was seen.