Premature androgenic alopecia and insulin resistance. Male equivalent of polycystic ovary syndrome?

BACKGROUND

Polycystic ovary syndrome (PCOS), the most frequent endocrinopathy in women with estimated prevalence of 5-10 %, is characterised by a hormonal and metabolic imbalance of polygene autosomal trait. The complexity of symptoms and genetic base started up the hypothesis on the existence of male equivalent of PCOS. Precocious loss of hair before 30 years of age was suggested as one of the male symptoms of this syndrome.

OBJECTIVES

The aim was to confirm the association of lower levels of follicle stimulating hormone (FSH) and sexual hormone binding globulin (SHBG) or higher free androgen index (FAI) in premature balding men with a reduced insulin sensitivity.

PATIENTS/METHODS

The study included 30 men with premature hair loss (defined as grade 3 vertex or more on the alopecia classification scale by Hamilton with Norwood modification) starting before 30 years of age. The hormonal values of the investigated group were compared with those regarded as normal reference values obtained in a group of 256 males in the age of 20-40 years during the Czech population study of iodine deficiency. In all men with premature baldness besides hormonal level determinations insulin tolerance test was carried out.

RESULTS

The observed group was divided into two subgroups. The first one showed similar hormonal changes as women with PCOS, namely subnormal SHBG, FSH or increased FAI. The other had either no anomalies in steroid spectrum or only lower SHBG. The groups did not differ either in BMI or in age. The group with hormonal profile resembling that of women with PCOS, showed significantly higher insulin resistance than the group without these changes.

CONCLUSIONS

The findings are consistent with the hypothesis that at least a part of the men with premature androgenic alopecia could be considered as a male equivalent of the polycystic ovary syndrome of the women. These premature balding men represent a risk group for the development of impaired glucose tolerance or diabetes mellitus type 2.

Endocrine manifestations of craniopharyngioma

RATIONALE

Due to the proximity of craniopharyngiomas to the hypothalamus and pituitary gland, most children and adolescents presenting with these tumors will exhibit significant endocrine dysfunction. After treatment, these impairments can become a major cause of morbidity and mortality.

METHODS

The postoperative course of children undergoing surgery for craniopharyngioma is reviewed.

CONCLUSION

Even if hormone levels seem to be adequate in the short term after treatment, deficiencies may develop over years and need to be monitored closely.

The ovarian markers of the FSH insufficiency in functional hypothalamic amenorrhoea

BACKGROUND

The purpose of this work was to revisit the gonadotrophin insufficiency of functional hypothalamic amenorrhoea (FHA) with the use of relevant ovarian markers.

METHODS

Serum anti-Mullerian hormone (AMH), estradiol (E2), inhibin B, LH and FSH were immunoassayed in 31 women with FHA and in 30 healthy women in early follicular phase. The ovarian antral follicle number (FN) was determined within two distinct diameter ranges (2-5 and 6-9 mm) by ultrasound in real time, the same day as the blood sampling.

RESULTS

The 2-5 mm FN was similar between the two groups, while the 6-9 mm FN was significantly less in FHA than in controls, in relation with lower serum FSH levels (r=0.428; P<0.024). Nine (29%) FHA patients had a low serum basal FSH level (i.e. <4.5 IU/l, 5th percentile of control values). In the 22 (71%) patients with apparently normal FSH, the mean 6-9 mm FN was similar to controls. However, in this sub-group, the mean AMH serum level and the AMH:2-5 mm FN ratio were significantly higher and the mean inhibin B serum level was significantly lower than in controls. No significant relationship was found between the serum LH levels and the FN, AMH or inhibin B values.

CONCLUSION

Only a minority of patients with FHA have a low serum basal FSH level, and we show that this is associated with fewer 6-9 mm follicles at the ovarian level. Despite a normal serum FSH level and 6-9 mm FN in the majority of patients with FHA, the functional follicle markers are abnormal. This suggests that the FSH action on the ovary is incomplete and is not properly reflected by its serum level nor by FN at ultrasound.

Targeted disruption of luteinizing hormone beta-subunit leads to hypogonadism, defects in gonadal steroidogenesis, and infertility

Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) act on gonadal cells to promote steroidogenesis and gametogenesis. Clarifying the in vivo roles of LH and FSH permits a feasible approach to contraception involving selective blockade of gonadotropin action. One way to address these physiologically important problems is to generate mice with an isolated LH deficiency and compare them with existing FSH loss-of-function mice. To model human reproductive disorders involving loss of LH function and to define LH-responsive genes, we produced knockout mice lacking the hormone-specific LHbeta-subunit. LHbeta-null mice are viable but demonstrate postnatal defects in gonadal growth and function resulting in infertility. Mutant males have decreased testes size, prominent Leydig cell hypoplasia, defects in expression of genes encoding steroid biosynthesis pathway enzymes, and reduced testosterone levels. Furthermore, spermatogenesis is blocked at the round spermatid stage, causing a total absence of the elongated spermatids. Mutant female mice are hypogonadal and demonstrate decreased levels of serum estradiol and progesterone. Ovarian histology demonstrates normal thecal layer, defects in folliculogenesis including many degenerating antral follicles, and absence of corpora lutea. The defects in both sexes are not secondary to aberrant FSH regulation, because FSH levels were unaffected in null mice. Finally, both male and female null mice can be pharmacologically rescued by exogenous human chorionic gonadotropin, indicating that LH-responsiveness of the target cells is not irreversibly lost. Thus, LHbeta null mice represent a model to study the consequences of an isolated deficiency of LH ligand in reproduction, while retaining normal LH-responsiveness in target cells.

Voice changes after androgen therapy for hypogonadotrophic hypogonadism

OBJECTIVES/HYPOTHESIS

Males with isolated hypogonadotropic hypogonadism (IHH) fail to undergo normal sexual development, including the lack of masculinization of the larynx. The objective of this study was to measure the mean vocal fundamental frequency (MF0) in IHH patients and determine the impact of androgen treatment. An additional aim was to compare the MF0 between IHH patients and controls.

STUDY DESIGN

Prospective observational study.

METHODS

Twenty-four patients with IHH were identified along with 30 normal males and females. Voice recordings were obtained on all subjects. Androgen therapy was administered to the IHH patients. The MF0 and serum sex hormone levels were measured before treatment and at intervals during therapy. These results were compared with the pretreatment data within the IHH group. Voice parameters were also compared between the pre- and posttreatment IHH patients and the normal males and females.

RESULTS

The MF0 in untreated IHH patients was 229 +/- 41 Hz. This was intermediate between the normal male (150 +/- 22 Hz, P < .001) and normal female patients (256 +/- 29 Hz, P < .01). After treatment, the MF0 in the IHH group decreased to 173 +/- 30 Hz (P < .0001); indeed, their posttreatment MF0 approached that of normal males (P < .08). Serum hormone levels responded to the injected testosterone, but these levels did not directly correlate with MF0.

CONCLUSIONS

MF0 in IHH patients is intermediate between normal male and female levels. After treatment with testosterone, these values approach the range of normal males. This prospective study details the impact of androgens on the larynx and vocal function in patients with IHH.

Apparent primary follicle-stimulating hormone deficiency is a rare cause of treatable male infertility

OBJECTIVE

To find the underlying defect in a case of primary FSH deficiency and to estimate the beneficial effect of FSH treatment.

DESIGN

Case report.

SETTING

University hospital fertility clinic.

PATIENT(S)

Normal, healthy, 37-year-old male patient with severe oligoteratozoospermia.

INTERVENTION(S)

Levels of FSH, LH, LHRH provocation test, karyotyping, genomic analysis on the Y-chromosomal AZF region and sequencing of the FSHB gene, FSH treatment.

MAIN OUTCOME MEASURE(S)

We compiled detailed clinical and molecular data on four pregnancies. We compare this case with a similar case published recently.

RESULT(S)

There were detectable but very low FSH levels after LHRH provocation; the LH response was not entirely normal, and no genomic abnormalities were found in the FSHB gene. The FSH treatment resulted in four pregnancies, two of which ended in abortion; the other two resulted in the birth of two healthy children. Both our case and the published case had detectable but abnormally low FSH levels on some occasions, but normal or highly normal inhibin B levels that differed from the expected low levels. Both patients had a normal male phenotype and no detectable mutation in the FSHB gene. The published case differed from our patient in that the published case was azoospermic whereas ours was extremely oligoteratozoospermic. The beneficial effect of FSH treatment was only shown in our patient.

CONCLUSION(S)

The published case and ours may have a common, as yet unidentified, underlying defect. The dramatic and immediate effect of FSH treatment on our patient's fertility was clearly demonstrated.

[Severe postmenopausal hyperandrogenism due to an ovarian lipoid cell tumor: a case report]

The case of a 62-year-old woman with severe post-menopausal hirsutism is described. Her clinical history revealed regular menstrual periods until menopause at the age of 50, hysterectomy for fibromatosis at 58 years, non-insulin dependent diabetes mellitus, hypertension, obesity, severe hirsutism, which had developed in the previous 3 years, with a deeping of the voice. Examination showed android obesity, hypertension and severe hirsutism involving the face and the trunk. Endocrine evaluation pointed out regular adrenal function, serum total and free-testosterone in the adult male range, with normal androstenedione, DHEAS and 17OHP levels. Estradiol was slightly increased and LH and FSH were inappropriately low for her post-menopausal age. Computed tomography of the abdomen showed regular adrenal glands, and a radio-labeled cholesterol scan was negative. A further pelvic transvaginal ultrasonography revealed a small cystic formation near the right ovary and a slight increase in the size of the left ovary. The patient underwent bilateral ovariectomy. Histological examination showed a lipoid cell tumor within the left ovary. Immunohistochemical studies were positive for inhibin and cytokeratin. After surgery, serum testosterone fell to normal levels, gonadotropins increased to menopausal levels, confirming that the tumor was able to produce both LH, and FSH-inhibiting factors, and hirsutism greatly improved. Periodic hormonal tests remained normal and CT of the abdomen and pelvic ultrasonography did not show alterations at a 3 years follow-up.

Lutropin alfa: new preparation. Combined with follitropin for follicular development: no better than menotropin

(1) The reference ovarian stimulant for women with severe FSH and LH deficiency and pituitary dysfunction is menotropin (postmenopausal urinary human gonadotrophin (hMG)). (2) A recombinant LH, lutropin alfa, has now been licensed for this use, in combination with recombinant FSH (follitropin alfa or follitropin beta). The evaluation file contains no data from trials comparing the follitropin-lutropin alfa combination with menotropin. (3) Two dose-finding studies involving a total of 78 women, and a double-blind trial comparing follitropin + placebo with follitropin + lutropin alfa, have shown that 75 IU/day lutropin alfa yields satisfactory follicular development in two-thirds of women whose plasma LH concentration is below 1.2 IU/I. Efficacy has not been demonstrated in women with higher plasma concentrations of LH. Similar results have been reported with menotropin. (4) The adverse effect profile of the follitropin + lutropin alfa combination is similar to that of menotropin. The main risk is an ovarian hyperstimulation syndrome. Monitoring of plasma estradiol concentrations, pelvic ultrasound findings, and clinical state are required to avoid severe ovarian hyperstimulation. There is no evidence that the risk differs between menotropin and the follitropin + lutropin alfa combination at adjusted doses. (5) In France, the combination of follitropin alfa + lutropin alfa costs about five times more than menotropin. (6) Menotropin remains the first line ovarian stimulant for women with severe deficiency of FSH and LH.

Characterization of normal spermiation and spermiation failure induced by hormone suppression in adult rats

At the end of spermatogenesis, elongated spermatids are released from supporting Sertoli cells via the process termed spermiation. Previous studies have shown that spermiation failure occurs after hormone suppression, in which spermatids are retained instead of releasing. However, the molecular mechanisms involved in spermiation and spermiation failure are largely unknown. The aims of the present study were, first, to characterize the ultrastructural events associated with normal spermiation and spermiation failure using light and electron microscopy and, second, to investigate the localization of cell adhesion-associated (beta1-integrin and cadherins) and junction-associated molecules (integrin-associated kinase [ILK], beta-catenin, and espin) during these processes. Four adult Sprague-Dawley rats received testosterone and estradiol implants and FSH antibody (2 mg kg-1 day-1) for 7 days to suppress testicular testosterone and FSH and to induce spermiation failure. Four rats treated with saline were used as controls. After testosterone and FSH suppression, spermiation at the ultrastructural level appeared to be normal until the final disengagement of the spermatids from Sertoli cells (stage VIII), at which stage a large number of retained spermatids were noted. Immunohistochemical localization of espin showed that during spermiation, removal of the ectoplasmic specialization (ES) occurred 30 h before spermatid disengagement, suggesting that non-ES junctions mediate the spermatid-Sertoli cell interaction before and during disengagement. beta1-Integrin and beta-catenin remained associated with spermatids after ES removal and until disengagement; however, ILK was removed along with the ES. Though detectable, N-cadherin was not associated with the spermatid-Sertoli cell junction. After testosterone and FSH suppression, beta1-integrin, but not N-cadherin or beta-catenin, remained associated with spermatids that failed to spermiate. In conclusion, hormone suppression-induced spermiation failure is caused by defects in the disengagement of spermatids from the Sertoli cell, and this process likely is mediated by beta1-integrin in an ILK-independent mechanism.

Pseudo-isolated FSH deficiency caused by an inhibin B-secreting granulosa cell tumour: case report

Isolated FSH deficiency due to a mutation in the FSHbeta subunit is characterized by an extremely low serum FSH concentration. We report a patient who presented with an FSH of 0.8 mIU/ml and infertility associated with anovulation. Endocrinological assessment and immunohistochemistry revealed that a granulosa cell tumour was secreting inhibin B and suppressing FSH; however, LH and estradiol were within their normal ranges. Upon removal of the tumour, inhibin B decreased and FSH levels rose to normal values. The patient subsequently conceived and delivered successfully. Based on this case and on those previously described in the literature, we suggest that inhibin B levels should be evaluated in anovulatory patients having a clinical presentation consistent with functional hypothalamic amenorrhoea and very low to normal values of FSH.

Analysis of the Cys82Arg mutation in follicle-stimulating hormone beta (FSHbeta) using a novel FSH expression vector

OBJECTIVE

To determine the effect of the Cys82Arg FSHbeta mutation from a patient with isolated FSH deficiency upon follicle-stimulating hormone (FSH) levels in vitro.

DESIGN

In vitro analysis of the Cys82Arg mutation and comparison with the phenotype.

SETTING

Tertiary medical center setting.

PATIENT(S)

DNA sequence of the FSHbeta gene and clinical description from a patient with isolated FSH deficiency.

INTERVENTION(S)

Construction of a new vector containing the cDNAs for the alpha-subunit and beta-subunit of FSH (palphaFSHbeta) followed by mutagenesis and transfection into Chinese hamster ovary cells.

MAIN OUTCOME MEASURE(S)

Immunoreactive and bioactive FSH levels from the CHO cellular media.

RESULT(S)

Although expression of both subunits was present, both immunoreactive and bioactive FSH levels were unmeasurable from cellular media containing the mutation versus wild type.

CONCLUSION(S)

The Cys82Arg mutation in a male with normal puberty and azoospermia results in profound deficiency of FSH in vitro, thereby confirming the molecular basis of hypogonadism in this patient and documenting the importance of the Cys residue at position 82 of the FSHbeta subunit.

Isolated follicle-stimulating hormone (FSH) deficiency in a young man with normal virilization who did not have mutations in the FSHbeta gene

OBJECTIVE

To determine the cause of isolated FSH deficiency in a young infertile man.

DESIGN

Case report.

SETTING

Clinical and genetic studies in an academic research environment.

PATIENT(S)

A 19-year-old man with normal virilization, azoospermia, and isolated FSH deficiency.

INTERVENTION(S)

Pituitary and gonadal functions were evaluated at baseline and after repeated GnRH stimulation. FSH was tested with both immunological and biological methods. The FSHbeta gene was sequenced in the patient and in a series of 50 controls.

MAIN OUTCOME MEASURE(S)

Clinical, endocrine, and genetic characterization of an infertile patient with isolated FSH deficiency.

RESULT(S)

LH and T secretions were normal. No interference in FSH measurement was detected, and serum FSH concentrations were very low and completely unresponsive to repeated GnRH stimulation. No circulating FSH-like bioactivity was detected by means of rat Sertoli cell bioassay. Other pituitary functions were unaffected, and no lesions were seen at pituitary nuclear magnetic resonance (NMR). Inhibin B and activin levels were normal, but a progressive decrease of activin concentrations was seen during GnRH stimulation. The coding sequence of the FSHbeta gene was normal, but the patient was homozygous for a novel G/T substitution in the promoter region within a P response element. This substitution was present in heterozygosity in eight out of 50 controls and in homozygosity in one man with normal FSH levels.

CONCLUSION(S)

We report an infertile male with isolated FSH deficiency but no evidence of mutations in the FSHbeta gene. The G/T substitution in the FSHbeta promoter represents a novel silent polymorphism, indicating that other defects in factors involved in FSH-specific expression should be taken into account.

FSH and TGF-beta superfamily members regulate granulosa cell connective tissue growth factor gene expression in vitro and in vivo

Connective tissue growth factor (CTGF) is a heparin-binding growth factor implicated in diverse epithelial cell types as a paracrine regulator of mitosis, angiogenesis, cellular taxis, and remodeling of the extracellular matrix. To understand the possible roles of CTGF in the ovarian paracrine system, we studied CTGF gene expression by granulosa cells in relation to their stage of cellular differentiation using both in vitro and in vivo methodologies. Untreated monolayer granulosa cell cultures from immature rats abundantly expressed the approximately 2.5-kb CTGF mRNA transcript (determined by Northern analysis), but had low levels of aromatase activity (an index of granulosa cell differentiation). Treatment for 48 h with FSH (0.1-10 ng/ml) dose-dependently inhibited (>or=50%) CTGF mRNA expression, but enhanced aromatase enzyme activity. This in vitro observation of CTGF mRNA down-regulation coinciding with FSH-induced granulosa cell maturation is substantiated by studies of in vivo ovarian CTGF expression in FSHbeta knockout mice. Northern blot and in situ hybridization analyses demonstrate high levels of CTGF expression in the granulosa cells of preantral follicles blocked from further development by the absence of FSH. The action of FSH (10 ng/ml) was mimicked in vitro by 8-bromo-cAMP (1.0 mM) and was augmented by the additional presence of androgen (1 micro M 5alpha-dihydrotestosterone), consistent with mediation by intracellular cAMP. Conversely, treatment of granulosa cell cultures with TGFbeta1 (0.1-10 ng/ml) dose-dependently increased CTGF mRNA levels up to 12-fold at a dose of 10 ng/ml, without affecting aromatase activity. Cotreatment with FSH (0.1-10 ng/ml) dose-dependently suppressed the stimulatory action of TGFbeta1 (10 ng/ml) on CTGF mRNA, but substantially enhanced aromatase activity beyond levels induced by FSH alone. Importantly, other TGFbeta superfamily members known to be produced in the ovary (growth/differentiation factor-9 and activin A; 10 ng/ml) stimulated granulosa cell CTGF mRNA in a similar fashion as TGFbeta1 (10 ng/ml), and this was also inhibited by FSH (10 ng/ml). These data show that granulosa cell CTGF gene expression is inversely related to the stage of granulosa cell differentiation, being directly inhibited by FSH via cAMP-mediated signaling. CTGF mRNA abundance in nondifferentiated granulosa cells is up-regulated in vitro by TGFbeta1, growth/differentiation factor-9, and activin, suggesting paracrine roles for these growth/differentiation factors in the regulation of CTGF synthesis in mammalian ovaries.

Use of GnRH agonist and human chorionic gonadotrophin tests for differentiating constitutional delayed puberty from gonadotrophin deficiency in boys

OBJECTIVES

The differentiation of constitutional delayed puberty (CDP) from gonadotrophin deficiency (GD) in boys at referral poses a difficult challenge. The effectiveness of the GnRH agonist (GnRH-a) test in distinguishing between the two conditions was evaluated and compared with findings of the GnRH and hCG stimulation tests. PATIENTS, METHODS AND DESIGN: The study sample included 32 prepubertal boys aged 14 years or older. Thirteen entered spontaneous puberty within 1 year of referral (group A) and 19 remained prepubertal (group B). All underwent the GnRH test (Relefact, Hoechst AG, 0.1 mg/m2 i.v. in one bolus), GnRH-a test (Decapeptyl, Ferring GmbH, 0.1 mg/m2 s.c.) and hCG stimulation (Chorigon, Teva, 1500 units i.m. on three alternate days) at 1-week intervals. All tests were performed at referral at 0800 h. Blood samples were collected before testing and at 30 and 60 min (GnRH test) or 4 h (GnRH-a) for LH and FSH determination, and before testing and at 4 h (GnRH-a) or on the seventh day (hCG) after stimulation for serum testosterone measurement.

RESULTS

The LH response to GnRH-a and the testosterone response to hCG stimulation were significantly higher in group A (LH, mean +/- SD 20.4 +/- 7.5 mIU/ml, range 10.8-32.6; testosterone, mean +/- SD 18.0 +/- 5.9 nmol/l, range 9.4-26, P < 0.0001) than in group B (LH, mean +/- SD 2.3 +/- 2.0 mIU/ml, range 0.7-6.9; testosterone, mean +/- SD 1.0 +/- 0.7 nmol/l, range 0.7-3.2), with no overlap between the groups. The cut-off for the LH response to GnRH-a was 8.0 mIU/ml, and for the testosterone response to hCG, 8 nmol/l. There were also significant differences between the groups in mean basal serum LH and FSH (LH, 1.1 +/- 0.5 vs. 0.6 +/- 0.2 mIU/ml, P < 0.05; FSH, 2.2 +/- 2.0 vs. 0.4 +/- 0.3 mIU/ml, P < 0.02) and their response to GnRH (LH, 11.4 +/- 4.4 vs. 2.7 +/- 1.1 mIU/ml, P < 0.0001; FSH, 5.1 +/- 3.4 vs. 2.5 +/- 2.4 mIU/ml, P < 0.0001), and mean serum testosterone level at 4 h after GnRH-a administration (1.9 +/- 1.0 vs. 0.9 +/- 0.4 nmol/l, P = 0.002), but all showed a great overlap in range. Mean age, testicular volume and basal serum testosterone levels were similar in the two groups at referral. One year later, the testicular volume of group A (5.0-12.0 ml) was significantly larger than that of group B (1.0-3.0 ml, P < 0.0001), which remained unchanged on re-examination 3.0 +/- 0.5 years later.

CONCLUSIONS

The GnRH-agonist test and the repeated-injection hCG test are reliable diagnostic tools for differentiating CDP from GD in boys.

The role of LH and FSH in ovarian androgen secretion and ovarian follicular development: clinical studies in a patient with isolated FSH deficiency and multicystic ovaries

Inactivating mutations have proven to be instructive in elucidating the role of FSH in human ovarian function. We performed a detailed reproductive endocrine evaluation of a patient with inactivating mutations in the FSH beta-subunit gene who was hypo-estrogenic and had LH excess. The patient underwent a pelvic ultrasound and overnight frequent blood sampling followed by a human chorionic gonadotrophin (HCG) stimulation test. One month later she received human recombinant FSH, followed 24 h later by a second HCG stimulation test. Despite a mean LH serum concentration and LH pulse characteristics typical for polycystic ovaries (PCOS), baseline and dexamethasone-suppressed free testosterone were low-normal. The administration of HCG led to minimal stimulation of 17-hydroxyprogesterone and androgens. The patient had multicystic ovaries containing follicles 3-5 mm in diameter and responded to FSH with prompt increases in estradiol and inhibin B. There were no clinical or laboratory consequences of LH excess in this FSH-deficient woman. These findings support the hypothesis that excessive LH stimulation alone does not cause ovarian hyperandrogenism. We also found that follicular development was present in the absence of FSH. These antral follicles had apparently developed normally, since estradiol and inhibin B increased promptly after FSH administration.

Prevalence and incidence of hypopituitarism in an adult Caucasian population in northwestern Spain

OBJECTIVE

To determine the prevalence and incidence of hypopituitarism in the general population.

POPULATION

The study population comprised an average population sample of 146,000 adult inhabitants in South Galicia (northwestern Spain). The Medical Register of the General Hospital of Vigo ensured virtually complete case ascertainment for diagnosed hypopituitarism in this sample population. Only patients residing in the study area were included. The diagnosis of hypopituitarism was based on baseline and hormonal dynamic tests.

DESIGN

The study comprised two cross-sectional surveys, the first from January to December 1992 and the second from January to December 1999, together with a longitudinal survey performed between January 1993 and December 1999.

MAIN RESULTS

In the first survey the prevalence of hypopituitarism was 29/100,000 (CI, 19.88-37.72), without sex differences. In the second survey, the prevalence observed was higher than in the first, 45.5/100,000 (CI, 34.92-56.08). In the second survey, which included almost all cases registered in the first study, the cause of hypopituitarism was a pituitary tumour in 61%, a non-pituitary tumour in 9% and a non-tumour cause in 30%. Around 50% of patients had 3-5 pituitary hormonal deficiencies, with LH/FSH being the most prevalent. Patients with tumour-induced hypopituitarism showed a tendency to suffer GH deficiency more frequently than those due to non-tumour causes. In the longitudinal study with a population of 1,020,764 people-years of observation, the average annual incidence rate of hypopituitarism was 4.21 cases/100,000 (CI, 2.95-5.47), with this incidence being similar for both sexes. The annual incidence of hypopituitarism remained stable during the study period.

CONCLUSION

We present for the first time data on the prevalence and incidence of hypopituitarism in the general adult population. These patients showed a tendency to suffer LH/FSH deficiency as the most prevalent hormone deficit. Furthermore, patients with hypopituitarism due to a tumour or its treatment showed a greater tendency to suffer GH deficiency than those with a non-tumour cause. These data may be useful for producing a rational programme for patients suffering from this condition and also for comparison with future data in our country and elsewhere in the world.

The role of follicle-stimulating hormone in spermatogenesis: lessons from knockout animal models

The development of knockout mouse models for the FSH-beta subunit, the FSH receptor, and LH-receptor performed in different laboratories has confirmed and extended our knowledge concerning the critical role of these hormone-signaling systems in spermatogenesis. In this article, we summarize the phenotypic changes observed in male FSH receptor knockout (FORKO) mice. Young FORKO males have underdeveloped testis with 50% reduction in Sertoli cells, suggesting that FSH-R signaling is required very early for gonadal development, maturity, and function. These mice experience delayed puberty with postponement in the formation of round spermatids. Adult males show reduction in serum testosterone levels despite normal circulating LH concentration, indicating disturbances in Sertoli-Leydig cell communication. As a consequence of reduced sperm production and sperm quality, adult FORKO males have reduced fertility. Aberrant sperm from FORKO males have retention of cytoplasmic droplets and inadequate DNA compaction, hallmarks of infertility in many species including man. Interestingly, these changes are also experimentally inducible in FSH- and/or FSH-R-immunized male bonnet monkeys, creating a state of infertility. Reports of human mutations in FSH-beta and the FSH receptor also indicate that spermatogenesis is dependent on this system. Further investigations in FORKO males should be helpful in uncovering the downstream genes involved in sustaining Sertoli cell function and maintenance of the quantitative and qualitative aspects of spermatogenesis. This might pave the way for treatment of male infertility and contraception.

Analysis of ovarian gene expression in follicle-stimulating hormone beta knockout mice

FSH is a heterodimeric glycoprotein hormone that is produced in the gonadotroph cells of the anterior pituitary. It acts on Sertoli cells of the testis and granulosa cells of the ovary. We previously demonstrated that FSHbeta knockout female mice are infertile due to a block in folliculogenesis preceding antral stage development. To investigate aberrations of ovarian gene regulation in the absence of FSH, we analyzed the expression of several important marker genes using Northern blot and in situ hybridization techniques. Key findings are as follows: 1) Follicles of FSHbeta knockout mice develop a well organized thecal layer, which is positive for P450 17alpha-hydroxylase and LH receptor messenger RNAs (mRNAs). This indicates that theca recruitment is completed autonomously with respect to FSH. 2) Granulosa cells in FSH-deficient mice demonstrate an increase in FSH receptor mRNA, and decreases in P450 aromatase, serum/glucocorticoid-induced kinase, and inhibin/activin subunit mRNAs. These data support studies that implicate FSH signaling cascades in the expression of these genes. 3) In contrast to the thecal layer, granulosa cell populations in FSHbeta knockout mice do not accumulate LH receptor mRNA. This suggests that although the granulosa cells have a block in proliferation at the antral follicle stage in the absence of FSH, they do not initiate programs of terminal differentiation as seen in luteinizing cells of wild-type ovaries. 4) Ovaries of FSH-deficient mice demonstrate a modest decrease in cyclin D2 mRNA, without up-regulation of cell cycle inhibitor mRNAs associated with luteinization (i.e. p15, p27, and p21). Although components of the FSH null phenotype may be caused by partial cyclin D2 loss of function, these findings indicate that the mechanisms of granulosa cell cycle arrest in FSHbeta knockout mice are distinct from those of cycle withdrawal at luteinization. Underscoring the usefulness of the FSH-deficient mouse model, this study clarifies aspects of gonadotropin-dependent folliculogenesis, thecal layer development, cycle control in granulosa cells, and luteinization.

Approaches to define the role of SF-1 at different levels of the hypothalamic-pituitary-steroidogenic organ axis

Targeted gene disruption has produced knockout mice lacking the orphan nuclear receptor steroidogenic factor 1 (SF-1). These SF-1 knockout mice lacked adrenal glands and gonads, resulting in adrenocortical insufficiency and sex reversal of their internal and external genitalia. They also had impaired expression of pituitary gonadotropins and agenesis of the ventromedial hypothalamic nucleus (VMH), confirming roles of SF-1 at multiple levels of the hypothalamic-pituitary-steroidogenic tissue axis. Using the Cre-loxP system, we now have generated mice in which SF-1 is inactivated selectively in the anterior pituitary. These pituitary-specific SF-1 knockout mice were sterile and failed to exhibit sexual maturation. Histologically, their gonads were markedly hypoplastic, weighing only approximately 5% of the gonads of wild-type mice. Consistent with an important role of SF-1 in gonadotropes, there were no cells in the pituitary gland that expressed either follicle-stimulating hormone (FSH) or luteinizing hormone (LH). These pituitary-specific SF-1 knockout mice are a novel genetic model of hypogonadotropic hypogonadism and establish essential roles of SF-1 in gonadotropin expression.

Mutations in the follicle-stimulating hormone-beta (FSH beta) and FSH receptor genes in mice and humans

Follicle-stimulating hormone (FSH), a dimeric glycoprotein synthesized in the anterior pituitary gland, is important for the production of sex steroids and gametes. FSH-beta (FSH beta) and FSH receptor (FSHR) knockout mice display impaired ovarian follicular development and infertility in females and small testes, oligospermia, and fertility in males. Humans with FSH beta gene mutations tend to have a more severe phenotype than those with FSHR gene mutations, although infertility and varying degrees of impaired sex steroid production occur in both types of mutations. Data from human and mouse mutations in the FSH beta and FSHR genes suggest that FSH is necessary for normal pubertal development and fertility in males and females.

Hypopituitarism following traumatic brain injury and aneurysmal subarachnoid hemorrhage: a preliminary report

OBJECT

Recognition of pituitary hormonal insufficiencies after head injury and aneurysmal subarachnoid hemorrhage (SAH) may be important, especially given that hypopituitarism-related neurobehavioral problems are typically alleviated by hormone replacement. In this prospective study the authors sought to determine the rate and risk factors of pituitary dysfunction after head injury and SAH in patients at least 3 months after insult.

METHODS

Patients underwent dynamic anterior and posterior pituitary function testing. Results of the tests were compared with those of 18 age-, sex-, and body mass index-matched healthy volunteers. The 22 head-injured patients included 18 men and four women (mean age 28+/-10 years at the time of injury) with initial Glasgow Coma Scale (GCS) scores of 3 to 15. Eight patients (36.4%) had a subnormal response in at least one hormonal axis. Four were growth hormone (GH) deficient. Five patients (four men, all with normal testosterone levels, and one woman with a low estradiol level) exhibited an inadequate gonadotroph response. One patient had both GH and thyrotroph deficiency and another had both GH deficiency and borderline cortisol deficiency. At the time of injury, all eight patients with pituitary dysfunction had an initial GCS score of 10 or less and, compared with the 14 patients without dysfunction, were more likely to have had diffuse swelling, seen on initial computerized tomography scans (p < 0.05), and to have sustained a hypotensive or hypoxic insult (p = 0.07). Of two patients with SAH who were studied (Hunt and Hess Grade IV) both had GH deficiency.

CONCLUSIONS

From this preliminary study, some degree of hypopituitarism appears to occur in approximately 40% of patients with moderate or severe head injury, with GH and gonadotroph deficiencies being most common. A high degree of injury severity and secondary cerebral insults are likely risk factors for hypopituitarism. Pituitary dysfunction also occurs in patients with poor-grade aneurysms. Postacute pituitary function testing may be warranted in most patients with moderate or severe head injury, particularly those with diffuse brain swelling and those sustaining hypotensive or hypoxic insults. The neurobehavioral effects of GH replacement in patients suffering from head injury or SAH warrant further study.

Mutations of follicle stimulating hormone-beta and its receptor in human and mouse: genotype/phenotype

The pituitary gonadotropin follicle stimulating hormone (FSH) interacts with its membrane-bound receptor, to produce biologic effects. Traditional functions of FSH include, follicular development and estradiol production in females and the regulation of Sertoli cell action and spermatogenesis in males. FSHbeta knock-out mice and transgenic mice, serve as models for FSH deficiency and excess, respectively. In addition, mutations of both FSHbeta and FSHR genes have been characterized in humans, although phenotypic effects of the ligand appear to be more profound than those of its receptor. FSH is essential for normal puberty and fertility in females, particularly ovarian follicular development beyond the antral stage. In males, FSH is necessary for normal spermatogenesis and when FSH function is completely absent, infertility occurs. With partial FSH deficiency in males, spermatogenesis is affected, but fertility may still be possible. FSH may also be necessary for normal androgen synthesis in males and females.