Hypopituitarism.

Hypopituitarism refers to deficiency of one or more hormones produced by the anterior pituitary or released from the posterior pituitary. Hypopituitarism is associated with excess mortality, a key risk factor being cortisol deficiency due to adrenocorticotropic hormone (ACTH) deficiency. Onset can be acute or insidious, and the most common cause in adulthood is a pituitary adenoma, or treatment with pituitary surgery or radiotherapy. Hypopituitarism is diagnosed based on baseline blood sampling for thyroid stimulating hormone, gonadotropin, and prolactin deficiencies, whereas for ACTH, growth hormone, and antidiuretic hormone deficiency dynamic stimulation tests are usually needed. Repeated pituitary function assessment at regular intervals is needed for diagnosis of the predictable but slowly evolving forms of hypopituitarism. Replacement treatment exists in the form of thyroxine, hydrocortisone, sex steroids, growth hormone, and desmopressin. If onset is acute, cortisol deficiency should be replaced first. Modifications in replacement treatment are needed during the transition from paediatric to adult endocrine care, and during pregnancy.

IGF-I levels reflect hypopituitarism severity in adults with pituitary dysfunction.

PURPOSE: To evaluate the utility of Insulin-like growth factor I (IGF-I) standard deviation score (SDS) as a surrogate marker of severity of hypopituitarism in adults with pituitary pathology. METHODS: We performed a retrospective data analysis, including 269 consecutive patients with pituitary disease attending a tertiary endocrine clinic in 1990-2015. The medical files were reviewed for the complete pituitary hormone profile, including IGF-I, and clinical data. Age-adjusted assay reference ranges of IGF-I were used to calculate IGF-I SDS for each patient. The main outcome measures were positive and negative predictive values of low and high IGF-I SDS, respectively, for the various pituitary hormone deficiencies. RESULTS: IGF-I SDS correlated negatively with the number of altered pituitary axes (p < 0.001). Gonadotropin was affected in 76.6 % of cases, followed by thyrotropin (58.4 %), corticotropin (49.1 %), and prolactin (22.7 %). Positive and negative predictive values yielded a clear trend for the probability of low/high IGF-I SDS for all affected pituitary axes. Rates of diabetes insipidus correlated with IGF-I SDS values both for the full study population, and specifically for patients with non-functioning pituitary adenomas. CONCLUSIONS: IGF-I SDS can be used to evaluate the somatotroph function, as a valid substitute to absolute IGF-I levels. Moreover, IGF-I SDS predicted the extent of hypopituitarism in adults with pituitary disease, and thus can serve as a marker of hypopituitarism severity.

Mutation spectrum and phenotypic variation in nine patients with SOX2 abnormalities.

Multiple mutations in SOX2 have been identified in patients with ocular anomalies and/or pituitary dysfunction. Here, we identified SOX2 abnormalities in nine patients. The molecular defects included one missense, one nonsense and four frameshift mutations, and three submicroscopic deletions involving SOX2. Three of the six mutations and all deletions were hitherto unreported. The breakpoints determined in one deletion were located within Alu repeats and accompanied by an overlap of 11 bp. Three of the six mutations encoded SOX2 proteins that lacked in vitro transactivation activity for the HESX1 promoter, whereas the remaining three generated proteins with ∼15-∼20% of transactivation activity. All cases manifested ocular anomalies of various severities, together with several complications including arachnoid cyst and hamartoma. There was no apparent correlation between the residual activity and clinical severity. The results indicate that molecular defects in SOX2 are highly variable and include Alu repeat-mediated genomic rearrangements. Our data provide further evidence for wide phenotypic variation of SOX2 abnormalities and the lack of genotype-phenotype correlation in patients carrying SOX2 lesions.

Idiopathic hypogonadotropic hypogonadism in selective human gonadotropin deficiency in adult man: a case report.

We report a rare case of idiopathic hypogonadotropic hypogonadism in an adult male (31-year-old), who underwent an endocrinological examination because of erectile dysfunction and suspected infertility. Laboratory data showed isolated gonadotropin deficiency. Magnetic resonance imaging (MRI) of the hypothalamic-pituitary unit showed no tumoral expansions. The patient was tested with gonadotropin releasing hormone (Gn-RH) (100 microg as an i.v. bolus injection). No significant LH and FSH responses were observed. Idiopathic hypogonadotropic hypogonadism is usually caused by hypothalamic lesions, however, since Gn-RH was unable to stimulate LH and FSH secretions, we supposed that our patient was affected by defective gonadotropin secretion at pituitary level.

Acute and long-term pituitary insufficiency in traumatic brain injury: a prospective single-centre study.

OBJECTIVE: To assess the prevalence of hypopituitarism following traumatic brain injury (TBI), describe the time-course and assess the association with trauma-related parameters and early post-traumatic hormone alterations. DESIGN: A 12-month prospective study. PATIENTS: Forty-six consecutive patients with TBI (mild: N = 22; moderate: N = 9; severe: N = 15). MEASUREMENTS: Baseline and stimulated hormone concentrations were assessed in the early phase (0-12 days post-traumatically), and at 3, 6 and 12 months postinjury. Pituitary tests included the Synacthen-test (acute +6 months) and the insulin tolerance test (ITT) or the GHRH + arginine test if the ITT was contraindicated (3 + 12 months). Insufficiencies were confirmed by retesting. RESULTS: Early post-traumatic hormone alterations mimicking central hypogonadism or hypothyroidism were present in 35 of the 46 (76%) patients. Three months post-traumatically, 6 of the 46 patients failed anterior pituitary testing. At 12 months, one patient had recovered, whereas none developed new insufficiencies. All insufficient patients had GH deficiency (5 out of 46), followed by ACTH- (3 out of 46), TSH- (1 out of 46), LH/FSH- (1 out of 46) and ADH deficiency (1 out of 46). Hypopituitary patients had more frequently been exposed to severe TBI (4 out of 15) than to mild or moderate TBI (1 out of 31) (P = 0.02). Early endocrine alterations including lowered thyroid and gonadal hormones, and increased total cortisol, free cortisol and copeptin were positively associated to TBI severity (P < 0.05), but not to long-term development of hypopituitarism (P > 0.1), although it was indicative in some. CONCLUSION: Long-term hypopituitarism was frequent only in severe TBI. During the 3-12 months follow-up, recovery but no new insufficiencies were recorded, indicating manifest hypothalamic or pituitary damage already a few months postinjury. Very early hormone alterations were not associated to long-term post-traumatic hypopituitarism. Clinicians should, nonetheless, be aware of potential ACTH deficiency in the early post-traumatic period.

Antipituitary antibodies against gonadotropin-secreting cells in adult male patients with apparently idiopathic hypogonadotropic hypogonadism.

CONTEXT: Hypogonadotropic hypogonadism (HH) can occur at any stage of life as an isolated congenital or acquired abnormality or within a more generalized pituitary or hypothalamic impairment. However, the defect in patients with idiopathic HH is still unknown. OBJECTIVE: The aim of this study was to investigate the prevalence of antipituitary antibodies (APA) in a group of HH patients with or without Kallmann's syndrome and to characterize their pituitary target. DESIGN: We conducted a cross-sectional cohort study. SETTING: The study was performed at the Endocrinology Unit of the Second University of Naples. PATIENTS: Twenty-one HH patients with normal sense of smell (group 1), 10 patients with Kallmann's syndrome (group 2), 13 patients with HH associated with other pituitary hormone deficiencies (group 3), and 50 normal controls were studied. MAIN OUTCOME MEASURES: APA were evaluated in patients and in controls by indirect immunofluorescence. Moreover, a magnetic resonance imaging (MRI) of the hypothalamic-pituitary region was performed in all three groups of patients. RESULTS: APA were detected at high titer in eight out of 21 patients in group 1 (38%) and in five of 13 in group 3 (38.4%), and at low titers in two out of 10 in group 2 (20%) and in three of 50 controls (6%). In patients of group 1, APA immunostained selectively gonadotropin-secreting cells, whereas in those of group 3, they immunostained other pituitary hormone-secreting cells also. None of patients in group 1 showed alterations on MRI, whereas all patients in group 2 showed aplasia/hypoplasia of the olfactory bulbs/tracts and/or of olfactory sulci. Among the five APA-positive patients in group 3, three had normal MRI, one had findings of empty sella, and one had findings of autoimmune hypophysitis. CONCLUSIONS: Our results suggest that some apparently idiopathic cases of HH, both isolated and associated with other pituitary impairment, can be caused by an early autoimmune process involving the gonadotrophs at pituitary level. Future longitudinal studies are needed to clarify the natural history of this process and the possible effect of early corticosteroid therapy.

Long-term follow-up of combined pituitary hormone deficiency in two siblings with a Prophet of Pit-1 gene mutation.

Combined pituitary hormone deficiency (CPHD) is a rare disorder resulting from an impaired pituitary function due to different causes, characterized by impaired secretion of growth hormone (GH) and one or more of the other anterior pituitary hormones. To date, 16 distinct human Prophet of Pit-1 (Prop1) gene mutations have been identified in patients with CPHD, inducing a phenotype involving GH, follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin and thyroid-stimulating hormone (TSH), and rarely adrenocorticotropic hormone, deficiency. Herein we present two siblings of different sexes from a family with parental consanguinity presenting the 301-302delAG mutation in the Prop1 gene. The female presented failure of growth from the age of 6 years and was treated for 10 years with GH, ending in a final height (standard deviation score) of -0.28. TSH deficiency was manifested after the initiation of GH and was treated with thyroxine while puberty was initiated with conjugated estrogens. The male presented TSH deficiency since childhood, treated with thyroxine, and growth failure at the age of 14 years, treated for a period of 2 years with GH. Puberty was initiated with increasing doses of testosterone, while human chorionic gonadotropin was added in order to achieve increased testicular volume. In conclusion, these two siblings of different sexes with CPHD carrying the 301-302delAG mutation in the Prop1 gene presented a variable phenotype characterized by GH, TSH, LH and FSH deficiency.

High risk of hypopituitarism after traumatic brain injury: a prospective investigation of anterior pituitary function in the acute phase and 12 months after trauma.

CONTEXT: Recent data have demonstrated that traumatic brain injury (TBI)-mediated hypopituitarism could be more frequent than previously known. However, most previous data were obtained from retrospective studies. OBJECTIVES: The aim of this study was to determine 1) the prevalence of anterior pituitary hormone deficiencies in the acute phase of TBI and after 12 months, 2) whether severity of trauma correlated with basal hormone levels, and 3) whether initial hormone deficiencies predicted medium-term hormonal status. DESIGN AND PATIENTS: Fifty-two TBI patients (43 men and nine women) were included in the prospective study. Pituitary function was evaluated within 24 h of admission and after 1 yr. RESULTS: Some 5.8% of the patients had TSH deficiency, 41.6% had gonadotropin deficiency, 9.8% had ACTH deficiency, and 20.4% had GH deficiency (GHD). Twelve months after TBI, 5.8% had TSH deficiency, 7.7% had gonadotropin deficiency, 19.2% had ACTH deficiency, and 37.7% had GHD. Twenty-six patients (50.9%) had at least one anterior pituitary hormone deficiency, 21 patients (41.2%) had isolated hormone deficiencies, and five patients (9.7%) had combined hormone deficiencies. Overall, the pituitary hormone deficiencies recovered in 30 (57.7%) patients after 1 yr, and new pituitary hormone deficiencies were present in 27 (51.9%) patients after 1 yr. CONCLUSIONS: GHD is the most common pituitary deficit 12 months after TBI, and 50.9% of the patients had at least one anterior pituitary hormone deficiency. Pituitary function may improve or worsen in a considerable number of patients over 12 months.

Long-term evolution of endocrine disorders and effect of GH therapy in 35 patients with pituitary stalk interruption syndrome.

We report long-term evolution of endocrine functions and the results of GH treatment in 35 patients (26 male and 9 female) with pituitary stalk interruption. At diagnosis, mean chronological age was 4.8 +/- 2.7 years, mean SDS for height -3.1 +/- 0.8 with a bone age retardation of 2.3 +/- 1.3 years and a mean SDS for growth velocity of -0.5 +/- 1.1; 80% presented complete GH deficiency (GHD) and 20% partial GHD; thyroid deficiency was present in 47.1% of children with complete GHD but absent in all partial GHD. Diagnosis was made during the first months of life in only 2 patients while 23% presented with severe neonatal distress; neonatal signs were only observed in the group with pituitary height below 2 mm (45.7% of patients). GHD was isolated in 40.6% of patients below 10 years while multiple hormone deficiencies was consistent at completion of growth in all patients. Height gain was significantly higher in patients who started GH treatment before 4 years (p = 0.002). GH treatment is very effective: in 13 patients, final height was -0.4 +/- 1.0, total height gain 3.2 +/- 1.2 and distance to target height -0.3 +/- 1.6 SDS.

Prevalence of hypopituitarism and growth hormone deficiency in adults long-term after severe traumatic brain injury.

OBJECTIVE: Traumatic brain injury (TBI) has been associated with hypopituitarism and GH deficiency. However, TBI-mediated hypopituitarism may be more frequent than previously thought. The present work, performed in patients with severe TBI at least 1 year before, had three aims: (i) to evaluate the prevalence of hypopituitarism, (ii) in particular to evaluate the prevalence of GH deficiency, and (iii) to compare three different tests of GH reserve in this cohort. DESIGN AND PATIENTS: From a nonselected group of 249 patients admitted to our Clinical Centre for severe TBI over the last 5 years, 200 of them answered a custom made questionnaire of symptoms of hypopituitarism enclosed in the invitation letter to participate in the study. A total of 170 (99 men and 14 women), accepted to participate in the study (study cohort); 57 had normal questionnaires and were not further studied, 14 discontinued the study, and 99 attended the hospital for dynamic tests of pituitary hormone deficiencies. From these, 44 subjects with IGF-I in the lower range were tested with GHRH+GHRP-6; ITT; and glucagon tests of GH reserve, on three different occasions. MEASUREMENTS: Pituitary hormones plus IGF-I and target gland hormones were analysed. RESULTS: With regard to the initial cohort of 170 subjects (100%), three (1.7%) showed diabetes insipidus; 10 (5.8%) TSH deficiency, 11 (6.4%) ACTH deficiency and 29 (17%) gonadotrophin deficiency. In 10 subjects (5.8%), GH deficiency was diagnosed by strict criteria. Finally, 15 (8.8%) showed combined deficit of several hormones. CONCLUSION: After severe head trauma, gonadotrophin deficiency was the most common pituitary deficit. GH deficiency showed a prevalence similar to ACTH and TSH deficits, i.e. near 6% of the cohort. Taken together, 24.7% of the subjects studied showed any type of pituitary hormone deficiency.

Nutritional hypogonadotropic hypogonadism presented with decreased ejaculatory volume.

Abstract A 19-year-old male college student presented with decreased ejaculatory volume. Endocrinological examinations demonstrated a hypogonadotropic hypogonadism (HH) caused by a gonadotropin-releasing hormone deficiency from the hypothalamus. Cranial magnetic resonance imaging did not demonstrate any abnormalities. The possible causative factor of this adult-onset HH was excessive weight-loss (-26% in 1 year) due to inadequate food intake and an irregular lifestyle. Semen analyses and serum gonadotropin and testosterone values gradually improved as the patient became accustomed to his new life and regained weight.

A window of opportunity: the diagnosis of gonadotropin deficiency in the male infant.

A common cause of micropenis is congenital hypogonadotropic hypogonadism, whether isolated or associated with multiple pituitary hormone deficiencies. The postnatal surge in FSH, LH, and testosterone in the male infant as a consequence of the continued function of the fetal GnRH pulse generator provides a 6-month window of opportunity to establish the diagnosis of hypogonadotropic hypogonadism and alert the clinician to the possibility of its association with multiple pituitary hormone deficiencies. When ACTH or GH deficiency or both deficiencies are present, hypoglycemia and cortisol deficiency can lead to neonatal and infantile death or increased morbidity. Establishing the diagnosis of hypogonadotropic hypogonadism in infancy preempts the uncertainties and delays in distinguishing constitutional delay in puberty from hypogonadotropic hypogonadism. Accordingly, hormone replacement therapy can be initiated at the normal age of pubertal onset. The ontogenesis of infantile testicular function, including the possible significance of the infantile surge in gonadotropins and testosterone, is reviewed. The molecular basis for certain developmental disorders associated with hypogonadotropic hypogonadism and micropenis is considered and the management and treatment of congenital hypopituitarism discussed.

Adult-onset idiopathic hypogonadotropic hypogonadism due to isolated pituitary gonadotropin deficiency.

A 25-year-old Japanese man with adult-onset idiopathic hypogonadotropic hypogonadism is reported. He had been delivered normally, had normal puberty, and experienced erectile dysfunction at age 24 years. Brain MRI revealed no abnormal findings and endocrinological data supported the diagnosis of isolated gonadotropin deficiency. Although most patients with idiopathic hypogonadotropic hypogonadism have a hypothalamic dysfunction, the lesion in this case may be considered to be in the pituitary since repetitive GnRH loading failed to increase serum LH and FSH.

Hypogonadotropic hypogonadism as a model of post-natal testicular anti-Müllerian hormone secretion in humans.

The pituitary gonadotropins are the main regulators of testicular hormonal secretion in humans. Hypogonadotropic hypogonadism (HH), characterized by the absence of secretion of endogenous gonadotropins is therefore a convenient model to asses the respective effects of luteinizing hormone (LH) (or human chorionic gonadotropin (hCG)), exogenous testosterone (T) and FSH on gonadal function. In order to investigate the hormonal control of AMH secretion in man, serum AMH levels were measured in adult patients with congenital HH (CHH) and with post-pubertal acquired HH (AHH) either untreated, during hCG or T therapy. In untreated CHH patients, serum AMH levels were significantly higher than in normal men and similar to those previously reported in prepubertal boys indicating the absence of pubertal maturation of Sertoli cells. In men with AHH, serum AMH levels were also significantly increased when compared to healthy men, but less than in CHH because a persistent testicular T secretion in these patients with less complete gonadotropin deficiency. The high AMH levels in AHH suggest that the post-pubertal suppression of AMH is a reversible phenomenon. In HH patients, hCG treatment induced an increase of plasma T associated with a dramatic decrease of serum AMH, whereas the similar increase in plasma T levels obtained with exogenous T induced only a partial decrease of serum AMH. This dissociation was related to the higher intratesticular T induced by hCG. Taken together, our results confirms the clinical relevance of previous data obtained in rodent models concerning the hormonal regulation of AMH secretion.

Moebius sequence and hypogonadotrophic hypogonadism.

A distinct form of Moebius sequence is associated with hypogonadotrophic hypogonadism. There have been five such cases to date. We now add a further case with detailed neurologic, endocrine, and autopsy findings and offer a hypothesis drawing parallels with the already established basis of hypogonadotrophic hypogonadism in the X-linked form of Kallman syndrome.

MR imaging and spectroscopy of a tuber cinereum hamartoma in a patient with growth hormone deficiency and hypogonadotropic hypogonadism.

To our knowledge, this is the first report of hypogonadotropic hypogonadism, or growth hormone deficiency, in a patient without non-Pallister-Hall syndrome who had hypothalamic hamartoma diagnosed on the basis of MR imaging and MR spectroscopy findings. On short-TE proton MR spectra, the N-acetylaspartate concentration in the hamartoma was lower than that in the thalamus but similar to that in the amygdala. However, myo-inositol concentration was elevated in the hamartoma compared with that in the amygdala and thalamus. This report stresses the advantages of short-TE spectroscopy and demonstrates that regional variations in spectra should be considered when reference structures are used.