Isolated anterior pituitary dysfunction in adulthood

Endocrinologic Dysfunctions and Neuropsychiatric Sequelae in Pediatric Patients With a History of Central Nervous System Infection (ENDLESS): A Prospective Monocentric Study

INTRODUCTION

Central nervous system (CNS) infections represent some of the most critical pediatric health challenges, characterized by high mortality rates and a notable risk of long-term complications. Despite their significance, standardized guidelines for endocrinological follow-up of CNS infection survivors are lacking, leading to reliance on the expertise of individual centers and clinicians.

MATERIALS AND METHODS

Prospective monocentric observational study conducted at the Fondazione Policlinico Universitario Agostino Gemelli in Rome, Italy. It included patients with a history of CNS infection, admitted to various pediatric departments of the hospital. The participants were selected based on a coded diagnosis of CNS infection and had completed their follow-up at the Pediatric Endocrinology Day Hospital after October 2019.

RESULTS

Eighty participants were included, comprising 53 patients with a prior CNS infection and 27 healthy controls, with a median age of 7.4 years (range 3.6-12.3 years). Endocrinologic alterations were detected in 13 patients, with 8 cases in those who had meningitis, 4 in encephalitis survivors, and 1 in a patient with a cerebral abscess. Patients with a history of CNS infections were shorter compared with healthy controls (P = 0.027). Moreover, those who had meningitis exhibited an increased risk of developing epilepsy (P = 0.01), neurosensory disabilities (P = 0.034) and the need for ventriculoperitoneal shunt insertion (P = 0.006). Patients with bacterial CNS infections were more prone to neurosensory and endocrine dysfunctions compared to those with viral or other infections. Significant differences were observed in hormone levels between previously infected patients and controls, specifically in TSH (P < 0.001), ACTH (P = <0.001), and cortisol (P = 0.019). IGF-1 levels were considerably lower in the infection group, both in absolute terms and when adjusted for sex and age (P < 0.001). The regression analysis suggested that the reduction in IGF-1 was more pronounced the earlier the CNS infection occurred, irrespective of infection type.

CONCLUSIONS

Our study found several endocrinologic imbalances in children who survived CNS infections.

Diagnosis of hypoprolactinemia

Prolactin is a polypeptide hormone composed of 199 amino acids, synthesized by lactotroph cells. Its primary effects are on the mammary gland and gonadal axes, but it also influences different organs and systems, particularly metabolic functions. Current literature has mainly focused on the diagnosis, monitoring, and treatment of hyperprolactinemia. Due to the lack of a well-established effective treatment for hypoprolactinemia, it is not clinically emphasized. Therefore, data on its diagnosis is limited. Hypoprolactinemia has been associated with metabolic dysfunctions such as type 2 diabetes mellitus, fatty liver, dyslipidemia, fertility problems, sexual dysfunction, and increased cardiovascular disease. While often seen as a part of combined hormone deficiencies due to pituitary damage, isolated prolactin deficiency is rare. Hypoprolactinemia can serve as a marker for extensive pituitary gland damage and dysfunction.Low or undetectable serum prolactin levels and the absence of a sufficient prolactin peak in the thyrotropin-releasing hormone (TRH) stimulation test are considered diagnostic for hypoprolactinemia. Gender appears to influence both basal prolactin levels and TRH stimulation test responses. Basal prolactin levels of, at least, 5 ng/mL for males and 7 ng/mL for females can be used as cut-off levels for normal prolactin reserve. Minimum peak prolactin responses of 18 ng/mL for males and 41 ng/mL for females to TRH stimulation can exclude hypoprolactinemia. However, larger population studies across different age groups and sexes are needed to better define normal basal prolactin levels and prolactin responses to the TRH stimulation test.

Could low prolactin levels after radiotherapy predict the onset of hypopituitarism?

Both local and external cranial radiotherapy (RT) can induce neurotoxicity and vascular damage of the hypothalamic-pituitary area, which can promote neuroendocrine alterations. While anterior pituitary insufficiency after RT has been extensively characterized, data on the effect of RT on prolactin (PRL) secretion are limited and heterogeneous, with different patterns of PRL behavior described in the literature. A progressive decline in PRL levels, reflecting a time-dependent, slowly evolving radiation-induced damage to the pituitary lactotroph cells has been reported. To date, the association between hypopituitarism and hypoprolactinemia in patients undergoing RT has not yet been fully investigated. The few available data suggest that lower PRL levels can predict an extent damage of the pituitary tissue and a higher degree of hypothalamic dysfunction. However, most studies on the effect of RT on pituitary function do not properly assess PRL secretion, as PRL deficiency is usually detected as part of hypopituitarism and not systematically investigated as an isolated disorder, which may lead to an underestimation of hypoprolactinemia after RT. In addition, the often-inadequate follow-up over a long period of time may contribute to the non-recognition of PRL deficiency after RT. Considering that hypoprolactinemia is associated with various metabolic complications, there is a need to define appropriate diagnostic and management criteria. Therefore, hypoprolactinemia should enter in the clinical investigation of patients at risk for hypopituitarism, mainly in those patients who underwent RT.

Effect of Cabergoline on weight and glucose metabolism in patients with acromegaly

PURPOSE

Cabergoline (CAB) has shown to have benefic effects on the metabolism in different clinical settings but its metabolic role in acromegaly disease has not been studied yet. Aim of our study was to evaluate the impact of CAB on glucose metabolism and weight in patients with acromegaly.

METHODS

All patients with acromegaly undergoing continuous treatment with CAB for at least 6 months were retrospectively screened. Exclusion criteria were discontinuation of CAB for more than one month, change of antidiabetic or other therapy for acromegaly, concomitant untreated hormonal deficiency, initiation of pregnancy and/or breastfeeding. All patients were evaluated in terms of biochemical disease control, glucose metabolism and weight at baseline (T0) and after the introduction of CAB therapy at 6 (T6) and 12 months (T12).

RESULTS

Twenty-six patients (15 females and 11 males) were evaluated at T0 and T6 and 19 patients (12 females and 7 males) were also evaluated at T12. Insulin-like growth factor I (IGF-I) and prolactin (PRL) levels were significantly lower at T6 and T12 compared to baseline (p < 0.001 for IGF-I, p < 0.05 for PRL) even if no further differences were observed between T12 and T6. Considering the entire cohort, no differences were appreciated regarding the metabolic parameters but a significant reduction in weight and body mass index (BMI) was observed at both T6 (p = 0.009 for weight, p = 0.021 for BMI) and T12 (p = 0.014 for weight, p = 0.017 for BMI) compared to baseline.

CONCLUSION

Our results confirm the efficacy of CAB in providing a significant improvement in the biochemical disease control but do not demonstrate a marked benefit on glucose metabolism of acromegaly patients. In such patients, CAB appears to have a rapid effect on weight and BMI, with significant changes noticeable as early as 6 months and persisting for at least 12 months.

Traumatic brain injury and prolactin

Traumatic brain injury (TBI) is a well-known etiologic factor for pituitary dysfunctions, with a prevalence of 15% during long-term follow-up. The most common hormonal disruption is growth hormone deficiency, followed by central adrenal insufficiency, central hypogonadism, and central hypothyroidism in varying order across studies. The prevalence of serum prolactin disturbances ranged widely from 0 to 85%. Prolactin release is mainly regulated by hypothalamic dopamine inhibition, and mediators such as TRH, serotonin, cytokines, and neurotransmitters have modulatory effects. Many factors, such as hypothalamic and/or pituitary gland injuries, as well as fluctuations in dopaminergic activity and other mediators and stress response, may cause derangements in serum prolactin levels after TBI. Although it is challenging to investigate the direct effects of TBI on serum prolactin levels due to many confounders, basal prolactin measurements and stimulation tests provide insight into the functionality of the hypothalamus and pituitary gland after TBI. Moreover, during the acute phase of TBI, prolactin levels appear to correlate with TBI severity. In contrast, in the chronic phase, hypoprolactinemia may function as an indirect indicator of pituitary dysfunction and reduced pituitary volume. Further investigations are needed to elucidate the pathophysiologic mechanisms underlying the prolactin trend following TBI, its significance, and its associations with other pituitary hormone dysfunctions. In this article, we re-evaluated our patients' TBI data regarding prolactin levels during prospective long-term follow-up, and reviewed the literature regarding the prevalence, pathophysiology, and clinical implications of serum prolactin disturbances during acute and chronic phases following TBI.

Cardiometabolic effects of hypoprolactinemia

The fall of PRL levels below the lower limit of the normal range configures the condition of hypoprolactinemia. Unlike PRL excess, whose clinical features and treatments are well established, hypoprolactinemia has been only recently described as a morbid entity requiring prompt identification and proper therapeutic approach. Particularly, hypoprolactinemia has been reported to be associated with the development of metabolic syndrome and impaired cardiometabolic health, as visceral obesity, insulin-resistance, diabetes mellitus, dyslipidaemia, chronic inflammation, and sexual dysfunction have been found more prevalent in patients with hypoprolactinemia as compared to those with normoprolactinemia. This evidence has been collected mainly in patients on chronic treatment with dopamine agonists for PRL excess due to a PRL-secreting pituitary tumour, and less frequently in those receiving the atypical antipsychotic aripiprazole. Nowadays, hypoprolactinemia appears to represent a novel and unexpected risk factor for cardiovascular diseases, as is the case for hyperprolactinemia. Nevertheless, current knowledge still lacks an accurate biochemical definition of hypoprolactinemia, since no clear PRL threshold has been established to rule in the diagnosis of PRL deficiency enabling early identification of those individual subjects with increased cardiovascular risk directly ascribable to the hormonal imbalance. The current review article focuses on the effects of hypoprolactinemia on the modulation of body weight, gluco-insulinemic and lipid profile, and provides latest knowledge about potential cardiovascular outcomes of hypoprolactinemia.

Utility of copeptin in predicting non-pathological postoperative polyuria in patients affected by acromegaly undergoing pituitary neurosurgery

PURPOSE

Copeptin efficiently predicts post-neurosurgical central diabetes insipidus (CDI) in patients with hypothalamic-pituitary lesions, but its role in characterizing changes in diuresis in individuals with acromegaly undergoing neurosurgery remains unexplored. Our study aimed to assess changes in postoperative fluid balance in acromegaly patients and correlate them with both copeptin and growth hormone (GH) levels.

METHODS

This was a secondary analysis of a prospective study involving 15 acromegaly patients undergoing endoscopic endonasal resection at our University Hospital. Fluid balance was assessed daily, and copeptin and GH levels were evaluated preoperatively (T0), and serially on the morning of the first (T2) and second (T3) postoperative day, with an additional measurement of copeptin one hour post-extubation (T1). Patients with pre-existing or post-neurosurgical CDI were excluded from the analysis.

RESULTS

Most patients (11/15) exhibited a negative fluid balance on the second postoperative day, with 4 developing polyuria. Postoperative GH levels did not differ significantly between polyuric and non-polyuric patients, but GH measured at T2 correlated significantly with negative total balance (r = -0.519, p = 0.048). Copeptin levels at T1 were significantly higher in those who developed polyuria (p = 0.013), and a copeptin value > 39.9 pmol/L at T1 showed excellent ability (Sensitivity 100%, Specificity 90.9%, p < 0.001) in predicting postoperative polyuria. Additionally, polyuric patients exhibited a higher T1 / T3 copeptin ratio (p = 0.013) and a negative fluid balance was associated with the remission of acromegaly at 12 months (p = 0.046).

CONCLUSION

The early assessment of copeptin, in addition to facilitating the rapid identification of individuals at increased risk of developing CDI, could also allow the recognition of subjects with a tendency towards non-pathological polyuria in the postoperative setting, at least in individuals affected by acromegaly.

Isolated Adrenocorticotropic Hormone Deficiency Diagnosed After the Cessation of Glucocorticoid Therapy for Eosinophilic Esophagitis: A Case Report

Isolated adrenocorticotropic hormone deficiency (IAD) is a rare pituitary disorder that can cause adrenal insufficiency. However, due to its nonspecific symptoms, its diagnosis is often difficult and may be delayed. Patients with IAD require lifelong glucocorticoid (GC) replacement therapy. Contrastingly, GC-induced secondary adrenal insufficiency is a reversible condition that arises when patients receiving GC therapy reduce their GC dosage or discontinue therapy. Differentiating between IAD and GC-induced secondary adrenal insufficiency is clinically crucial. We report a unique case that required differentiation between these two conditions. A 71-year-old Japanese woman presented with symptoms of adrenal insufficiency after discontinuation of GC therapy for eosinophilic esophagitis. We conducted detailed interviews and repeated the endocrinological examinations. We concluded that her symptoms were owing to IAD rather than GC-induced secondary adrenal insufficiency. She began a lifelong hydrocortisone replacement therapy. This case suggests that when caring for patients undergoing GC therapy, it is important to consider the possibility of coexisting IAD and arrange endocrinological examinations if signs of adrenal insufficiency arise during the gradual reduction of GC treatment.

Diagnosing and treating the elderly individual with hypopituitarism

Hypopituitarism in the elderly is an underestimated condition mainly due to the non-specific presentation that can be attributed to the effects of aging and the presence of comorbidities. Diagnosis and treatment of hypopituitarism often represent a challenging task and this is even more significant in the elderly. Diagnosis can be insidious due to the physiological changes occurring with aging that complicate the interpretation of hormonal investigations, and the need to avoid some provocative tests that carry higher risks of side effects in this population. Treatment of hypopituitarism has generally the goal to replace the hormonal deficiencies to restore a physiological balance as close as possible to that of healthy individuals but in the elderly this must be balanced with the risks of over-replacement and worsening of comorbidities. Moreover, the benefit of some hormonal replacement therapies in the elderly, including sex hormones and growth hormone, remains controversial.

Morbidities and mortality among hospitalized patients with hypopituitarism: Prevalence, causes and management

Hypopituitarism is a highly heterogeneous multisystem disorder that can have a major impact on long-term morbidity and mortality, but even more so during acute medical conditions requiring hospitalization. Recent studies suggest a significant in-hospital burden with prolonged length of stay, increased rate of intensive care unit (ICU) admission, and initiation of mechanical ventilation - all of which may lead to an increased risk of in-hospital mortality. On the one hand, patients with hypopituitarism are often burdened by metabolic complications, including obesity, hypertension, dyslipidemia, and hyperglycemia, which alone, or in combination, are known to significantly alter relevant physiological mechanisms, including metabolism, innate and adaptive immune responses, coagulation, and wound healing, thereby contributing to adverse in-hospital outcomes. On the other hand, depending on the extent and the number of pituitary hormone deficiencies, early recognition of hormone deficiencies and appropriate management and replacement strategy within a well-organized multidisciplinary team are even stronger determinants of short-term outcomes during acute hospitalization in this vulnerable patient population. This review aims to provide an up-to-date summary of recent advances in pathophysiologic understanding, clinical implications, and recommendations for optimized multidisciplinary management of hospitalized patients with hypopituitarism.

Neuregulin 4 (Nrg4) cooperates with melatonin to regulate the PRL expression via ErbB4/Erk signaling pathway as a potential prolactin (PRL) regulator

Neuregulin-4 (Nrg4) and melatonin play vital roles in endocrine diseases. However, there is little discussion about the function and potential mechanism of Nrg4 and melatonin in prolactin (PRL) regulation. The human normal pituitary data from Gene Expression Profiling Interactive Analysis (GEPIA) database was used to explore the correlation between NRG4 and PRL. The expression and correlation of NRG4 and PRL were determined by Immunofluorescence staining (IF) and human normal pituitary tissue microarray. Western Blot (WB) was used to detect the expression of PRL, p-ErbB2/3/4, ErbB2/3/4, p-Erk1/2, Erk1/2, p-Akt and Akt in PRL-secreting pituitary GH3 and RC-4B/C cells treated by Nrg4, Nrg4-small interfering RNA, Erk1/2 inhibitor FR180204 and melatonin. The expression of NRG4 was significantly positively correlated with that of PRL in the GEPIA database and normal human pituitary tissues. Nrg4 significantly increased the expression and secretion of PRL and p-Erk1/2 expression in GH3 cells and RC-4B/C cells. Inhibition of Nrg4 significantly inhibited PRL expression. The increased levels of p-Erk1/2 and PRL induced by Nrg4 were abolished significantly in response to FR180204 in GH3 and RC-4B/C cells. Additionally, Melatonin promotes the expression of Nrg4, p-ErbB4, p-Erk1/2, and PRL and can further promote the expression of p-Erk1/2 and PRL in combination with Nrg4. Further investigation into the function of Nrg4 and melatonin on PRL expression and secretion may provide new clues to advance the clinical control of prolactinomas and hyperprolactinemia.

Lost Connection: A Case Report of Interrupted Pituitary Stalk Syndrome

Pituitary stalk interruption syndrome is a triad of thin (<1 mm) or complete absence of the pituitary stalk with either an aplastic or ectopic posterior lobe of the pituitary gland and a hypoplastic or absent anterior lobe of the pituitary. Patients present with growth retardation, short height, seizures, intellectual disability, and absence of sexual maturation at the expected time. Here, we presented a case of a 12-year-old male with stunted growth. Upon examination, there was reduced height, more than 3 standard deviations below the average for his chronological age. Laboratory results showed reduced levels of growth hormone and thyrotropin. Dual-energy X-ray absorptiometry revealed osteoporosis, while an X-ray of the wrist for bone age corresponded to seven years. MRI imaging confirmed the classical triad of findings for pituitary stalk interruption syndrome. Consequently, the patient was referred back to the endocrinology clinic for further management.

The Growing Understanding of the Pituitary Implication in the Pathogenesis of Long COVID-19 Syndrome: A Narrative Review

Long COVID-19, also known as post-acute sequelae of SARS-CoV-2 infection, is a condition where individuals who have recovered from the acute phase of COVID-19 continue to experience a range of symptoms for weeks or even months afterward. While it was initially thought to primarily affect the respiratory system, it has become clear that Long COVID-19 can involve various organs and systems, including the endocrine system, which includes the pituitary gland. In the context of Long COVID-19, there is a growing understanding of the potential implications for the pituitary gland. The virus can directly affect the pituitary gland, leading to abnormalities in hormone production and regulation. This can result in symptoms such as fatigue, changes in appetite, and mood disturbances. Long COVID-19, the persistent and often debilitating condition following acute COVID-19 infection, may be explained by deficiencies in ACTH and Growth hormone production from the pituitary gland. Corticotropin insufficiency can result in the dysregulation of the body's stress response and can lead to prolonged feelings of stress, fatigue, and mood disturbances in Long COVID-19 patients. Simultaneously, somatotropin insufficiency can affect growth, muscle function, and energy metabolism, potentially causing symptoms such as muscle weakness, exercise intolerance, and changes in body composition. Recently, some authors have suggested the involvement of the pituitary gland in Post COVID-19 Syndrome. The exact mechanisms of viral action on infected cells remain under discussion, but inflammatory and autoimmune mechanisms are primarily implicated. The aim of our study will be to review the main pituitary complications following COVID-19 infection. Moreover, we will explain the possible involvement of the pituitary gland in the persistence of Post COVID-19 Syndrome.

Idiopathic isolated adrenocorticotropic hormone deficiency: a systematic review of a heterogeneous and underreported disease

Isolated adrenocorticotropic hormone deficiency (IAD) is considered to be a rare disease. Due to the nonspecific clinical presentation, precise data on the prevalence and incidence are lacking. In this systematic review, we aimed to analyse the clinical characteristics, association with autoimmune diseases, and management of acquired idiopathic IAD cases. A structured search was conducted after developing a search strategy combining terms for acquired (idiopathic) IAD. Articles describing an adult case with a diagnosis of ACTH deficiency using dynamic testing, no deficiency of other pituitary axes, and MRI of the brain/pituitary protocolled as normal, were included. Exclusion criteria were cases describing congenital IAD, cases with another aetiology for IAD, and articles where full text was not available. In total 42 articles were included, consisting of 85 cases of acquired idiopathic IAD. Distribution by sex was approximately equal (F:M; 47:38). Lethargy was the most common presenting symptom (38%), followed by weight loss (25%), anorexia (22%), and myalgia/arthralgia (12%). Eight cases (9.5%) presented with an Addison crisis. 31% of cases had an autoimmune disease at diagnosis of which Hashimoto hypothyroidism was the most frequent. Data about follow-up was scarce; dynamic testing was repeated in 4 cases of which 2 showed recovery of the adrenal axis. We report the largest case series of acquired idiopathic IAD to date. Our systematic review highlights the lack of a clear definition and diagnostic work-up. Based on the findings in this review a proposition is made for a flowchart to diagnose acquired idiopathic IAD.

Functional Overlay Model of Persistent Post-Concussion Syndrome

Persistent post-concussion syndrome (PPCS) is a complex and debilitating condition that can develop after head concussions or mild traumatic brain injury (mTBI). PPCS is characterized by a wide range of symptoms, including headaches, dizziness, fatigue, cognitive deficits, and emotional changes, that can persist for months or even years after the initial injury. Despite extensive research, the underlying mechanisms of PPCS are still poorly understood; furthermore, there are limited resources to predict PPCS development in mTBI patients and no established treatment. Similar to PPCS, the etiology and pathogenesis of functional neurological disorders (FNDs) are not clear neither fully described. Nonspecific multifactorial interactions that were also seen in PPCS have been identified as possible predispositions for FND onset and progression. Thus, we aimed to describe a functional overlay model of PPCS that emphasizes the interplay between functional and structural factors in the development and perpetuation of PPCS symptoms. Our model suggests that the initial brain injury triggers a cascade of physiological and psychological processes that disrupt the normal functioning of the brain leading to persistent symptoms. This disruption can be compounded by pre-existing factors, such as genetics, prior injury, and psychological distress, which can increase the vulnerability to PPCS. Moreover, specific interventions, such as cognitive behavioral therapy, neurofeedback, and physical exercise can target the PPCS treatment approach. Thus, the functional overlay model of PPCS provides a new framework for understanding the complex nature of this condition and for developing more effective treatments. By identifying and targeting specific functional factors that contribute to PPCS symptoms, clinicians and researchers can improve the diagnosis, management, and ultimately, outcomes of patients with this condition.