Symptoms of gonadal dysfunction are more predictive of hypopituitarism than nonspecific symptoms in screening for pituitary dysfunction following moderate or severe traumatic brain injury

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.

Neuroendocrine Disruptions Following Head Injury

PURPOSE OF REVIEW

This article reviews hypopituitarism after TBI, the importance of pituitary hormones, and related controversies, concluding with a suggested patient approach.

RECENT FINDINGS

While earlier studies focused on increased pituitary deficiencies after moderate-severe TBI, recent studies have focused on deficiencies after mild TBI. There has been increasing focus on the role of growth hormone after injury; growth hormone is the most frequent reported deficiency at 1 year post-TBI, and an area with unresolved questions. While more research is needed to quantify the risk of deficiencies in special populations, and establish the natural history, increasing data indicate an increase in hypopituitarism after other acquired brain injuries; the potential role of pituitary hormone deficiencies after stroke and after COVID-19 infection is an area of active inquiry. Given the negative health effects of untreated hypopituitarism and the opportunity to intervene via hormone replacement, it is important to recognize the role of pituitary hormone deficiencies after TBI.

Pathophysiology of Pediatric Traumatic Brain Injury

The national incidence of traumatic brain injury (TBI) exceeds that of any other disease in the pediatric population. In the United States the Centers for Disease Control and Prevention (CDC) reports 697,347 annual TBIs in children ages 0–19 that result in emergency room visits, hospitalization or deaths. There is a bimodal distribution within the pediatric TBI population, with peaks in both toddlers and adolescents. Preclinical TBI research provides evidence for age differences in acute pathophysiology that likely contribute to long-term outcome differences between age groups. This review will examine the timecourse of acute pathophysiological processes during cerebral maturation, including calcium accumulation, glucose metabolism and cerebral blood flow. Consequences of pediatric TBI are complicated by the ongoing maturational changes allowing for substantial plasticity and windows of vulnerabilities. This review will also examine the timecourse of later outcomes after mild, repeat mild and more severe TBI to establish developmental windows of susceptibility and altered maturational trajectories. Research progress for pediatric TBI is critically important to reveal age-associated mechanisms and to determine knowledge gaps for future studies.

Menopause, anti-Müllerian hormone and cognition in a cohort of women with persistent symptoms following TBI: a case for future research

Objectives: Primary: To explore anti-Müllerian Hormone (AMH) levels in community dwelling women following TBI. Secondary: To explore the relation of AMH to menstrual cycle, cognition, distress and symptoms of menopause.Setting: Large adult TBI outpatient clinic in Toronto Canada.Research design: Prospective study of 10 women with persistent symptoms who were one or more years post TBI.Methods: Consenting participants provided a serum sample for AMH levels, and completed the Menopause Rating Scale (MRS), Symptom Checklist-90 r (SCL-90 r), Repeatable Battery for the Assessment of Neurological Status (RBANS) and a health questionnaire.Main outcomes and results: This study found lower than expected levels of AMH in 50% of participants relative to age matched norms and 50% of participants experienced new onset of menstrual changes. Also notable were findings of lower-than-expected cognitive scores in women over 35 and reports of menopause-related symptoms across all ages groups.Conclusions: As our understanding of the role of AMH grows, examining changes in this novel biomarker in the long-term post-TBI is warranted. Future research should be sufficiently powered to expand on and validate the study's findings.

Insights into non-classic and emerging causes of hypopituitarism

Hypopituitarism is defined as one or more partial or complete pituitary hormone deficiencies, which are related to the anterior and/or posterior gland and can have an onset in childhood or adulthood. The most common aetiology is a sellar or suprasellar lesion, often an adenoma, which causes hypopituitarism due to tumour mass effects, or the effects of surgery and/or radiation therapy. However, other clinical conditions, such as traumatic brain injury, and autoimmune and inflammatory diseases, can result in hypopituitarism, and there are also genetic causes of hypopituitarism. Furthermore, the use of immune checkpoint inhibitors to treat cancer is increasing the risk of hypopituitarism, with a pattern of hormone defects that is different from the classic patterns and depends on mechanisms that are specific for each drug. Moreover, autoantibody production against the pituitary and hypothalamus has been demonstrated in studies investigating the development or worsening of some cases of hypopituitarism. Finally, evidence suggests that posterior pituitary damage can affect oxytocin secretion. The aim of this Review is to summarize current knowledge on non-classic and emerging causes of hypopituitarism, so as to help clinicians improve early identification, avoid life-threatening events and improve the clinical care and quality of life of patients at risk of hypopituitarism.

Traumatic Brain Injury as Frequent Cause of Hypopituitarism and Growth Hormone Deficiency: Epidemiology, Diagnosis, and Treatment

Traumatic brain injury (TBI)-related hypopituitarism has been recognized as a clinical entity for more than a century, with the first case being reported in 1918. However, during the 20^th century hypopituitarism was considered only a rare sequela of TBI. Since 2000 several studies strongly suggest that TBI-mediated pituitary hormones deficiency may be more frequent than previously thought. Growth hormone deficiency (GHD) is the most common abnormality, followed by hypogonadism, hypothyroidism, hypocortisolism, and diabetes insipidus. The pathophysiological mechanisms underlying pituitary damage in TBI patients include a primary injury that may lead to the direct trauma of the hypothalamus or pituitary gland; on the other hand, secondary injuries are mainly related to an interplay of a complex and ongoing cascade of specific molecular/biochemical events. The available data describe the importance of GHD after TBI and its influence in promoting neurocognitive and behavioral deficits. The poor outcomes that are seen with long standing GHD in post TBI patients could be improved by GH treatment, but to date literature data on the possible beneficial effects of GH replacement therapy in post-TBI GHD patients are currently scarce and fragmented. More studies are needed to further characterize this clinical syndrome with the purpose of establishing appropriate standards of care. The purpose of this review is to summarize the current state of knowledge about post-traumatic GH deficiency.

Anti-Pituitary and Anti-Hypothalamus Autoantibody Associations with Inflammation and Persistent Hypogonadotropic Hypogonadism in Men with Traumatic Brain Injury

Traumatic brain injury (TBI) and can lead to persistent hypogonadotropic hypogonadism (PHH) and poor outcomes. We hypothesized that autoimmune and inflammatory mechanisms contribute to PHH pathogenesis. Men with moderate-to-severe TBI (n = 143) were compared with healthy men (n = 39). The TBI group provided blood samples 1-12 months post-injury (n = 1225). TBI and healthy control (n = 39) samples were assayed for testosterone (T) and luteinizing hormone (LH) to adjudicate PHH status. TBI samples 1-6 months post-injury and control samples were assayed for immunoglobulin M (IgM)/immunoglobulin G (IgG) anti-pituitary autoantibodies (APA) and anti-hypothalamus autoantibodies (AHA). Tissue antigen specificity for APA and AHA was confirmed via immunohistochemistry (IHC). IgM and IgG autoantibodies for glial fibrillary acid protein (GFAP) (AGA) were evaluated to gauge APA and AHA production as a generalized autoimmune response to TBI and to evaluate the specificity of APA and AHA to PHH status. An inflammatory marker panel was used to assess relationships to autoantibody profiles and PHH status. Fifty-one men with TBI (36%) had PHH. An age-related decline in T levels by both TBI and PHH status were observed. Injured men had higher APA IgM, APA IgG, AHA IgM, AHA IgG, AGA IgM, and AGA IgG than controls (p < 0.0001 all comparisons). However, only APA IgM (p = 0.03) and AHA IgM (p = 0.03) levels were lower in the PHH than in the non-PHH group in multivariate analysis. There were no differences in IgG levels by PHH status. Multiple inflammatory markers were positively correlated with IgM autoantibody production. PHH was associated with higher soluble tumor-necrosis-factor receptors I/II, (sTNFRI, sTNFRII), regulated on activation, normal T-cell expressed and secreted (RANTES) and soluble interleukin-2-receptor-alpha (sIL-2Rα) levels. Higher IgM APA, and AHA, but not AGA, in the absence of PHH may suggest a beneficial or reparative role for neuroendocrine tissue-specific IgM autoantibody production against PHH development post-TBI.

Prevalence of Anterior Pituitary Dysfunction Twelve Months or More following Traumatic Brain Injury in Adults: A Systematic Review and Meta-Analysis

The objective of this study is to systematically review clinical studies that have reported on the prevalence of chronic post-traumatic brain injury anterior pituitary dysfunction (PTPD) 12 months or more following traumatic brain injury (TBI). We searched Medline, Embase, and PubMed up to April 2017 and consulted bibliographies of narrative reviews. We included cohort, case-control, and cross-sectional studies enrolling at least five adults with primary TBI in whom at least one anterior pituitary axis was assessed at least 12 months following TBI. We excluded studies in which other brain injuries were indistinguishable from TBI. Study quality was assessed using the Newcastle-Ottawa Scale (NOS) score. We also considered studies that determined growth hormone deficiency and adrenocorticotrophic hormone reserve using provocation test to be at low risk of bias. Data were extracted by four independent reviewers and assessed for risk of bias using a data extraction form. We performed meta-analyses using random effect models and assessed heterogeneity using the I² index. We identified 58 publications, of which 29 (2756 participants) were selected for meta-analysis. Twelve of these were deemed to be at low risk of bias and therefore "high-quality," as they had NOS scores greater than 8 and had used provocation tests. The overall prevalence of at least one anterior pituitary hormone dysfunction for all 29 studies was 32% (95% confidence interval [CI] 25-38%). The overall prevalence in the 12 high-quality studies was 34% (95% CI 27-42%). We observed significant heterogeneity that was not solely explained by the risk of bias. Studies with a higher proportion of participants with mild TBI had a lower prevalence of PTPD. Our results show that approximately one-third of TBI sufferers have persistent anterior pituitary dysfunction 12 months or more following trauma. Future research on PTPD should differentiate between mild and moderate/severe TBI.

Genome-wide methylation study of whole blood cells DNA in men with congenital hypopituitarism disease

Congenital hypopituitarism (CH) is a relatively rare disease that is characterized by the deficiency of one or more hormones secreted by the pituitary gland, which leads to metabolic disorders, amenorrhea and infertility. However, the underlying molecular mechanisms of CH have not yet been fully elucidated. The present study evaluated the genome-wide methylation level of whole blood DNA in 12 patients with CH and 12 age-matched controls using Illumina Human Methylation 450 array, in order to determine the roles of epigenetic regulation in the pathogenesis of CH. The results demonstrated that the methylation levels of 51 CpG sites were significantly different between the patients with CH and the controls. Functional enrichment analysis identified that the aberrant methylated genes were enriched in gene sets associated with metabolic or cellular process, immune system process and reproduction. In addition, two CpG sites on genes LIM domain kinase 2 (LIMK2) and piwi-like RNA-mediated gene silencing 2 (PIWIL2), which are involved in spermatogenesis and/or testicular development, were identified to be hypermethylated in male patients with CH. The hypermethylation of these sites was further validated in another 40 patients with CH and 40 matched controls with a quantitative bisulfite pyrosequencing method, and the methylation levels of these two loci demonstrated promising diagnostic capacities for CH. The present results suggested that aberrant methylation of genes may be involved in the pathogenesis of CH, and hypermethylation of LIMK2 and PIWIL2 may contribute to the infertility of male patients with CH. Further studies are required to elucidate the underlying mechanisms of the epigenetic regulation of these genes.

Pituitary dysfunction and association with fatigue in stroke and other acute brain injury

BACKGROUND

Poststroke fatigue (PSF) is a highly prevalent and debilitating condition. However, the etiology remains incompletely understood. Literature suggests the co-prevalence of pituitary dysfunction (PD) with stroke, and the question raises whether this could be a contributing factor to the development of PSF. This study reviews the prevalence of PD after stroke and other acquired brain injuries and its association with fatigue.

SUMMARY

We performed a bibliographic literature search of MEDLINE and EMBASE databases for English language studies on PD in adult patients with stroke, traumatic brain injury (TBI) or aneurysmatic subarachnoid hemorrhage (aSAH). Forty-two articles were selected for review. Up to 82% of patients were found to have any degree of PD after stroke. Growth hormone deficiency was most commonly found. In aSAH and TBI, prevalences up to 49.3% were reported. However, data differed widely between studies, mostly due to methodological differences including the diagnostic methods used to define PD and the focus on the acute or chronic phase. Data on PD and outcome after stroke, aSAH and TBI are conflicting. No studies were found investigating the association between PD and PSF. Data on the association between PD and fatigue after aSAH and TBI were scarce and conflicting, and fatigue is rarely been investigated as a primary end point.

KEY MESSAGES

Data according to the prevalence of PD after stroke and other acquired brain injury suggest a high prevalence of PD after these conditions. However, the clinical relevance and especially the association with fatigue need to be established.

Long-term Consequences of Traumatic Brain Injury in Bone Metabolism

Traumatic brain injury (TBI) leads to long-term cognitive, behavioral, affective deficits, and increase neurodegenerative diseases. It is only in recent years that there is growing awareness that TBI even in its milder form poses long-term health consequences to not only the brain but to other organ systems. Also, the concept that hormonal signals and neural circuits that originate in the hypothalamus play key roles in regulating skeletal system is gaining recognition based on recent mouse genetic studies. Accordingly, many TBI patients have also presented with hormonal dysfunction, increased skeletal fragility, and increased risk of skeletal diseases. Research from animal models suggests that TBI may exacerbate the activation and inactivation of molecular pathways leading to changes in both osteogenesis and bone destruction. TBI has also been found to induce the formation of heterotopic ossification and increased callus formation at sites of muscle or fracture injury through increased vascularization and activation of systemic factors. Recent studies also suggest that the disruption of endocrine factors and neuropeptides caused by TBI may induce adverse skeletal effects. This review will discuss the long-term consequences of TBI on the skeletal system and TBI-induced signaling pathways that contribute to the formation of ectopic bone, altered fracture healing, and reduced bone mass.

Risk of Erectile Dysfunction After Traumatic Brain Injury: A Nationwide Population-Based Cohort study in Taiwan

Introduction:

In our study, we aimed to investigate the association between a traumatic brain injury (TBI) and subsequent erectile dysfunction (ED). This is a population-based study using the claims dataset from The National Health Insurance Research Database.

Methods:

We included 72,642 patients with TBI aged over 20 years, retrospectively, selected from the longitudinal health insurance database during 2000–2010, according to the ICD-9-CM. The control group consisted of 217,872 patients without TBI that were randomly chosen from the database at a ratio of 1:3, with age- and index year matched. Cox proportional hazards analysis was used to estimate the association between the TBI and subsequent ED.

Results:

After a 10-year follow-up, the incidence rate of ED was higher in the TBI patients when compared with the non-TBI control group (24.66 and 19.07 per 100,000, respectively). Patients with TBI had a higher risk of developing ED than the non-TBI cohort after the adjustment of the confounding factors, such as age, comorbidity, residence of urbanization and locations, seasons, level of care, and insured premiums (adjusted hazard ratio (HR) = 2.569, 95% CI [1.890, 3.492], p < .001).

Conclusion:

This is the first study using a comprehensive nationwide database to analyze the association of ED and TBI in the Asian population. After adjusted the confounding factors, patients with TBI have a significantly higher risk of developing ED, especially organic ED, than the general population. This finding might remind clinicians that it’s crucial in early identification and treatment of ED in post-TBI patients.

Chronic endocrine consequences of traumatic brain injury - what is the evidence?

Traumatic brain injury (TBI) is a major public health problem with potentially debilitating consequences for the individual. Hypopituitarism after TBI has received increasing attention over the past decade; development of the condition as a consequence of TBI was previously hardly mentioned in textbooks on the subject. Hypopituitarism has been reported in more than 25% of patients with TBI and is now thought to be one of the most important causes of treatable morbidity in TBI survivors. However, most clinicians dealing with neuroendocrine diseases and TBI generally do not see such a high incidence of hypopituitarism. This disproportion is not clearly explained, but recent data indicate that diagnostic testing, which is designed for high-risk populations and not for a cohort of patients with, for example, de novo isolated growth hormone deficiency (the predominant finding in TBI), might have overestimated the true risk and disease burden of hypopituitarism. In this Opinion article, we discuss current recommendations for post-traumatic hypopituitarism in light of recent evidence.

The screening and management of pituitary dysfunction following traumatic brain injury in adults: British Neurotrauma Group guidance

Pituitary dysfunction is a recognised, but potentially underdiagnosed complication of traumatic brain injury (TBI). Post-traumatic hypopituitarism (PTHP) can have major consequences for patients physically, psychologically, emotionally and socially, leading to reduced quality of life, depression and poor rehabilitation outcome. However, studies on the incidence of PTHP have yielded highly variable findings. The risk factors and pathophysiology of this condition are also not yet fully understood. There is currently no national consensus for the screening and detection of PTHP in patients with TBI, with practice likely varying significantly between centres. In view of this, a guidance development group consisting of expert clinicians involved in the care of patients with TBI, including neurosurgeons, neurologists, neurointensivists and endocrinologists, was convened to formulate national guidance with the aim of facilitating consistency and uniformity in the care of patients with TBI, and ensuring timely detection or exclusion of PTHP where appropriate. This article summarises the current literature on PTHP, and sets out guidance for the screening and management of pituitary dysfunction in adult patients with TBI. It is hoped that future research will lead to more definitive recommendations in the form of guidelines.

MANAGEMENT OF ENDOCRINE DISEASE: Neuroendocrine surveillance and management of neurosurgical patients

Advances in the management of traumatic brain injury, subarachnoid haemorrhage and intracranial tumours have led to improved survival rates and an increased focus on quality of life of survivors. Endocrine sequelae of the acute brain insult and subsequent neurosurgery, peri-operative fluid administration and/or cranial irradiation are now well described. Unrecognised acute hypopituitarism, particularly ACTH/cortisol deficiency and diabetes insipidus, can be life threatening. Although hypopituitarism may be transient, up to 30% of survivors of TBI have chronic hypopituitarism, which can diminish quality of life and hamper rehabilitation. Patients who survive SAH may also develop hypopituitarism, though it is less common than after TBI. The growth hormone axis is most frequently affected. There is also accumulating evidence that survivors of intracranial malignancy, who have required cranial irradiation, may develop hypopituitarism. The time course of the development of hormone deficits is varied, and predictors of pituitary dysfunction are unreliable. Furthermore, diagnosis of GH and ACTH deficiency require dynamic testing that can be resource intensive. Thus the surveillance and management of neuroendocrine dysfunction in neurosurgical patients poses significant logistic challenges to endocrine services. However, diagnosis and management of pituitary dysfunction can be rewarding. Appropriate hormone replacement can improve quality of life, prevent complications such as muscle atrophy, infection and osteoporosis and improve engagement with physiotherapy and rehabilitation.

ACTH and gonadotropin deficiencies predict mortality in patients treated for nonfunctioning pituitary adenoma: long-term follow-up of 519 patients in two large European centres

CONTEXT AND OBJECTIVE

Nonfunctioning pituitary adenomas (NFPAs) are the most common subtype of pituitary tumour. Hypopituitarism is observed in NFPAs due to tumour- or treatment-related factors and may increase mortality risk. Here, we analysed the associations of hypopituitarism, hormone replacement and mortality in a large NFPA cohort derived from two large European centres.

DESIGN, SETTING AND PARTICIPANTS

Case note review of all patients treated for NFPA in University Hospitals Birmingham and Beaumont Hospital Dublin between 1999 and 2014 was performed.

MAIN OUTCOME MEASURES

Clinical presentation, treatment strategies, pituitary function and vitality status were recorded in each patient. A multivariate Cox regression model was used to examine the association between hypopituitarism, hormone replacement and premature mortality.

RESULTS

A total of 519 patients were included in the analysis. Median duration of follow-up was 7·0 years (0·5-43). A total of 81 deaths were recorded (15·6%). On multivariate analysis, adrenocorticotropic hormone (ACTH) and gonadotropin (Gn) deficiencies were associated with an increased relative risk of death (OR 2·26, 95% CI 1·15-4·47, P = 0·01 and OR 2·56, 95% CI 1·10-5·96, P = 0·01, respectively). Increased hydrocortisone (HC) (P-trend = 0·02) and lower levothyroxine (LT4) doses (P-trend = 0·03) were associated with increased risk of death. Mortality increased with the degree of pituitary failure observed (P-trend = 0·04).

CONCLUSION

ACTH and gonadotropin-deficient patients have higher mortality rates compared to those with intact hormonal axes. Excessive HC and suboptimal LT4 replacement may also increase risk of death. Complex associations between hormone deficiency and replacement underpin the increased mortality risk in NFPA patients.