Endocrines, Volume 6, Issue 3 (September 2025) – 9 articles

Pancreatic neuroendocrine neoplasms (PNENs) are a diverse group of rare tumor subtypes, representing less than 2% of all pancreatic tumors. Often detected late in the clinical course, they are associated with high rates of morbidity and mortality. Hereditary syndromes such as multiple endocrine neoplasia type-1 and von Hippel–Lindau are associated with the development of PNENs, although only a small portion of total tumors have a genetic basis. This review aims to explore the recent advances in laboratory diagnostics, imaging modalities, medical management, and surgical approaches to hormone-producing PNENs (including some common, less common, and some rare subtypes), with the goal of assisting physicians in the integration of evidence-based information into their practice. Full article

Hormonal contraceptives (HCs) are widely used and generally well tolerated; however, their neuroendocrinological effects remain underappreciated in clinical decision-making. Beyond ovulation suppression, HCs influence brain function by modulating key neurotransmitters such as GABA, serotonin, and dopamine, as well as neurosteroids like allopregnanolone and β-endorphin. These interactions help explain why some users experience mood swings, anxiety, or changes in sexual desire, while others report improvements in well-being. In this narrative review, we explore how different estrogenic and progestin components affect central pathways involved in emotional regulation and cognition. Evidence suggests that estradiol or estetrol-based formulations combined with anti-androgenic progestins like drospirenone or nomegestrol acetate may offer a more favourable neuroendocrine profile, particularly in women with a history of mood disorders or hormonal sensitivity. Understanding these neuroendocrine mechanisms may support more personalized contraceptive choices, particularly in women with mood disorders and hormonal vulnerability. Full article

In healthy humans, insulin at physiological concentrations exerts acute vasodilatory actions on both resistance and terminal arterioles, leading, respectively, to increased total blood flow and the microvascular network volume being perfused. The process of increasing capillary network volume is frequently referred to as “capillary recruitment”. Together these two vascular actions of insulin enhance the delivery of oxygen, nutrients, and insulin itself to tissues. Both processes are diminished by insulin resistance. Here we examined interactions between insulin’s acute (within 2 h) actions on blood pressure (both central and peripheral) and on capillary recruitment in healthy controls and in four distinct groups of people with heightened cardio-metabolic disease (CMD) risk: individuals with obesity, metabolic syndrome, and type 1 or type 2 diabetes. Insulin increased microvascular blood volume (MBV) more effectively in controls than in each of the four CMD risk groups (p < 0.001). Conversely, insulin lowered both central and peripheral systolic pressure (p < 0.05 or less) in each of the CMD risk groups but not in the controls. The insulin-induced blood pressure decrements were greater in the metabolic syndrome, type 2 diabetes, and obesity groups (p < 0.05 or less) than in the controls. The greater blood pressure declines likely reflect decreased sympathetic baroreceptor reflex tone. These effects on blood pressure combined with the diminished dilation of terminal arterioles due to microvascular insulin resistance in the CMD risk subjects led to decreased distal microvascular perfusion as evidenced by changes in MBV. These findings highlight the complex interplay between insulin’s actions on resistance and terminal arterioles in individuals with a high CMD risk, underscoring the importance of addressing microvascular dysfunction in these conditions. Full article

Background/Objectives: This study investigated the relationship between glycemic control and increased glomerular filtration rate (eGFR), as assessed by serum creatinine and the CKiD equation in children and adolescents with T1DM. Methods: This cross-sectional observational study involved 80 T1DM patients (4–19 years) attending the Interdisciplinary Center for Diabetes. Biochemical, anthropometric, and skeletal muscle mass parameters were evaluated. The GFR was estimated using the CKiD equation expressed in mL/min/1.73 m². Results: Our results showed that nearly 19.0% of the included patients presented increased values for eGFR, and most had poor glycemic control. Patients with HbA1c levels above 8% presented eGRF > 130. There was a positive correlation between hyperglycemia, elevated HbA1c, and fat percentage with higher eGRF values. In addition, the reduction in lean mass and skeletal muscle mass was related to elevated eGRF. Conclusions: Our study indicates that children and adolescents with T1DM who have elevated HbA1c, lower lean mass, and less than five years of diagnosis of diabetes are more likely to present higher eGRF values. Full article

Background/Objectives: Continuous glucose monitoring (CGM) has transformed diabetes management, with time in range (TIR) emerging as a key glycemic metric. However, TIR lacks sensitivity to glycemic variability, leading to the introduction of time in tight range (TiTR), which defines a narrower range (70–140 mg/dL). This review synthesizes current evidence on TiTR’s clinical relevance and its potential to predict complications. Methods: A literature search was conducted, primarily using PubMed as the main database, to identify studies that specifically evaluate TiTR and its clinical implications, published until February 2025. Results: Preliminary data indicate that a 10% increase in TiTR is associated with a 23.8% reduction in microvascular complications. While TiTR aligns more closely with physiological glucose control, standardized targets remain undefined. Conclusions: This study provides clinicians with insights into optimizing glycemic control beyond traditional metrics. The correlation of TiTR with other glycemic markers and its association with diabetes-related complications suggest that TiTR can complement traditional measures to provide a more comprehensive assessment of glycemic status. From a clinical perspective, incorporating TiTR into routine practice may help personalize treatment strategies, improve risk stratification, and support more precise therapeutic decisions, particularly in patients using continuous glucose monitoring (CGM). Future research should refine TiTR thresholds and evaluate its integration into diabetes management, particularly in populations using advanced technologies. Full article

Objective: To investigate the association between serum 25-hydroxyvitamin D [25(OH)D] levels and clinical, hormonal, and auxological features in girls with idiopathic central precocious puberty (CPP). Methods: This retrospective study included 122 girls diagnosed with idiopathic CPP. Participants were stratified into three groups based on serum 25(OH)D concentrations: deficient (<20 ng/mL), insufficient (20–30 ng/mL), and sufficient (>30 ng/mL). Clinical and hormonal parameters were compared across groups. Spearman’s correlation and multiple linear regression analyses were used to explore the relationship between vitamin D levels and peak luteinizing hormone (LH) response to gonadotropin-releasing hormone (GnRH) stimulation. Results: No significant differences were observed among the vitamin D groups in terms of age at diagnosis, body mass index (BMI), or other auxological measures. However, serum 25(OH)D levels showed a weak but significant positive correlation with LH peak values (rho = 0.23, p = 0.037). In multivariable regression analysis, vitamin D levels remained an independent predictor of LH peak (β = 0.125, p = 0.036), whereas BMI standard deviations (SDS), growth velocity SDS, and age at diagnosis did not show significant associations. Conclusions: Higher serum vitamin D levels are independently associated with greater LH peak responses in girls with idiopathic CPP. These findings support a potential modulatory role of vitamin D in the neuroendocrine mechanisms underlying pubertal onset and warrant further prospective studies to clarify its clinical relevance. Full article

Background/Objectives: Endocrine hormones play critical roles in regulating physiological processes, and previous studies have reported their associations with psychiatric disorders. Levels of endocrine hormones and the risk of developing psychiatric disorders are influenced by both genetic and non-genetic factors. However, the shared genetic basis underlying these associations remains largely unexplored. This study aims to dually evaluate the genetic correlations among endocrine hormones, including thyroid and sex hormones, as well as between endocrine hormone metrics and psychiatric disorders to identify potential shared genetic architectures. Methods: We obtained genome-wide association study summary statistics for six thyroid hormone metrics, three sex hormone metrics, and ten psychiatric disorders from predominantly European-ancestry populations. Genetic correlations were computed using linkage disequilibrium score regression after harmonizing variant data to ensure consistency across studies. Results: Significant genetic correlations were observed among thyroid and sex hormone metrics, indicating a strong shared genetic basis. Sex hormones exhibited multiple genetic correlations with psychiatric disorders, including negative correlations between sex hormone-binding globulin and attention-deficit hyperactivity disorder (ADHD) (p = 3.95 × 10⁻¹²) and major depressive disorder (p = 4.67 × 10⁻⁵), and positive genetic correlations with anorexia nervosa (p = 2.86 × 10⁻¹²) and schizophrenia (p = 2.00 × 10⁻⁴). Testosterone and estradiol had negative genetic correlations with ADHD and major depressive disorder, while testosterone had positive genetic correlations with anorexia nervosa and schizophrenia. Although thyroid hormone metrics did not exhibit Bonferroni-significant genetic correlations, nominal associations were observed, such as a negative genetic correlation between thyroid-stimulating hormone and major depressive disorder (p = 2.33 × 10⁻²). Conclusions: These findings suggest a shared genetic basis between endocrine hormones and psychiatric disorders, particularly for sex hormones. Future studies leveraging larger, more diverse populations are warranted to validate and extend the genetic correlations observed in this study. Full article

Background/Objectives: Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare autoimmune disorder caused by mutations in the AIRE gene. Approximately 60% of affected females develop premature ovarian insufficiency (POI) by age 30, often most commonly due to steroidogenic autoantibodies. Although APECED is typically diagnosed in childhood, its reproductive implications are underrecognized. This study reports a case of successful fertility preservation in an adult woman with APECED and reviews the relevant literature. Methods: We describe the clinical course of a 37-year-old woman with genetically confirmed APECED who underwent ovarian stimulation for fertility preservation. A comprehensive PubMed search was also conducted to identify English-language case reports on fertility preservation in APECED-associated POI. Results: The patient experienced menarche at age 13, adrenal insufficiency at 14, and menstrual irregularities from age 18. Genetic analysis confirmed an AIRE mutation (NM_000383: exon 11: c.1400+1G>A). Given her relatively high anti-Müllerian hormone level, she opted for fertility preservation and underwent six cycles of ovarian stimulation, resulting in the cryopreservation of 17 mature oocytes. During ovarian stimulation, multiple follicular developments were observed, but serum E2 levels remained low. The literature review identified fewer than 20 reported cases addressing fertility preservation in APECED, highlighting its rarity and the lack of standardized management. Conclusions: Although APECED frequently leads to early POI due to impaired steroidogenesis, residual ovarian function may persist. Early assessment of ovarian reserve and timely fertility counseling are crucial, even in asymptomatic patients or those diagnosed in childhood. Reproductive planning should be integrated into the long-term care of women with APECED. Full article

Cholestyramine, a bile acid sequestrant, has been used primarily for lipid-lowering purposes but has also shown potential in managing hyperthyroidism and thyrotoxicosis. The objective of this review is to assess the efficacy, safety, and clinical indications of cholestyramine in the treatment of hyperthyroidism, thyrotoxicosis, and associated conditions, particularly when conventional therapies fail or are contraindicated. A literature review of clinical guidelines, original research articles, and case reports was conducted, focusing on studies that explored cholestyramine’s use in the treatment of hyperthyroidism, thyrotoxicosis, and levothyroxine overdose. Cholestyramine has demonstrated effectiveness in rapidly reducing thyroid hormone levels in these conditions. Studies indicates that cholestyramine accelerates the reduction of T3 and T4 levels when used as adjunctive therapy alongside standard treatments, particularly in severe or refractory cases. Evidence from case reports also supports its utility in managing conditions such as amiodarone-induced thyrotoxicosis, thyroid storm, and preparation for thyroidectomy. However, the long-term effectiveness of cholestyramine remains uncertain, with potential challenges regarding gastrointestinal side effects and medication interactions. Further studies are needed to integrate it more widely into clinical guidelines for the management of thyroid disorders. Full article