Genetic diagnosis of endocrine disorders in Cyprus through the Cyprus Institute of Neurology and Genetics: an ENDO-ERN Reference Center.

The report covers the current and past activities of the department Molecular Genetics-Function and Therapy (MGFT) at the Cyprus Institute of Neurology and Genetics (CING), an affiliated Reference Center for the European Reference Network on Rare Endocrine Conditions (Endo-ERN).The presented data is the outcome of > 15 years long standing collaboration between MGFT and endocrine specialists from the local government hospitals and the private sector. Up-to-date > 2000 genetic tests have been performed for the diagnosis of inherited rare endocrine disorders. The major clinical entities included Congenital Adrenal Hyperplasia (CAH) due to pathogenic variants in CYP21A2 gene and Multiple Endocrine Neoplasia (MEN) type 2 due to pathogenic variants in the RET proto-oncogene. Other rare and novel pathogenic variants in ANOS1, WDR11, FGFR1, RNF216, and CHD7 genes were also found in patients with Congenital Hypogonadotropic Hypogonadism. Interestingly, a few patients with Disorders of Sexual Differentiation (DSD) shared rare pathogenic variants in the SRD5A2, HSD17B3 and HSD3B2 while patients with Glucose and Insulin Homeostasis carried theirs in GCK and HNF1A genes. Lastly, MGFT over the last few years has established an esteemed diagnostic and research program on premature puberty with emphasis on the implication of MKRN3 gene on the onset of the disease and the identification of other prognosis biomarkers.As an Endo-ERN member MGFT department belongs to this large European network and holds the same humanistic ideals which aim toward the improvements of health care for patients with rare endocrine conditions in respect to improved and faster diagnosis.

Dysphagia as a Manifestation of Endocrine and Metabolic Disorders.

Dysphagia is a common manifestation of endocrine and metabolic diseases. Swallowing is a complex neuromuscular process, with an interplay of sensory and motor function, that has voluntary and involuntary control. Disruptions in any of these processes can cause significant dysphagia. Endocrine disorders and metabolic derangements are systemic conditions that affect multiple organ systems. They contribute to the development of neuropathies, myopathies, and motility disorders that lead to swallowing difficulty. Malnutrition and critical illness can lead to deconditioning and atrophy which can cause dysphagia, which in turn can lead to further malnutrition and deconditioning.

Men With Type II Diabetes in Peru: The Role of Masculine Gender Norms in the Perception of Family Support.

Type II diabetes is increasingly becoming a problem in Latin American countries such as Peru. People living with diabetes must incorporate several behavioral changes in their everyday lives, which are done outside the purview of medical professionals. Support from friends and family members is essential to the successful management of any chronic condition. Our study discusses the role of family involvement in supporting the management of diabetes among Peruvian men and examines how masculine norms play a role in the way such support is received and perceived, and their influence in motivation to adhere to treatment recommendations. In-depth interviews with 20 men from a low socioeconomic status, aged 27 to 68 with a diagnosis of Type II diabetes were conducted. Our analysis suggests the importance of the close, complex, and integrated experience that connects family members and patients with a chronic condition. Participant accounts demonstrate they receive multiple forms of support from a diverse range of social relationships. The overwhelming majority of the people giving the support were female and were especially significant in supporting management practices. The participants' accounts were able to demonstrate how living with a chronic condition, such as diabetes, affects the whole family-physically, mentally, and emotionally-and they experience the disease as one unit. Our study demonstrates the need for a family health experience approach that considers masculine gender norms around health and provides relevant insights to inform family-based treatments and therapies to allow for more and better targeted health care for men.

Lipoprotein alterations in endocrine disorders - a review of the recent developments in the field.

Dyslipidemia is one of the most common disorders worldwide, which, if left untreated, results in a multitude of complications. Thus proper diagnostics, which includes identifying of secondary causes of dyslipidemia is crucial. Endocrine disorders are an important cause of secondary dyslipidemia. This paper aims to review the publications on lipoprotein alterations in endocrine disorders from the past two years and provide an overview of the recent discoveries in this dynamically developing and large field. Significant changes in lipoprotein serum concentrations are present in most endocrinological diseases and can be modified with proper treatment. Some lipoproteins have also been proposed as markers in some endocrine diseases, e.g., thyroid carcinoma. From the scope of endocrine disorders, the largest number of studies explored the lipoprotein changes in polycystic ovary syndrome and in women during the menopausal and peri-menopausal period. Even though the association of thyroid disorders with dyslipidemia is already well studied, new research has delivered some exciting findings about lipoprotein alterations in euthyroid patients with either positive antithyroid peroxidase antibodies or reduced sensitivity to thyroid hormones. The problem of the adverse metabolic profile, including dyslipidemia in hypoprolactinemia has been recognized. Moreover, this review describes other significant discoveries encompassing lipoprotein alterations in disorders of the adrenals, thyroid, parathyroid glands, pituitary, and gonads. The up-to-date knowledge of the influence of endocrine disorders and hormonal changes on serum lipoproteins is prudent as it can significantly impact therapeutic decisions.

Occult endocrine disorders newly diagnosed in patients with post-COVID-19 symptoms.

Determination of long COVID requires ruling out alternative diagnoses, but there has been no report on the features of alternative diagnoses. This study was a single-center retrospective study of outpatients who visited our clinic between February 2021 and June 2023 that was carried out to determine the characteristics of alternative diagnoses in patients with post-COVID-19 symptoms. In a total of 731 patients, 50 patients (6.8%) were newly diagnosed with 52 diseases requiring medical intervention, and 16 (32%) of those 50 patients (2.2% of the total) were considered to have priority for treatment of the newly diagnosed disorders over long COVID treatment. The proportion of patients with a new diagnosis increased with advance of age, with 15.7% of the patients aged 60 years or older having a new diagnosis. Endocrine and metabolic diseases and hematological and respiratory diseases were the most common, being detected in eight patients (16%) each. Although 35 of the 52 diseases (67%) were related to their symptoms, endocrine and metabolic diseases were the least associated with specific symptoms. Other disorders that require attention were found especially in elderly patients with symptomatic long COVID. Thus, appropriate assessment and differentiation from alternative diagnoses are necessary for managing long COVID.

Probiotics ameliorate endocrine disorders via modulating inflammatory pathways: a systematic review.

Probiotics has offered a new prospect to treat and manage a variety of endocrine disorders such as obesity, diabetes, non- alcoholic fatty liver disease and metabolic syndrome. The precise mechanisms by which probiotics exert their beneficial effects on endocrine disorders and its associated problems are still indecisive. It seems that regulating the immune system and suppressing pro-inflammatory pathways like tumor necrosis factor-α and interleukin-6 or triggering anti-inflammatory pathways like interleukin-4 and 10 may be one of the potential mechanisms in the managing of endocrine disorders. In this systematic review, we hypothesized that various probiotic strains (Lactobacillus, Biofidiobacteria, Streptococcus, Entrococcus, Clostridium, and Bacillus) alone or in combination with each other could manage endocrine disorders via modulating inflammatory pathways such as suppressing pro-inflammatory cytokines (IL-6, IL-12, TNF-α, TNF-ß, NFκB, and MCP-1), stimulating anti-inflammatory cytokines (IL-4,IL-6, IL-22, IL-23, IL-33, and TGF-ß) and maintaining other factors like C-reactive protein, Toll like receptors, LPS, and NK cells. Data source this search was performed in PubMed and Scopus. Both human and animal studies were included. Among more than 15,000 papers, 25 studies were identified as eligible for more assessments. Quality assessment of the studies was cheeked by two researchers independently by title and abstract screening, then article which have inclusion criteria were included, and data retrieved from the included full text studies as the authors had originally reported. Results specified that Lactobacillus has been the most widely used probiotic as well as which one exhibiting the extend of the therapeutic effects on endocrine disorders, especially obesity by modulating immune responses. Also, most studies have revealed that probiotics through suppressing pro-inflammatory pathways specially via reducing levels TNF-α cytokine exhibited protective or beneficial effects on endocrine diseases particularly obesity as well as through decreasing level of IL-6 induced therapeutic effects in diabetes. This systematic review suggests that probiotics could ameliorate endocrine disorders via their immunomodulatory effects.

Quality of Life and Hormonal Impairment in Pediatric Patients With Craniopharyngiomas.

INTRODUCTION: Craniopharyngiomas (CP) are tumors in the sellar region that, despite a high survival rate, are associated with significant morbidity, including hypothalamic, hormonal, and visual dysfunction. This study aimed to assess the quality of life (QoL) in pediatric patients with CP and to evaluate its relationship with various factors, with a focus on the impact of endocrine dysfunction. METHODS: In this observational cross-sectional study, patients with CP aged between 0 and 18 years, currently followed up in a tertiary hospital by a multidisciplinary team, were included. QoL was assessed using the validated PEDS-QL4.0 questionnaire, which was administered to parents. This tool estimates Global QoL (QoL-G), further divided into Physical (QoL-P) and Psychosocial (QoL-PS) dimensions, including Emotional (QoL-Em), Social (QoL-S), and School (QoL-Sc) aspects. In Portugal, the estimated average QoL-G is 79.8, QoL-P is 83.5, and QoL-PS is 78.2. Variables studied included gender, current and diagnostic age, follow-up time, presence of hydrocephalus, hypothalamic involvement, type of resection (total or subtotal), radiotherapy, visual impairment, hormonal deficits, and therapy. RESULTS: The study included 11 patients with a median age of 15.2 years (interquartile ratio (IQR), 9.7-17.9 years) and a mean age at diagnosis of 9.3±4.1 years. Of these patients, 54.5% were male, and 36.4% were obese. Subtotal resection was performed in 72.7% of cases. Hydrocephalus was present in 54.5% of the patients, hypothalamic involvement in 63.7%, radiotherapy was received by 81.8%, and visual impairment was noted in 54.5%. All patients presented with at least one hormonal deficit. The average QoL-G was 69.9±22.5, with QoL-P at 66.9±30.0 and QoL-PS at 70.9±21.4. A worse QoL-S was associated with female gender (p=0.030) and subtotal resection (p=0.048). Worse QoL-G, QoL-P, QoL-Em, and QoL-PS were linked to hypothalamic involvement (p values 0.008, 0.025, 0.015, and 0.009, respectively). Irradiated patients had worse QoL-G (p=0.006). Treatment with sexual hormones enhanced QoL-Global (p=0.035) and QoL-Emotional (p=0.020), while treatment for adrenal insufficiency and diabetes insipidus improved QoL-Emotional (p=0.021 and p=0.013). No significant associations with visual deficit or obesity were found. CONCLUSIONS: Pediatric patients with CP appear to have poorer QoL-G, QoL-P, and QoL-PS compared to the healthy Portuguese population. However, the small sample size limits statistically significant associations with many of these variables. Predictors of worse QoL include female gender, hypothalamic involvement, subtotal resection, and radiotherapy. The results may be biased due to the small sample size, questionnaire administration to parents, and possible inadequacy of the questionnaire for the studied population. There is a need for a more suitable tool to enable a more precise assessment of QoL in these patients.

Thyroid and Its Ripple Effect: Impact on Cardiac Structure, Function, and Outcomes.

Thyroid dysfunction is a widespread and complex issue in the field of endocrine disorders. It has a significant impact on multiple physiological systems, particularly on the heart. This review explores the complex interaction between thyroid dysfunction and cardiac dynamics, examining the detailed network of molecular, cellular, and systemic changes that underlie the close connection between these two physiological areas. Thyroid dysfunction, which includes both hyperthyroidism and hypothyroidism, is a common endocrine condition that affects millions of people worldwide. The thyroid hormones thyroxine and triiodothyronine regulate various metabolic activities essential for maintaining cellular balance. Disruptions in thyroid function result in widespread consequences, affecting the cardiovascular system. Thyroid hormones directly impact cardiac muscle cells, controlling their ability to contract, their electrical properties, and their reaction to hypertrophy. Thyroid dysfunction goes beyond the level of individual cells and involves complex interactions among vascular dynamics, neurohormonal control, and endothelial function. These factors all contribute to the development of cardiovascular illness. The impact of thyroid dysfunction on cardiac structure, function, and outcomes is not limited to a one-way pattern. Instead, it involves a dynamic two-way interaction. The manifestations of this condition can vary from minor changes in the electrical activity of the heart to more obvious structural abnormalities, such as an increase in the size of the heart muscle and a decrease in its ability to relax during the filling phase. Furthermore, the correlation between thyroid dysfunction and adverse cardiovascular outcomes, such as heart failure and arrhythmias, highlights the clinical importance of this connection. This review provides a complete overview of the relationship between thyroid dysfunction and cardiac dynamics by analyzing a wide range of research from clinical, molecular, and epidemiological perspectives. This study seeks to enhance our comprehension of the comprehensive effects of thyroid dysfunction on the anatomy and function of the heart by explaining the complex molecular mechanisms and systemic consequences. The goal is to establish a basis for informed clinical treatment and future research efforts.

Multi-omics Investigations in Endocrine Systems and Their Clinical Implications.

Innovative techniques such as the "omics" can be a powerful tool for the understanding of intracellular pathways involved in homeostasis maintenance and identification of new potential therapeutic targets against endocrine-metabolic disorders. Over the last decades, proteomics has been extensively applied in the study of a wide variety of human diseases, including those involving the endocrine system. Among the most endocrine-related disorders investigated by proteomics in humans are diabetes mellitus and thyroid, pituitary, and reproductive system disorders. In diabetes, proteins implicated in insulin signaling, glucose metabolism, and ß-cell activity have been investigated. In thyroid diseases, protein expression alterations were described in thyroid malignancies and autoimmune thyroid illnesses. Additionally, proteomics has been used to investigate the variations in protein expression in adrenal cancers and conditions, including Cushing's syndrome and Addison's disease. Pituitary tumors and disorders including acromegaly and hypopituitarism have been studied using proteomics to examine changes in protein expression. Reproductive problems such as polycystic ovarian syndrome and endometriosis are two examples of conditions where alterations in protein expression have been studied using proteomics. Proteomics has, in general, shed light on the molecular underpinnings of many endocrine-related illnesses and revealed promising biomarkers for both their detection and treatment. The capacity of proteomics to thoroughly and objectively examine complex protein mixtures is one of its main benefits. Mass spectrometry (MS) is a widely used method that identifies and measures proteins based on their mass-to-charge ratio and their fragmentation pattern. MS can perform the separation of proteins according to their physicochemical characteristics, such as hydrophobicity, charge, and size, in combination with liquid chromatography. Other proteomics techniques include protein arrays, which enable the simultaneous identification of several proteins in a single assay, and two-dimensional gel electrophoresis (2D-DIGE), which divides proteins depending on their isoelectric point and molecular weight. This chapter aims to summarize the most relevant proteomics data from targeted tissues, as well as the daily rhythmic variation of relevant biomarkers in both physiological and pathophysiological conditions within the involved endocrine system, especially because the actual modern lifestyle constantly imposes a chronic unentrained condition, which virtually affects all the circadian clock systems within human's body, being also correlated with innumerous endocrine-metabolic diseases.

Oncological and endocrinological outcomes for children and adolescents with testicular and ovarian sex cord-stromal tumors. Results of the TGM13 National Registry.

RATIONALE: Sex cord-stromal tumors (SCST) are hormonally active and rare. The aim was to describe their endocrinological presentation and outcomes. METHOD: Patients (< 19 years) registered in the TGM13 registry between 2014 and 2021 for SCST were selected. RESULTS: Sixty-three ovarian SCST (juvenile granulosa tumor (JGT) n = 34, Sertoli-Leydig cell tumor (SLCT) n = 17, other SCST n = 12) were included. Median age was 13.1 years (0.4-17.4). Germline DICER1 pathogenic variant was present in 9/17 SLCT. Sixty-one were FIGO stage I (IC n = 14). Adjuvant chemotherapy was administered for 15. Seven had recurrence (FIGO IA n = 3, IX n = 2, III n = 2), leading to one death. With a median follow-up of 42 months (2.5-92), the 3-year progression-free survival (PFS) was 89% (95% CI 76%-95%). Median age was 6.4 years (0.1-12.9) among the 15 testicular SCST (Leydig cell tumor n = 6, JGT n = 5, Sertoli cell tumor n = 3, mixed SCST n = 1). Tumor-nodes-metastases (TNM) stage was pSI in 14. Eight underwent a tumorectomy, 7 an orchiectomy. None experienced recurrence. Endocrinological data were reviewed for 41 patients (18 prepubescent). Endocrine symptoms were present at diagnosis in 29/34 females and 2/7 males (gynecomastia). After a median follow-up of 11 months, 15 patients had persistent endocrine abnormalities: gynecomastia/breast growth (2 males, 1 prepubescent female), precocious/advanced puberty (4 prepubescent females), and hirsutism/menstruation disorders/voice hoarseness/hot flashes (8 pubescent females). The mean height at the last follow-up was within normal ranges (+0.3 standard deviation). CONCLUSIONS: SCSTs have a favorable prognosis. Tumorectomy appears safe with testicular primary. Endocrinological disorders, common at diagnosis, may persist warranting endocrinological follow-up.

Diabetes-induced male infertility: potential mechanisms and treatment options.

Male infertility is a physiological phenomenon in which a man is unable to impregnate a fertile woman during a 12-month period of continuous, unprotected sexual intercourse. A growing body of clinical and epidemiological evidence indicates that the increasing incidence of male reproductive problems, especially infertility, shows a very similar trend to the incidence of diabetes within the same age range. In addition, a large number of previous in vivo and in vitro experiments have also suggested that the complex pathophysiological changes caused by diabetes may induce male infertility in multiple aspects, including hypothalamic-pituitary-gonadal axis dysfunction, spermatogenesis and maturation disorders, testicular interstitial cell damage erectile dysfunction. Based on the above related mechanisms, a large number of studies have focused on the potential therapeutic association between diabetes progression and infertility in patients with diabetes and infertility, providing important clues for the treatment of this population. In this paper, we summarized the research results of the effects of diabetes on male reproductive function in recent 5 years, elaborated the potential pathophysiological mechanisms of male infertility induced by diabetes, and reviewed and prospected the therapeutic measures.

Microbiota Implications in Endocrine-Related Diseases: From Development to Novel Therapeutic Approaches.

This comprehensive review article delves into the critical role of the human microbiota in the development and management of endocrine-related diseases. We explore the complex interactions between the microbiota and the endocrine system, emphasizing the implications of microbiota dysbiosis for the onset and progression of various endocrine disorders. The review aims to synthesize current knowledge, highlighting recent advancements and the potential of novel therapeutic approaches targeting microbiota-endocrine interactions. Key topics include the impact of microbiota on hormone regulation, its role in endocrine pathologies, and the promising avenues of microbiota modulation through diet, probiotics, prebiotics, and fecal microbiota transplantation. We underscore the importance of this research in advancing personalized medicine, offering insights for more tailored and effective treatments for endocrine-related diseases.

PCOS and vitamin D: a clinical appraisal.

PURPOSE: Polycystic ovary syndrome (PCOS) is the most common endocrine-reproductive disease linked not just to infertility but also to serious comorbidities. There is a reported association between low vitamin D levels and multiple health conditions including PCOS. This narrative review aims to analyze the role of vitamin D in PCOS development, use of the vitamin D in the treatment of PCOS, and the molecular basis of these observations. METHODS: A Medline and PubMed research was performed, during the years 1990-2023, using a combination of keywords on such topic. According to the author's evaluation and target, papers were identified and included for a narrative review. RESULTS: There are associations between lower levels of vitamin D and PCOS, as well as with insulin resistance, metabolic syndrome, hyperandrogenemia, metabolic and endocrine disorders as well as the onset of oxidative stress and pro-inflammatory milieu, in PCOS women. CONCLUSION: Vitamin D has a role in pathologic changes linked to PCOS. Molecular and clinical investigations which give new information about the role of vitamin D in the development of PCOS and related endocrine and metabolic disturbance are further needed.

Role of Mediterranean diet in endocrine diseases: a joint overview by the endocrinologist and the nutritionist.

PURPOSE: The purpose of this review is to examine the current evidence on the potential role of Mediterranean diet (MD) in the prevention and management of endocrine disorders and to highlight the importance of interdisciplinary collaboration between endocrinologists and nutritionists. METHODS: A literature search was conducted using PubMed and Google Scholar databases to identify relevant studies published in English. Studies were selected based on their relevance to the role of MD in the prevention and management of endocrine disorders. The search terms included "Mediterranean diet," "endocrine disorders," "thyroid disorders," "gonadal disorders," and "neuroendocrine tumors". RESULTS: The studies reviewed suggest that MD may have a beneficial effect in the prevention and management of various endocrine disorders, including thyroid disorders, gonadal disorders, and neuroendocrine tumors. MD has been associated with decreased risk of nodular thyroid disease and thyroid cancer, improved male and female reproductive health, and a potential role in the management of neuroendocrine tumors. MD's anti-inflammatory and antioxidant properties, as well as its high levels of phytochemicals, may play a role in its beneficial effects. CONCLUSION: Interdisciplinary collaboration between endocrinologists and nutritionists is essential for the optimal management of endocrine disorders, including the potential role of MD in their prevention and management. While further research is needed, the current evidence suggests that MD may have a protective effect against endocrine disorders, and its incorporation into dietary recommendations may be beneficial.

Pollution and endometriosis: A deep dive into the environmental impacts on women's health.

BACKGROUND: The interaction between pollution and endometriosis is a pressing issue that demands immediate attention. The impact of pollution, particularly air and water pollution, or occupational hazards, on hormonal disruption and the initiation of endometriosis remains a major issue. OBJECTIVES: This narrative review aims to delve into the intricate connection between pollution and endometriosis, shedding light on how environmental factors contribute to the onset and severity of this disease and, thus, the possible public health policy implications. DISCUSSION: Endocrine-disrupting chemicals (EDCs) in pollutants dysregulate the hormonal balance, contributing to the progression of this major gynaecological disorder. Air pollution, specifically PM2.5 and PAHs, has been associated with an increased risk of endometriosis by enhancing chronic inflammation, oxidative stress, and hormonal imbalances. Chemical contaminants in water and work exposures, including heavy metals, dioxins, and PCBs, disrupt the hormonal regulation and potentially contribute to endometriosis. Mitigating the environmental impact of pollution is required to safeguard women's reproductive health. This requires a comprehensive approach involving stringent environmental regulations, sustainable practices, responsible waste management, research and innovation, public awareness, and collaboration among stakeholders. CONCLUSION: Public health policies have a major role in addressing the interaction between pollution and endometriosis in a long-term commitment.

Dyslipidaemia in endocrine disorders.

Lipid disorders are common in several endocrine conditions. Diabetes mellitus, hypothyroidism and Cushing's syndrome are the common endocrine disorders with dyslipidemia. Dyslipidemia has a significant impact on endocrine and metabolic health and the risk of atherosclerotic cardiovascular disease. In most cases of dyslipidemia, the suspicion of endocrine diseases must be based on clinical symptoms and signs. Optimal management of the dyslipidemia requires treatment of the underlying endocrine condition. Lipid lowering therapy is a useful adjunct or a requirement in many cases. The Indian guidelines provide a pragmatic and practical approach to the management of lipid disorders in endocrine disease, as well as endocrine vigilance with lipid therapy.

Knowledge of osteoporosis prevention among people with endocrine disorders: A cross-sectional study.

People with endocrine disorders are at an increased risk of osteoporosis, yet their knowledge of osteoporosis prevention is rarely studied. This study aimed to assess the knowledge related to osteoporosis prevention and its associated factors among people with endocrine disorders in China. A cross-sectional study was conducted in a Chinese hospital's Department of Metabolism and Endocrinology. A total of 562 people with endocrine disorders completed the Chinese version of the Osteoporosis Prevention and Awareness Tool to assess their knowledge of osteoporosis prevention. Results showed that participants had a mean knowledge of 59.36 ± 23.90 out of 100, with only 52.1% scoring above 60 points. Being female, having higher education, with comorbidities, with a recent osteoporosis diagnosis, and having received health education related to osteoporosis prevention were associated with higher knowledge of osteoporosis prevention. Our study indicates that more efforts are needed to improve the knowledge related to osteoporosis prevention among people with endocrine disorders. This may be realized by strengthening and expanding diverse education, focusing on males and those with lower education and without comorbidities.

Impact of Variation between Assays and Reference Intervals in the Diagnosis of Endocrine Disorders.

Method-related variations in the measurement of hormones and the reference intervals used in the clinical laboratory can have a significant, but often under-appreciated, impact on the diagnosis and management of endocrine disorders. This variation in laboratory practice has the potential to lead to an errant approach to patient care and thus could cause harm. It may also be the source of confusion or result in excessive or inadequate investigation. It is important that laboratory professionals and clinicians know about these impacts, their sources, and how to detect and mitigate them when they do arise. In this review article, we describe the historical and scientific context from which inconsistency in the clinical laboratory arises. Examples from the published literature of the impact of the method, reference interval, and clinical decision threshold-related discordances on the assessment and monitoring of various endocrine disorders are discussed to illustrate the sources, causes, and effects of this variability. Its potential impact on the evaluation of growth hormone deficiency and excess, thyroid and parathyroid disorders, hyperandrogenism, hypogonadism, glucocorticoid excess and deficiency, and diabetes mellitus is elaborated. Strategies for assessment and mitigation of the discordance are discussed. The clinical laboratory has a responsibility to recognise and address these issues, and although a lot has been accomplished in this area already, there remains more to be done.