Population data evidence of interdependence of the limbs of hormonal feedback loops.

The fundamental models underlying hormonal physiological regulation and homeostasis remain poorly understood. We aimed to derive quantitative evidence regarding these models from the study of population data of balance points of different parameters and their respective controlling hormones. We studied the slopes of correlations between concentrations of circulating free thyroxine and thyrotropin, calcium and parathyroid hormone, haemoglobin and erythropoietin, and glucose and insulin in such population data, as well as the slopes of the limbs of various feedback loops estimated empirically and by reverse engineering of the population data. We used computer simulations to model the factors that influence the slopes derived from the population data, and then matched these simulations with the empirically derived slopes. Our simulations showed that changes to the population distribution of feedback loop limbs may alter the slopes of correlations within population data in specific ways. Non-random (interdependent) associations of the limbs of feedback loops may also have this effect, as well as producing discrepancies between the slopes of feedback limb loops determined experimentally and the same slopes determined by derivation from population data. Our corresponding empirical findings were consistent with the presence of such interdependence in the free thyroxine/thyrotropin, haemoglobin/erythropoietin and glucose /insulin systems. The glucose/insulin data provided evidence consistent with increasing interdependence with age in childhood. Our findings therefore provide strong evidence that the interdependence of the limbs of feedback loops is a general feature of endocrine homeostatic regulation. This interdependence potentially bestows evolutionary homeostatic and regulatory advantages.

Memory in female adolescents with congenital adrenal hyperplasia due to 21-hydroxylase deficiency.

INTRODUCTION: In females with congenital adrenal hyperplasia (CAH), the influence of hyperandrogenism and glucocorticoid supplementation on neurocognition is controversial. OBJECTIVES: To identify possible differences in visual working memory and verbal memory in adolescent girls with CAH due to 21-hydroxylase deficiency and matched controls. Moreover, to study if any relationship between variables associated with CAH and the scores of the selected memory tests was present. MATERIAL AND METHODS: In total 39 individuals were studied, female adolescents with CAH and age and pubertal stage matched healthy male and female controls (13 in each group). Sociodemographic, clinical, hormonal, and neurocognitive variables were explored. In female adolescents with CAH, variables related to the disease (age at diagnosis, clinical form, time since diagnosis, and glucocorticoid doses) were correlated with the scores obtained for neurocognitive variables. RESULTS: The mean age was 13.9 ± 3.3 years. In female adolescents with CAH the results were worse compared to controls in Free Recall (p = 0.039) and in Visual Memory Span score (p = 0.016). Age at diagnosis was negatively correlated to number of hits (p = 0.04), number recalled backward (p = 0.03), Visual Memory Span test score (p = 0.04) and Total Free Recall (p = 0.04), i.e., memory was worse with later diagnosis. CONCLUSIONS: Female adolescents with CAH had worse visual working memory compared to matched controls, but not in verbal memory. Age at diagnosis was negatively associated with the memory tests.

Prevalence and Incidence of Fractures in Patients With Nonfunctional Adrenal Tumors.

Importance: It is unclear whether nonfunctional adrenal tumors (NFATs) are associated with fractures. Objective: To analyze fracture frequencies in individuals with NFATs. Design, Setting, and Participants: A national retrospective cohort study was conducted in patients with NFATs diagnosed in Sweden between January 1, 2005, and December 31, 2019, and control participants without adrenal tumors followed up until death or the end of 2019. Individuals with a diagnosis of adrenal hormonal excess or previous malignant tumors were excluded. Sensitivity analyses were performed in subgroups of individuals with a combination of gallbladder, biliary tract, and pancreas diseases (for whom it was assumed that controls would also have undergone computed tomography) and 3- and 12-month survival free of malignant tumors after the NFAT diagnosis. The data were analyzed from September to November 2023. Exposures: Diagnosis of NFATs. Main Outcomes and Measures: Main study outcomes were prevalence and incidence of fractures after adjustment for sex, age, and comorbidities. Secondary outcomes were fragility fractures, fractures with fall on the same level, and fracture locations (distal arm and vertebral and hip fractures). Fracture incidence after adrenalectomy was also studied. Results: Among 20 390 patients, 12 120 (59.4%) were women, and the median (IQR) age was 66 (57-73) years; among 125 392 controls, 69 994 (55.8%) were women, and the median (IQR) age was 66 (57-73) years. Previous fractures were more common in patients diagnosed with NFATs compared with controls (4310 of 20 390 [21.1%] vs 20 323 of 125 392 [16.2%]; odds ratio [OR], 1.39; 95% CI, 1.34-1.45; adjusted OR [AOR], 1.27; 95% CI, 1.23-1.33). During the follow-up period (median [IQR], 4.9 [2.2-8.2] years), incident fractures were more common in patients with NFATs (3127 of 20 390 [15.3%] vs 16 086 of 125 392 [12.8%]; hazard ratio [HR], 1.40; 95% CI, 1.34-1.45; adjusted HR [AHR], 1.27; 95% CI, 1.22-1.33). An association between NFATs and vertebral fractures was found (AOR, 1.51; 95% CI, 1.33-1.72; AHR, 1.83; 95% CI, 1.60-2.09). In men younger than 50 years, NFATs were associated with fractures (AOR, 1.45; 95% CI, 1.21-1.74; AHR, 1.48; 95% CI, 1.20-1.82). There was no association among individuals who had undergone adrenalectomy (AHR, 1.12; 95% CI, 0.90-1.38). The association between NFATs and fractures remained significant and of similar magnitude in all sensitivity analyses. Conclusions and Relevance: In this cohort study, NFATs were associated with fractures, particularly among younger men; thus, patients with NFATs should have bone health evaluation with appropriate treatment and monitoring, especially in younger men.

Adrenal tumors in patients with neuroendocrine neoplasms.

PURPOSE: To study the prevalence of primary adrenal tumors and adrenal metastases in patients with neuroendocrine neoplasms (NENs) and describe these in detail. NENs can be further divided into neuroendocrine tumor (NET) and neuroendocrine carcinoma (NEC). METHODS: A review of medical files was conducted for all patients who underwent a 68Gallium-DOTATOC-PET/CT during 2010-2023 or adrenalectomy during 1999-2023 at the Karolinska University Hospital. RESULTS: In total, 68Gallium-DOTATOC-PET/CT was performed on 1750 individuals with NEN, among whom 12 (0.69%) had adrenal tumors. Of these, 9 (0.51%) were NEN metastases. Out of 1072 adrenalectomies, 4 (0.37%) showed evidence of NEN metastases. Thus, 16 patients with NEN exhibited adrenal tumors. The adrenal tumors were found on average 5 years after the NEN diagnosis and 19% of the adrenal tumors with simultaneous NEN were benign. Few had all adrenal hormones measured. None had an adrenal insufficiency nor an adrenal biopsy. Another synchronous metastasis was found in 69% at the time of the adrenal tumor discovery. During the median 2-year follow-up, 38% of the subjects had deceased (with the exclusion of individuals presenting supposedly benign adrenal tumors 31%) all due to tumor complications. A comparison between individuals identified through 68Gallium-DOTATOC-PET/CT and those who underwent adrenalectomy revealed a higher prevalence of NETs in the former group and NECs in the latter group. CONCLUSION: Adrenal primary tumors and adrenal metastases are infrequent occurrences in patients with NEN. Most cases involved the presence of NEN metastasis upon the initial discovery of adrenal tumors. The overall prognosis was found to be favorable.

Surgical outcome after thyroidectomy due to Graves' disease and Lugol iodine treatment: a retrospective register-based cohort study.

PURPOSE: This study aimed to investigate the relationship between Lugol iodine treatment in a rescue setting and surgical outcomes in Graves' disease patients. METHODS: The retrospective register-based cohort study included 813 patients who had undergone primary total thyroidectomy with a primary diagnosis of Graves' disease (ICD-code E05.0) at Karolinska University Hospital in Stockholm, Sweden, between January 2008 and December 2015. Of 813 patients, 33 (4.1%) were given Lugol iodine before surgery and the remaining, the non-Lugol group, did not. The study's primary outcomes were post-operative calcium treatment day 1, calcium and vitamin D supplements at discharge and follow-up. Secondary outcomes were laryngeal nerve damage and bleeding (defined as re-operation). RESULTS: Differences were found between the Lugol and non-Lugol groups in the treatment of calcium day 1 (45.5% vs 26.7%, p = 0.018), at discharge (36.4% vs. 16.2%, p = 0.002) and vitamin D supplements at discharge (36.4% vs. 19.1%, p = 0.015) as surrogate variables for hypocalcemia post-operatively. No differences could be seen at 4-6 weeks and six-months follow-up. There were no differences between the Lugol and non-Lugol groups in terms of operation time, laryngeal nerve damage, and bleeding. CONCLUSION: Patients in our cohort undergoing thyroidectomy due to Graves' disease pre-operatively treated with Lugol iodine as a rescue therapy had a higher risk of experiencing short term post-operative hypocalcemia.

Establishment and representativeness of the Stockholm Sodium Cohort: A laboratorial and pharmacoepidemiologic database covering 1.6 million individuals in the Stockholm County.

OBJECTIVE: Hyponatremia is associated with considerable morbidity and mortality, but causal links have been difficult to establish. Here, we describe the establishment and representativeness of the Stockholm Sodium Cohort (SSC), designed to study etiologies and outcomes of hyponatremia. STUDY DESIGN AND SETTING: All residents of Stockholm County undertaking at least one serum sodium test between 2005-2018 were included in the SSC. Individual-level test results from over 100 laboratory parameters relevant to hyponatremia were collected and linked to data on demographics, socioeconomic status, healthcare contacts, diagnoses and dispensed prescription medications using national registers. RESULTS: A total of 1,632,249 individuals, corresponding to 64% of the population of Stockholm County, were included in the SSC. Coverage increased with advancing age, ranging from 32% in children and adolescents (≤18 years) to 97% among the oldest (≥80 years). The coverage of SSC included the vast majority of patients in Stockholm County diagnosed with diabetes mellitus (93%), myocardial infarction (98%), ischemic stroke (97%), cancer (85%), pneumonias requiring inpatient care (95%) and deaths (88%). CONCLUSION: SSC is the first cohort specifically designed to investigate sodium levels in a large, population-based setting. It includes a wide range of administrative health data and laboratory analyses. The coverage is high, particularly among elderly and individuals with comorbidities. Consequently, the cohort has a large potential for exploration of various aspects of hyponatremia.

Approach to the Patient: Reninoma.

A reninoma is a functional tumor of afferent arteriolar juxtaglomerular cells that secretes the enzyme renin, leading to hyperactivation of the renin-angiotensin-aldosterone system. Reninoma is a potentially curable cause of pathological secondary hyperaldosteronism that results in often severe hypertension and hypokalemia. The lack of suppression of plasma renin contrasts sharply with the much more common primary aldosteronism, but diagnosis is often prompted by screening for that condition. The major differential diagnosis of reninoma is renovascular hypertension. Fewer than 200 cases of reninoma have been described. Reninomas have been reported across a broad demographic but have a 2:1 predilection for women, often of childbearing age. Aldosterone receptor blockade, angiotensin-converting enzyme inhibitors, or angiotensin receptor blockers offer effective medical management but are contraindicated in pregnancy, so surgical curative resection is ideal. The current optimal imaging and biochemical workup of reninoma and management approach (ideally, tumor excision with subtotal renal resection) are described.

Increased Prevalence of Accidents and Injuries in Congenital Adrenal Hyperplasia: A Population-based Cohort Study.

CONTEXT: It has been suggested that injuries and accidents are increased in females with congenital adrenal hyperplasia (CAH), but the prevalence is unclear. OBJECTIVE: To study the prevalence of injuries and accidents in females and males with CAH. DESIGN, SETTING, AND PARTICIPANTS: Patients with CAH (n = 714, all 21-hydroxylase deficiency) were compared with matched controls (n = 71 400). Data were derived by linking National Population-Based Registers. MAIN OUTCOME MEASURES: Prevalence of injuries and accidents. RESULTS: Mean age was 29.8 ± 18.4 years. Injuries were more prevalent in patients with CAH than in controls (relative risk, 1.34; 95% CI, 1.24-1.44), and this was found in both sexes (females: 1.43; 1.29-1.58; males: 1.25; 1.12-1.38). In the classical phenotype, the prevalence of injuries was higher, especially in females but not in the nonclassic phenotype. In the genotype groups, injuries were mainly increased in females. Head injuries were increased in all patients with CAH and in the different phenotypes and were mainly driven by females. More patients with CAH born before the introduction of neonatal screening had had an injury compared with controls (1.48; 1.35-1.62); this was seen in both sexes. In patients with CAH born after the introduction of screening, the prevalence of injuries was overall increased (1.20; 1.07-1.35), and in females with CAH but not in males. Accidents showed a similar pattern to injuries in all comparisons. CONCLUSION: Patients with CAH had an increased prevalence of both injuries and accidents, especially in females and in those born before the neonatal screening program. Patients with nonclassic phenotype were hardly affected.

A clinical perspective on ectopic Cushing's syndrome.

Cushing's syndrome (CS) refers to the clinical features of prolonged pathological glucocorticoid excess. About 10-20% of individuals with CS have ectopic CS (ECS), that is, an adrenocorticotropin (ACTH)-producing tumour outside the pituitary gland. ACTH-secreting neuroendocrine neoplasia (NENs) can arise from many organs, although bronchial NEN, small cell lung cancer (SCLC), pancreatic NEN, thymic NEN, medullary thyroid cancer (MTC), and pheochromocytoma are the most common. Patients with ECS frequently present with severe hypercortisolism. The risk of life-threatening complications is high in severe cases, unless the hypercortisolism is effectively treated. A good outcome in ECS requires a methodical approach, incorporating prompt diagnosis, tumour localization, control of cortisol excess, and resection of the primary tumour when possible.

Factors underlying a disproportionate increase in hospital admissions for adrenal insufficiency in women aged 20-29 years.

Since the year 2000, admissions for adrenal insufficiency (AI) and adrenal crises (AC) have shown a particular increase in young adult females. We examined data on acute non-surgical hospitalisations for AI/AC from New South Wales, Australia, to determine relevant factors that may have contributed to this increase. Data were analysed to ascertain associations between various comorbid psychosocial issues, identified by relevant ICD-10-AM codes in each record, and ACs. From 2005 to 2021. There were 877 admissions for an acute non-surgical illness in this age group. The average admission rate for females [63.5/million/year] was almost twice that for males [34.0/million/year] (p<0.01), as was the average female AC admission rate [14.7/million/year] relative to that in males [6.75/million/year] (p=NS). Infection was present in 41.6% (n=365) of the admissions and Type 1 diabetes mellitus was present in 12.2% (n=107). Overall, psychosocial factors were considered by the senior clinician to have contributed to the illness episode in 22.1% of all admissions and 29.0% of AC admissions. Having one or more psychosocial problems was associated with an AC in females (37.4%, n=49, in those having an AC, p<0.001) but not males. Females with an AC also had a higher mean composite psychosocial, psychiatric and drug/alcohol score [0.47 (0.67)] than females without an AC [0.32 (0.62) p<0.05]. No comparable associations were found in male patients. An increase in the rates of hospitalisations that included a code for at least one psychosocial problem was highly correlated with increases in admission rates for both ACs (r=0.82, p<0.001) and all AI (r=0.98, p<0.001) in females but there was no such relationship in males. This new evidence suggests that psychosocial factors may play an important role in ongoing rates of ACs in treated AI (incidence approximately 6-8 ACs/100PY) particularly in young adult females. In order to minimize AC episodes, all barriers to self-management need exploration on an individual patient basis and with regard to the patient population as a whole.

Lung Carcinoids: A Comprehensive Review for Clinicians.

Lung carcinoids are neuroendocrine tumors, categorized as typical or atypical carcinoids based on their histological appearance. While most of these tumors are slow-growing neoplasms, they still possess malignant potential. Many patients are diagnosed incidentally on chest X-rays or CT scans. Presenting symptoms include cough, hemoptysis, wheezing, dyspnea, and recurrent pneumonia. Endocrine symptoms, such as carcinoid syndrome or ectopic Cushing's syndrome, are rare. Surgery is the primary treatment and should be considered in all patients with localized disease, even when thoracic lymph node metastases are present. Patients with distant metastases may be treated with somatostatin analogues, chemotherapy, preferably temozolomide-based, mTOR inhibitors, or peptide receptor radionuclide therapy (PRRT) with 177Lu-DOTATATE. Most patients have an excellent prognosis. Poor prognostic factors include atypical histology and lymph node metastases at diagnosis. Long-term follow-up is mandatory since metastases may occur late.

Cardiovascular risk in Cuban adolescents and young adults with congenital adrenal hyperplasia.

BACKGROUND: Hyperandrogenism and supraphysiologic glucocorticoid replacement may lead to subclinical atherosclerosis in people with congenital adrenal hyperplasia (CAH) and predispose the development of cardiovascular diseases from an early age. OBJECTIVES: To determine if cardiometabolic risk factors and subclinical atherosclerosis are more frequent in patients with CAH due to 21-hydroxylase deficiency (21OHD) and if there is an association with clinical, hormonal and treatment of 21OHD. MATERIAL AND METHODS: A descriptive prospective cross-sectional study exploring clinical variables, biochemical, hormonal variables, endothelial dysfunction (flow-mediated dilation < 5%) and carotid intima media thickness (≥ 95 percentile in adolescents and ≥ 75 percentile in adults) and epicardial fat. Adolescents and young patients with 21OHD were compared with controls matched by age, sex, body mass index and Tanner stage. RESULTS: Forty four subjects (22 with CAH), 36 (82%) females, with a mean age of 17.1 ± 5.5 years (range 10-30 years) were included. Family history revealed diabetes, hypertension, and hypercholesterolemia with high frequencies in both groups. The blood pressure was similar in both groups. Blood glucose levels were lower and triglycerides higher in patient (both p < 0.01). Epicardial fat was similar between groups and in patients with CAH it was related to cholesterol levels ​​(r = 0.679, p < 0.01), time since CAH diagnosis (r = 0.462, p = 0.03) and glucocorticoid dose (r = 0.499, p = 0.04). Carotid intima media thickness (CIMT) had a tendency to be increased in patients (p = 0.07) and was directly related to 17-hydroxyprogesterone (r = 0.510, p = 0.018), diastolic blood pressure (r = 0.444, p = 0.04) and the homeostatic model assessment (HOMA) index (r = 0.507, p = 0.01). Endothelial dysfunction was not different between groups. CONCLUSIONS: Some cardiometabolic risk factors were increased in patients with CAH and were associated with clinical, hormonal and treatment parameters of CAH. Cardiometabolic risk should be evaluated regularly in patients with CAH.

Incidence of Dysmagnesemia among Medically Hospitalized Patients and Associated Clinical Characteristics: A Prospective Cohort Study.

Background: Magnesium (Mg) disorders are common among hospitalized patients and are linked to poor health outcomes. We aimed to determine the incidence of dysmagnesemia among medically hospitalized patients and to identify factors that are associated with dysmagnesemia. Methods: A prospective cohort study was conducted at Sultan Qaboos University Hospital (SQUH) from April 1st, 2022, to October 31st, 2022, and involved hospitalized adult patients (≥18 years) under the care of the general internal medicine unit. The patients' serum total magnesium (Mg) concentrations were categorized as hypomagnesemia (≤0.69 mmol/L), hypermagnesemia (≥1.01 mmol/L), or dysmagnesemia, which encompassed either hypomagnesemia or hypermagnesemia. Results: Of the 304 patients evaluated, dysmagnesemia was observed in 22.0%, which comprised of 17.4% with hypomagnesemia and 4.6% with hypermagnesemia. Statistically significant associations were identified between hypermagnesemia and chronic kidney disease (CKD) (p = 0.05) and elevated creatinine levels (p < 0.01) and lower estimated glomerular filtration rate (eGFR) (p < 0.01). Hypomagnesemia was linked to lower ionized calcium (p = 0.03) and admission due to infectious diseases (p = 0.02). However, ordered regression analysis did not find any significant associations with the different magnesium groups. Conclusion: Dysmagnesemia was prevalent among hospitalized patients and was associated with different factors; however, ordered regression analysis did not find any association with the different magnesium group, probably due to the limited number of included individuals.

The Stability of Analytes of Ionized Magnesium Concentration and Its Reference Range in Healthy Volunteers.

This study aimed to determine the stability of refrigerated analytes of iMg concentration at different time intervals and to establish iMg reference range in a cohort of healthy Omani volunteers (≥18 years). The concentrations of iMg were measured using the direct ion-selective electrode technique. Pearson's and Lin's concordance correlation coefficients along with the Bland-Altman plot were used to assess the levels of agreement between iMg concentrations of fresh and refrigerated blood samples at different time intervals. The study included 167 volunteers (51% females) with a median age of 21 (range: 20-25) years. The median, 2.5th, and 97.5th percentiles for fresh iMg reference ranges were 0.55, 0.47, and 0.68 mmol/L, respectively. The overall agreement between the fresh and refrigerated iMg concentrations was poor (rho-c = 0.51; p < 0.001). However, according to Altman's definition, iMg concentrations of the refrigerated samples for a period of ≤1 h had an excellent correlation with the fresh iMg concentrations (Lin's rho-c = 0.80), with a small average bias difference of 0.009 (95%CI; -0.025-0.043). A cut-off refrigeration period within ≤1 h at 2-8 °C can be considered an alternate time frame for the gold standard measurement (fresh or within 0.5 h).

Adrenal and periadrenal schwannoma: histological, molecular and clinical characterization of an institutional case series.

PURPOSE: Adrenal schwannoma (AS) and periadrenal schwannoma (PAS) are exceedingly rare Schwann cell tumors that develop from the adrenal medulla and periadrenal peripheral nerves respectively. The underlying genetic events are elusive. METHODS: We searched our institutional database for AS/PAS cases and reviewed the histology and clinical outcome. Comprehensive molecular work-up was performed. RESULTS: We found reports of 4 AS/PAS cases diagnosed between 1992 and 2022 among the 1248 adrenal lesions submitted for histopathology during the same time period (0.32%). Two patients were male, two were female, and the age span was 59-80 years. Median size was 70 mm (range 50-100 mm), and from a radiology perspective, the lesions were initially suspected of malignant lesions originating from either adrenals or kidneys. Hormonal analyses were normal in all cases. Histologically, three cases were annotated as cellular AS or PAS, and one case was annotated as microcystic AS. Molecular characterization using focused next-generation sequencing did not identify SMARCB1 or NF2 mutations, alterations previously associated to schwannoma at other anatomical sites. The postoperative period was without complications for all patients, and follow-up did not show any signs of relapse or metastatic disease. CONCLUSION: AS/PAS are rare neoplasms that are most often benign, and the molecular etiology is most likely not related to mutations in established schwannoma-related genes. Since these tumors may be misinterpreted as malignant, knowledge of this entity is essential for radiologists, endocrinologists, surgeons and pathologists.

Hypermagnesemia in Clinical Practice.

Hypermagnesemia is a relatively uncommon but potentially life-threatening electrolyte disturbance characterized by elevated magnesium concentrations in the blood. Magnesium is a crucial mineral involved in various physiological functions, such as neuromuscular conduction, cardiac excitability, vasomotor tone, insulin metabolism, and muscular contraction. Hypomagnesemia is a prevalent electrolyte disturbance that can lead to several neuromuscular, cardiac, or nervous system disorders. Hypermagnesemia has been associated with adverse clinical outcomes, particularly in hospitalized patients. Prompt identification and management of hypermagnesemia are crucial to prevent complications, such as respiratory and cardiovascular negative outcomes, neuromuscular dysfunction, and coma. Preventing hypermagnesemia is crucial, particularly in high-risk populations, such as patients with impaired renal function or those receiving magnesium-containing medications or supplements. Clinical management of hypermagnesemia involves discontinuing magnesium-containing therapies, intravenous fluid therapy, or dialysis in severe cases. Furthermore, healthcare providers should monitor serum magnesium concentration in patients at risk of hypermagnesemia and promptly intervene if the concentration exceeds the normal range.