Consensus guidance for monitoring individuals with islet autoantibody-positive pre-stage 3 type 1 diabetes.

Given the proven benefits of screening to reduce diabetic ketoacidosis (DKA) likelihood at the time of stage 3 type 1 diabetes diagnosis, and emerging availability of therapy to delay disease progression, type 1 diabetes screening programmes are being increasingly emphasised. Once broadly implemented, screening initiatives will identify significant numbers of islet autoantibody-positive (IAb+) children and adults who are at risk of (confirmed single IAb+) or living with (multiple IAb+) early-stage (stage 1 and stage 2) type 1 diabetes. These individuals will need monitoring for disease progression; much of this care will happen in non-specialised settings. To inform this monitoring, JDRF in conjunction with international experts and societies developed consensus guidance. Broad advice from this guidance includes the following: (1) partnerships should be fostered between endocrinologists and primary-care providers to care for people who are IAb+; (2) when people who are IAb+ are initially identified there is a need for confirmation using a second sample; (3) single IAb+ individuals are at lower risk of progression than multiple IAb+ individuals; (4) individuals with early-stage type 1 diabetes should have periodic medical monitoring, including regular assessments of glucose levels, regular education about symptoms of diabetes and DKA, and psychosocial support; (5) interested people with stage 2 type 1 diabetes should be offered trial participation or approved therapies; and (6) all health professionals involved in monitoring and care of individuals with type 1 diabetes have a responsibility to provide education. The guidance also emphasises significant unmet needs for further research on early-stage type 1 diabetes to increase the rigour of future recommendations and inform clinical care.

Consensus Guidance for Monitoring Individuals With Islet Autoantibody-Positive Pre-Stage 3 Type 1 Diabetes.

Given the proven benefits of screening to reduce diabetic ketoacidosis (DKA) likelihood at the time of stage 3 type 1 diabetes diagnosis, and emerging availability of therapy to delay disease progression, type 1 diabetes screening programs are being increasingly emphasized. Once broadly implemented, screening initiatives will identify significant numbers of islet autoantibody-positive (IAb+) children and adults who are at risk for (confirmed single IAb+) or living with (multiple IAb+) early-stage (stage 1 and stage 2) type 1 diabetes. These individuals will need monitoring for disease progression; much of this care will happen in nonspecialized settings. To inform this monitoring, JDRF, in conjunction with international experts and societies, developed consensus guidance. Broad advice from this guidance includes the following: 1) partnerships should be fostered between endocrinologists and primary care providers to care for people who are IAb+; 2) when people who are IAb+ are initially identified, there is a need for confirmation using a second sample; 3) single IAb+ individuals are at lower risk of progression than multiple IAb+ individuals; 4) individuals with early-stage type 1 diabetes should have periodic medical monitoring, including regular assessments of glucose levels, regular education about symptoms of diabetes and DKA, and psychosocial support; 5) interested people with stage 2 type 1 diabetes should be offered trial participation or approved therapies; and 6) all health professionals involved in monitoring and care of individuals with type 1 diabetes have a responsibility to provide education. The guidance also emphasizes significant unmet needs for further research on early-stage type 1 diabetes to increase the rigor of future recommendations and inform clinical care.

Nondisclosure of Type 1 Diabetes in Adolescence: A Single-Center Experience.

Objective: The aim of this study was to assess the extent of nondisclosure of type 1 diabetes in adolescents and investigate its association with several psychosocial parameters and clinical outcomes. Research design and methods: This was a cross-sectional study based on data collected from 69 adolescents with type 1 diabetes who were 12-18 years of age and followed at our diabetes clinic. The degree of disclosure, demographics, diabetes management, and psychosocial issues were assessed via questionnaires. Clinical parameters were derived from medical records. Associations between nondisclosure status and clinical and psychosocial study variables were assessed. Results: Fifty-three participants (77%) reported some extent of nondisclosure. Nondisclosure was associated with low self-esteem, reduced friend support, and increased diabetes-related worries. Nondisclosure was also found to be associated with diminished self-care behaviors related to insulin administration and with elevated A1C. Conclusion: Our results demonstrate that nondisclosure of type 1 diabetes in adolescents may be more common than initially recognized and is likely associated with unfavorable psychological outcomes and reduced self-care and diabetes management. Our results emphasize the importance of social interactions and disclosure in adolescents and may serve as a potential stepping stone to address other social barriers hindering diabetes management.

Clinical and immunological characteristics of children diagnosed with-Type 1 diabetes during the COVID-19 pandemic.

AIMS: To find clinical and immunological signatures of the SARS-CoV-2 and the COVID-19 pandemic on children newly diagnosed with type 1 diabetes (T1D). METHODS: A single-centre, retrospective, observational study comparing the clinical and immunological characteristics of children diagnosed with T1D the year before and during the first 2 years of the COVID-19 pandemic. Data extracted from the medical records included clinical and demographic parameters, COVID-19 PCR results and the presence of anti-islet, thyroid and celiac-related antibodies. Also obtained from the medical records was a family history of T1D, celiac disease and autoimmune thyroid disease in a first-degree family member. RESULTS: A total of 376 children were diagnosed with T1D during the study period. A total of 132 in the pre-COVID era and 246 in the first 2 years of the pandemic. At diagnosis, the pH in children with DKA was lower, and HbA1c tended to be higher in the COVID-19 group compared to the pre-COVID-19 group (7.30 [7.18, 7.35] vs 7.33 [7.19, 7.36], p = 0.046) and (110.9 [86.9, 129.5] vs 100 [80.3, 129.5], p = 0.067]) respectively. Multiple islet antibodies (IA) were significantly more common among patients in the pre-COVID-19 group compared to the COVID-19 group (72% vs 61%, p = 0.032). Tissue transglutaminase antibodies were more common among children diagnosed in the COVID-19 compared to the pre-COVID group (16.6% vs 7.9%, p = 0.022). CONCLUSIONS: Our findings suggest that SARS-CoV-2 and the environmental alterations caused by the pandemic affected the clinical characteristics and the immunological profile of children diagnosed with T1D. It is, therefore, plausible that the virus plays a role in the autoimmune process causing T1D.

Disordered eating behaviours in adolescents with type 1 diabetes can be influenced by their weight at diagnosis and rapid weight gain subsequently.

AIMS: To assess the prevalence and disease-related risk factors for disordered eating behaviours among adolescents with type 1 diabetes and also to search for risk factors at disease diagnosis that can predict the development of disordered eating behaviours. METHODS: A retrospective observational study of 291 adolescents aged 15-19 years with type 1 diabetes who completed the Diabetes Eating Problem Survey-Revised (DEPS-R) as is routine in our diabetes clinic. The prevalence of disordered eating behaviours and risk factors for their development was assessed. RESULTS: In 84 (28.9%) adolescents, disordered eating behaviours were found. Disordered eating behaviours were positively associated with female sex (ß = 3.01 [SE = 0.97], p = 0.002), higher BMI-Z score (ß = 2.08 [SE = 0.49], p < 0.001), higher HbA1c (ß = 0.19 [SE = 0.03], p < 0.001) and treatment with multiple daily injections of insulin (ß = 2.19 [SE = 1.02], p = 0.032). At type 1 diabetes diagnosis, higher BMI-Z score (ß = 1.54 [SE = 0.63], p = 0.016) for those diagnosed before age 13 years and increased weight gain at 3 months post-diagnosis (ß = 0.88 [SE = 0.25], p = 0.001) in females diagnosed at age 13 years or older were found to be risk factors for disordered eating behaviours. CONCLUSIONS: Disordered eating behaviours are common among adolescents with type 1 diabetes and are associated with various parameters, including BMI at diagnosis and the rate of weight gain at 3 months post-diagnosis in females. Our findings highlight the need for early preventive efforts for disordered eating behaviours and interventions to avoid late diabetes complications.

A fly GWAS for purine metabolites identifies human FAM214 homolog medusa, which acts in a conserved manner to enhance hyperuricemia-driven pathologies by modulating purine metabolism and the inflammatory response.

Elevated serum urate (hyperuricemia) promotes crystalline monosodium urate tissue deposits and gout, with associated inflammation and increased mortality. To identify modifiers of uric acid pathologies, we performed a fly Genome-Wide Association Study (GWAS) on purine metabolites using the Drosophila Genetic Reference Panel strains. We tested the candidate genes using the Drosophila melanogaster model of hyperuricemia and uric acid crystallization ("concretion formation") in the kidney-like Malpighian tubule. Medusa (mda) activity increased urate levels and inflammatory response programming. Conversely, whole-body mda knockdown decreased purine synthesis precursor phosphoribosyl pyrophosphate, uric acid, and guanosine levels; limited formation of aggregated uric acid concretions; and was sufficient to rescue lifespan reduction in the fly hyperuricemia and gout model. Levels of mda homolog FAM214A were elevated in inflammatory M1- and reduced in anti-inflammatory M2-differentiated mouse bone marrow macrophages, and influenced intracellular uric acid levels in human HepG2 transformed hepatocytes. In conclusion, mda/FAM214A acts in a conserved manner to regulate purine metabolism, promotes disease driven by hyperuricemia and associated tissue inflammation, and provides a potential novel target for uric acid-driven pathologies.

Adjustment of Insulin Pump Settings in Type 1 Diabetes Management: Advisor Pro Device Compared to Physicians' Recommendations.

AIMS: To compare insulin dose adjustments made by physicians to those made by an artificial intelligence-based decision support system, the Advisor Pro, in people with type 1 diabetes (T1D) using an insulin pump and self-monitoring blood glucose (SMBG). METHODS: This was a multinational, non-interventional study surveying 17 physicians from 11 countries. Each physician was asked to provide insulin dose adjustments for the settings of the pump including basal rate, carbohydrate-to-insulin ratios (CRs), and correction factors (CFs) for 15 data sets of pumps and SMBG of people with T1D (mean age 18.4 ± 4.8 years; eight females; mean glycated hemoglobin 8.2% ± 1.4% [66 ± 11mmol/mol]). The recommendations were compared among the physicians and between the physicians and the Advisor Pro. The study endpoint was the percentage of comparison points for which there was an agreement on the direction of insulin dose adjustments. RESULTS: The percentage (mean ± SD) of agreement among the physicians on the direction of insulin pump dose adjustments was 51.8% ± 9.2%, 54.2% ± 6.4%, and 49.8% ± 11.6% for the basal, CR, and CF, respectively. The automated recommendations of the Advisor Pro on the direction of insulin dose adjustments were comparable )49.5% ± 6.4%, 55.3% ± 8.7%, and 47.6% ± 14.4% for the basal rate, CR, and CF, respectively( and noninferior to those provided by physicians. The mean absolute difference in magnitude of change between physicians was 17.1% ± 13.1%, 14.6% ± 8.4%, and 23.9% ± 18.6% for the basal, CR, and CF, respectively, and comparable to the Advisor Pro 11.7% ± 9.7%, 10.1% ± 4.5%, and 25.5% ± 19.5%, respectively, significant for basal and CR. CONCLUSIONS: Considerable differences in the recommendations for changes in insulin dosing were observed among physicians. Since automated recommendations by the Advisor Pro were similar to those given by physicians, it could be considered a useful tool to manage T1D.

Diagnosing Growth Hormone Deficiency: Can a Combined Arginine and Clonidine Stimulation Test Replace 2 Separate Tests?

OBJECTIVE: Given the large number of false-positive growth hormone deficiency (GHD) diagnoses from a single growth hormone (GH) stimulation test in children, 2 different pharmacologic tests, performed on separate days or sequentially, are required. This study aimed to assess the reliability and safety of a combined arginine-clonidine stimulation test (CACST). METHODS: This was a retrospective, single-center, observational study. During 2017-2019, 515 children aged >8 years underwent GH stimulation tests (CACST: n = 362 or clonidine stimulation test [CST]: n = 153). The main outcome measures used to compare the tests were GH response (sufficiency/deficiency) and amplitude and timing of peak GH and safety parameters. RESULTS: Population characteristics were as follows: median age of 12.2 years (interquartile range [IQR]: 10.7, 13.4), 331 boys (64%), and 282 prepubertal children (54.8%). The GHD rate was comparable with 12.7% for CACST and 14.4% for CST followed by a confirmatory test (glucagon or arginine) (P = .609). Peak GH was higher and occurred later in response to CACST compared with CST (14.6 ng/mL [IQR: 10.6, 19.4] vs 11.4 ng/mL [IQR: 7.0, 15.8], respectively, P < .001; 90 minutes [IQR: 60, 90] vs 60 minutes [IQR: 60, 90], respectively, P < .001). No serious adverse events occurred following CACST. CONCLUSION: Our findings demonstrate the reliability and safety of CACST in detecting GHD in late childhood and adolescence, suggesting that it may replace separate or sequential GH stimulation tests. By diminishing the need for the second GH stimulation test, CACST saves time, is more cost-effective, and reduces discomfort for children, caregivers, and medical staff.

Mifepristone Increases Life Span of Virgin Female Drosophila on Regular and High-fat Diet Without Reducing Food Intake.

Background: The synthetic steroid mifepristone is reported to have anti-obesity and anti-diabetic effects in mammals on normal and high-fat diets (HFD). We previously reported that mifepristone blocks the negative effect on life span caused by mating in female Drosophila melanogaster. Methods: Here we asked if mifepristone could protect virgin females from the life span-shortening effect of HFD. Mifepristone was assayed for effects on life span in virgin females, in repeated assays, on regular media and on media supplemented with coconut oil (HFD). The excrement quantification (EX-Q) assay was used to measure food intake of the flies after 12 days mifepristone treatment. In addition, experiments were conducted to compare the effects of mifepristone in virgin and mated females, and to identify candidate mifepristone targets and mechanisms. Results: Mifepristone increased life span of virgin females on regular media, as well as on media supplemented with either 2.5 or 5% coconut oil. Food intake was not reduced in any assay, and was significantly increased by mifepristone in half of the assays. To ask if mifepristone might rescue virgin females from all life span-shortening stresses, the oxidative stressor paraquat was tested, and mifepristone produced little to no rescue. Analysis of extant metabolomics and transcriptomics data suggested similarities between effects of mifepristone in virgin and mated females, including reduced tryptophan breakdown and similarities to dietary restriction. Bioinformatics analysis identified candidate mifepristone targets, including transcription factors Paired and Extra-extra. In addition to shortening life span, mating also causes midgut hypertrophy and activation of the lipid metabolism regulatory factor SREBP. Mifepristone blocked the increase in midgut size caused by mating, but did not detectably affect midgut size in virgins. Finally, mating increased activity of a SREBP reporter in abdominal tissues, as expected, but reporter activity was not detectably reduced by mifepristone in either mated or virgin females. Conclusion: Mifepristone increases life span of virgin females on regular and HFD without reducing food intake. Metabolomics and transcriptomics analyses suggest some similar effects of mifepristone between virgin and mated females, however reduced midgut size was observed only in mated females. The results are discussed regarding possible mifepristone mechanisms and targets.

Growth assessment of children during the COVID-19 pandemic-Can we rely on parental measurements?

AIM: The COVID-19 pandemic prompted the rapid development of remote medical services. During lockdown periods, children's growth data were obtained from parents' home assessments. This study aimed to assess the accuracy of home height and weight measurements and analyse their utility in clinical decision-making. METHODS: A retrospective, single-centre observational study. Children aged 3-18 years were measured for weight and height at home using guidance provided to parents on proper measurements techniques before subsequent professional re-evaluation at our endocrine institution clinic. The two sets of measurements were compared and analysed according to various clinical parameters. RESULTS: Height measurements at home and in the clinic were comparable (diff = 0.1 ± 1.3cm, p = 0.42) amongst the 107 children (mean age 10.2 ± 3.7, 56.1% males) participating in the study, except in overweight and obese children where they were significantly higher in the clinic (diff = 0.86 ± 1.48cm, p = 0.018). Weight and BMI were significantly higher in the clinic (diff = 0.45 ± 0.8kg and diff = 0.3 ± 0.6kg/m2 , p<0.001 and p<0.001, respectively). CONCLUSIONS: Height measurements of children by their parents were accurate except in obese and overweight children, whereas weight measurements tended to be lower than in the clinic. With proper guidance, parents' home measurements of height and weight are accurate and suitable for clinical decision-making.

Age-related changes in polycomb gene regulation disrupt lineage fidelity in intestinal stem cells.

Tissue homeostasis requires long-term lineage fidelity of somatic stem cells. Whether and how age-related changes in somatic stem cells impact the faithful execution of lineage decisions remains largely unknown. Here, we address this question using genome-wide chromatin accessibility and transcriptome analysis as well as single-cell RNA-seq to explore stem-cell-intrinsic changes in the aging Drosophila intestine. These studies indicate that in stem cells of old flies, promoters of Polycomb (Pc) target genes become differentially accessible, resulting in the increased expression of enteroendocrine (EE) cell specification genes. Consistently, we find age-related changes in the composition of the EE progenitor cell population in aging intestines, as well as a significant increase in the proportion of EE-specified intestinal stem cells (ISCs) and progenitors in aging flies. We further confirm that Pc-mediated chromatin regulation is a critical determinant of EE cell specification in the Drosophila intestine. Pc is required to maintain expression of stem cell genes while ensuring repression of differentiation and specification genes. Our results identify Pc group proteins as central regulators of lineage identity in the intestinal epithelium and highlight the impact of age-related decline in chromatin regulation on tissue homeostasis.

Dyslipidemia and cardiovascular disease risk factors in patients with type 1 diabetes: A single-center experience.

BACKGROUND: Type 1 diabetes (T1D) contributes to altered lipid profiles and increases the risk of cardiovascular disease (CVD). Youth with T1D may have additional CVD risk factors within the first decade of diagnosis. AIM: To examine risk factors for dyslipidemia in young subjects with T1D. METHODS: Longitudinal and cross-sectional retrospective study of 170 young subjects with T1D (86 males; baseline mean age 12.2 ± 5.6 years and hemoglobin A1c 8.4% ± 1.4%) were followed in a single tertiary diabetes center for a median duration of 15 years. Predictors for outcomes of lipid profiles at last visit (total cholesterol [TC], triglycerides [TGs], low-density lipoprotein-cholesterol [LDL-c], and high-density lipoprotein-cholesterol [HDL-c]) were analyzed by stepwise linear regression models. RESULTS: At baseline, 79.5% of the patients had at least one additional CVD risk factor (borderline dyslipidemia/dyslipidemia [37.5%], pre-hypertension/hypertension [27.6%], and overweight/obesity [16.5%]) and 41.6% had multiple (≥ 2) CVD risk factors. A positive family history of at least one CVD risk factor in a first-degree relative was reported in 54.1% of the cohort. Predictors of elevated TC: family history of CVD (ß[SE] = 23.1[8.3], P = 0.006); of elevated LDL-c: baseline diastolic blood pressure (DBP) (ß[SE] = 11.4[4.7], P = 0.003) and family history of CVD (ß[SE] = 20.7[6.8], P = 0.017); of elevated TGs: baseline DBP (ß[SE] = 23.8[9.1], P = 0.010) and family history of CVD (ß[SE] = 31.0[13.1], P = 0.020); and of low HDL-c levels: baseline DBP (ß[SE] = 4.8[2.1], P = 0.022]). CONCLUSION: Our findings suggest that elevated lipid profiles are associated with DBP and a positive family history of CVD. It is of utmost importance to prevent and control modifiable risk factors such as these, as early as childhood, given that inadequate glycemic control and elevation in blood pressure intensify the risk of dyslipidemia.

Pediatric reference values of TSH should be personalized according to BMI and ethnicity.

OBJECTIVE: The need for personalization of the reference values of thyroid function tests has been previously suggested. We aimed at determining TSH reference values in a large cohort of children according to age, sex, BMI, and ethnicity. DESIGN: A population-based cohort study. METHODS: The study cohort included 75 549 healthy children aged 5-18 years. Data analyzed included age, gender, TSH, FT4 levels, BMI and ethnicity. Multivariate logistic regression analysis examined the associations between the study parameters. RESULTS: TSH in the Jewish population is lower than in the non-Jewish population (median: 2.1 IU/L (IQR: 1.5) vs 2.2 IU/L (IQR: 1.5), P < 0.0001). TSH is significantly affected by BMI for children defined as underweight, normal weight, overweight or obese, levels increased as weight diverged from the normal range (median levels: 2.1 IU/L (IQR: 1.4), 2.0 IU/L (IQR: 1.3), 2.1 IU/L (IQR: 1.4), 2.4 (IQR: 1.5), respectively, P < 0.001). The 2.5 percentile is affected by gender and BMI (P < 0.02 and P < 0.001, respectively), while the 97.5 percentile is affected by ethnic origin and BMI (P < 0.001 for both). New TSH reference intervals (RI) adjusted according to BMI and ethnicity are suggested. Comparison of the old and new RI demonstrate the significance of RI personalization: 25.1% of the children with TSH levels above the old RI are within the new RI, while 2.3% of the children who were in the old RI are below the new RI. CONCLUSIONS: TSH reference values in children are affected by BMI and ethnicity. Reference values should be individualized accordingly to improve future clinical decision-making and treatment.

Multiplexing DNA methylation markers to detect circulating cell-free DNA derived from human pancreatic ß cells.

It has been proposed that unmethylated insulin promoter fragments in plasma derive exclusively from ß cells, reflect their recent demise, and can be used to assess ß cell damage in type 1 diabetes. Herein we describe an ultrasensitive assay for detection of a ß cell-specific DNA methylation signature, by simultaneous assessment of 6 DNA methylation markers, that identifies ß cell DNA in mixtures containing as little as 0.03% ß cell DNA (less than 1 ß cell genome equivalent). Based on this assay, plasma from nondiabetic individuals (N = 218, aged 4-78 years) contained on average only 1 ß cell genome equivalent/mL. As expected, cell-free DNA (cfDNA) from ß cells was significantly elevated in islet transplant recipients shortly after transplantation. We also detected ß cell cfDNA in a patient with KATP congenital hyperinsulinism, in which substantial ß cell turnover is thought to occur. Strikingly, in contrast to previous reports, we observed no elevation of ß cell-derived cfDNA in autoantibody-positive subjects at risk for type 1 diabetes (N = 32), individuals with recent-onset type 1 diabetes (<4 months, N = 92), or those with long-standing disease (>4 months, N = 38). We discuss the utility of sensitive ß cell cfDNA analysis and potential explanations for the lack of a ß cell cfDNA signal in type 1 diabetes.

Cohesin controls intestinal stem cell identity by maintaining association of Escargot with target promoters.

Intestinal stem cells (ISCs) maintain regenerative capacity of the intestinal epithelium. Their function and activity are regulated by transcriptional changes, yet how such changes are coordinated at the genomic level remains unclear. The Cohesin complex regulates transcription globally by generating topologically-associated DNA domains (TADs) that link promotor regions with distant enhancers. We show here that the Cohesin complex prevents premature differentiation of Drosophila ISCs into enterocytes (ECs). Depletion of the Cohesin subunit Rad21 and the loading factor Nipped-B triggers an ISC to EC differentiation program that is independent of Notch signaling, but can be rescued by over-expression of the ISC-specific escargot (esg) transcription factor. Using damID and transcriptomic analysis, we find that Cohesin regulates Esg binding to promoters of differentiation genes, including a group of Notch target genes involved in ISC differentiation. We propose that Cohesin ensures efficient Esg-dependent gene repression to maintain stemness and intestinal homeostasis.

Clinically Accurate Prediction of Glucose Levels in Patients with Type 1 Diabetes.

Background and Aims: Accurate prediction of glucose levels in patients with type 1 diabetes mellitus (T1DM) is critical both for their glycemic control and for the development of closed-loop systems. Methods: In this study, we utilized real-life, retrospective, continuous glucose monitoring data from 141 T1DM patients (9,083 connection days, 1,592,506 glucose measurements) and in silico data generated by the UVA/Padova T1DM simulator to evaluate different computational methods for glucose prediction. We evaluated the performance of the models using both measures of numerical accuracy, measured by the root mean square error, and clinical accuracy, measured by the percentage of time in each of the Clarke error grid (CEG) zones, and compared the predictions done by autoregressive (AR) models, tree-based methods, artificial neural networks, and a novel model that we devised and optimized for this task. Results: Our novel model, constructed on real-life data, achieved clinical accuracy of 99.3% and 95.8% in predicting the glucose level 30 and 60 min ahead, respectively, and reduced the percentage of glucose predictions in zones C-E of the CEG by 60.6% and 38.4% in these prediction horizons, compared with a standard AR model. The model was superior to all other models across all age groups and achieved higher clinical accuracy in subgroups of patients with high glucose variability and greater time spent in hypoglycemia. Compared with real-life data, when evaluated on in silico data, the model had a higher clinical and numerical accuracy. Conclusions: A model that optimizes for CEG zones may significantly improve clinical accuracy and clinical outcomes of treatment decisions in T1DM patients. Results obtained from simulated data may overestimate the performance of models on real-life data.

Astrocyte senescence promotes glutamate toxicity in cortical neurons.

Neurodegeneration is a major age-related pathology. Cognitive decline is characteristic of patients with Alzheimer's and related dementias and cancer patients after chemo- or radio-therapies. A recently emerged driver of these and other age-related pathologies is cellular senescence, a cell fate that entails a permanent cell cycle arrest and pro-inflammatory senescence-associated secretory phenotype (SASP). Although there is a link between inflammation and neurodegenerative diseases, there are many open questions regarding how cellular senescence affects neurodegenerative pathologies. Among the various cell types in the brain, astrocytes are the most abundant. Astrocytes have proliferative capacity and are essential for neuron survival. Here, we investigated the phenotype of primary human astrocytes made senescent by X-irradiation, and identified genes encoding glutamate and potassium transporters as specifically downregulated upon senescence. This down regulation led to neuronal cell death in co-culture assays. Unbiased RNA sequencing of transcripts expressed by non-senescent and senescent astrocytes confirmed that glutamate homeostasis pathway declines upon senescence. Our results suggest a key role for cellular senescence, particularly in astrocytes, in excitotoxicity, which may lead to neurodegeneration including Alzheimer's disease and related dementias.

Diagnosis of Growth Hormone Deficiency in Children: The Efficacy of Glucagon versus Clonidine Stimulation Test.

INTRODUCTION: The diagnosis of childhood growth hormone deficiency (GHD) requires a failure to respond to 2 GH stimulation tests (GHSTs) performed with different stimuli. The most commonly used tests are glucagon stimulation test (GST) and clonidine stimulation test (CST). This study assesses and compares GST and CST's diagnostic efficacy for the initial evaluation of short children. METHODS: Retrospective, single-center, observational study of 512 short children who underwent GHST with GST first or CST first and a confirmatory test with the opposite stimulus in cases of initial GH peak <7.5 ng/mL during 2015-2018. The primary outcome measure was the efficacy of the GST first or CST first in diagnosing GHD. RESULTS: Population characteristics include median age of 9.3 years (interquartile range 6.2, 12.1), 78.3% prepubertal, and 61% boys. Subnormal GH response in the initial test was recorded in 204 (39.8%) children: 148 (45.5%) in GST first and 56 (30%) in CST first, p < 0.001. Confirmatory tests verified GHD in 75/512 (14.6%) patients. Divergent results between the initial and confirmatory tests were more prevalent in GST first than CST first (103/148 [69.6%] vs. 26/56 [46.4%], p < 0.001) indicating a significantly lower error rate for the CST first compared to the GST first. In multivariate analysis, the only significant predictive variable for divergent results between the tests was the type of stimulation test (OR = 0.349 [95% CI 0.217, 0.562], p < 0.001). CONCLUSIONS: Screening of GH status with CST first is more efficient than that with GST first in diagnosing GHD in short children with suspected GHD. It is suggested that performing CST first may reduce the need for a second provocative test and avoid patients' inconvenience of undergoing 2 serial tests.