INfluenza VaccInation To mitigate typE 1 Diabetes (INVITED): a study protocol for a randomised, double-blind, placebo-controlled clinical trial in children and adolescents with recent-onset type 1 diabetes.

INTRODUCTION: Children and adolescents with recent-onset type 1 diabetes (T1D) commonly maintain a certain level of insulin production during the remission phase, which can last months to years. Preserving ß-cell function can reduce T1D complications and improve glycaemic control. Influenza vaccination has pleiotropic effects and administration of the vaccine during the early phases of T1D may offer ß-cell protection. This study aims to assess the effect of influenza vaccination on preserving ß-cell function in children and adolescents with recent-onset T1D. METHODS AND ANALYSIS: The INfluenza VaccInation To mitigate typE 1 Diabetes trial is a randomised, double-blind, placebo-controlled, multicentre trial in paediatric patients with recent-onset T1D aged 7-17 years. 100 participants will be randomised in a 1:1 ratio to receive either a standard inactivated quadrivalent influenza vaccine or a placebo within 14 days of diagnosis. The primary outcome is a difference in mean change (from baseline to 12 months) in C-peptide level between groups during a 2-hour mixed-meal tolerance test. Secondary outcomes include mean change (from baseline to 6 months) in C-peptide levels, haemoglobin A1c, ambulatory glucose profiles and insulin requirements. Exploratory outcomes are diabetes-related autoantibodies, inflammatory markers and serum haemagglutinin inhibition antibody titres against the influenza viruses. The current treatment for T1D is largely symptomatic, relying on insulin administration. There is a pressing need for novel pharmacological approaches aimed at modulating the immune system to preserve residual ß-cell function. Existing immunotherapies are cost-prohibitive and associated with multiple side effects, whereas influenza vaccination is inexpensive and generally well tolerated. A positive outcome of this study holds potential for immediate implementation into standard care for children and adolescents with recent-onset T1D and may guide future research on immune modulation in T1D. ETHICS AND DISSEMINATION: Ethical approval was obtained from Danish Health Authorities prior to participant enrollment. The trial results will be submitted to a peer-reviewed journal. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT05585983 and EudraCT Number 2022-500906-17-01.

Multi-omics analysis reveals drivers of loss of ß-cell function after newly diagnosed autoimmune type 1 diabetes: An INNODIA multicenter study.

AIMS: Heterogeneity in the rate of ß-cell loss in newly diagnosed type 1 diabetes patients is poorly understood and creates a barrier to designing and interpreting disease-modifying clinical trials. Integrative analyses of baseline multi-omics data obtained after the diagnosis of type 1 diabetes may provide mechanistic insight into the diverse rates of disease progression after type 1 diabetes diagnosis. METHODS: We collected samples in a pan-European consortium that enabled the concerted analysis of five different omics modalities in data from 97 newly diagnosed patients. In this study, we used Multi-Omics Factor Analysis to identify molecular signatures correlating with post-diagnosis decline in ß-cell mass measured as fasting C-peptide. RESULTS: Two molecular signatures were significantly correlated with fasting C-peptide levels. One signature showed a correlation to neutrophil degranulation, cytokine signalling, lymphoid and non-lymphoid cell interactions and G-protein coupled receptor signalling events that were inversely associated with a rapid decline in ß-cell function. The second signature was related to translation and viral infection was inversely associated with change in ß-cell function. In addition, the immunomics data revealed a Natural Killer cell signature associated with rapid ß-cell decline. CONCLUSIONS: Features that differ between individuals with slow and rapid decline in ß-cell mass could be valuable in staging and prediction of the rate of disease progression and thus enable smarter (shorter and smaller) trial designs for disease modifying therapies as well as offering biomarkers of therapeutic effect.

ALLOPURINOL TREATMENT IMPROVES INSULIN RESISTANCE IN NON-DIABETIC PATIENTS WITH RENAL STONE.

Hyperuricemia is an objective risk factor of derangement of fasting serum glucose and type 2 diabetes (T2D), yet whether hyperuricemia has a causative influence on insulin resistance is still debatable. In this study, we tested the hypothesis that lowering uric acid in hyperuricemic nondiabetic subjects might improve insulin resistance. Patients with renal stone and hyperuricemia (n=15) were recruited from the private clinic of Ib-Sina Local Teaching Hospital in Mosul city and prospectively placed on allopurinol (300mg/day) for 6 months. Serum uric acid (SUA), fasting serum glucose (FSG), fasting insulin, and C-peptide were measured using commercial kits. Results confirmed that allopurinol has significantly (P<0.05) reduced c-peptide and insulin together with a non-significant (p>0.05) reduction of serum glucose levels. In conclusion, allopurinol has improved insulin level and glycemic control in a healthy individual, these findings could be used as a template for using allopurinol in diabetic patients to improve glycemic control or future studies could be directed toward structural modification of allopurinol which hopefully might lead to innovation of new antidiabetic drugs.

Evaluation of Fasting Glucose-Insulin-C-Peptide-Derived Metabolic Indices for Identifying Metabolic Syndrome in Young, Healthy Adults.

Metabolic syndrome (MetS) is a condition defined by a cluster of symptoms, including excessive adipose tissue, impaired glucose homeostasis, dyslipidemia, and high blood pressure (BP). We aimed to evaluate the correlation between the MetS criteria (IDF) and fasting glucose-insulin-C-peptide-derived indices in a cohort of 128 healthy young adults who were 20-35 years old at the time of this study. We measured fasting serum glucose, insulin, C-peptide (CP), HDL-cholesterol, triglycerides, and hsCRP; HOMA-IR INS, HOMA-IR CP1, HOMA-IR CP2, HOMA-BETA, HOMA-BETA CP, QUICKI, disposition index (DI), CP index (CPI), and 20/C-peptide*glucose. Significant correlations were found between BMI and all HOMA indices, QUICKI, and CPI; waist circumferences and HOMA-IR INS, HOMA-BETA, and QUICKI (for both sexes); glucose and HOMA-IR INS/CP1/CP2, HOMA-BETA CP, DI, and QUICKI; HDL-cholesterol and HOMA-IR INS, HOMA-BETA, and QUICKI for males and females only with QUICKI; triglycerides and HOMA-IR INS, HOMA-BETA, and QUICKI; systolic BP and HOMA-IR INS, HOMA-BETA; diastolic BP and DI. The cut-off values for HOMA-IR INS, HOMA-BETA, and QUICKI in the combined group (females + males) were 1.855, 82.250, 0.355; 2.115, 106.370, 0.345 for males; 1.805, 71.305, 0.355 for females. A stronger correlation was found between males' indices and hsCRP. In conclusion, CP-derived indices do not add significant information, and the male sex is more predisposed to MetS.

Cohort profile: the 'Biomarkers of heterogeneity in type 1 diabetes' study-a national prospective cohort study of clinical and metabolic phenotyping of individuals with long-standing type 1 diabetes in the Netherlands.

PURPOSE: The 'Biomarkers of heterogeneity in type 1 diabetes' study cohort was set up to identify genetic, physiological and psychosocial factors explaining the observed heterogeneity in disease progression and the development of complications in people with long-standing type 1 diabetes (T1D). PARTICIPANTS: Data and samples were collected in two subsets. A prospective cohort of 611 participants aged ≥16 years with ≥5 years T1D duration from four Dutch Diabetes clinics between 2016 and 2021 (median age 32 years; median diabetes duration 12 years; 59% female; mean glycated haemoglobin (HbA1c) 61 mmol/mol (7.7%); 61% on insulin pump; 23% on continuous glucose monitoring (CGM)). Physical assessments were performed, blood and urine samples were collected, and participants completed questionnaires. A subgroup of participants underwent mixed-meal tolerance tests (MMTTs) at baseline (n=169) and at 1-year follow-up (n=104). Genetic data and linkage to medical and administrative records were also available. A second cross-sectional cohort included participants with ≥35 years of T1D duration (currently n=160; median age 64 years; median diabetes duration 45 years; 45% female; mean HbA1c 58 mmol/mol (7.4%); 51% on insulin pump; 83% on CGM), recruited from five centres and measurements, samples and 5-year retrospective data were collected. FINDINGS TO DATE: Stimulated residual C-peptide was detectable in an additional 10% of individuals compared with fasting residual C-peptide secretion. MMTT measurements at 90 min and 120 min showed good concordance with the MMTT total area under the curve. An overall decrease of C-peptide at 1-year follow-up was observed. Fasting residual C-peptide secretion is associated with a decreased risk of impaired awareness of hypoglycaemia. FUTURE PLANS: Research groups are invited to consider the use of these data and the sample collection. Future work will include additional hormones, beta-cell-directed autoimmunity, specific immune markers, microRNAs, metabolomics and gene expression data, combined with glucometrics, anthropometric and clinical data, and additional markers of residual beta-cell function. TRIAL REGISTRATION NUMBER: NCT04977635.

A Systematic Review of the Accuracy of Insulin and C-peptide Secretion Ratios During the Oral Glucose Tolerance Test to Diagnose Insulinoma.

Background: Insulinoma is one of the causes of recurrent hypoglycemia, one of the chief complaints for emergency department admission. The gold standard in diagnosing insulinoma is a 72-hour fasting test which is inconvenient and inefficient as it requires hospitalization. Research has found that measurement of insulin and C-peptide during OGTT may help diagnose insulinoma. We aimed to assess the diagnostic value of OGTT in diagnosing insulinoma. Methodology: The literature search was conducted on 19 August 2022 using several databases (MEDLINE, Scopus, Embase, and ScienceDirect). All studies that measured OGTT as diagnostic tools in diagnosing insulinoma and 72-hour fasting test as reference standard were included. The quality assessment of the selected studies was based on the Centre of Evidence-Based Medicine University of Oxford and the Quality Assessment of Diagnostic Accuracy-2 tool (QUADAS-2). Analysis of the included studies was performed qualitatively. This study was registered on PROSPERO (CRD42022360205). Results: A total of two case-control studies (106 patients) were included, which were at risk of bias and low concern of applicability. Both studies demonstrated that the combination of insulin and C-peptide levels measured during OGTT had high specificity, sensitivity, positive predictive value, and negative predictive value in diagnosing insulinoma compared to the reference standard. A logistic regression model of 8.305 - (0.441 × insulin 2-h/0-h) - (1.679 × C-peptide 1-h/0-h) >0.351 has the highest diagnostic value in one study (AUC 0.97, Sensitivity 86.5%, Specificity 95.2%, PPV 94.1, NPV 88.9). Conclusion: The measurement of 0-h and 2-h insulin and C-peptide levels during 2-h OGTT was found in two small case-control studies with a total of 106 patients to have good sensitivity and specificity. However, due to these limitations, future research is still needed to validate the potential use of OGTT for the diagnosis of insulinoma.

Novel Autologous Dendritic Cell Therapy AVT001 for Type 1 Diabetes.

BACKGROUND: CD8+ T regulatory (Treg) cells that recognize the nonclassical class 1b molecule Qa-1/human leukocyte antigen E (Q/E CD8+ Treg cells) are important in maintaining self-tolerance. We sought to investigate the role that these T cells play in type 1 diabetes (T1D) pathogenesis and whether an intervention targeting this mechanism may delay T1D progression. METHODS: We conducted a phase 1/2, randomized, double-blind, placebo-controlled trial of the autologous dendritic cell therapy AVT001 that included participants at least 16 years of age, within 1 year of T1D diagnosis, and with ex vivo evidence of a defect in Q/E CD8+ Treg function. Patients were randomly assigned in a 2:1 ratio to AVT001 or placebo, which was administered in three monthly intravenous infusions. The primary end point was safety; efficacy end points included changes from baseline in C-peptide area under the curve (AUC) during a 4-hour mixed meal, hemoglobin A1c (HbA1c), and insulin dose. RESULTS: Sixteen patients received AVT001, and nine received placebo. Similar rates and severity of adverse events were observed in both groups. None of the patients in the AVT001 group had serious adverse events through visit day 360. Compared with placebo, treatment with ATV001 was associated with less decline from baseline log-transformed C-peptide AUC (nmol/l), with the treatment effect between AVT001 and placebo at day 150 of 0.09 (95% confidence interval [CI], 0.03 to 0.15) and at day 360 of 0.10 (95% CI, 0.04 to 0.15). No clear differences in change in HbA1c and insulin dose from baseline were observed between groups. Estimated treatment effects of AVT001 versus placebo at day 360 were -0.17% (95% CI, -0.60 to 0.26%) for HbA1c and -0.06 U/kg/day (95% CI, -0.14 to 0.02) for daily insulin dose. CONCLUSIONS: In this phase 1/2 trial, AVT001 did not result in dose-limiting adverse events. Potential signals of efficacy observed here warrant further evaluation in a fully powered trial. (Funded by Avotres Inc. and the Division of Diabetes, Endocrinology, and Metabolic Diseases; ClinicalTrials.gov number, NCT03895996.).

The substitute ENSO 16 has low impact on glucose metabolism in healthy humans: a randomized, double-blind, active-controlled, cross-over trial.

High sugar consumption is associated with cardiovascular diseases and diabetes. Current sugar substitutes may cause taste sensations and gastrointestinal symptoms. ENSO 16 is a combination of 16 different sugar substitutes and plant fibers and has been designed as a sugar alternative. The impact on plasma glucose metabolism as well as on gastrointestinal tolerance has not been investigated yet. 17 healthy participants were enrolled in this randomized, double-blind trial. Participants received a single oral dose of 30 g glucose or 30 g ENSO 16 and crossed over to the alternate treatment after a 7 day wash out period. The study endpoint was the effect on plasma glucose, insulin, C-peptide concentrations and gastrointestinal disorders. A questionnaire regarding gastrointestinal symptoms was used for individual subjective scoring. The mean baseline adjusted plasma glucose AUC0-180 min was significantly greater after glucose administration compared to ENSO 16 (n = 15, p = 0.0128, paired t-test). Maximum plasma glucose elevation over baseline was 117 mg*dl-1 and 20 mg*dl-1 after oral glucose or ENSO 16, respectively. Insulin and C-peptide AUC0-180 min were significantly greater after glucose compared to ENSO 16 intake (p < 0.01, Wilcoxon rank sum test). The mean maximal concentrations of plasma glucose, insulin and C-peptide after glucose intake were 1.5, 4.6 and 2.7-fold greater after glucose intake compared to ENSO 16 intake, respectively. Adverse reactions were mostly mild and not different between treatments. Conclusion. ENSO 16 has only a small impact on plasma glucose metabolism. This may be of interest in a dietary context and may help to reduce calory intake.Trail registration NCT05457400. First registration: 14/07/2022. https://clinicaltrials.gov/study/NCT05457400 .

Associations between time in range and insulin secretory capacity in Japanese patients with type 2 diabetes.

Impaired insulin secretory capacity is associated with high glycemic variability in patients with type 2 diabetes (T2DM). However, there are no existing reports on the association between insulin secretory capacity and time in range (TIR). This retrospective study involved 330 T2DM admitted for diabetes education who underwent intermittently scanned continuous glucose monitoring (isCGM) and had their fasting serum C-peptide immunoreactivity (S-CPR) measured within 5 days of admission. The baseline characteristics were as follows: age, 60.2 years; glycated hemoglobin (HbA1c), 9.2%; S-CPR, 2.2 ng/mL; S-CPR index (S-CPR [ng/mL]/fasting plasma glucose [mg/dL] × 100), 1.6; and TIR, 60.3%. TIR correlated significantly with the S-CPR index, which was confirmed by multivariate analysis that included various factors such as HbA1c. Receiver operating characteristic (ROC) analysis showed that 1.88 was the optimal S-CPR index level to predict TIR ≥ 70%. In addition to HbA1c and biguanide use, the S-CPR index was a significant factor associated with TIR > 70%. S-CPR index values of ≥ 1.88 also correlated significantly with TIR > 70%. In conclusion, insulin secretory capacity is associated with TIR in Japanese T2DM, suggesting that the S-CPR index might be a potentially useful biomarker insulin secretory capacity, in association with TIR.Trial registration UMIN0000254333.

Ultrasensitive Hierarchical AuNRs@SiO2@Ag SERS Probes for Enrichment and Detection of Insulin and C-Peptide in Serum.

Introduction: Insulin and C-peptide played crucial roles as clinical indicators for diabetes and certain liver diseases. However, there has been limited research on the simultaneous detection of insulin and C-peptide in trace serum. It is necessary to develop a novel method with high sensitivity and specificity for detecting insulin and C-peptide simultaneously. Methods: A core-shell-satellites hierarchical structured nanocomposite was fabricated as SERS biosensor using a simple wet-chemical method, employing 4-MBA and DTNB for recognition and antibodies for specific capture. Gold nanorods (Au NRs) were modified with Raman reporter molecules and silver nanoparticles (Ag NPs), creating SERS tags with high sensitivity for detecting insulin and C-peptide. Antibody-modified commercial carboxylated magnetic bead@antibody served as the capture probes. Target materials were captured by probes and combined with SERS tags, forming a "sandwich" composite structure for subsequent detection. Results: Under optimized conditions, the nanocomposite fabricated could be used to detect simultaneously for insulin and C-peptide with the detection limit of 4.29 × 10-5 pM and 1.76 × 10-10 nM in serum. The insulin concentration (4.29 × 10-5-4.29 pM) showed a strong linear correlation with the SERS intensity at 1075 cm-1, with high recoveries (96.4-105.3%) and low RSD (0.8%-10.0%) in detecting human serum samples. Meanwhile, the C-peptide concentration (1.76 × 10-10-1.76 × 10-3 nM) also showed a specific linear correlation with the SERS intensity at 1333 cm-1, with recoveries 85.4%-105.0% and RSD 1.7%-10.8%. Conclusion: This breakthrough provided a novel, sensitive, convenient and stable approach for clinical diagnosis of diabetes and certain liver diseases. Overall, our findings presented a significant contribution to the field of biomedical research, opening up new possibilities for improved diagnosis and monitoring of diabetes and liver diseases.

[Evaluation of endogenous residual insulin secretion by C-peptide measurement]. / Évaluation de la sécrétion résiduelle d'insuline par le dosage du peptide-C.

C-peptide measurement allows an estimation of the residual endogenous insulin secretion in diabetic patients. Nowadays plasmatic testing is convenient and unexpensive, but we lack standardized tests. Therefore, there are no official recommendation regarding its use. As an indication, in some circumstances, C-peptide measurement could be used to specify the type of diabetes, help guide the treatment strategy and potentially assess the risk for complications. Its use is still limited and not recommended on a routine base for all patients living with diabetes, but in the future, tests standardization and establishment of reference ranges could give more insight on the clinical relevance of C-peptide measurement.

Le dosage du peptide-C est une mesure permettant d'évaluer la sécrétion endogène résiduelle d'insuline chez les patients diabétiques. Le dosage plasmatique est facilement réalisable actuellement, pour un coût modeste, mais l'absence de standardisation des tests ne permet pas d'émettre des recommandations officielles par rapport à son utilisation. À titre indicatif, dans certaines situations, le dosage du peptide-C peut être utilisé pour préciser le type de diabète, guider les traitements médicamenteux et potentiellement évaluer les risques de complications. Son utilisation est pour le moment limitée et n'est pas recommandée en routine pour tous les patients atteints de diabète, mais à l'avenir, la formalisation du dosage et l'établissement de valeurs de référence pourraient permettre de définir son utilisation clinique.

Reference Standards for C-Peptide in Korean Population: A Korean Endocrine Hormone Reference Standard Data Center Study.

BACKGRUOUND: The Korean Endocrine Hormone Reference Standard Data Center (KEHRS DC) has created reference standards (RSs) for endocrine hormones since 2020. This study is the first of its kind, wherein the KEHRS DC established RSs for serum Cpeptide levels in a healthy Korean population. METHODS: Healthy Korean adults were recruited from May 2021 to September 2023. After excluding participants according to our criteria, serum samples were collected; each participant could then choose between fasting glucose only or fasting glucose plus an oral glucose tolerance test (OGTT). If their sample showed high glucose (≥100 mg/dL) or hemoglobin A1c (HbA1c) (≥5.70%), their C-peptide levels were excluded from analyzing the RSs. RESULTS: A total of 1,532 participants were recruited; however, only the data of 1,050 participants were analyzed after excluding those whose samples showed hyperglycemia or high HbA1c. Post-30-minute OGTT data from 342 subjects and post-120-minute OGTT data from 351 subjects were used. The means±2 standard deviations and expanded uncertainties of fasting, post-30-minute and 120-minute OGTT C-peptide levels were 1.26±0.82 and 0.34-3.18, 4.74±3.57 and 1.14-8.33, and 4.85±3.58 and 1.25-8.34 ng/mL, respectively. Serum C-peptide levels correlated with obesity, serum glucose levels, and HbA1c levels. CONCLUSION: The RSs for serum C-peptide levels established in this study are expected to be useful in both clinical and related fields.

Gastric emptying in newly diagnosed, treatment-naïve Han Chinese with type 2 diabetes and the impact of 4-week insulin pump therapy.

AIM: To evaluate gastric emptying (GE) and the glycaemic response to a 75-g oral glucose load in newly diagnosed, treatment-naïve Han Chinese with type 2 diabetes (T2D) before insulin pump therapy, after 4 weeks of insulin pump therapy, and 12-15 months after insulin pump therapy. MATERIALS AND METHODS: Twenty participants with T2D (baseline glycated haemoglobin [± SD] 10.7% [± 1.2%] 93 [± 10] mmol/mol) ingested a 75-g glucose drink containing 150 mg 13C-acetate, to determine the gastric half-emptying time, and underwent assessment of plasma glucose and serum insulin, C-peptide and glucagon-like peptide-1 (GLP-1) over 180 min before and after 4 weeks of insulin pump therapy (discontinued for 48 h before re-assessment). Data were compared to those in 19 healthy participants matched for sex and age. After 12-15 months, GE was re-measured in 14 of the T2D participants. RESULTS: At baseline, participants with T2D exhibited substantially augmented fasting and post-glucose glycaemia, diminished insulin secretion, and more rapid GE (p < 0.05 each), but comparable GLP-1, compared to healthy participants. Following insulin pump therapy, insulin secretion increased, GLP-1 secretion was attenuated, fasting and post-glucose glycaemia were lower, and GE was slowed (p < 0.05 each). The slowing of GE in T2D participants was sustained over 12-15 months of follow-up. CONCLUSIONS: In newly diagnosed Han Chinese with T2D, GE is often accelerated despite poor glycaemic control and is slowed by short-term insulin pump therapy. The effect on GE is maintained for at least 12 months.

Exploring the Role of Metabolic Hormones in Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease characterized by progressive loss of motor neurons. Emerging evidence suggests a potential link between metabolic dysregulation and ALS pathogenesis. This study aimed to investigate the relationship between metabolic hormones and disease progression in ALS patients. A cross-sectional study was conducted involving 44 ALS patients recruited from a tertiary care center. Serum levels of insulin, total amylin, C-peptide, active ghrelin, GIP (gastric inhibitory peptide), GLP-1 active (glucagon-like peptide-1), glucagon, PYY (peptide YY), PP (pancreatic polypeptide), leptin, interleukin-6, MCP-1 (monocyte chemoattractant protein-1), and TNFα (tumor necrosis factor alpha) were measured, and correlations with ALSFRS-R, evolution scores, and biomarkers were analyzed using Spearman correlation coefficients. Subgroup analyses based on ALS subtypes, progression pattern of disease, and disease progression rate patterns were performed. Significant correlations were observed between metabolic hormones and ALS evolution scores. Insulin and amylin exhibited strong correlations with disease progression and clinical functional outcomes, with insulin showing particularly robust associations. Other hormones such as C-peptide, leptin, and GLP-1 also showed correlations with ALS progression and functional status. Subgroup analyses revealed differences in hormone levels based on sex and disease evolution patterns, with male patients showing higher amylin and glucagon levels. ALS patients with slower disease progression exhibited elevated levels of amylin and insulin. Our findings suggest a potential role for metabolic hormones in modulating ALS progression and functional outcomes. Further research is needed to elucidate the underlying mechanisms and explore the therapeutic implications of targeting metabolic pathways in ALS management.

Influence of relatively short-term culture on adult porcine islets for xenotransplantation.

Porcine islet xenotransplantation is a promising therapy for severe diabetes mellitus. Maintenance of the quality and quantity of porcine islets is important for the success of this treatment. Here, we aimed to elucidate the influence of relatively short-term (14 days) culture on adult porcine islets isolated from three micro-minipigs (P111, P112 and P121). Morphological characteristics of islets changed little after 14 days of culture. The viability of cultured islets was also maintained at a high level (> 80%). Furthermore, cultured islets exhibited similar glucose-stimulated insulin secretion and insulin content at Day 14 were preserved comparing with Day 1, while the expressions of Ins, Gcg and Sst were attenuated at Day 14. Xenotransplantation using diabetic nude mice showed no normalization of blood glucose but increased levels of plasma porcine C-peptide after the transplantation of 14 day cultured porcine islets. Histological assessment revealed that relatively short-term cultured porcine islets were successfully engrafted 56 days following transplantation. These data show that relatively short-term culture did not impair the quality of adult porcine islets in regard to function, morphology, and viability. Prevention of impairment of gene correlated with endocrine hormone is warranted for further improvement.

Circulating total and H-specific GDF15 levels are elevated in subjects with MASLD but not in hyperlipidemic but otherwise metabolically healthy subjects with obesity.

BACKGROUND: Growth differentiation factor 15 (GDF15) is a mitokine, the role of which, total or H-specific, in modulating energy metabolism and homeostasis in obesity-related diseases, such as metabolic dysfunction associated steatotic liver disease (MASLD), has not been fully elucidated in adult humans. We aimed to investigate the fasting and stimulated levels of GDF15, total and H-specific, glucose-dependent insulinotropic polypeptide (GIP) and C-peptide, in two physiology interventional studies: one focusing on obesity, and the other on MASLD. METHODS: Study 1 investigated individuals with normal weight or with obesity, undergoing a 3-h mixed meal test (MMT); and study 2, examined adults with MASLD and controls undergoing a 120-min oral glucose tolerance test (OGTT). Exploratory correlations of total and H-specific GDF15 with clinical, hormonal and metabolomic/lipidomic parameters were also performed. RESULTS: In study 1, 15 individuals were included per weight group. Fasting and postprandial total and H-specific GDF15 were similar between groups, whereas GIP was markedly higher in leaner individuals and was upregulated following a MMT. Baseline and postprandial C-peptide were markedly elevated in people with obesity compared with lean subjects. GIP was higher in leaner individuals and was upregulated after a MMT, while C-peptide and its overall AUC after a MMT was markedly elevated in people with obesity compared with lean subjects. In study 2, 27 individuals were evaluated. Fasting total GDF15 was similar, but postprandial total GDF15 levels were significantly higher in MASLD patients compared to controls. GIP and C-peptide remained unaffected. The postprandial course of GDF15 was clustered among those of triglycerides and molecules of the alanine cycle, was robustly elevated under MASLD, and constituted the most notable differentiating molecule between healthy and MASLD status. We also present robust positive correlations of the incremental area under the curve of total and H-specific GDF15 with a plethora of lipid subspecies, which remained significant after adjusting for confounders. CONCLUSION: Serum GDF15 levels do not differ in relation to weight status in hyperlipidemic but otherwise metabolically healthy individuals. In contrast, GDF15 levels are significantly increased in MASLD patients at baseline and they remain significantly higher compared to healthy participants during OGTT, pointing to a role for GDF15 as a mitokine with important roles in the pathophysiology and possibly therapeutics of MASLD. Trial registration ClinicalTrials.gov NCT03986684, NCT04430946.

Alpha-1 Antitrypsin Augmentation Therapy in Chronic Pancreatitis Patients Undergoing Total Pancreatectomy and Islet Autotransplantation: A Randomized, Controlled Study.

Stress-induced islet graft loss during the peri-transplantation period reduces the efficacy of islet transplantation. In this prospective, randomized, double-blind clinical trial, we evaluated the safety and efficacy of 60 mg/kg human alpha-1 antitrypsin (AAT) or placebo infusion weekly for four doses beginning before surgery in chronic pancreatitis (CP) patients undergoing total pancreatectomy and islet autotransplantation (TP-IAT). Subjects were followed for 12 months post-TP-IAT. The dose of AAT was safe, as there was no difference in the types and severity of adverse events in participants from both groups. There were some biochemical signals of treatment effect with a higher oxygen consumption rate in AAT islets before transplantation and a lower serum C-peptide (an indicator of islet death) in the AAT group at 15 min after islet infusion. Findings per the statistical analysis plan using a modified intention to treat analysis showed no difference in the C-peptide area under the curve (AUC) following a mixed meal tolerance test at 12 months post-TP-IAT. There was no difference in the secondary and exploratory outcomes. Although AAT therapy did not show improvement in C-peptide AUC in this study, AAT therapy is safe in CP patients and there are experiences gained on optimal clinical trial design in this challenging disease.

A study of size-selective renal elimination using a novel human model.

The recently discovered selective glomerular hypofiltration syndromes have increased interest in the actual elimination of molecules in the human kidney. In the present study, a novel human model was introduced to directly measure the single-pass renal elimination of molecules of increasing size. Plasma concentrations of urea, creatinine, C-peptide, insulin, pro-BNP, ß2-microglobulin, cystatin C, troponin-T, orosomucoid, albumin, and IgG were analysed in arterial and renal venous blood from 45 patients undergoing Transcatheter Aortic Valve Implantation (TAVI). The renal elimination ratio (RER) was calculated as the arteriovenous concentration difference divided by the arterial concentration. Estimated glomerular filtration rate (eGFR) was calculated by the CKD-EPI equations for both creatinine and cystatin C. Creatinine (0.11 kDa) showed the highest RER (21.0 ± 6.3%). With increasing molecular size, the RER gradually decreased, where the RER of cystatin C (13 kDa) was 14.4 ± 5.3% and troponin-T (36 kDa) was 11.3 ± 4.6%. The renal elimination threshold was found between 36 and 44 kDa as the RER of orosomucoid (44 kDa) was -0.2 ± 4.7%. The RER of creatinine and cystatin C showed a significant and moderate positive linear relationship with eGFR (r = 0.48 and 0.40). In conclusion, a novel human model was employed to demonstrate a decline in renal elimination with increasing molecular size. Moreover, RERs of creatinine and cystatin C were found to correlate with eGFR, suggesting the potential of this model to study selective glomerular hypofiltration syndromes.

Early Metabolic Endpoints Identify Persistent Treatment Efficacy in Recent-Onset Type 1 Diabetes Immunotherapy Trials.

OBJECTIVE: Mixed-meal tolerance test-stimulated area under the curve (AUC) C-peptide at 12-24 months represents the primary end point for nearly all intervention trials seeking to preserve ß-cell function in recent-onset type 1 diabetes. We hypothesized that participant benefit might be detected earlier and predict outcomes at 12 months posttherapy. Such findings would support shorter trials to establish initial efficacy. RESEARCH DESIGN AND METHODS: We examined data from six Type 1 Diabetes TrialNet immunotherapy randomized controlled trials in a post hoc analysis and included additional stimulated metabolic indices beyond C-peptide AUC. We partitioned the analysis into successful and unsuccessful trials and analyzed the data both in the aggregate as well as individually for each trial. RESULTS: Among trials meeting their primary end point, we identified a treatment effect at 3 and 6 months when using C-peptide AUC (P = 0.030 and P < 0.001, respectively) as a dynamic measure (i.e., change from baseline). Importantly, no such difference was seen in the unsuccessful trials. The use of C-peptide AUC as a 6-month dynamic measure not only detected treatment efficacy but also suggested long-term C-peptide preservation (R2 for 12-month C-peptide AUC adjusted for age and baseline value was 0.80, P < 0.001), and this finding supported the concept of smaller trial sizes down to 54 participants. CONCLUSIONS: Early dynamic measures can identify a treatment effect among successful immune therapies in type 1 diabetes trials with good long-term prediction and practical sample size over a 6-month period. While external validation of these findings is required, strong rationale and data exist in support of shortening early-phase clinical trials.

Safety and efficacy of teplizumab in the treatment of type 1 diabetes mellitus: An updated systematic review and meta-analysis of randomized controlled trials.

AIM: To provide updated efficacy and safety information for teplizumab in the treatment of Stage 3 type 1 diabetes mellitus (T1DM). MATERIALS AND METHODS: The PubMed, Embase and Cochrane databases were searched for randomized controlled trials (RCTs) comparing teplizumab to placebo for T1DM that reported any of the following outcomes: (1) C-peptide area under the curve (AUC); (2) glycated haemoglobin (HbA1c) levels; (3) insulin requirements; and (4) adverse events. Heterogeneity was examined with I2 statistics. p values <0.05 were taken to indicate statistical significance. The continuous endpoints were compared through the pooled mean difference (MD) and binary endpoints were assessed using risk ratios, both with 95% confidence intervals (CIs). Statistical analyses were performed using Review Manager Web software. RESULTS: Eight RCTs with 1052 patients (754 receiving teplizumab) were included. Teplizumab significantly increased the AUC of C-peptide levels at 6 (MD 0.10 nmol/L, 95% CI 0.05, 0.16), 12 (MD 0.13 nmol/L, 95% CI 0.06, 0.20), 18 (MD 0.18 nmol/L, 95% CI 0.09, 0.27) and 24 months (MD 0.16 nmol/L, 95% CI 0.02, 0.31), significantly reduced HbA1c levels at 6 (MD -0.57%, 95% CI -1.07, -0.08) and 12 months (MD -0.31%, 95% CI -0.59, -0.02), and significantly reduced insulin requirements at 6 (MD -0.12 U/kg, 95% CI -0.16, -0.08), 12 (MD -0.11 U/kg, 95% CI -0.15, -0.07), 18 (MD -0.17 U/kg, 95% CI -0.26, -0.09) and 24 months (MD -0.11 U/kg, 95% CI -0.22, -0.01). CONCLUSION: Teplizumab increases AUC of C-peptide levels and decreases HbA1c levels and insulin use, without raising serious adverse event risk.