Biomarkers of Heterogeneity in Type 1 Diabetes

Study Overview
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Brief Summary
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Biomarkers of heterogeneity in type 1 diabetes: establishment of a biobank and an integrated approach to clinical and metabolic phenotyping of individuals with established T1DM. In this project the investigators are searching for biomarkers in 600 patients with established (>5 years) diabetes. The inter-relation and patterns of expression in clinical, (auto)immune, metabolic, inflammatory and other parameters, and (potential) biomarkers are investogated. Blood and urine samples are collected annually (over 3 years) in standardized conditions and biobanked. In addition, 150 patients will undergo additional metabolic testing (such as mixed meal-tests).

Detailed Description
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Identifying biomarkers of type 1 diabetes heterogeneity can help to stage the disease, and identify risks such as the early development of damage and complications. Type 1 diabetes has long been considered to be an autoimmune disease in which failure of immune tolerance induces a specific immune attack on insulin-producing beta-cells. Recent research shows that the pathophysiology of type 1 diabetes is heterogeneous, involving various beta-cell-specific processes, different genetic predispositions, and several disease stages. It is very important to recognize this heterogeneity as it results in an accumulation of differences in outcomes during the course of the disease. This heterogeneity requires further elucidation as a heterogeneous disease is likely to require multiple approaches to stop or cure the pathophysiological pathways. This underscores the need for more biomarkers to identify this heterogeneity, the different phases of disease and the effects of interventions and cures. In many countries and research groups, data and samples from newly-diagnosed individuals (i.e. within the first 6 months after diagnosis) have been collected and studied. Fewer data and samples are available from patients with longer disease duration. This prompted JDRF to grant a strategic research agreement (SRA) to Diabeter and UMC Groningen. Both clinics have access to a substantial clinical database since 1998 with medical record data of > 3500 type 1 diabetes patients. In this BIOMARKER project, the investigators intend to analyze hormonal, biochemical, immunological, inflammatory and psychological biomarkers of type 1 diabetes in patients with a disease duration of > 5 years. A sample repository (serum, plasma, urine, DNA, RNA) is established which is also accessible to other interested collaborators. The collection currently includes: Fasting samples (serum, plasma, urine, DNA, RNA) from 600 patients with type 1 diabetes (> 5 years duration) taken annually at 3 timepoints Samples from 150 patients who underwent Mixed Meal Tolerance Tests (MMTT with 5 timepoints) at 2 occasions (1-year interval) Data from questionnaires on psychosocial burden, quality of life, neuropathy and hypoglycaemia completed by the patients Clinical datasets on their health, diabetes history, family history and clinical course during treatment

Official Title
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Biomarkers of Heterogeneity in Type 1 Diabetes: an Integrated Approach to Clinical and Metabolic Phenotyping of Individuals With Established Type 1 Diabetes

Conditions
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Type 1 Diabetes

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Type 1 diabetes determined by either autoantibodies or based on clinical and historical data or both At least 5 years (1825 days) of type 1 diabetes Minimum age 16 years Treated for type 1 diabetes at a diabetes center participating in this study Subject understands study protocol and agrees to comply with it and has been able to read the patient information sheet, has had time to ask questions and get answers and gives signed informed consent. Exclusion Criteria: Non-type 1 diabetes Patients with a duration of type 1 diabetes below 5 years Patients under the age of 16 years Pregnancy and breastfeeding, until 3 months (12 weeks) after childbirth or breastfeeding On experimental medication or participating in other studies with conflicting goals and schedules Diseases or conditions that the investigator/physician believes to be a contraindication to participate Unwilling to be informed on incidental findings.

Ages Eligible for Study
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Minimum Age: 16 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| 600-cohort<br>Patients with long-term (> 5 years) type 1 diabetes aged 16 years and older As this is an observational study there is no intervention. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline remaining C-peptide production at 1 year and 2 years as measured by the Beckman ultrasensitive C-peptide assay | Samples: fasting blood (serum) | baseline, 1 year, 2 years | 
| Change in prevalence of impaired awareness of hypoglycaemia between baseline and 2-year timepoint as measured by adapted Clarke hypoglycaemia awareness survey | Correlation with C-peptide and clinical parameters | baseline, 2 years | 
| Genome-wide Association Study (GWAS) by Illumina 720k chip |  | cross-sectional: baseline | 
| Assessment of glucagon response after stimulation with a mixed meal tolerance test as measured by the Mercodia glucagon assay (ELISA) |  | baseline | 
| Change in patient-reported outcomes between baseline and 2 year timepoint as measured by WHO-5, PAID-20 and WHOQOL surveys | Quality of Life and problem areas in diabetes | baseline, 2 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Heterogeneity, Biomarkers, C-peptide, Glucagon, Impaired awareness of hypoglycemia, Mixed meal tolerance test, Genetics