Type1 Diabetes Mellitus

The purpose of this study is to gain more information about the step-by-step process that causes someone to develop type 1 diabetes. Scientists think that a person's own immune system, directed by genetic and environmental factors play a major role in its development. Participation involves a blood draw, a brief medical history questionnaire and measurements of height and weight. Some participants will be asked to return for annual follow-up visits for 10 years.

Type 1 diabetes (T1D) results from destruction of insulin-producing beta cells in the pancreas by the body's own immune system (autoimmunity). It is not fully understood what causes this type of diabetes and why there is variation in age of onset and severity between people who develop the disease. The aim of this work is to study very unusual people who develop T1D extremely young, as babies under 2 years of age (EET1D). The investigators think that, for the condition to have developed that early, they must have an unusual or extreme form of autoimmunity. Studying people with EET1D will enable us to look at exactly what goes wrong with the immune system because they have one of the most extreme forms of the disease. Much may be learned about the disease from a small number of rare individuals. The investigators aim to confirm that they have autoimmune type 1 diabetes and then try to understand how they have developed diabetes so young by studying their immune system genes, the function of their immune system, and environmental factors (such as maternal genetics) that may play a role in their development of the disease. People with diabetes diagnosed under 12 months are very rare, live all over the world. and are usually referred to Exeter for genetic testing. Individuals will be contacted via their clinician to ask for more information about their diabetes and their family history. Samples will be collected to study whether they still make any of their own insulin and whether they make specific antibodies against their beta cells in the pancreas. Separately, their immune system will be studied in depth using immune cells isolated from a blood sample. These cells will undergo cutting edge techniques by Dr Tim Tree at King's College London, by Professor Bart Roep at Leiden University Medical Center, Netherlands, and Dr Cate Speake, Benaroya Research Institute, Seattle (USA). Some of these tests have never been used in people of young ages around the world, so an aim of this project will be to develop methods that can be used to study people even if they live far away. Additional funding extended the study for a further 3 years (Phase 2) to include recruitment of infants without diabetes, aged 0-6 years, as controls to enable assessment of how the abnormalities found in autoimmune and non-autoimmune diabetes compare to normal early life development of the immune system. An additional funding award extended the study (Phase 3) until November 2028, to advance the EXE-T1D program into its third phase, building on major discoveries from phases 1 and 2 to identify, validate, and target immune pathways that drive extremely early-onset type 1 diabetes (eeT1D) and are likely relevant to T1D across all ages. eeT1D cases, diagnosed within the first two years of life, represent particularly aggressive onset of beta-cell autoimmunity. They offer a unique lens to uncover mechanisms of immune dysregulation, informed by both polygenic and monogenic causes. The central aim is to move from pathway discovery to demonstration of novel druggable targets with potential to delay or prevent T1D onset across all ages.

The goal of this longitudinal clinical trial is to measure variability of interstitial glucose levels with a user-friendly real-time continuous glucose monitoring (CGM) technology at regular intervals in normo- and dysglycemic multiple autoantibody-positive individuals (age 5-39 years), in comparison with single autoantibody-positive individuals in the same age range. Participants will asked to undergo repeated oral glucose tolerance tests (OGTTs) (age 5-39 years) and hyperglycemic clamp tests (age 12-39 years) in parallel for a period of at least 2-3 years. In case of confirmed dysglycemia, we propose to perform CGM and OGTT every 3 months. The main questions the study aims to answer are: 1. Do the amplitude and time trends of CGM-derived glycemic variability indices and OGTT- and clamp-derived variables differ between the intermediate, high and very high risk groups? 2. Can (changes in) CGM-derived glycemic variability indices predict/detect dysglycemia in initially normoglycemic (single or multiple autoantibody-positive) individuals with the same diagnostic efficiency as OGTT- or clamp-derived variables? 3. Can (changes in) CGM-derived glycemic variability indices predict clinical onset in (stage 1 or 2) multiple autoantibody-positive individuals with the same diagnostic efficiency as OGTT- or clamp-derived variables? 4. Can correlating (changes in) CGM-derived indices with (changes in) OGTT- and clamp-derived variables help to better understand the sequence of events leading to dysglycemia and clinical onset, as well as the relative contribution of beta cell function and insulin action to glycemic variability according to disease stage and biological and phenotypical characteristics of the individuals?

Epidemiologic studies have revealed a tremendous increase in the prevalence of diabetes and related mortality worldwide. In order to meet all the challenges in the treatment of metabolic diseases in China, the National Metabolic Management Center (MMC) was founded in 2016. The objective of the MMC is to launch a new metabolic disease management model based on the Internet health information platform. It allows the application and evaluation of diabetes treatment strategies at these centers. The proprietary electronic medical database in the MMC will help the dynamic big-data analysis in diabetes epidemiology, prevention, diagnosis, and treatment. It will also provide prospective data support including economic evaluation in management of chronic diseases for the Healthy China 2030 strategy. Objective 1. The purpose of the present study is to establish a multi-center nationwide prospective database of diabetes patients in MMCs, including clinical data, biological samples library so as to explore the epidemiology, genetics, new biomarkers, risk factors, and prognostic methods related to diabetes and its complications, as well as other metabolic diseases. 2. To collect cross-sectional data from patients seen and treated at each MMC centers so as to evaluate: the current status of care of patients with diabetes and its related complications, as well as other risk factors treatment strategies at these centers. Patients'costs and quality of life (QoL) will also be evaluated. 3. To collect the prospective data of patients treated at each MMC centers in order to evaluate the strategies for the achievement of treatment goals, changes in management, control of risk factors, incidence and progression of all-diabetes related clinical endpoints (including mortality), behavioral changes, psychological well being as well as costs and QoL.

This study is a multicenter cross-sectional research project, planning to enroll 1000 patients with Type 1 Diabetes Mellitus (T1DM). By reviewing clinical data, physical examinations, questionnaires, continuous glucose monitoring, and subcutaneous fat ultrasound, we aim to understand the current status of treatment and metabolism in Chinese T1DM patients and analyze the potential factors that may affect their blood sugar control and metabolic indicators. A cost-effectiveness analysis will be conducted on Chinese T1DM patients using continuous glucose monitoring systems to identify the groups that benefit most from these systems.