An observational study in Type 1 Diabetes Mellitus (T1DM), Healthy Control and Relatives to/Carers of Patients, sponsored by Second Xiangya Hospital of Central South University. Recruiting at 1 site in China. Open to participants aged 3 Years to 70 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-23.
Sponsored by Second Xiangya Hospital of Central South University · Observational
To analyze the environmental risk factors for type 1 diabetes in China.
Type 1 diabetes (T1D) is a hyperglycemic disease caused by absolute insulin deficiency. It has an acute and early onset, and patients require lifelong insulin therapy. Global T1D incidence is rising yearly. China has the fourth-largest number of T1D patients and the second-fastest increase in incidence, with a marked rise in adults. T1D results from genetic and environmental factors that cause immune destruction of pancreatic β cells. Genetic risk is relatively clear: HLA DR4-DQ8 and DR3-DQ2 carry the highest risk, and over 70 related loci have been identified. However, environmental factors remain insufficiently characterized. Studies of migrants, socioeconomic differences, and mobile populations suggest that environment and lifestyle have significant effects. Since China's genetic background has not changed substantially while incidence continues to rise, environment-induced immune dysregulation combined with genetic susceptibility may be key. International cohorts such as TEDDY and DAISY confirm that diet, viral infections, and gut microbiota can trigger islet autoimmunity. Among specific factors, high maternal early-pregnancy BMI, rapid childhood growth, and obesity increase risk; vitamin D is protective, and China's north-high/south-low incidence gradient may relate to sunlight and vitamin D. Gluten may trigger islet autoimmune inflammation via gut microbiota and immune activation. Viral infection, pollution, chemical exposure, and socioeconomic status may also contribute. Most evidence comes from European and American populations, while Chinese studies are limited. Therefore, systematically identifying China-specific environmental risk factors has important scientific and public-health value. In summary, genetics determines susceptibility, while modifiable environmental factors are critical in triggering and progression and are key to early prevention and precision management of T1D.
3,754 studies on the registry are indexed under Diabetes Mellitus, Type 1; 600 are open to participants now.
This study's planned enrollment of 11,240 is above the median of 125 across 792 observational studies indexed under Diabetes Mellitus, Type 1.
Browse Diabetes Mellitus, Type 1 studies →Second Xiangya Hospital of Central South University is the lead sponsor of 87 studies on the registry; 50 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Individuals with type 1 diabetes, first-degree relatives of individuals with type 1 diabetes, and controls recruited from 18 provinces in China.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Individuals with type 1 diabetes (no age restriction):
First-degree relatives:
Exclusion Criteria:
Individuals with type 1 diabetes
First-degree relatives:
Common exclusion criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Controls matched to the recruited patients.
First-degree relatives of patients with type 1 diabetes.
patients with type 1 diabetes
Change From Baseline in Fasting C-peptide Concentration at 1 Year
Fasting C-peptide concentration will be measured at baseline and at 1 year after enrollment. The change from baseline will be calculated as the C-peptide concentration at 1 year minus the baseline concentration and reported in pmol/L.
Time frame: Baseline to 1 year after enrollment
Change From Baseline in 2-Hour Postprandial C-peptide Concentration at 1 Year
Two-hour postprandial C-peptide concentration will be measured at baseline and at 1 year after enrollment. The change from baseline will be calculated as the 2-hour postprandial C-peptide concentration at 1 year minus the baseline concentration and reported in pmol/L.
Time frame: Baseline to 1 year after enrollment
Serum Islet Autoantibodies seroconversion.
Serum islet autoantibodies, including glutamic acid decarboxylase autoantibody (GADA), insulinoma-associated protein 2 autoantibody (IA-2A), zinc transporter 8 autoantibody (ZnT8A), and insulin autoantibody (IAA), will be measured at baseline and 1 year after enrollment.
Time frame: Baseline to 1 year after enrollment
Change From Baseline in Number of Positive Serum Islet Autoantibodies at 1 Year
Serum islet autoantibodies, including glutamic acid decarboxylase autoantibody (GADA), insulinoma-associated protein 2 autoantibody (IA-2A), zinc transporter 8 autoantibody (ZnT8A), and insulin autoantibody (IAA), will be measured at baseline and 1 year after enrollment. The number of positive islet autoantibodies will be recorded at each time point, and the change from baseline will be calculated as the number at 1 year minus the number at baseline.
Time frame: Baseline to 1 year after enrollment
Plan to share: No
No publications or documents are linked to this record.
Started Aug 2024 (actual). Primary completion is estimated for Jul 2027, 35 months after the start.
Of 249 non-industry observational studies under Diabetes Mellitus, Type 1, half reached primary completion within 30 months of starting (the median), counting those still running; a quarter within 12 and three quarters within 78. This study's planned 35 months is above that.
Counting every sponsor, half of 299 studies reached it within 30 months; a quarter within 12 and three quarters within 69.
How these figures are worked out, and which studies are left out of them.
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Second Xiangya Hospital of Central South University