Type 1 diabetes (T1D) has an insidious onset and rapid progression. Many patients first present with severe complications such as diabetic ketoacidosis, imposing a heavy burden on individuals, families, and society. Therefore, strengthening early screening and early prevention of T1D is of great practical significance. At the recently held 27th Annual Conference of the Chinese Diabetes Society (CDS 2025), Professor Zhou Zhiguang from the National Clinical Research Center for Metabolic Diseases, the Second Xiangya Hospital of Central South University, shared the latest research advances in the early identification of T1D.
I. Early Screening and Prevention of T1D Are Becoming Standardized
Early-stage T1D can be divided into two phases: the subclinical stage (Stage 1, 2) and the early clinical stage (Stage 3A, 3B). The subclinical stage is usually asymptomatic, but immune abnormalities and pancreatic β‑cell damage have already occurred.
Stage 1: Characterized by positivity for multiple islet autoantibodies, with basically normal blood glucose.
Stage 2: Dysglycemia develops, but does not yet meet clinical diagnostic criteria.As the disease progresses, patients enter the early clinical stage (Stage 3) and gradually develop typical diabetic symptoms.The 2021 Chinese Guidelines for T1D first clarified the concept of the subclinical stage and identified it as a critical window for intervention. Studies show that the 5‑year risk of progression to overt diabetes is 44% for Stage 1 T1D individuals and 75% for Stage 2.Early intervention in T1D helps delay disease progression, postpone insulin initiation, and prolong the “honeymoon period”.
In recent years, guidelines for early screening and monitoring of T1D have been issued successively worldwide, further promoting the standardization of early screening and prevention of T1D.In addition, starting from October 1, 2024, the ICD‑10 code E10 has been updated with subclassifications for pre-symptomatic T1D to support early diagnosis and standardized clinical management.
Against this background, the 2024 Chinese Expert Consensus on Screening, Monitoring and Management of High‑Risk Populations for Type 1 Diabetes systematically proposed a standardized workflow for screening, monitoring and management of high‑risk individuals for T1D in China. It emphasizes identifying high‑risk individuals as early as possible through standardized screening and follow‑up mechanisms, implementing early interventions, thereby improving the overall level of early prevention, diagnosis and treatment of T1D in China, reducing disease burden, and improving long‑term patient outcomes.
II. Early Screening Strategies for T1D
- Goals of T1D Screening
Early screening for T1D aims to identify high‑risk and subclinical individuals for effective prevention and management, reduce the incidence of diabetic ketoacidosis (DKA), delay the progression of complications, lower the risks of hospitalization and death, and provide opportunities for early intervention and clinical trials.Meanwhile, early management of high‑risk populations helps improve glycemic control, self‑management, and psychological adaptation, and provides a cohort basis for research on the pathogenesis of T1D. - Target Populations for T1D Screening
The 2024 Screening Consensus recommends screening for first‑degree relatives of T1D patients aged 1–45 years, including relatives of classic T1D and latent autoimmune diabetes in adults (LADA).Studies show that the risk of T1D in first‑degree relatives is about 10 times that in the general population, and can reach approximately 70% in identical twins.LADA is the most common autoimmune diabetes in Chinese adults, with genetic characteristics similar to T1D. Domestic studies have found a high prevalence of multiple autoantibodies in first‑degree relatives of LADA patients, similar to European and American populations, indicating that they are also a high‑risk group requiring early screening.
In addition to first‑degree relatives, if conditions permit, screening should also include individuals carrying T1D‑high‑risk HLA susceptibility genes or with a high genetic risk score (GRS), as well as those with other autoimmune diseases.Studies show that most T1D patients have no family history, but more than 100 susceptibility loci have been identified, among which HLA class II genes account for about 40%–50% of genetic susceptibility. Combined detection of HLA and non‑HLA loci with GRS contributes to risk prediction and early identification.
Benefits of early screening: Multiple prospective studies have confirmed that early screening and intervention for T1D can bring significant clinical benefits, including improved metabolic control, preserved islet function, and reduced risks of acute and chronic complications. - Screening Tools
A Chinese T1D Genetic Risk Score tool (C‑GRS) has been proposed as a new screening tool. Based on the Chinese population, this model integrates 33 relevant single nucleotide polymorphism (SNP) loci and comprehensively evaluates HLA and non‑HLA genetic variations to improve risk prediction.
Islet autoantibodies (IAb) are currently the most effective and widely used predictive markers for T1D, mainly including: Insulin autoantibodies (IAA)
Glutamic acid decarboxylase antibodies (GADA)
Protein tyrosine phosphatase antibodies (IA‑2A)
Zinc transporter 8 antibodies (ZnT8A)
Combined testing is recommended for early screening. Islet cell antibodies (ICA) are not recommended for routine use.The order of antibody appearance varies:
Early‑onset childhood T1D often presents with IAA first, followed by IA‑2A (with or without GADA).
Adolescents and adults more often develop GADA first, with relatively slow progression of β‑cell destruction.The number of antibodies is closely related to disease risk:
10‑year risk: ~14.5% for single antibody positivity,
~25% for 2 antibodies,
~40% for 3 antibodies,
~50% for 4 antibodies.Thus, combined testing is of great value for risk assessment.
The 2024 Screening Consensus recommends combined detection of GADA, IAA, IA‑2A, and ZnT8A for early T1D screening to significantly improve sensitivity and accuracy.The radioligand assay is the gold standard; standardized chemiluminescent assays are also acceptable.Re-testing is recommended within 3 months for initial positive results; confirmation requires ≥2 consecutive positive results, followed by risk assessment and follow‑up.
According to JDRF guidelines, 推广 of IAb screening is encouraged. For IAb‑positive individuals, blood glucose parameters should be further measured, and follow‑up and dynamic monitoring strengthened, to seize the window for subclinical immune intervention and the optimal timing for intervention in new‑onset Stage 3 T1D, thereby prolonging β‑cell function as much as possible.
Glycemic parameters: The 2024 Screening Consensus recommends that individuals with positive IAb screening undergo blood glucose testing to determine T1D staging and better predict disease risk.