ABSTRACT Aims In China, information on individuals who test positive for islet autoantibodies (IAb), including single IAb‐positive individuals and those with early‐stage Type 1 diabetes (T1D), and their risk of progression to Stage 3 T1D is limited. The goal of this study is to assess the risk of progression to T1D in first‐degree relatives (FDRs) of people with T1D in China. Materials and Methods This prospective, longitudinal study, being conducted at approximately 50 hospitals in China, will screen FDRs of individuals with T1D to identify those at risk for developing the disease by testing for the presence of IAb in the blood. IAb‐positive individuals will undergo further testing for up to 5 years, with the primary objective of assessing their risk of Stage 3 T1D onset. During the monitoring period, participants with single IAb‐positivity will be tested for glycated haemoglobin (HbA1c) and IAb every year; those with multiple IAb‐positivity will have an HbA1c and oral glucose tolerance test (OGTT) every year (Stage 1 T1D), or OGTT or random blood glucose test in alternate 6‐monthly intervals and HbA1c every 3 months (Stage 2 T1D). Participants who develop Stage 3 T1D during monitoring can undergo extended follow‐up to assess changes in β‐cell function, glycaemic outcomes and IAb status during the first 12 months after diagnosis. The study plans to enrol 5500 participants; enrolment is ongoing. Conclusions Through early screening and monitoring of disease progression in FDRs of T1D probands, this study will provide a comprehensive understanding of T1D progression in the Chinese population. Trial Registration: Chinese Clinical Trial Registry identifier: ChiCTR2600119032
Guo et al. (2026) studied this question.