Abstract
Type 1 diabetes (T1D) has two pre-symptomatic phases (stages 1 and 2) with progressive destruction of beta cells which have been identified through longitudinal cohort studies in recent decades. The definition of T1D, with hyperglycaemia that may or may not be symptomatic, is now defined as stage 3. There is growing evidence that screening for stages 1 and 2 reduces rates of diabetic ketoacidosis and prevents long-term complications. These stages can be defined by the presence of islet autoantibodies which are markers of autoimmune beta cell damage. Furthermore, genetic risk scores, which combine a variety of single nucleotide polymorphisms, identify people at high genetic risk of future T1D. Thus, they provide an opportunity to select high-risk individuals for islet autoantibody testing. Individuals identified as having stage 1 or 2 T1D require ongoing monitoring to detect hyperglycaemia and the need for insulin replacement. These individuals may also be eligible for emerging immunotherapies in future to delay progression to stage 3. This review article explores the current evidence for screening and summarises the recommended clinical care for early-stage T1D.