What Have Slow Progressors Taught Us About T1D—Mind the Gap!

Purpose of Review: Progression rate from islet autoimmunity to clinical diabetes is unpredictable. In this review, we focus on an intriguing group of slow progressors who have high-risk islet autoantibody profiles but some remain diabetes free for decades. Recent Findings: Birth cohort studies show that islet autoimmunity presents early in life and approximately 70% of individuals with multiple islet autoantibodies develop clinical symptoms of diabetes within 10 years. Some “at risk” individuals however progress very slowly. Recent genetic studies confirm that approximately half of type 1 diabetes (T1D) is diagnosed in adulthood. This creates a conundrum; slow progressors cannot account for the number of cases diagnosed in the adult population. Summary: There is a large “gap” in our understanding of the pathogenesis of adult onset T1D and a need for longitudinal studies to determine whether there are “at risk” adults in the general population; some of whom are rapid and some slow adult progressors.