It is generally believed that the onset of type 2 diabetes can be insidious and evade detection for prolonged time periods (1,2). Type 1 diabetes, however, often displays a sudden clinical onset due to the development of insufficient insulin secretory capacity following a pre-diabetic period characterized by the presence of pancreatic islet autoantibodies. Type 1 diabetes usually presents with symptoms, the most frequent being polyuria and polydipsia (97%) and weight loss (46%) in one recent study of newly diagnosed patients (3). The article by Triolo et al. (4), in this issue of Diabetes Care , addresses the period in the development of type 1 diabetes between the onset of hyperglycemia that meets diagnostic criteria for diabetes and its clinical presentation. Triolo et al. present evidence that the onset of type 1 diabetes can occur without clinical symptoms and be difficult to detect with the current approach to diagnosis, which is based on fasting plasma glucose (FPG) measurement (5). These conclusions are based on the results of semiannual oral glucose tolerance tests for diabetes diagnosis among the Diabetes Prevention Trial–Type 1 (DPT-1) participants. The occurrence of asymptomatic type 1 diabetes in the DPT-1 population has been previously reported (6). The important additional findings are the value of A1C in the detection of diabetes and the comparatively low occurrence of diabetic ketoacidosis (DKA) at diagnosis of diabetes. The authors conclude by advising that “high-risk relatives may benefit from close attention or screening in order to prevent DKA at diagnosis” (4). The …