Diabetes mellitus type 1 (also called diabetes mellitus 1 or diabetes 1) is caused by the production of antibodies against the insulin-producing pancreatic islet cells. Diabetes mellitus 1 is the most severe type of diabetes mellitus; current diabetes statistics suggest that it accounts for 5%-10% of diabetes diagnoses. Children with this type of diabetes (formerly known as juvenile-onset diabetes) often develop diabetes symptoms (polydipsia, polyuria, weight loss, hunger) rapidly. Patients with type 1 diabetes do not usually respond to oral diabetes medications but require life-long insulin replacement.