1. Kristi M. Cowell, MD* 1. *Resident in Medicine & Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, NY Type 2 diabetes mellitus is a disease characterized by insulin resistance and a relative insulin deficiency leading to chronic hyperglycemia. With the increase in sedentary lifestyle and obesity among children and adolescents, the incidence of type 2 diabetes has risen dramatically in the last decade. Diagnosis and management of type 2 diabetes in children can be particularly challenging. Unfortunately, few large, long-term studies of type 2 diabetes in children exist. Many of the current recommendations for children are extrapolated from adult studies. Additionally, type 2 diabetes often evolves from years of progressively increasing insulin resistance without hyperglycemia, which can make the distinction between type 2 diabetes and insulin resistance conditions difficult and somewhat arbitrary. Patients may meet diagnostic criteria for type 2 diabetes by one test method and yet have normal results or “prediabetes” by another test method performed during the same time period. Fortunately, this distinction does not affect management recommendations significantly, which are the same for children who have “diet-controlled” type 2 diabetes, have “prediabetes,” or are “at high risk” for these conditions. Finally, children may have a form of diabetes mellitus that has features of both type 1 and type 2 disease, so-called “mixed diabetes” or “double diabetes.” Diabetes mellitus and hyperglycemia can present with polyuria, polydipsia, polyphagia, nocturia, enuresis, weight loss, or vaginal candidiasis, but many children who have type 2 diabetes are asymptomatic. Although most commonly associated with type 1 diabetes, diabetic ketoacidosis is the presenting symptom in 5% to 25% of adolescents who have type 2 diabetes. Inherited and acquired risk factors predispose children to type 2 diabetes. Obesity (particularly abdominal obesity), family history of type 2 diabetes, racial/ethnic background, puberty, and the presence of a condition associated with insulin resistance should prompt the pediatrician to consider the child's risk for developing type 2 …