Type 2 Diabetes Mellitus in Youth: An emerging epidemic

This is double the current worldwide prevalence, which is estimated to be 150 million. The major part of this increase will occur in developing countries. Several factors are thought to account for this steep rise, but one of the most important is the marked rise in obesity. Obesity increases insulin resistance, which is the hallmark of Type 2 DM. Type 2 DM, via chronic hyperglycemia, exerts its deleterious effects through the development of both micro- vascular and macrovascular long-term complications that lead to substantial morbidity, mortality, and healthcare expenditures. Type 2 DM was traditionally considered to be an adult disease. However, an alarming trend in the growing epidemic of Type 2 DM is the number of new cases being diagnosed in children and in youth. Many argue that this rise can be explained by the growing prevalence of obesity amongst children and adolescents. This issue of Endocrinology Rounds reviews the epidemiology, screening, diagnosis, and treatment of Type 2 DM in youth. Epidemiology Obesity is the single most prevalent nutritional disease affecting children and adoles- cents in the United States. 3 It has significant negative psychosocial and disease-related con- sequences. Recent estimates (1999-2000) from the United States National Health and Nutrition Examination Study reveal that 15.5% of adolescents aged 12-19 years have a body mass index (BMI) above the 95 th percentile for age and gender. Furthermore, 15.3% of 6-11-year-olds and 10.4% of 2-5-year-olds also have a BMI above the 95 th percentile. 4