Approach to the obese adolescent with new-onset diabetes.

The prevalence of both type 1 and type 2 diabetes among children and adolescents has been steadily increasing over the last few decades. However, as the general pediatric population becomes more obese and more ethnically diverse, reliance on phenotypic characteristics for distinguishing between these types of diabetes is becoming increasingly untenable. Yet, the recognition of differences in treatment strategies, associated disorders, and both short- and long-term diabetes and cardiovascular outcomes supports the importance of diagnostic efforts to make a distinction between diabetes types. An approach to determination of diabetes type is discussed, focused on the presence or absence of autoimmunity and assessment of β-cell function. At the time of diagnosis, it is generally not possible to be certain of diabetes type, and therefore, initial treatment decisions must be made based on aspects of the presenting physiology, with adjustments in treatment approach made as the individual's course proceeds and additional information becomes available. The apparent overlap between type 1 and type 2 diabetes that occurs in obese adolescents has resulted in some controversy regarding mixed forms of diabetes that are ultimately semantic, but this does raise interesting questions about the treatment of type 1 diabetes in the presence of an insulin-resistant phenotype. Finally, the lack of information about the efficacy of treatment of cardiovascular risk factors, such as dyslipidemia and hypertension, along with the well-documented challenges in adherence to chronic illness treatment in this population, creates substantial challenges.