The American Diabetes Association's Professional Practice Committee, in a recent release, highlighted changes in classification and diagnosis for the 2018 Standards of Medical Care in Diabetes. One of the updates includes the following summary of current diabetes diagnostic categories, most of which are familiar; however, it includes additional consideration of diabetes due to other, less recognized causes (bolded below):

• Type 1 diabetes (due to autoimmune beta-cell destruction, usually leading to absolute insulin deficiency)
• Type 2 diabetes (due to a progressive loss of beta-cell insulin secretion, frequently on the background of insulin resistance)
• Gestational diabetes mellitus (GDM) (diabetes diagnosed in the second or third trimester of pregnancy that was not clearly overt diabetes prior to gestation)
Specific types of diabetes due to other causes, e.g., monogenic diabetes syndromes (such as neonatal diabetes and maturity-onset diabetes of the young [MODY]), diseases of the exocrine pancreas (such as cystic fibrosis and pancreatitis), and drug- or chemical-induced diabetes (such as with glucocorticoid use, in the treatment of HIV/AIDS, or after organ transplantation)

Chief Scientific, Medical and Mission Officer William T. Cefalu, MD, stated in a recent press release, “Since 1989, the American Diabetes Association has provided annual updates to the Standards of Care, and the Standards are accepted as the global standard for diabetes care. As new technology, research and treatments continue to improve and emerge, we are pleased that we will have the capacity to provide real-time updates to the Standards of Care throughout the year.”

An additional focus in the 2018 Standards has also been placed on new evidence describing the potential limitations in standard A1c measurements. Since the A1c measures blood glucose over time, recognition of the potential limitation for individuals with reduced red blood cell (RBC) life expectancy, whether impacted by genetics or medical conditions, is critical in leveling the playing field for treatment and management.

In addition to medical conditions that are associated with altered RBC turnover, interference and inaccurate assay and variants seen with individualized hemoglobin characteristics are also highlighted in the latest standards of medical care. This clarifies the appropriate use of the A1c test for general evaluation, monitoring efficacy of drug therapy, and diagnosing diabetes.

The ADA 2018 Standards of Care also clarifies that community screening should only be considered in specific situations in which an adequate referral system for positive tests is established. In this update, the ADA emphasizes the need for awareness of these limitations and the actions to take, which include, but are not limited to, the use of the correct A1C test and considering alternate diagnostic tests, such as the fasting plasma glucose test or the oral glucose tolerance test, when there is disagreement between A1C and blood glucose.