A simple office-based test could confirm prediabetes and make a significant impact on halting progression to more serious disease. Hemoglobin (Hb) A1c measurements are appropriate for that use, a recent study suggests (Am J Prev Med. 2011;40:11-17).

Researchers sought to determine the composite risks of developing diabetes and cardiovascular disease (CVD) among adults with different HbA1c test results, and to compare those risks with those of adults who met the American Diabetes Association (ADA) definition for prediabetes.

Using data from the 2005-2006 National Health and Nutrition Examination Survey, the investigators calculated that adults meeting the 2003 ADA definition for prediabetes had a 33.5% chance of developing type 2 diabetes over 7.5 years, and a 10.7% of developing CVD over 10 years. Researchers then found that using HbA1c levels alone, a reading in the range of 5.5% to <6.5% would identify a patient population with comparable risks for developing diabetes (32.4%) and CVD (11.4%). Using a slightly higher cutoff for HbA1c (>5.7%) would identify adults with risks of 41.3% for diabetes and 13.3% for CVD. These risks were comparable to those carried by participants in the Diabetes Prevention Program study.