Prediabetes definitions using HbA_1c were more specific and provided modest improvements in risk discrimination for clinical complications, while the definition using the American Diabetes Association (ADA) fasting glucose concentration cutoff was more sensitive overall, a recent study concluded. In a prospective analysis of the Atherosclerosis Risk in Communities (ARIC) study, the risk of future outcomes across different prediabetes definitions were compared based on fasting glucose concentration, HbA_1c, and 2 h glucose concentration over 2 decades of follow-up. Researchers found:

• Participants included those who did not have diagnosed diabetes and who attended visit 2 (1990-1992; n=10,844), and who attended visit 4 (1996-1198; n=7,194).
• Prediabetes defined using the ADA fasting glucose concentration cutoff was the most sensitive for major clinical outcomes.
• However, using the ADA HbA_1c cutoff and IEC HbA_1c cutoff , and the WHO fasting glucose concentration cutoff were more specific.
• After demographic adjustment, HbA_1c–based definitions of prediabetes had higher hazard ratios and better risk discrimination for chronic kidney disease, CVD, peripheral arterial disease, and all-cause mortality, compared to fasting glucose concentration-based definitions.