Glycated Hemoglobin as an Integrator of Cardiovascular Risk in Individuals Without Diabetes: Lessons from Recent Epidemiologic Studies.

PURPOSE OF REVIEW: Prediabetes, or dysglycemia in the absence of diabetes, is a prevalent condition typically defined by a glycated hemoglobin (HgbA1c) of 5.7- < 6.5%. This article reviews current contemporary data examining the association between prediabetes and cardiovascular disease (CVD) as well as HgbA1c as a continuous measure of cardiovascular risk across the glycemic spectrum. RECENT FINDINGS: Dysglycemia in the prediabetic range is associated with an increased risk of both subclinical and clinical CVD, including atherosclerotic CVD, chronic kidney disease, and heart failure. Several recent large, prospective studies demonstrate roughly linear risk with increasing HgbA1c, even below the threshold for prediabetes. "High-risk" patients with prediabetes have similar CVD risk as those with diabetes. HgbA1c below the threshold for diabetes stratifies CVD risk. Use of HgbA1c as a continuous measure, rather than simply dichotomized, may inform current and future prevention strategies. Given the high population attributable risk associated with prediabetes, targeted prevention strategies in this population warrant dedicated study.