An Update on Measures of Preoperative Glycemic Control

Glycemic control represents a modifiable preoperative risk factor in surgery. Traditionally, hemoglobin A1c (HbA1c) and plasma glucose are utilized as measures of glycemic control. However, studies show mixed results regarding the ability of these conventional measures to predict adverse surgical outcomes. This may be explained by the time window captured by HbA1c and serum glucose: long-term and immediate glycemic control, respectively. Fructosamine, glycosylated albumin, and 1,5-anhydroglucitol constitute alternative metrics of glycemic control that are of growing interest but are underutilized in the field of surgery. These nontraditional measures reflect the temporal variations in glycemia over the preceding days to weeks. Therefore, they may more accurately reflect glycemic control within the time window that most significantly affects surgical outcomes. Additionally, these alternative measures are predictive of negative outcomes, even in the nondiabetic population and in patients with chronic renal disease and anemia, for whom HbA1c performs poorly. Adopting these newer metrics of glycemia may enhance the value of preoperative evaluation, such that the effectiveness of any preoperative glycemic control interventions can be assessed, and adverse outcomes associated with hyperglycemia better predicted. The goal of this review is to provide an update on the preoperative management of glycemia and to describe alternative metrics that may improve our ability to predict and control for the negative outcomes associated with poor glycemic control.