Introduction: Current guidelines set the goal of diabetes control to a glycated hemoglobin A1c (HbA1c) level of <7% in order to prevent macrovascular events. However, we often experience diabetes patients with cerebral infarction (CI), even though their HbA1c level is well-controlled. A reason for this disparity between the diabetes control status and CI onset may be the limitation of HbA1c as a diabetes control indicator. HbA1c reflects the mean blood glucose level over the past 2-3 months. Therefore, with HbA1c, we cannot evaluate short-term blood glucose control and glycemic variability, which are reported as risk factors for CI. Measurement of 1,5-anhydro-D-glucitol (1,5AG) allows the evaluation of these factors.
Hypothesis: 1,5AG can be used to evaluate the risk of CI in patients with well-controlled diabetes.
Methods: We retrospectively reviewed the medical records of 1169 patients with diabetes who received treatment for CI at our hospital between 2009 and 2014. These patients were divided into the following two groups according to their HbA1c-based diabetes control status: a CI-low group (HbA1c <7%, n=549) and a CI-high group (HbA1c ≧7%, n=620). We also included a non-CI group of 394 diabetes patients without CI (control group), and these patients were further divided into the following two groups in the same manner: a nonCI-low group (n=199) and a nonCI-high group (n=195). The 1,5AG levels were compared between the CI-low and nonCI-low groups, and the CI-high and nonCI-high groups.
Results: There was no difference in the 1,5AG level between the CI-high and nonCI-high groups (8.8±7.3% vs. 8.9±7.1%, p=0.83). However, the 1,5AG level was significantly lower in the CI-low group than in the nonCI-low group (12.5±8.1% vs. 15.2±8.8%, p<0.001). This difference remained significant after adjusting for age and sex.
Conclusion: The results of this study show that short-term glycemic control and glycemic variability have a significant relationship with existing CI especially in patients with good diabetes control. The 1,5AG level may be a surrogate measure of the risk of CI in patients with HbA1c levels that indicate good diabetes control.