α-2-Macroglobulin in Saliva Is Associated with Glycemic Control in Patients with Type 2 Diabetes Mellitus

BACKGROUND Subjects with type 2 diabetes mellitus (DM2) require an adequate glycemic control to avoid diabetic complications. Currently, saliva biomarkers are used as a diagnostic tool and can be indicative of the degree of progression and control of various diseases. Several studies indicate that α-2-macroglobulin levels are elevated in diabetic patients. METHODS 120 subjects with DM2 were enrolled and classified into two groups according to their glycemic control (percentage of glycated hemoglobin-A1c (HbA1c), <7% adequate glycemic control group; >7% inadequate glycemic control group). The relationship between α-2-macroglobulin levels from saliva samples and HbA1c was subsequently evaluated. RESULTS We found a positive correlation between α-2-macroglobulin and HbA1c (r = 0.778 and P < 0.0001). Area under the receivers operating characteristic (ROC) curve of α-2-macroglobulin indicated a positive discrimination threshold of α-2-macroglobulin (AUC = 0.903, CI 95%: 0.847-0.959, P < 0.0001) to diagnose glycemic control. CONCLUSIONS Our data strongly suggest that the level of saliva α-2-macroglobulin is an indicator for the degree of glycemic control in diabetic patients and represents a promising alternative method to evaluate this parameter.