Evaluation of glycated albumin levels in tears and saliva as a marker in patients with diabetes mellitus.

AIMS:Glycated albumin (GA) is a biomarker, whose level reflects glycemic control status over the previous 2 weeks. To develop a non-invasive method for evaluating glycemic control in people with diabetes mellitus, we investigated the measurement of GA levels in tears and saliva, which could be collected noninvasively. METHODS:Tear and saliva samples were collected from 48 participants with diabetes mellitus. The GA levels in the tear and saliva specimens were measured by Liquid Chromatography-Mass Spectrometry (LC-MS/MS). RESULTS:GA levels in both tear and saliva samples were significantly correlated with the GA levels in the blood (P < 0.001). Multiple regression analysis revealed that these correlations were maintained even after adjustments for the BMI, age, and nephropathy stage (P < 0.001). CONCLUSION:GA levels in tear and saliva specimens, as diabetes-related biomarkers, can be measured non-invasively. Since this measurement can be performed noninvasively and not as frequently as compared with the more invasive finger prick method, it is expected to reduce the burden on people with diabetes in terms of both the invasiveness and cost-effectiveness. In the future, we would like to verify the effect of regular GA measurement on the glycemic control while considering the clinical cost-effectiveness.