Salivary glycated albumin could be as reliable a marker of glycemic control as blood glycated albumin in people with diabetes

Aims: Measurements of diabetes-related biomarkers are necessary to assess glycemic control. The commonly used finger-prick blood glucose and HbA1c measurements are invasive, as is blood glycated albumin (GA) measurement. Therefore, we developed a non-invasive method, namely, measurement of the salivary GA with high accuracy using a high-performance liquid chromatography (HPLC) method. Methods: We recruited participants with diabetes mellitus admitted to The University of Tokyo Hospital. Blood and saliva samples were collected at three time points (fasting and 2-hour postprandial at admission and fasting at discharge). After partial purification using an antibody-based column, the samples were subjected to GA measurement by HPLC method. Results: Among the 56 participants with diabetes mellitus enrolled in the study, there was a correlation between the GA levels measured in blood and saliva at the three time points described above (n = 45, R-2 = 0.985, P < 0.001; n = 48, R-2 = 0.973, P < 0.001; n = 51, R-2 = 0.979, P < 0.001). Multiple regression analysis revealed the associations were maintained even after adjustments for age, BMI, and nephropathy stage. Conclusions: This exploratory research revealed that the salivary GA levels by this method were accurate and might be able to replace blood GA measurement. The home salivary GA measurement is expected to be developed that may reduce the burden and complications in people with diabetes mellitus and improve the quality of life.