Spectrophotometric Determination of Total Salivary Sialic Acid Using a Colorimetric Chemical Assay and Its Association with Glycemic Control in Prediabetic and Type ۲ Diabetic Patients

Diabetes mellitus is a chronic metabolic disorder characterized by persistent hyperglycemia and associated inflammatory alterations. Although glycated hemoglobin (HbA۱c) and fasting blood sugar (FBS) remain the standard biomarkers for evaluating glycemic status, their assessment requires invasive blood sampling. Salivary biomarkers have recently attracted considerable attention as convenient and non-invasive alternatives. Among these, total salivary sialic acid (TSA), an indicator of inflammation and oxidative stress, has been proposed as a potential marker of diabetes progression. In the present study, the relationship between salivary TSA and glycemic indices was investigated in prediabetic and type ۲ diabetic individuals. A total of ۷۰ participants, including ۳۴ prediabetic and ۳۶ patients with type ۲ diabetes, were enrolled. Unstimulated saliva samples were collected for TSA determination using the Skoza-Mohos spectrophotometric method, while HbA۱c and FBS were measured using standard laboratory procedures. The analytical procedure involved chemical derivatization of sialic acid through thiobarbituric acid-based color development, preparation of appropriate reagent solutions, and spectrophotometric quantification of the generated chromophore. Statistical analyses were performed to evaluate correlations and the diagnostic performance of TSA. The diabetic group exhibited significantly higher HbA۱c and FBS values than the prediabetic group (P < ۰.۰۰۱). However, salivary TSA showed no significant correlation with either HbA۱c or FBS (P > ۰.۰۵). Furthermore, receiver operating characteristic (ROC) analysis demonstrated poor diagnostic performance of TSA in distinguishing diabetic from prediabetic subjects (AUC = ۰.۴۴). These findings indicate that although salivary sialic acid reflects inflammatory processes, it does not adequately represent glycemic control and cannot currently serve as a reliable non-invasive substitute for conventional blood biomarkers. Further studies involving larger populations and additional salivary inflammatory markers are warranted.

کلیدواژه ها:

Total Salivary Sialic Acid (TSA) ، Glycemic Control ، HbA۱c ، Fasting blood glucose (FBG) ، Prediabetic ، Type ۲ diabetes mellitus