Comparative Efficacy of Salivary, Buccal, and Hemoglobin Biomarkers in Blood Glucose Monitoring: Implications for Type 2 Diabetes Management

Background and objectives: Blood-based monitoring remains the gold standard for diabetes management, yet non-invasive alternatives like salivary diagnostics offer significant potential. This study evaluated salivary glucose, buccal cell glycogen, oral glucose tolerance (OGTT), and glycated hemoglobin (HbA1c). Materials and Methods: 370 participants classified into three groups: uncontrolled diabetes (n=135), managed diabetes (n=135), and non-diabetic controls (n=100). Salivary and blood samples were collected under standardized protocols, with glucose levels quantified via enzymatic assays, HbA1c via fluorescence immunoassay, and buccal cell glycogen via periodic acid-Schiff (PAS) staining. Results: A significant differences in salivary glucose levels across groups (highest in uncontrolled diabetics: 204 mg/dl vs. controls: 111 mg/dl; p<0.05), correlating strongly with blood glucose (r=0.372, p=0.043). PAS-positive buccal cells were markedly elevated in diabetics (uncontrolled: 9.15 ± 2.37; controlled: 4.47 ± 1.83; controls: 0.93 ± 1.31; p=0.001), with staining intensity reflecting glycemic status. OGTT profiles in saliva mirrored serum trends, peaking at 1-hour post-glucose intake. ROC analysis revealed high diagnostic accuracy for salivary glucose (AUC=0.932) and PAS-positive cells (AUC=0.752) in distinguishing diabetics from controls. Conclusions: The integration of salivary glucose and buccal cell glycogen assessments offers a robust, non-invasive approach for diabetes screening. Standardization of collection protocols and interdisciplinary collaboration are critical to advancing saliva-based diagnostics, enabling early detection and holistic management of Type 2 Diabetes Mellitus.