Correlation of salivary glucose level with blood glucose level in diabetes mellitus

BACKGROUND: Saliva is a unique fluid, which is important for normal functioning of the oral cavity. Diabetes mellitus (DM) is a disease of absolute or relative insulin deficiency characterized by insufficient secretion of insulin by pancreatic beta-cells. The diagnosis of diabetes through blood is difficult in children, older adults, debilitated and chronically ill patients, so diagnosis by analysis of saliva can be potentially valuable as collection of saliva is noninvasive, easier and technically insensitive, unlike blood. The aim of the study was to correlate blood glucose level (BGL) and salivary glucose level (SGL) in DM patients. METHODOLOGY: A cross-sectional study was conducted in 120 patients, who were categorized as 40 controlled diabetics, 40 uncontrolled diabetics and 40 healthy, age- and sex-matched individuals constituted the controls. The blood and unstimulated saliva samples were collected from the patients at the different intervals for fasting, random and postprandial levels. These samples were then subjected for analysis of glucose in blood and saliva using glucose oxidase/peroxidase reagent in HITACHI 902((R)) Automatic analyzer, and the results were recorded. RESULTS: The mean SGLs were higher in uncontrolled and controlled diabetic groups than in nondiabetic group. A highly statistically significant correlation was found between fasting saliva glucose and fasting blood glucose in all the groups. CONCLUSION: With increase in BGL, increase in SGL was observed in patients with diabetes suggesting that SGL can be used for monitoring glycemic level in DM.