Evaluation of parotid salivary glucose level for clinical diagnosis and monitoring type 2 diabetes mellitus patients

Background. To investigate the relationships among blood glucose, mixed saliva glucose, and parotid glucose in type 2 diabetes patients and to evaluate the diagnostic and monitoring value of salivary gland glucose in patients with type 2 diabetes (type 2DM). Material and Methods. Thirty patients with type 2DM and 30 healthy age- and sex-matched individuals were included in this study. Glucose levels in unstimulated mixed saliva and in unstimulated parotid saliva were measured by the glucose oxidase peroxidase method. Results. The blood glucose and parotid salivary glucose levels in type 2DM patients were significantly higher than those in the controls (P<0.05). The blood glucose, parotid salivary glucose, and mixed salivary glucose were 7.46±1.44 mmol/L, 0.18±0.19 mmol/L, and 3.17×10-2±2.84×10-2 mmol/L, respectively, in the type 2DM group; the corresponding glucose levels in the control group were 5.56±0.71 mmol/L, 7.70×10-2±6.02×10-2 mmol/L, and 3.47×10-2±2.79×10-2 mmol/L. The parotid salivary and blood glucose levels in type 2DM patients were strongly correlated; the linear regression equation for blood glucose and parotid salivary glucose was Y=6.267X+6.360, with r=0.810. However, mixed salivary glucose levels were not significantly different in the type 2 diabetes group compared with the control group. Conclusion. Our results suggest that parotid salivary glucose has potential as a biomarker to monitor type 2DM and as a painless, noninvasive method for the management of type 2DM.