Salivary flow rate and salivary glucose concentration in patients with diabetes mellitus influence of severity of diabetes.

Eleven diabetics (eight with type I diabetes) aged 20 to 45 years underwent salivary investigations on two occasions, one to five months apart, during different metabolic control. Stimulated salivary flow rate showed a great inter-individual variation, and was not changed by improved metabolic control. Salivary glucose concentration was lower during the period of better metabolic control. In stimulated parotid saliva a positive correlation between glucose levels in saliva and blood was seen. A blood glucose threshold for glucose excretion at about 10-15 mmol/L might be present. There were no significant differences in pH, buffering capacity, total amount of protein, amylase, lysozyme, peroxidase or electrolytes (Na+, K+, Ca2+, PO42- and Mg2+) in the saliva between the two occasions of different metabolic control. In conclusion, the degree of diabetic metabolic control does not seem to be of major importance for salivary flow rate or composition in diabetics except for the salivary glucose concentration.