Salivary composition in diabetic patients

Salivary composition and flow rate were examined in 35 patients with insulin-dependent diabetes mellitus (IDDM) and compared to 31 healthy controls. Significantly lower whole-saliva flow rate was observed in the IDDM patients, but was not correlated with the subjective complaint of xerostomy. Glucose concentration was significantly higher in the parotid saliva of the IDDM patients. Potassium concentration was significantly higher in whole and parotid, resting and stimulated saliva, as was total protein concentration in resting whole and in stimulated parotid saliva of the diabetics. No significant difference between diabetics and healthy controls was found in sodium and IgA concentration or in amylase activity. The significantly higher glucose, lower flow rate, and higher potassium and protein concentrations indicate that salivary glands are affected in IDDM. The subjective complaint of dry mouth, often present in diabetics, while not correlated with salivary flow rate, might reflect qualitative changes in salivary composition and/or altered mucosal perception. Salivary glucose concentration, although significantly higher in the diabetics, was not significantly correlated with serum glucose, preventing the use of saliva for monitoring blood sugar.