Some properties of mixed saliva in diabetic autonomic neuropathy

INTRODUCTION: The purpose of this work was to determine the influence of diabetic autonomic neuropathy on some basic properties of saliva such as volume of stimulated mixed saliva, concentration and secretion rates of sodium, potassium and calcium ions, and of glucose. MATERIAL AND METHODS: The study was carried out in 55 patients (25 females and 30 males). The study group consisted of 19 patients with type 2 diabetes mellitus and autonomic neuropathy affecting the cardiovascular system--DM-N(+). Two control groups were formed. One of them included 18 diabetic patients without any autonomic neuropathy--DM-N(-), the other (K) comprised 18 patients without diabetes. In the latter group there were nine patients on atropine (K-A) due to bradycardia and nine patients on propranolol (K-P) due to tachycardia. In the latter group, saliva samples were collected before and after administration of atropine or propranolol. RESULTS: A significantly lower (p < 0.001) mean volume of stimulated mixed saliva was found in diabetic patients with autonomic neuropathy (1.91 +/- 0.34 mL) and control patients on atropine (K-A) (2.24 +/- 0.68 mL) as compared to DM-N(-) (5.37 +/- 0.78 mL) and K-P patients (5.51 +/- 1.05 mL). The volume of saliva did not correlate with glycosylated haemoglobin in either DM-N(-) or DM-N(+) groups. Secretion of glucose, as well as sodium, potassium and calcium ions to saliva was significantly lower in diabetics with autonomic neuropathy DM-N(+) and in non-diabetics after administration of atropine. CONCLUSION: Based on these results it was concluded that secretion of stimulated mixed saliva, glucose, as well as sodium, potassium and calcium ions is significantly reduced in autonomic neuropathy. These findings may be associated with lesions to parasympathetic nerve fibers caused by long-lasting diabetes.