Dry Mouth Found to be More Prevalent in Type 1 Diabetes Than Type 2
A common side effect of diabetes is xerostomia, a condition in which a patient has a consistently dry mouth resulting from reduced or absent saliva flow. This can lead to damage of hard and soft oral tissues and the slow destruction of salivary glands. A study recently published in Advances in Clinical and Experimental Medicine sought to discover how common this condition is in patients with type 1 and type 2 diabetes. The study was conducted by Barbara Malicka and colleagues, department of conservative dentistry and pedodontics, Wroclaw Medical University, Poland. They evaluated the frequency of severity in xerostomia symptoms and salivary flow according to the type of diabetes, the level of metabolic control, and its duration throughout the course of diabetes.
A pool of 156 male and female patients were evaluated for xerostomia symptoms. Group C1 included 34 patients with type 1 diabetes, with a mean age of 37.5 years (18 women). Group C2 included 59 patients with type 2 diabetes, with a mean age 65.0 years (28 women). The participants were matched to the age and sex of 63 healthy individuals, who were split up into two control groups: K1 (n=30, mean age 37 years, 16 women) and K2 (n=33, mean age 63.7 years, 16 women). Subgroups were then assigned to patients with both types of diabetes according to the metabolic control, which was expressed by glycated hemoglobin levels (HbA1c) of HbA1c ≤8.5% and HbA1c >8.5%, and further subdivisions were assigned for the duration of diabetes (≤10 years and >10 years). Samples of saliva were taken from all participants in the morning at least 1 hour after eating or drinking, and they were collected from the mouth floor by a plastic pipette that was then inserted into a graded test tube and placed on ice. The salivary flow rate was calculated at mL/min. All participants were administered the Fox’s test, a 10-item questionnaire that aids in diagnosing xerostomia. The data was analyzed using a Mann-Whitney test with at significance level of P<.05.
Xerostomia was diagnosed more frequently in patients with type 1 diabetes, accompanied by a lower salivary flow rate than in age-matched controls (0.38 ± 0.19 mL/min vs 0.53 ± 0.20 mL/min, P<.01). However, patients with type 2 diabetes had, on average, a 20% lower salivary flow rate than controls. Compared with controls, both groups of patients with diabetes expressed dryness occurring during the day, during the night, or after waking up. There were also reports of taste disorders, and a large number of patients with type 2 diabetes reported the need to drink water at night. Patients with type 1 diabetes from metabolic control subgroup A1 had significantly more reports of taste disorders compared with patients with well-controlled type 2 diabetes, but there were no major differences in the salivary flow rate in type 1 and 2 with regard to diabetic control levels.
“Our study has revealed a statistically significantly lower salivary flow rate in type 1 diabetics as compared to the age-matched control group...and only slightly lower salivary flow rate in type 2 diabetes (on average by 20% as compared with the respective control group),” the authors wrote. The team determined that cases of dry mouth occur far more frequently in type 1 diabetes, while the results for type 2 remain inconclusive. The authors acknowledged that there may be several causes of the reduced salivary secretion in those with diabetes, and that “structural pathologies of complex etiologies with regard to salivary glands occur, which leads to disorders in the production of saliva.” – Elizabeth Ellis
