The Prevalence of Xerostomia in Older Thai Individuals with Type II Diabetes Mellitus and Its Association with Type of Toothpaste and Oral Functions: A Cross-Sectional Study Using Questionnaires

Aim: To investigate the prevalence of xerostomia in older people with diabetes mellitus and its impacts on oral functions, as well as to determine potential risk factors for xerostomia. Methods: An analytical cross-sectional study was conducted on 623 older type 2 diabetes mellitus (T2DM) Thai people using valid structural questionnaires. Patients were interviewed, and data were recorded. Xerostomia was assessed using subjective symptom questionnaires. Risk factors for xerostomia were analyzed using bivariate and multiple logistic regression analyses. Results: Among the study participants, 38.4% of the older T2DM people had xerostomia, which is associated with sex, age, type of toothpaste, years of diabetes, hemoglobin A1c level, other systemic diseases, medication, smoking, alcohol consumption, and denture wearing. It was significant that xerostomia was associated with toothpaste containing spicy herbal extracts (OR: 9.32 [3.46 to 15.25]), while toothpaste containing artificial sweeteners tended to lower the risk of xerostomia. In addition, older T2DM adults with xerostomia had greater impaired oral functions, which include difficulties in speaking (OR: 3.31 [1.11 to 9.80]), tasting (OR: 5.12 [3.26 to 8.06]), swallowing (OR: 3.59 [2.32 to 5.53]), and chewing (OR: 3.34 [1.15 to 5.82]). Conclusions: Xerostomia is prevalent in older Thai people with T2DM. The results suggest that toothpaste containing spicy herbal extracts might increase the risk of xerostomia, resulting in various oral function problems. Therefore, greater awareness of xerostomia in this group should be raised to monitor dental health, and professionals should work in parallel with other aspects of oral health promotion.