Oral dryness and peripheral neuropathy in subjects with type 2 diabetes

Two common complaints related to diabetes mellitus are oral dryness (xerostomia) and peripheral neuropathy (PN) and there is some evidence of a relationship between them. Therefore, we formulated a hypothesis that type 2 diabetic subjects with xerostomia in our study also exhibited PN. The study included 102 randomly sampled type 2 diabetic patients from a healthcare district in mid-Sweden. Besides clinical and X-ray examinations, patients were asked whether they experienced oral dryness. PN was defined through thorough foot examination and the use of a modified neuropathy symptom score (NSS) and neuropathy disability score (NDS). Other diabetes-related variables were extracted from medical records. More than half of the individuals (53.5%) reported oral dryness and 23.8% were diagnosed with PN. None of the variables in a stepwise regression analysis could explain the variance in oral dryness, besides "pain in the legs," which contributed with 5% to the explanation. Our hypothesis that type 2 diabetic subjects with xerostomia also were affected with PN could not be verified in this study, but the results must be interpreted with caution as relatively few subjects were affected with both oral dryness and PN (13.8%). Further and larger controlled studies are needed before the hypothesis can be definitely rejected. Despite our incomplete understanding about the relation between oral dryness and PN, professionals in oral health as well as in primary health have to strive for increased knowledge in this field.