Background: It is estimated that 3.6% and 13.6% of the Danish population have undiagnosed type 2 diabetes mellitus and prediabetes, respectively. Periodontitis is an established complication associated with diabetes (DM). Identification of individuals with DM and prediabetes is important to reduce DM-related complications, including periodontitis. The objective of this study is to identify individuals with undiagnosed DM or prediabetes among patients attending a dental setting for diagnosis and treatment.

Methods: A total of 291 adults with no history of DM was included in the study (periodontitis patients: n = 245; non-periodontitis control individuals: n = 46). Participants answered questionnaires concerning general health, including family history of DM. Body mass index, waist circumference, fat percentage, and glycated hemoglobin (HbA1c) level were recorded chairside. Periodontal examination was performed and radiographic bone level measured. All individuals were informed about their HbA1c test result and were referred to their physician if HbA1c level was above guideline levels for DM or prediabetes according to the American Diabetes Association.

Results: Nine (3.1%) and 79 (27.1%) individuals were identified with HbA1c levels corresponding to guideline levels for DM and prediabetes, respectively. Higher proportions of patients with undiagnosed DM and prediabetes were observed in the periodontitis group (32.7%) than in the control group (17.4%) (P = 0.054). Identification of DM and prediabetes based on a diagnosis of periodontitis yielded a sensitivity of 0.91 and a specificity of 0.19.

Conclusions: This study confirms that individuals with undiagnosed DM and prediabetes can be identified in the dental office by chairside recordings of HbA1c levels. Routine measurement of HbA1c levels in dental offices, eventually restricted to those at risk, may help identification of individuals with DM and prediabetes at early stages of disease, which may prevent future complications.