Association between the number of teeth and incident pre-diabetes among middle-aged adults with periodontal disease: a retrospective cohort analysis of Japanese claims data

Abstract

ObjectivesTo investigate the association between the number of teeth and the new onset of pre-diabetes.DesignRetrospective cohort study.SettingThe National Database of Health Insurance Claims and Specific Health Checkups of Japan, which holds information from both the yearly health check-up programme known as the ‘Specific Health Checkup’ and health insurance claims data.Participants1 098 371 normoglycaemic subjects who participated in the Specific Health Checkup programme every year from fiscal year (FY) 2015 to FY 2018 and had dental insurance claims data with a diagnosis of periodontal disease during FY 2016.Outcome measuresIncidence of pre-diabetes or diabetes observed at the Specific Health Checkup during FY 2018.ResultsAmong the participants, 1 77 908 subjects developed pre-diabetes, and 579 developed diabetes at the check-up during the subsequent follow-up year. Compared with the subjects with 26–28 teeth, those with 20–25, 15–19 or 1–14 teeth were associated with an increased likelihood of developing pre-diabetes or diabetes onset with adjusted ORs of 1.03 (95% CI: 1.02 to 1.05), 1.06 (1.03 to 1.09) and 1.07 (1.04 to 1.11), respectively. No clear modifications were observed for age, sex, body mass index or current smoking.ConclusionsHaving fewer teeth was associated with a higher incidence of pre-diabetes. Due to the limitations of this study, however, causality remains undetermined.