Periodontal disease and the incident risk of diabetes mellitus in Japanese men and women: a 12-year cohort study.

AIMS/INTRODUCTION: This study assessed the association between periodontal disease and the development of diabetes mellitus, as well as the effects of sex differences and obesity on this association.

MATERIALS AND METHODS

The study included 4051 employees (2497 men and 1554 women) aged 35-55 years at a metal product manufacturing company in Japan. Periodontal disease was assessed using the Community Periodontal Index. Diabetes mellitus was determined based on annual health checkups.

RESULTS

The prevalence of periodontal disease was 36.9% (41.9% in men and 29.5% in women). During the 12-year follow-up, 229 participants developed diabetes. The cumulative incidence rates (per 1000 person-years) were 10.1 for all participants, 7.8 for those without periodontal disease, and 14.5 for those with periodontal disease. The multivariate-adjusted hazard ratio (HR) for diabetes incidence in the periodontal disease group was 1.36 (95% confidence interval: 1.04-1.78); this was significantly higher than in the non-periodontal disease group. In men, the multivariate-adjusted HR for diabetes incidence was significantly higher in the periodontal disease group, at 1.37 (1.02-1.83), than in the non-periodontal disease group. No significant association was detected in women. When stratified according to sex and obesity status, the non-obese male group showed a significantly higher HR for diabetes incidence in the periodontal disease group (1.75 [1.15-2.66]) compared with the non-periodontal disease group.

CONCLUSIONS

This 12-year prospective cohort study demonstrated that periodontal disease significantly increased the risk of diabetes; the association was more pronounced in men, particularly non-obese men.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13340-025-00815-z.