Results The log-rank test showed that the cumulative incidence of diabetes between the three groups was significantly different (P<0.01). A Cox regression analysis model adjusted for sex, age, smoking habits, number of teeth present, and oral hygiene status showed that the diabetes development hazard ratio (HR) for the periodontal pocket ≥6 mm group was 1.44 (95% confidence interval [CI]; 1.04-2.00) when compared with that of the healthy periodontal pocket group. In the sensitivity analysis of individuals aged ≥40 years, the HR for the periodontal pocket ≥6 mm group was 1.55 (95% CI; 1.11-2.16) when compared with that of the healthy periodontal pocket group. Similarly, among men aged ≥40 years, the HR for the periodontal pocket ≥6 mm group was 1.72 (95% CI; 1.04-2.85) when compared with that of the healthy periodontal pocket group. However, no significant association between new onset of diabetes and periodontal pocket depth was found for women aged ≥40 years (HR=1.39, 95% CI; 0.89-2.18).