Relationship between periodontal status and levels of glycated hemoglobin.

The objective of this study was to assess whether there is a bi-directional relationship between periodontal status and diabetes. Study 1 included 5,856 people without periodontal pockets of ≥ 4 mm at baseline. Relative risk was estimated for the 5-year incidence of periodontal pockets of ≥ 4 mm (CPI scores 3 and 4, with the CPI probe), in individuals with glycated hemoglobin (HbA1c) levels of ≥ 6.5% at baseline. Study 2 included 6,125 people with HbA1c < 6.5% at baseline. The relative risk was assessed for elevation of HbA1c levels in 5 years, with baseline periodontal status, assessed by CPI. Relative risk of developing a periodontal pocket was 1.17 (p = 0.038) times greater in those with HbA1c of ≥ 6.5% at baseline, adjusted for body mass index (BMI), smoking status, sex, and age. Relative risks for having HbA1c ≥ 6.5% at 5-year follow-up in groups with periodontal pockets of 4 to 5 mm and ≥ 6 mm at baseline were 2.47 (p = 0.122) and 3.45 (p = 0.037), respectively, adjusted for BMI, alcohol consumption, smoking status, sex, and age. The risk of developing periodontal disease was associated with levels of HbA1c, and the risk of elevations of HbA1c was associated with developing periodontal pockets of more than 4 mm.