Association Between the Severity of Periodontitis and Osteoarthritis in Middle-Aged and Older Patients With Type 2 Diabetes Mellitus: A Nationwide Population-Based Study.

OBJECTIVE: Periodontitis and osteoarthritis are major public health concerns that result in decreased quality of life among middle-aged and older adults. We sought to examine whether the severity of periodontitis is related to osteoarthritis according to the presence of type 2 diabetes mellitus. METHODS: This study included 3,527 participants age >/=50 years from the Korean National Health and Nutrition Examination Survey. Periodontitis was assessed using the Community Periodontal Index; severe periodontitis was defined as periodontal tissue forming deep periodontal pockets >/=6-mm depth. Osteoarthritis was defined as Kellgren/Lawrence grade >/=2 on radiographic images of the knee or hip area with joint pain. The odds ratios (ORs) and 95% confidence intervals (95% CIs) for osteoarthritis according to the severity of periodontitis, stratified by type 2 diabetes mellitus, were calculated using multiple logistic regression analyses. RESULTS: Participants with type 2 diabetes mellitus were more likely to have osteoarthritis as the severity of periodontitis increased (nonsevere periodontitis OR 1.23 [95% CI 0.67-2.32]; severe periodontitis OR 3.01 [95% CI 1.51-5.84]) after adjusting for age, sex, body mass index, smoking status, alcohol consumption, regular exercise, education level, household income, hypertension, and frequent tooth-brushing. However, this positive association was not found in individuals without type 2 diabetes mellitus after adjusting for the same covariables. CONCLUSION: Severe periodontitis was positively and significantly associated with osteoarthritis in middle-aged and older individuals with type 2 diabetes mellitus. Our findings suggest that the oral inflammation manifesting in periodontitis may be at least partly involved in the pathogenesis of osteoarthritis, particularly in patients with type 2 diabetes mellitus.