Evaluation of the association between the number of natural teeth and anemia among Korean adults using nationally representative data

Background: Anemia as a chronic disease is defined as anemia occurring in chronic infections with inflammatory conditions. The purpose of this study is to assess the association between the number of natural teeth and anemia using nationally representative data. Methods: This study involved a cross-sectional analysis using data from the Korean National Health and Nutrition Examination Survey from 2010 to 2012. A total of 16,875 respondents aged > 19 years without missing values were included in this study. The association between the number of natural teeth and anemia was evaluated by multivariable logistic regression analyses after adjusting for age, sex, body mass index, smoking habits, drinking habits, exercise levels, income levels, education levels, vitamin D levels, diabetes, toothbrushing frequency, energy intake, and percentage of fat in total energy intake among Korean adults. Results: There was a significant decrease in prevalence of anemia and a significant increase in hemoglobin levels in participants with more natural teeth (P < 0.05). Adjusted odds ratios and their 95% confidence intervals for anemia in participants with numbers of natural teeth of < 15, 15 to 19, 20 to 24, or 24 to 28 were 1 (reference), 0.856(0.591 to 1.24), 0.659(0.5 to 0.868), and 0.607(0.463 to 0.797), respectively, with adjustment for confounding factors (P < 0.05). Conclusion: The number of natural teeth is negatively associated with anemia in Korean adults, and the number of natural teeth may be considered an independent risk indicator of anemia.