Association between the number of remaining teeth and hs-CRP among older Korean adults: a cross-sectional study using the 2022 Korea National Health and Nutrition Examination Survey

Objectives: This study examined the association between the number of remaining teeth and high-sensitivity C-reactive protein (hs-CRP), a marker of systemic inflammation, among Korean adults aged ≥65 years using data from the first year (2022) of the Ninth Korea National Health and Nutrition Examination Survey (KNHANES). Methods: The study included 1,256 adults aged ≥65 years. The dependent variable was log-transformed hs-CRP level, and the primary independent variable was the number of remaining teeth, categorized as <20 or ≥20. Descriptive statistics were calculated, and associations were examined using complex-sample simple and multiple linear regression analyses. Results: In the simple regression analyses, age, sex, family composition, household income, smoking, dyslipidemia, and number of remaining teeth were significantly associated with log-transformed hs-CRP levels. After adjustment in the multiple regression analysis, age, family composition, dyslipidemia, and number of remaining teeth remained significantly associated with the outcome. Older adults with fewer than 20 remaining teeth had significantly higher hs-CRP levels than those with 20 or more teeth (B = 0.176, SE = 0.060, p = 0.004). Conclusions: Having fewer remaining teeth was associated with higher hs-CRP levels, suggesting a potential link between oral health and systemic inflammation in older adults. These findings suggest that maintaining natural teeth promotes healthy aging.