Tooth Loss and Uncontrolled Diabetes Among Korean Adults With Type 2 Diabetes: Insights From the Korea National Health and Nutrition Examination Survey (KNHANES) 2014–2018

ABSTRACT Objectives The relationship between tooth loss and glycemic control status in diabetes is inconclusive. Material and Methods Using data from the 2014–2018 Korean National Health and Nutrition Examination Survey (KNHANES), 2146 adults with diabetes aged ≥ 40 years were categorized by number of remaining teeth (0–19, 20–27, and ≥ 28). Uncontrolled diabetes and poorer glycemic control were defined as HbA1c ≥ 6.5% and ≥ 7.0%, respectively. Multivariable logistic regression models calculated the odds ratio (OR) for uncontrolled diabetes and poorer glycemic control according to the number of remaining teeth. Results No significant association was observed in men. In women, fewer remaining teeth were associated with higher odds of uncontrolled diabetes (per 1‐tooth increase OR 0.961, 95% CI 0.937–0.986; p = 0.002), and compared with ≥ 28 teeth, OR were higher in the 0–19 teeth (OR 2.500, 95% CI 1.535–4.074) and the 20–27 teeth (OR 1.679, 95% CI 1.073–2.629) (all p = 0.002). Furthermore, among women, the associations persisted in both 40–59 years (per 1‐tooth increase OR 0.878, 95% CI 0.780–0.988; p = 0.030) and ≥ 60 years (per 1‐tooth increase OR 0.965, 95% CI 0.939–0.992; p = 0.011). Among women aged ≥ 60 years, those with 0–19 teeth had higher odds of uncontrolled diabetes (OR 1.994, 95% CI 1.041–3.818; p = 0.029) and poorer glycemic control (OR 2.498, 95% CI 1.321–4.723; p = 0.008) compared with those with ≥ 28 teeth. Conclusions Fewer remaining teeth were associated with poorer glycemic control among women with diabetes, independent of periodontitis. This association was most pronounced in women aged ≥ 60 years. Large cohort studies are warranted to clarify causality and to evaluate the roles of periodontitis and dental caries in this relationship.