Insulin resistance indices and periodontitis in patients with diabetes: A nationwide population-based study

Insulin resistance, a key risk factor in type 2 diabetes contributes to the initiation and progression of periodontitis. Although several studies have reported associations between non-insulin-based insulin resistance indices and periodontitis in the general population, these associations have not been investigated in patients with diabetes, who may benefit more from the clinical application of such indices.

This study analyzed data from 64,971 adults from the Korea National Health and Nutrition Examination Survey (2010-2018). Associations between non-insulin-based insulin resistance indices, including triglyceride/high-density lipoprotein cholesterol (TG/HDL), the metabolic score for insulin resistance (METS_IR), triglyceride glucose index (TyG), TyG indices adjusted for body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR), and periodontitis were assessed. Associations and diagnostic accuracy were evaluated using ordinal logistic regression and receiver operating characteristic (ROC) analyses.

Ordinal logistic regression revealed that METS_IR had the strongest association with periodontitis (odds ratio [OR] = 1.401). In the group with poorly controlled diabetes (HbA1c ≥ 7.0%), all insulin resistance indices had higher ORs when compared with the group with well-controlled diabetes, with METS_IR showing the highest OR in both groups. ROC analysis revealed that TyG*WHtR had the highest diagnostic accuracy (area under the curve [AUC] = 0.6719).

Among patients with diabetes, METS_IR was the most strongly associated with periodontitis, and TyG*WHtR exhibited the highest diagnostic accuracy. These indices may be useful tools for the early identification of high-risk periodontitis in patients with diabetes.

To our knowledge, this is the first comprehensive evaluation of the association between multiple blood test-derived insulin resistance indices and periodontitis in patients with diabetes. The analysis identified metabolic score for insulin resistance (METS_IR) and triglyceride glucose index*waist-to-height ratio (TyG*WHtR) as the indices with the closest association with periodontitis and the highest diagnostic accuracy, respectively. These indices were closely linked to the risk of periodontitis in patients with diabetes, and TyG*WHtR was the most effective predictor. These simple blood test indices may allow early-stage periodontal health risk assessment and management in patients with diabetes.