Insulin Resistance Indices and Masticatory Function in Postmenopausal Korean Women: A 15‐Year Nationwide Survey

BACKGROUND: Postmenopausal women experience increased visceral adiposity and insulin resistance owing to oestrogen deficiency, which may affect oral structure and function. Their relation to oral health is unclear. OBJECTIVES: To examine the associations of five non-insulin-based insulin resistance indices with tooth loss and masticatory discomfort in postmenopausal Korean women. METHODS: This cross-sectional study analysed 14 265 naturally postmenopausal women aged ≥ 40 years from the Korea National Health and Nutrition Examination Survey 2010-2024. Triglycerides, HDL cholesterol, the triglyceride-to-HDL cholesterol ratio, the triglyceride-glucose index and the metabolic score for insulin resistance (METS-IR) were standardised, so estimates are expressed per 1 standard deviation. Missing teeth were analysed by survey-weighted negative binomial regression, and fewer than 20 remaining teeth and masticatory discomfort by survey-weighted logistic regression. Discrimination was characterised descriptively using receiver operating characteristic curves. RESULTS: Masticatory discomfort was associated with triglycerides (odds ratio 1.065, 95% confidence interval 1.030-1.102), HDL cholesterol (0.919, 0.886-0.952), the triglyceride-to-HDL cholesterol ratio (1.072, 1.035-1.111) and the triglyceride-glucose index (1.069, 1.032-1.108), but not with METS-IR (1.036, 0.997-1.076). No index was associated with missing teeth or with fewer than 20 remaining teeth. Estimates were unchanged after adjustment for survey cycle. Discrimination was attributable almost entirely to age: adding any index to an age-only model raised the area under the curve by at most 0.0014 and 0.016, respectively. CONCLUSION: Several indices showed small associations with self-reported masticatory discomfort but none with tooth loss. These findings describe patterns of association and do not establish any index as a tool for screening or for integrated medical-dental management.