Association between visceral adiposity index and risk of dental caries: findings from the national health and nutrition examination survey

The specific role of visceral adiposity in dental caries risk remains underexplored. This study investigated the association between visceral adiposity index (VAI) and dental caries outcomes in a nationally representative adult population. This cross-sectional study analyzed NHANES 2011–2018 data from 7,048 adults aged ≥ 20 years with complete VAI and dental information. VAI was calculated using gender-specific formulas incorporating waist circumference, BMI, triglycerides, and HDL-cholesterol. Untreated dental caries was defined as presence of active decay, while dental caries experience included decayed, missing, or filled teeth. Multivariable logistic regression models assessed associations, adjusting for demographic, socioeconomic, and clinical factors. Significant non-linear associations were observed between VAI and both dental caries outcomes (P for non-linearity < 0.001). In fully adjusted models, each unit increase in VAI was associated with 7.4% higher odds of untreated dental caries (OR = 1.074, 95% CI: 1.032–1.118, P < 0.001) and 9.4% higher odds of dental caries experience (OR = 1.094, 95% CI: 1.011–1.183, P = 0.026). Quartile analysis revealed a dose–response relationship for untreated dental caries, with the highest VAI quartile showing 65.1% higher odds compared to the lowest quartile (OR = 1.651, 95% CI: 1.324–2.059, P < 0.001). Significant effect modifications were observed by education level (P for interaction = 0.042) and hyperlipidemia status (P for interaction = 0.009). Visceral adiposity, as measured by VAI, is independently associated with increased dental caries risk, representing a potential modifiable risk factor warranting clinical attention.