A novel nutritional index and risk of edentulism: evidence from cross-sectional, prospective, and trajectory analyses

Abstract Background Nutritional status, recognized as a modifiable determinant of oral health, has recently gained increasing attention in the context of edentulism. The triglyceride–total cholesterol–body weight index (TCBI) is a novel nutritional indicator derived from routine clinical measures. However, its association with edentulism remains unclear. This study was designed to assess the association between TCBI and edentulism risk. Methods This study utilized survey data provided by the China Health and Retirement Longitudinal Study (CHARLS). Three analyses were performed: cross-sectional (n = 9,686), prospective (participants without baseline edentulism, n = 8,568), and trajectory analyses (TCBI trajectories and incident edentulism, n = 4,921). Logistic regression, Cox proportional hazards models, group-based trajectory modeling, and restricted cubic spline analyses were applied. Sensitivity analyses using cumulative TCBI during follow-up were also conducted. Results In the cross-sectional analysis, individuals in the highest TCBI tertile demonstrated a significantly lower risk of prevalent edentulism (adjusted OR = 0.80, 95% CI: 0.65–0.97). In the prospective analysis, higher TCBI levels were independently associated with a reduced risk of incident edentulism (adjusted HR = 0.85, 95% CI: 0.77–0.92). Trajectory modeling demonstrated that individuals with persistently high TCBI had the lowest risk of incident edentulism (adjusted HR = 0.59, 95% CI: 0.40–0.89). These associations remained robust in sensitivity analyses. Conclusion TCBI was consistently and inversely associated with edentulism across cross-sectional, prospective, and trajectory analyses. As a readily obtainable nutritional index, TCBI may have clinical utility for the early identification and risk prediction of edentulism.