The co-morbidity of diabetes and hypertension is a major health threat to the elderly population, creating an urgent need for simple assessment of their shared pathophysiological mechanism—insulin resistance. The triglyceride-glucose (TyG) index serves as an effective surrogate marker, but its predictive value for co-morbidity in community-dwelling older adults requires validation with large-scale, real-world data.This study is a cross-sectional analysis based on health examination data from 33,254 community-dwelling older adults. The TyG index was calculated and participants were grouped by tertiles. Statistical analysis was performed using SPSS 27.0. Logistic regression models were employed to assess the association between TyG index and co-morbidity risk, sequentially constructing an unadjusted model, a model adjusted for demographics (age, sex), and a fully adjusted model (further incorporating self-care ability, physical activity, smoking, and alcohol consumption) to control for confounders.This study is the first to systematically evaluate the association between the TyG index and diabetes-hypertension co-morbidity (rather than a single disease) in a natural community-based elderly population exceeding 30,000 individuals. It also concurrently analyzed a series of TyG-derived indicators, providing more comprehensive evidence.The finding that higher exercise frequency was associated with higher co-morbidity risk suggests possible reverse causality in this cross-sectional design, highlighting the need for prospective studies to confirm causality. The results support the potential use of the TyG index as a preliminary screening tool for co-morbidity risk in primary care, which could streamline the identification of high-risk individuals.The analysis indicates that the TyG index is a strong independent risk factor for co-morbidity, and this association remains robust after multivariable adjustment. This reinforces the hypothesis of the central role of insulin resistance in the development of co-morbidity.The TyG index is significantly associated with the risk of diabetes-hypertension co-morbidity among community-dwelling adults aged 65 and above. It represents a reliable and simple risk marker with potential public health application value.