Abstract
OBJECTIVES: Insulin resistance (IR) is closely associated with atherosclerosis and adverse cardiovascular events. The triglyceride-glucose (TyG) index is an effective indicator for assessing IR. This study aims to explore the relationship between the TyG index and the risk of arterial stiffness progression. METHODS: This retrospective cohort study included adults who had undergone at least 2 health examinations with arteriosclerosis testing at the Health Management Medical Center of the Third Xiangya Hospital, Central South University, between January 2012 and December 2022. Clinical data were collected. The TyG index was calculated using the formula of ln (triglycerides×fasting blood glucose/2). The baseline TyG index was assessed as both a continuous variable and as a quartile-based categorical variable. The progression of arteriosclerosis was evaluated by the annual change rate of brachial-ankle pulse wave velocity (baPWV) and the new onset of increased arterial stiffness. Linear regression model and Cox proportional hazard model were used to explore whether the TyG index is an independent risk factor for arterial stiffness progression. Subgroup analyses were performed based on age, gender, body mass index (BMI), and the presence of type 2 diabetes, hypertension, or hyperlipidemia to determine the characteristics of the association between the TyG index and arterial stiffness progression. RESULTS: A total of 4 971 participants were included, with a follow-up period of (3.01±1.98) years. During follow-up, the annual baPWV change rate was (24.94±81.15) cm/s, and 278 cases of new onset of increased aterial stiffness were recorded. After fully adjusting for confounding factors, the baseline TyG index was independently positively correlated with both the annual baPWV change rate (β=17.5, 95% CI 9.00 to 25.94, P<0.001) and the risk of new onset of increased aterial stiffness [hazard ratio (HR)=1.43, 95% CI 1.18 to 1.74, P<0.001] when the TyG index was treated as a continuous variable. When treated as a categorical variable, higher TyG index quartiles were associated with progressively higher baPWV change rates and new onset of increased arterial stiffness (all P<0.05). In subgroups of participants aged ≥45 years, males, BMI<28 kg/m(2), those with or without hypertension, and those without type 2 diabetes or hyperlipidemia, the baseline TyG index (both continuous and categorical) was significantly associated with new onset of increased arterial stiffness (all P<0.05), with no significant interactions observed across subgroups (all P>0.05). CONCLUSIONS: The TyG index is independently associated with an increased risk of arterial stiffness progression and may serve as a useful indicator for assessing arterial stiffness progression risk in health check-up populations.