Hyperinsulinemia and its associations with arterial stiffness and myocardial injury: a real-world cohort study

Hyperinsulinemia is an early metabolic abnormality commonly associated with insulin resistance, but its relationship with cardiovascular injury in real-world populations remains incompletely understood. We examined whether fasting insulin is related to arterial stiffening and early myocardial biomarker abnormalities in a large health-examination population. This real-world retrospective analysis enrolled 30,343 adults who received routine health examinations from January 2017 to November 2021. For individuals with multiple visits, the earliest examination was used as the baseline record. Fasting insulin was evaluated in quartile categories, a log-transformed continuous exposure, and a hyperinsulinemia indicator based on the cohort-specific 75th percentile. The binary arterial-stiffness endpoint was defined using a mean baPWV (brachial-ankle pulse wave velocity) threshold of 1400 cm/s or higher. Myocardial injury was evaluated by cardiac troponin I or T. Logistic regression models were fitted to quantify the relationships of fasting insulin and HOMA-IR (homeostatic model assessment of insulin resistance) with baPWV-related outcomes and myocardial injury markers. Dose-response patterns were explored using restricted cubic spline modeling. Subgroup analysis and sensitivity analysis were performed. Python (3.13.0) was used for statistical analysis. Higher insulin categories were accompanied by greater adiposity, blood pressure, glucose, HOMA-IR, triglycerides, baPWV, and arterial-stiffness. Hyperinsulinemia was correlated with arterial stiffness in the unadjusted model and adjusted model (OR, 1.31; 95% CI, 1.22–1.40, P < 0.001). Compared with the lowest insulin quartile, the highest quartile was associated with markedly increased odds of arterial stiffness (OR, 1.56; 95% CI, 1.41–1.74, P < 0.001). Spline curves indicated that fasting insulin and HOMA-IR were positively and non-linearly related to mean baPWV. In contrast, the association between hyperinsulinemia and composite myocardial injury was not statistically significant. In this large real-world health examination cohort, hyperinsulinemia was independently and consistently associated with increased arterial stiffness. However, its association with subclinical myocardial injury was weaker. These results support fasting insulin as a potential early metabolic indicator of vascular stiffening, whereas its relationship with myocardial injury requires further longitudinal investigation.