Independent linear association between flow-mediated dilation and predicted intermediate-to-high 10-year ASCVD risk in patients with type 2 diabetes: a retrospective study

Background Vascular endothelial dysfunction precedes atherosclerosis in type 2 diabetes (T2DM). However, the specific nature of the association between flow-mediated dilation (FMD) and the intermediate-to-high 10-year atherosclerotic cardiovascular disease (ASCVD) risk remains to be fully elucidated. This study aimed to investigate this correlation in a large sample of Chinese patients with T2DM. Methods We retrospectively analyzed 1,272 T2DM patients managed at the National Metabolic Management Center (MMC) between March 2020 and March 2025. Endothelial function was assessed via brachial artery FMD (dysfunction: FMD < 6.5%). Multivariate linear and logistic regressions identified independent factors. Restricted cubic spline (RCS) models assessed non-linear associations between FMD and the intermediate-to-high 10-year ASCVD risk. Results Overall, 78.9% (n=1,003) exhibited endothelial dysfunction. Multivariate analysis identified older age, higher systolic blood pressure, male sex, smoking, hypertension, and the intermediate-to-high ASCVD risk were independently associated with impaired FMD (all p < 0.05). FMD showed an independent inverse association with intermediate-to-high 10-year ASCVD risk (OR = 0.90, 95% CI: 0.82-0.99, p < 0.05) and moderate discriminative ability (AUC = 0.700, 95% CI: 0.66–0.75). Crucially, RCS analysis confirmed a linear negative correlation between FMD and the intermediate-to-high ASCVD risk ( p -overall = 0.004), with no evidence of non-linearity ( p -non-linear = 0.653). Conclusions Endothelial dysfunction is highly prevalent in T2DM. FMD was independently, inversely and linearly associated with the intermediate-to-high calculated 10-year ASCVD risk.