Type 2 diabetes mellitus worsens arterial stiffness in hypertensive patients through endothelial dysfunction

Aims/hypothesis Endothelium-derived factors are thought to be physiological modulators of large artery stiffness. The aim of the study was to investigate whether endothelial function could be a determinant of arterial stiffness in essential hypertensive patients, in relation with the concomitant presence of type 2 diabetes mellitus. Methods The study included 341 participants (84 hypertensive patients with and 175 without type 2 diabetes mellitus, 82 matched controls). Brachial artery endotheliumdependent flow-mediated dilation (FMD) was determined by high-resolution ultrasound and computerised edge detection system. Applanation tonometry was used to measure carotid-femoral pulse wave velocity (PWV). Results Hypertensive patients with diabetes had higher PWV (10.1±2.3 m/s vs 8.6±1.4 m/s, p<0.001) and lower FMD (3.51±2.07 vs 5.16±2.96%, p<0.001) than non-diabetic hypertensive patients, who showed impaired vascular function when compared with healthy participants (7.9±1.6 m/s and 6.68±3.67%). FMD was significantly and negatively correlated to PWV only in hypertensive diabetic patients (r0-0.456, p<0.001), but not in hypertensive normoglycaemic patients (r0-0.088, p00.248) or in healthy participants (r00.008, p00.946). Multivariate analysis demonstrated that, in the diabetic group, FMD remained an independent predictor of PWV after adjustment for confounders (r200.083, p00.003). Subgroup analysis performed in non-diabetic hypertensive patients revealed that neither obesity nor the metabolic syndrome affected the relationship between FMD and PWV. Conclusions/interpretation Endothelial dysfunction is a determinant of aortic stiffness in hypertensive diabetic patients but not in hypertensive patients without diabetes. These results suggest that type 2 diabetes mellitus on top of hypertension might worsen arterial compliance by endothelium-related mechanisms. © Springer-Verlag 2012.