title: Type 2 diabetes mellitus worsens arterial stiffness in hypertensive patients through endothelial dysfunction.
abstract: OBJECTIVE
  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 endothelium-dependent 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 (r = -0.456, p < 0.001), but not in hypertensive normoglycaemic patients (r = -0.088, p = 0.248) or in healthy participants (r = 0.008, p = 0.946). Multivariate analysis demonstrated that, in the diabetic group, FMD remained an independent predictor of PWV after adjustment for confounders (r(2) = 0.083, p = 0.003). Subgroup analysis performed in non-diabetic hypertensive patients revealed that neither obesity nor the metabolic syndrome affected the relationship between FMD and PWV.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Internal Medicine, University of Pisa, Via Roma 67, 56126, Pisa, Italy.
authors.forename: R M
authors.initials: RM
authors.lastname: Bruno
authors.forename: G
authors.initials: G
authors.lastname: Penno
authors.forename: G
authors.initials: G
authors.lastname: Daniele
authors.forename: L
authors.initials: L
authors.lastname: Pucci
authors.forename: D
authors.initials: D
authors.lastname: Lucchesi
authors.forename: F
authors.initials: F
authors.lastname: Stea
authors.forename: L
authors.initials: L
authors.lastname: Landini
authors.forename: G
authors.initials: G
authors.lastname: Cartoni
authors.forename: S
authors.initials: S
authors.lastname: Taddei
authors.forename: L
authors.initials: L
authors.lastname: Ghiadoni
authors.forename: S
authors.initials: S
authors.lastname: Del Prato
mesh_terms: D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000503:physiopathology; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D014463:Ultrasonography; D059289:Vascular Stiffness / Q000502:physiology*