Association between one-hour post-load plasma glucose levels and vascular stiffness in essential hypertension.

Objectives: Pulse wave velocity (PWV) is a surrogate end-point for cardiovascular morbidity and mortality. A plasma glucose value >= 155 mg/dl for the 1-hour post-load plasma glucose during an oral glucose tolerance test (OGTT) is able to identify subjects with normal glucose tolerance (NGT) at high-risk for type-2 diabetes (T2D) and for subclinical organ damage. Thus, we addressed the question if 1-hour post-load plasma glucose levels, affects PWV and its central hemodynamic correlates, as augmentation pressure (AP) and augmentation index (AI). Methods: We enrolled 584 newly diagnosed hypertensives. All patients underwent OGTT and measurements of PWV, AP and AI. Insulin sensitivity was assessed by Matsuda-index. Results: Among participants, 424 were NGT and 160 had impaired glucose tolerance (IGT). Of 424 NGT, 278 had 1-h post-load plasma glucose <155 mg/dl (NGT < 155) and 146 had 1-h post-load plasma glucose >= 155 mg/dl (NGT > 155). NGT >= 155 had a worse insulin sensitivity and higher hs-CRP than NGT < 155, similar to IGT subjects. In addition, NGT >= 155 in comparison with NGT, 155 had higher central systolic blood pressure (134 +/- 12 vs 131 +/- 10 mmHg), as well as PWV (8.4 +/- 3.7 vs 6.7 +/- 1.7 m/s), AP (12.5 +/- 7.1 vs 9.8 +/- 5.7 mmHg) and AI (29.4 +/- 11.9 vs 25.1 +/- 12.4%), and similar to IGT. At multiple regression analysis, 1-h post-load plasma glucose resulted the major determinant of all indices of vascular stiffness. Conclusion: Hypertensive NGT >= 155 subjects, compared with NGT< 155, have higher PWV and its hemodynamic correlates that increase their cardiovascular risk profile.