Macro- and microvascular alterations in patients with metabolic syndrome: sugar makes the difference

Metabolic syndrome (MS) is associated with adverse cardiovascular events, although its prognostic significance over and beyond the clustering risk factors is controversial. Moreover, there are no data on the possible differentiation of target organ damage among patients with MS according to the grade of its distinct components. We studied 500 hypertensive patients with MS and we assessed vascular damage according to glucose metabolic status (1, normal glucose metabolism (NG); 2, impaired fasting glucose (IFG); 3, impaired glucose tolerance (IGT); and 4, diabetes mellitus II (DM II)). Macrovascular damage was assessed with arterial stiffness by measuring carotid-femoral pulse wave velocity (PWV). Microvascular damage was assessed with albumin excretion by estimating the albumin-creatinine ratio (ACR). There was a significant progressive increase in PWV from group 1 to group 4 (from 7.97 to 8.83 to 8.94 to 10.27 m s(-1), respectively) that remained statistically significant even after adjustment for several confounders (P<0.001). Similar trends were also observed for ACR (from 27.44 to 29.94 to 36.26 to 73.07 mg g(-1), P<0.001). In multiple regression analysis, both PWV and ACR were independently related to glucose metabolic status (P=0.001 and P<0.001, respectively). Vascular alterations among patients with MS differ according to the grade of glucose dysregulation. Considering the adverse prognostic role of arterial stiffness and microalbuminuria, it might be argued that the cardiovascular risk is not homogeneously distributed among patients with MS but is largely determined by glucose metabolic status.