Separate impact of metabolic syndrome and altered glucose tolerance on early markers of vascular injuries

Abstract

Objective: We investigated the separate impact of metabolic syndrome (MS) and altered glucose tolerance on early markers of vascular injuries.

Methods: Intima-media thickness (IMT) and pulse wave analysis (PWA), were evaluated in 132 overweight or obese subjects, with (MS(+)) or without (MS(-)) MS; subjects were further classified as normotolerant (NT) or with altered glucose tolerance (AGT) according to a 2 h oral glucose tolerance test (OGTT).

Results: In MS(+) patients, IMT was higher than in the MS(-) group, and PWA revealed higher augmentation pressure (Aug, the contribution that wave reflection makes to systolic arterial pressure) and lower subendocardial viability ratio (SEVR, an estimate of myocardial perfusion). When analyzed according to glucose tolerance, IMT was higher in MS(+)NT subjects and AGT patients with and without MS, vs. MS(-)NT subjects. Logistic regression modeling showed that both AGT and MS were independently associated with increased IMT. However, only MS remained associated with IMT after adjustment for age. SEVR was reduced only in MS(+) patients, independently of glucose tolerance. In both groups, Aug and AugI were higher in the AGT group, but the correlation with 2 h-plasma glucose disappeared when corrected for age.

Conclusion: Both MS and AGT altered IMT, but the effect of AGT disappears when age is added to the multiple regression model. In contrast, arterial stiffness was affected differently in the two categories: in subjects with MS, the subendocardial viability ratio (an estimate of myocardial perfusion) was impaired, while in subjects with AGT, both Aug and AugI were increased. These data suggest that applying the definition of MS might help to better characterize cardiovascular risk in subjects with altered glucose tolerance or obesity.