Correlation of ultrasound parameters in patients with metabolic syndrome

Aim: Data regarding the relationship between brachial artery flow mediated dilatation (FMD) and carotid intimal media thickness (IMT) are controversial. We evaluated whether impaired endothelium dependent response in patients with metabolic syndrome is associated with increased IMT. Methods: We studied a group of 26 patients diagnosed with metabolic syndrome defined according to NCEP criteria. Exclusion criteria were the presence of ischemic heart disease and insulin dependent diabetes mellitus. An ultrasound technique was used to measure brachial artery FMD response and carotid IMT. From 26 patients, 9 patients were diagnosed with type 2 diabetes. Results : Age-adjusted mean FMD value was 9.23±4.1% and mean value of IMT was 0.63±0.07. We didn't find a significant correlation between FMD and IMT (r=-0.19, p>0.05). The mean value of FMD was lower in diabetic patients versus non-diabetic patients (8.44±3.8% vs. 9.65±4.8%, p>0.05), while IMT mean value was higher (0.56±0.04 vs. 0.67±0.08, p>0.05), but without reaching statistical significance. In the diabetic subgroup, we observed a borderline significant small correlation between FMD and IMT (r=-0.24, p=0.061). Conclusion: This study suggests that in patients with metabolic syndrome and without cardiovascular disease, FMD is not strictly associated with IMT, probably because significant IMT and advanced deterioration of FMD appear in a later stage of disease. We expect to find a more significant FMD-IMT correlation in patients with metabolic syndrome and diabetes, with advanced endothelial dysfunction and subsequent morphologic alteration of arterial wall.