Age-Associated Changes in Carotid Intima–Media Thickness in Relation to Redox Balance Indices in Metabolic Syndrome

Abstract

Metabolic syndrome (MetS) is defined by the World Health Organisation (WHO) as a pathologic condition characterized by abdominal obesity, insulin resistance, hypertension, and hyperlipidaemia. The components of MetS and the associated cardiovascular risks may disrupt the vascular endothelial function and the structure of the vascular wall, increasing the risk of atherosclerosis and vascular diseases. In this study we evaluated the relationship between the carotid intima–media thickness (CIMT), the redox balance parameters of plasma asymmetric dimethylarginine (ADMA), malondialdehyde (MDA), and heme oxygenase 1 (HO-1), and the expression of oxidative stress-related nuclear factor kappa B (NF-kB), nuclear factor erythroid 2-related factor 2 (Nrf2), and HO-1 in peripheral blood mononuclear cells (PBMCs) in MetS. Significantly higher CIMT was established in MetS patients aged ≥ 55 years as compared with the control group (0.96 ± 0.29 vs. 0.74 ± 0.21, p < 0.05). Expression was higher in MetS patients aged < 55 years (83% for NF-kB, p < 0.05; 251% for Nrf2, p < 0.05, and 337% for HO-1, p < 0.05) in comparison to the control group. Similarly, expression was higher in CIMT < 0.90 mm than the control group by 80% for NF-kB, p < 0.01; 260% for Nrf2, p < 0.05, and 303% for HO-1, p < 0.05. In contrast, gene expression was under-regulated in the subgroups of MetS patients aged ≥ 55 years and MetS patients with CIMT ≥ 0.90 mm. Significantly higher plasma levels for MDA, ADMA, and HO-1 were established in the age < 55 and age ≥ 55 MetS subgroups and the CIMT < 0.90 mm and CIMT ≥ 0.90 mm subgroups. In conclusion, MetS individuals aged ≥ 55 are at higher risk of increased CIMT and impaired redox balance.