The role of oxidized LDL in the Metabolic Syndrome
Atherosclerosis is considered to be an inflammatory disease.
Atherosclerosis is considered to be an inflammatory disease. Unlike native (unmodified) LDL that lacks inflammatory properties, oxidized LDL (oxLDL) is an emerging risk factor that activates circulating monocytes and stimulates their ability to infiltrate the vascular wall. The resulting inflammation is a primary stage in atherogenesis and common in the metabolic syndrome (Cipolletta et al. Diabetes 54:2779-2786, 2005).
Holvoet et al. (Atherosclerosis 194:245-252, 2007) have shown that the prevalence of cardiovascular disease is higher in individuals with the metabolic syndrome or with higher levels of oxLDL. The highest prevalence was found in persons with the Metabolic Syndrome combined with elevated oxLDL. Sigurdardottir et al. (J Intern Med 252:440-447, 2002), found that the Metabolic Syndrome was accompanied by high plasma oxLDL concentrations compared with those without the syndrome. Moreover they found that oxLDL levels were associated with most of the risk factors constituting the Metabolic Syndrome and was, in addition related to small LDL particle size.
These findings suggest that any interventions that succeed in lowering the levels of oxLDL may also ameliorate the effects of the Metabolic Syndrome.
So far, lifestyle and therapeutic interventions have been proposed as a key to success. Studies suggest that a gluten-free vegan diet (Elkan et al. Arthritis Res Ther 10:34, 2008) reduces concentrations of oxLDL. Similar results were seen with grape juice and vitamin E supplementation (Castilla et al. Am J Clin Nutr 87:1053-1061, 2008). These studies have been too small to determine causality. However, they confirm other findings that suggest antioxidant supplementation is effective in lowering oxLDL. Verreth et al. (Circulation 110:3259-3269, 2004), showed that decreased deposition of oxLDL occurred due to improved balance between pro-oxidant and antioxidant enzymes in adipose tissue.
In a study by Tjonna et al. (Circulation 118:346-354, 2008), high intensity exercise training was highly beneficial in preventing the Metabolic Syndrome as well as reducing oxLDL levels.
According to current studies, monitoring oxLDL levels may be useful in cardiovascular risk stratification of patients with the Metabolic Syndrome.
For more information please click here to read the poster Metabolic Syndrome