Adipokines, biomarkers of endothelial activation, and metabolic syndrome in patients with ankylosing spondylitis

Abstract

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease associated with accelerated atherosclerosis and increased risk of cardiovascular (CV) disease. AS patients also display a high prevalence of features clustered under the name of metabolic syndrome (MeS). Anti-TNF- α therapy was found to be effective to treat AS patients by suppressing inflammation and also improving endothelial function. Previously, it was demonstrated that a short infusion of anti-TNF- α monoclonal antibodyinfliximab induced a rapid and dramatic reduction in serum insulin levels and insulin resistance along with a rapid improvement of insulin sensitivity in nondiabetic AS patients. The role of adipokines, MeS-related biomarkers and biomarkers of endothelial cell activation and inflammation seem to be relevant in different chronic inflammatory diseases. However, its implication in AS has not been fully established. Therefore, in this review we summarize the recent advances in the study of the involvement of these molecules in CV disease or MeS in AS. The assessment of adipokines and biomarkers of endothelial cell activation and MeS may be of potential relevance in the stratification of the CV risk of patients with AS.

Figure 1

Pathophysiologic context that encompasses all the molecules reviewed in this paper. Ankylosing spondylitis patients display a high incidence of features clustered under the name of metabolic syndrome, which include obesity, dyslipidemia, hypertension, alterations in glucose metabolism, including insulin resistance, and also a dysregulation of adipokines. Moreover, all these pathologic features are associated with inflammation and lead to endothelial dysfunction and, consequently, to an enhanced risk of CV disease (mainly due to accelerated atherosclerosis) and CV death in these patients. Anti-TNF-α treatment not only suppresses inflammation, reducing thus ankylosing spondylitis activity, but it also improves endothelial function in these patients. The molecules that will be reviewed in this paper are included in this figure inside blue dashed boxes. *Anti-TNF-α improves insulin resistance and endothelial function and also reduces inflammation. ADMA: asymmetric dimethylarginine; Angpt-2: angiopoietin-2; OPG: osteoprotegerin; OPN: osteopontin; RBP-4: retinol binding protein-4.