Omentin: a biomarker of cardiovascular risk in individuals with axial spondyloarthritis

Abstract

Cardiovascular (CV) disease is the main cause of mortality in axial spondyloarthritis (axSpA). CV risk is enhanced by dysregulation of adipokines. Low omentin levels were associated with metabolic dysfunction and CV disease in conditions different from axSpA. Accordingly, we evaluated the genetic and functional implication of omentin in CV risk and subclinical atherosclerosis in a cohort of 385 axSpA patients. Subclinical atherosclerosis was evaluated by carotid ultrasound. Omentin rs12409609, in linkage disequilibrium with a polymorphism associated with CV risk, was genotyped in 385 patients and 84 controls. Serum omentin levels were also determined. omentin mRNA expression was assessed in a subgroup of individuals. Serum and mRNA omentin levels were lower in axSpA compared to controls. Low serum omentin levels were related to male sex, obesity, inflammatory bowel disease (IBD) and high atherogenic index. rs12409609 minor allele was associated with low omentin mRNA expression in axSpA. No association was observed with subclinical atherosclerosis at the genetic or functional level. In conclusion, in our study low omentin serum levels were associated with CV risk factors in axSpA. Furthermore, rs12409609 minor allele may be downregulating the expression of omentin. These data support a role of omentin as a CV risk biomarker in axSpA.

Figure 1

Omentin levels in axSpA and controls. Reduced serum (a) and mRNA expression (b) levels of omentin in axSpA patients when compared to healthy controls, after adjustment for potential confounding factors. Horizontal bars in Fig. 1a indicate the mean value of each group.

Figure 2

Omentin serum levels and cardiovascular risk factors. Differences in serum omentin levels between obese and non-obese axSpA patients (a), axSpA patients showing or not an AI indicative of dyslipidemia (AI ≥ 4) (b), and axSpA patients with and without IBD (c), after adjustment for potential confounding factors. Horizontal bars indicate the mean value of each group.

Figure 3

Omentin mRNA expression levels and rs12409609. Association of omentin rs12409609 minor (T) allele with low omentin mRNA expression in axSpA patients, both when genotypes and alleles were assessed. p-values displayed were obtained after adjustment for potential confounding factors.