Clinical and Serological Associations of Subclinical Atherosclerosis in Spondyloarthropathy

Abstract

Background: Patients with spondyloarthropathy (SpA) have a higher risk of subclinical atherosclerosis (SCA). We assessed clinical and serological determinants of SCA in Indian SpA patients. Methods: Patients with SpA (fulfilling ASAS 2010 criteria; n = 104) attending our hospital were recruited; mean carotid intima-media thickness (CIMT) was performed by carotid ultrasonography, along with clinical assessment and traditional risk factor evaluation. Microparticles were extracted from plasma and total, as well as endothelial microparticles (EMP), platelet microparticles, T lymphocyte microparticles and B lymphocyte microparticles, were analysed by flow cytometry. Serum samples were analysed for inflammatory cytokines previously implicated in atherosclerosis, namely interleukin 1β (IL-1β), IL-6, IL-17, IL-27, IL-33 and tumour necrosis factor-alpha. Thirty-eight healthy controls were used for comparison. Subgroup analyses compared parameters between SpA with SCA (i.e., with carotid plaque or more than 75th percentile of CIMT for that age and sex in the Indian population) versus those without SCA. Ethical approval and written, informed consent were obtained. Results: Despite significantly younger age, lower body mass index and higher total cholesterol in controls compared to SpA, those with SpA had higher CIMT. Traditional cardiovascular risk factors (older age, higher waist-hip ratio) and novel markers of inflammation (serum IL-1β, IL-6) were associated with SCA. While total microparticles, EMP, T lymphocyte and B lymphocyte microparticles were increased in SpA than in healthy controls, they were not associated with SCA. Conclusions: Traditional risk factors and serum inflammatory cytokines IL-1β and IL-6 are associated with higher SCA in Indian SpA patients.