Association between Oxidative Stress, Cardiovascular Risk, and Disease Activity in Patients with Spondyloarthritis: A Cross-Sectional Study in a Tunisian Cohort

Abstract

Introduction-Aim: Spondyloarthritis (SpA) is a chronic inflammatory disease associated with an increased cardiovascular (CV) risk that is not fullyexplained by traditional risk factors. This study aimed to investigate the associations between oxidative stress markers, CV risk profile, and diseaseactivity in a Tunisian cohort of patients with SpA.Methods: We conducted a monocentric, cross-sectional study involving 101 patients diagnosed with SpA according to the 2009 ASAS criteria.We collected sociodemographic, clinical, and biological data. Disease activity was assessed using the Bath Ankylosing Spondylitis Disease ActivityIndex (BASDAI) and the Ankylosing Spondylitis Disease Activity Score with C-reactive protein (ASDAS-CRP). The CV risk profile was evaluatedthrough anthropometric measurements, lipid profile, homocysteine, and the SCORE2 index. Oxidative stress status was determined by measuringglutathione peroxidase (GPx) activity, serum levels of oligo-elements (copper, zinc, selenium).Results: The cohort consisted of 101 patients with a mean age of 40.59 ± 11.41 years. A high prevalence of CV risk factors was observed, includingoverweight/obesity (57.4%), hypertension (31.7%), atherogenic dyslipidemia (73.3%with elevatednon-HDLcholesterol), andhyperhomocysteinemia(58.4%). Patients with active disease (ASDAS-CRP ≥ 2.1) exhibited significantly lower GPx activity (p=0.024). Serum copper levels and the copper/zinc (Cu/Zn) ratio were significantly elevated in patients with systemic inflammation (p < 0.001). A significant negative correlation was foundbetween GPx activity and disease activity scores (BASDAI and ASDAS-CRP).Conclusion: Oxidative stress is closely linked to systemic inflammation and disease activity, with decreased GPx activity and an elevated Cu/Zn ratioemerging as potential biomarkers of inflammatory status.