Arterial Stiffness in Systemic Lupus Erythematosus and Its Correlation with Disease Severity: A Case Control Study

Abstract

Introduction: Arterial stiffness is an emerging field of interest in atherosclerosis. Patients with systemic lupus erythematosus (SLE) are predisposed to have premature atherosclerosis. Aims: To compare the arterial stiffness among patients with SLE and non-SLE controls. The study also compared arterial stiffness among SLE patients in relation to disease activity (SLEDAI) and end organ damage (SLICC index). Study Design: Case control study. Place and Duration of Study: Patients attending rheumatology clinic and those admitted to medical wards of the Internal Medicine and Nephrology departments of Government Medical College Hospital, Thiruvananthapuram. Methodology: 53 SLE patients and 53 non-SLE controls were studied. Data was obtained in a structured format. Arterial stiffness indices were obtained by measuring the brachial ankle pulse wave velocity (baPWV). The SLEDAI Score and SLICC Damage index were measured in the SLE group. Age-matched controls were obtained from the general population. Results: SLE patients had higher brachial ankle pulse wave velocity (baPWV) than the control non-SLE population (1194.9 ± 169.6 cm/s vs 1008.5 ± 62.5 cm/s; p<0.001), Mean arterial stiffness index (ASI) among SLE patients was significantly higher than that of control (26.2 ± 3.9 mm Hg vs. 23.7 ± 3.7 mm Hg, p=.001), mean augmentation index(AI) among SLE patients was significantly higher when compared with the control non-SLE population (13.9± 6.7% vs 6.2 ± 1.7%, p<0.001). Patients with SLE-related end organ damage (SLICC index ≥1) had baPWV elevated over those with SLICC index=0 (1234.5 ± 181.5 cm/s.1 vs 1124.1 ± 121.1 cm/s, p=.021). No significant difference was observed between the mean ASI among the patients with SLICC index ≥1 and those with SLICC=0. (26.9 ± 4.1 mm Hg vs 24.8 ± 3.3 mm Hg, p=.070), and mean AI among SLICC index ≥1 was significantly higher than that of SLICC index ≥1 (15.6 ± 6.7% vs 11.1 ± 5.8%, p= .017). Patients with high disease activity (SLEDAI ≥6) had baPWV of 1278.9 ± 131.0 cm/s (95%CI 1229 cm/s.1-1328.7 cm/s) vs (1093.4 ± 156.5 cm/s; 95% CI 1027.3 cm/s -1159.4 cm/s p<0.001) when compared with those having low activity (SLEDAI<6). Conclusion: Patients with SLE had increased arterial stiffness. End organ damage and high disease activity among SLE patients correlated to increased arterial stiffness, and is contributory to an increased risk of atherosclerosis.