Ankle-Brachial Index in Systemic Lupus Erythematosus: A Senegalese Case-Control Study

Systemic lupus erythematosus (SLE) is associated with accelerated atherosclerosis and increasing cardiovascular risk which is recognized as a major cause of morbidity and death. Whether subclinical atherosclerosis has been evaluated by several methods, there are very limited data about Ankle-Brachial Index (ABI) in patients with systemic lupus erythematosus. The aim of the present study was to compare this index, between SLE patients and controls. We conducted a case-control study in the Department of Internal Medicine of our institution during the period from August 1, 2017 to December 31, 2018. We included 100 subjects, including 50 SLE patients and 50 control cases. This included 44 women and 6 men in patients with an identical distribution in controls. The mean age was 33.5 ± 11.3 years for cases and 33.3 ± 11.3 years (p-value: 0.93) for controls subjects. There was higher frequency of cardiovascular risk factors such as dyslipidemia (p-value at 0.009), low level of serum HDL-cholesterol (p-value  0.001), hypertriglyceridemia (p-value at 0.000) and hyperuricemia (p-value at 0.000) in patients with SLE. Overweight/obesity was higher in controls subjects (p-value at 0.028). There was no statistically significant difference in the frequency of diabetes-mellitus, smoking and high blood pressure. The abnormally ABI was recorded in 19 patients with SLE (38%) and 8 controls (16%) with a p-value: 0.01 and odds ratio: 3.22. Eight patients (16%) and four controls (8%) had low ABI without significant difference (p-value: 0.11 but odds-ratio at 2.98). Eleven patients with SLE (22%) and five controls (10%) had high ABI (p-value: 0.05 and odds-ratio: 3.24). In patients with SLE only disease activity (cSLEDAI) at the inclusion of the study was correlated to abnormal ABI. Conclusion: This study showed an increasing prevalence of abnormal ABI in black African patients with SLE compared to controls with a correlation between disease activity and abnormal ABI.