Peripheral arterial disease in systemic lupus erythematosus: prevalence and risk factors

To analyze the prevalence of peripheral arterial disease (PAD) and cardiovascular (CV) risk factors in a cohort of patients with systemic lupus erythematosus (SLE) and to identify variables potentially related to PAD.

The study included 216 patients with SLE from the Lupus-Cruces prospective observational cohort. The ankle brachial index (ABI) was determined in each patient, with values < 0.9 considered diagnostic of PAD. Demographic and clinical variables, presence of traditional risk factors and CV events, cardiovascular risk calculated by Systematic Coronary Risk Evaluation (SCORE), and treatments received by each patient were analyzed.

Ninety-two percent of patients were women. The mean age (SD) was 49 years (15), with a mean followup (SD) of 12 years (9). The prevalence of low ABI was 21%. CV risk factors were frequent: smoking, 30% of patients; high blood pressure, 32.7%; diabetes mellitus, 3.2%; hypercholesterolemia, 34.1%; and metabolic syndrome, 9.7%. The following variables were associated with low ABI in the univariate analysis: age (p < 0.001), hypertension (p = 0.002), diabetes (p = 0.018), hypercholesterolemia (p = 0.018), CV events (p < 0.001), SCORE (p = 0.004), cumulative dose of cyclophosphamide (p = 0.03), and fibrinogen levels (p = 0.002). In the multivariate analysis, the only independent variable in the final model was age (OR 1.04, 95% CI 1.02-1.07, p < 0.001), with a tendency for the presence of any vascular risk factor (diabetes, hypertension, hypercholesterolemia, or current smoking; OR 2.3, 95% CI 0.99-5.1, p = 0.053).

The prevalence of low ABI in patients with SLE is higher than expected. While the association with CV risk factors and vascular disease in other territories was strong, we could not identify SLE-specific variables independently associated with PAD.