Cutaneous lupus erythematosus and systemic lupus erythematosus are associated with clinically significant cardiovascular risk: a Danish nationwide cohort study

Systemic lupus erythematosus (SLE) is a well-known cardiovascular risk factor. Less is known about cutaneous lupus erythematosus (CLE) and the risk of developing cardiovascular disease (CVD). Therefore, we investigated the risk of mortality and adverse cardiovascular events in patients diagnosed with SLE and CLE. We conducted a cohort study of the entire Danish population aged ≥ 18 and ≤ 100 years, followed from 1997 to 2011 by individual-level linkage of nationwide registries. Multivariable adjusted Cox regression models were used to estimate the hazard ratios (HRs) for a composite cardiovascular endpoint and all-cause mortality, for patients with SLE and CLE. A total of 3282 patients with CLE and 3747 patients with SLE were identified and compared with 5,513,739 controls. The overall HR for the composite CVD endpoint was 1.31 (95% CI 1.16-1.49) for CLE and 2.05 (95% CI 1.15-3.44) for SLE. The corresponding HRs for all-cause mortality were 1.32 (95% CI 1.20-1.45) for CLE and 2.21 (95% CI 2.03-2.41) for SLE. CLE and SLE were associated with a significantly increased risk of CVD and all-cause mortality. Local and chronic inflammation may be the driver of low-grade systemic inflammation.