Background Patients with systemic lupus erythematosus (SLE) have increased mortality related to cardiovascular disease (CVD) and the age is one of important risk factors for the development of CVDs. However, the comparative risk of CVDs in patients with older onset SLE has not been well studied. This study aimed to compare the CVD risk in patients with SLE occurred after the age of 40 compared to those with diabetes mellitus (DM).

Methods Incident SLE patients aged over 40 years and age-sex matched (1:4:4) controls with DM or general population were identified from the nationwide claims database in Korea between 2008 and 2018. We defined CVD risk as ischemic heart disease, stroke, and cardiac death. The incidence rate (IR), incidence rate ratio (IRR), and adjusted hazard ratio (HR) of CVDs were calculated using generalized estimating equation models.

Results We identified 4,272 SLE, 17,003 DM, and 17,088 general population patients aged over 40 years. Their mean age was 53.1 (±9.7) and 87.1% of them were female. The IR per 1,000 person-years (PYs) of CVDs for SLE, DM, and general population were 16.8, 11.7, and 5.7, respectively. Compared to general population, patients with SLE (IRR 3.27, 95% CI 2.78–3.85) and DM (IRR 2.77, 95% CI 2.02–2.56) showed higher CVD risk compared to general population. Increased risk of CVDs in SLE patients was highest in their forties (IRR 4.13, 95% CI 3.06, 5.59). After adjusting confounders, the CVD risk of SLE (HR 1.99, 95% CI 1.66–2.38) was higher than DM (HR 1.39, 95% CI 1.22–1.58) patients.

Conclusions Older onset SLE patients had increased CVD risk compared to general population. Even after adjustment for confounders, older onset SLE patients showed higher CVD risk than DM patients in Korea.