Mortality and comorbidities in Korean Systemic Lupus Erythematosus Patients

Abstract

Background: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by various organ involvement. Despite improved treatment, disease activity fluctuates, leading to diverse complications and a higher mortality rate. Also, racial and ethnic disparities in clinical manifestations underscore the awareness of mortality rates and causes of death in SLE patients. Objectives: This study aimed to investigate mortality rates and compare the cardiovascular risk and cancer incidence in Korean SLE patients. Methods: Using database from National Health Insurance Service between 2008 and 2018, we analyzed mortality rates all-cause and cause-specific death in incident SLE patients stratified by age and gender. And, we compared cardiovascular risk and identified risk factors among incident SLE patients compared to age- and gender- matched controls (1:4 ratio). Utilizing the Korea Healthcare Bigdata Linked Platform held by national healthcare organizations between 2008 and 2017, we analyzed the incidence rates of overall and site-specific cancer and influence of immunosuppressive agent. Results: From 2008 to 2018, a total of 11,375 Korean SLE patients were recruited, of whom 86.1% were female. The mortality rate among Korean SLE patients was 1,262.62 per 100,000 person-years, with the leading causes of death being SLE itself, cardiovascular disease, cancer, and infections. Additionally, the risk of major adverse cardiovascular events in SLE patients was 2.4 times higher compared to the general population, especially in 18-39 age group. In subgroup analysis, a total of 4,272 SLE patients aged over 40 years had a two-fold increased overall cardiovascular risk, and age, male gender, and certain types of medication exposure were associated with cardiovascular disease. Among 10,013 prevalent Korean SLE patients, 368 developed cancers, resulting in an overall cancer incidence rate of 59.07 per 10,000 person-years. Thyroid cancer was the most common cancer, followed by breast, stomach, colorectal, and cervical cancer. However, the use of immunosuppressive agents did not show a statistically significant association with cancer development. Conclusion: Through a comprehensive analysis utilizing various nationwide databases, this study provided insights into key factors related to the morbidity and mortality of Korean SLE patients. These findings emphasize the critical importance of risk assessment to improve outcomes for SLE patients. Addressing the heightened cardiovascular and cancer risk in Korean SLE patients could contribute to more tailored and effective strategies. Further studies are warranted to evaluate the independent influence of death-related factors and offer comprehensive information to enhance treatment strategies.