ObjectivesPatients with systemic lupus erythematosus (SLE) are at high risk of cardiovascular disease (CVD), fragility fractures, and malignancies. However, data regarding these comorbidities among Chinese SLE patients are limited. We aimed to determine the prevalence of and risk factors for these three major comorbidities in a large cohort of Chinese SLE patients.MethodsIn this cross-sectional study, demographic, clinical, and common comorbidity profiles were obtained from the medical records of SLE patients enrolled in the Chinese SLE Treatment and Research group (CSTAR) registry. Univariate and multivariate logistic regression analyses were performed to identify possible risk factors related to these comorbidities.ResultsA total of 38,105 SLE patients were included (92.2% women). The median age at registration was 34.0 years (interquartile range, 27.0-46.0 years). The prevalence rates of the three important comorbidities at baseline were as follows: CVD, 1.9% (95% confidence interval [CI]: 1.8-2.0%); fragility fractures, 0.7% (95% CI: 0.6-0.8%); and malignancies, 0.7% (95% CI: 0.6-0.8%). In the multivariable-adjusted model, lupus anticoagulant, anticardiolipin antibody, anti-beta 2GP1 antibody, neuropsychiatric involvement, and hematological involvement were positively associated with CVD in SLE patients. Mucocutaneous manifestations, hyperimmunoglobulinemia, hypocomplementemia, anti-dsDNA, anti-Sm, and anti-nRNP/U1RNP antibody, and hydroxychloroquine therapy were negatively associated with CVD. The multivariate analysis revealed that age older than 50 years and hypocomplementemia were associated with fragility fractures and malignancies.ConclusionCVD, fragility fractures, and malignancies commonly occur in SLE patients. Patients with traditional and SLE-related factors should be more carefully monitored for these important comorbidities.Key Points center dot SLE patients have an increased risk of cardiovascular disease, fragility fractures, and malignancy. However, data regarding these comorbidities among Chinese SLE patients are limited.center dot Several associated risk factors for these three comorbidities of SLE were identified.Characteristics, symptom severity, and QOL differ in different age groups.center dot Lupus patients with traditional and SLE-related factors should be more carefully monitored for the presence of these comorbidities.ConclusionCVD, fragility fractures, and malignancies commonly occur in SLE patients. Patients with traditional and SLE-related factors should be more carefully monitored for these important comorbidities.Key Points center dot SLE patients have an increased risk of cardiovascular disease, fragility fractures, and malignancy. However, data regarding these comorbidities among Chinese SLE patients are limited.center dot Several associated risk factors for these three comorbidities of SLE were identified.Characteristics, symptom severity, and QOL differ in different age groups.center dot Lupus patients with traditional and SLE-related factors should be more carefully monitored for the presence of these comorbidities.