25-Hydroxyvitamin D and cardiovascular disease in patients with systemic lupus erythematosus: Data from a large international inception cohort

Objective. An association between 25-hydroxyvitamin D [25(OH)D, vitamin D] deficiency and increased cardiovascular risk factors (CVRF) and cardiovascular disease (CVD) has been shown in general population studies. Vitamin D deficiency has been noted in systemic lupus erythematosus (SLE), and cardiovascular disease is a major cause of morbidity and mortality in SLE. The objectives of this study are to estimate the associations of 25(OH)D levels with CVRF and determine whether low baseline 25(OH)D levels predict future cardiovascular events in patients participating in an international inception cohort. Methods. Data were collected on 890 participants including demographics, SLE activity and damage assessments, CVRF and events, medications, laboratory assessments of 25(OH)D levels and inflammatory markers. Multiple logistic and Cox regressions were used to estimate the associations of baseline 25(OH)D levels with baseline CVRF, and CVD events. The models were adjusted for age, sex, race, season, country, with and without body mass index. Results. Patients in the higher quartiles of 25(OH)D were less likely to have hypertension and hyperlipidemia, were more likely to have lower C-reactive protein, and lower Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) at baseline when compared with the first quartile. Vitamin D levels were not independently associated with CVD event incidence, however hazard ratios for CVD event incidence decreased with successively higher quartiles. Conclusion. Lower baseline 25(OH)D levels are associated with higher risk for CVRF and more active SLE at baseline. There may be a trend towards a lower likelihood of CVD events in those with higher baseline 25(OH)D levels. © 2014 American College of Rheumatology.