25-Hydroxyvitamin D levels are associated with mortality and cardiovascular events in systemic lupus erythematosus.

Abstract

We assessed the association between 25-hydroxyvitamin D (25(OH)D) levels and rates of mortality and cardiovascular events (stroke, myocardial infarction, angina/bypass) in patients with systemic lupus erythematosus (SLE). The Hopkins Lupus Cohort began measuring 25(OH)D quarterly in 2009. We examined associations between 25(OH)D levels-baseline, mean in the last year, and most recent values-and both mortality and cardiovascular events (stroke, myocardial infarction, angina/bypass). Two analyses were conducted: (i) a prospective analysis of events occurring after the first 25(OH)D measurement, and (ii) a lifetime analysis including events before cohort entry. All models adjusted for age, sex (female or male), race, and body mass index. The prospective analysis included 11,302 person-years from 1768 patients. Patients with 25(OH)D <20 ng/mL had the highest mortality and cardiovascular event rates. Compared to those with levels of 30-39 ng/mL, those with levels <20 ng/mL at cohort entry had significantly increased risk of death (hazard ratio [HR] 2.05, 95% CI: 1.19-3.54, P = .0095) and cardiovascular events (HR 2.98, 95% CI: 1.30-6.85, P = .010). Risk of myocardial infarction alone was not statistically significant (HR 1.90, P = .30), but risk of angina/bypass was elevated (HR 3.53, 95% CI: 1.13-11.0, P = .030). The lifetime analysis suggested these associations, with a U-shaped pattern for myocardial infarction risk. An initial 25(OH)D level <20 ng/mL was associated with increased mortality and cardiovascular events (but not stroke) in SLE. The U-shaped curve for myocardial infarction mirrors our previous work in adverse pregnancy outcomes. Lack of association with mean or recent 25(OH)D levels questions the impact of supplementation on risk modification.