Low baseline levels double death risk and triple cardiovascular events, say Hopkins researchers.
Low baseline levels of 25-hydroxyvitamin D are associated with increased mortality and cardiovascular events in patients with systemic lupus erythematosus, new findings from the Hopkins Lupus Cohort suggest.
The study followed 1768 patients over 11,302 person-years and examined the relationship between vitamin D status and major cardiovascular outcomes, including stroke, myocardial infarction, and angina or bypass procedures.
Results were published in the Annals of the Rheumatic Diseasesthis month.
Patients with 25(OH)D levels below 20ng/mL at cohort entry were found to have significantly higher risks of death and cardiovascular events compared with those whose levels ranged from 30 to 39ng/mL.
Low vitamin D was associated with a twofold increase in the risk of death (hazard ratio 2.05, 95% CI 1.19–3.54, P = .0095) and nearly a threefold increase in cardiovascular events (hazard ratio 2.98, 95% CI 1.30–6.85, P = .010).
The risk of myocardial infarction alone did not reach statistical significance, but the risk for angina or bypass procedures was significantly elevated (hazard ratio 3.53, 95% CI 1.13–11.0, P = .030).
Lifetime analyses suggested similar trends and revealed a U-shaped association for myocardial infarction, consistent with previous observations in adverse pregnancy outcomes among patients with SLE.
Mean and most recent 25(OH)D levels were not significantly associated with mortality or cardiovascular events, raising questions about the effectiveness of vitamin D supplementation in modifying long-term risk once baseline deficiency is present, the authors wrote.
The findings emerged from both prospective analyses, examining events after the first 25(OH)D measurement, and lifetime analyses that included events occurring prior to cohort entry.
Importantly, mean or most recent 25(OH)D levels were not consistently associated with outcomes, raising questions about the efficacy of supplementation in altering long-term risk.
Patients in the cohort were 92% female, 48% White, and 40% African American, with a mean age at cohort entry of 42 years. A total of 50.3% had hypertension, 9.4% had diabetes, 52.6% had hyperlipidaemia, and 14% had hypothyroid. A third had ever smoked, 12.3% were current smokers and 42.6% were obese.
The researchers said their study was the first to assess initial vitamin D levels in relation to both mortality and cardiovascular outcomes in SLE using robust longitudinal data.
The findings suggest that initial vitamin D deficiency may serve as a marker for heightened cardiovascular risk, although the role of supplementation in modifying this risk remained uncertain.
Given the near-universal prevalence of vitamin D insufficiency in SLE, these results may inform early risk stratification and underscore the need for further research into whether correcting deficiency could translate into measurable clinical benefit, the researchers said.
