Background In recent years, vitamin D deficiency has been linked to disease activity and pathogenesis of systemic autoimmune diseases (SAD) like systemic lupus erythematosus (SLE) and inflammatory joint diseases (IJD) such as rheumatoid arthritis (RA). In the general population, the association between vitamin D with risk for cardiovascular diseases (CVD) is still debatable. While people with IJD and SAD tend to be vitamin D deficient and suffer from an elevated CVD burden, the effect of vitamin D on their cardiometabolic risk factors is of much interest.
Objectives To provide an overall conclusion on whether vitamin D deficiency contributes to an increased cardiovascular morbidity in these patients, a systematic literature review was done.
Methods A systematic literature search was done in PubMed/MEDLINE and EMBASE to identify all articles that assessed the association of vitamin D with cardiovascular disease and its risk factors in patients with IJD (rheumatoid arthritis (RA), psoriatic arthritis (PsA), ankylosing spondylitis) and SAD (systemic lupus erythematosus (SLE), Behcet's disease, vasculitis, Sjogren syndromes, systemic sclerosis). Eligible studies were assessed for quality and risk of bias according to the Cochrane Handbook Chapter 126.96.36.199. (Higgins JPT. GS. Cochrane Handbook for Systematic Review of Interventions The Cochrane Collaboration 2011.)
Results In total 3273 abstracts were identified. After screening, selection and quality assessment, 16 studies were included (6 case-control and 10 cohort studies), which described only RA and SLE except for one study which focused on PsA. Therefore, this study focused on RA and SLE because they are the most frequent IJD and with highest CVD risk respectively. In RA patients (n=812) vitamin D deficiency was associated with presence of (components)of metabolic syndrome (OR =1.8 (95% CI: 1.3; 2.5), P=0.001) in RA, especially dyslipidemia (OR 1.7; 95% CI:1.1–2.5; P=0.013) and obesity. No studies with prospective design in RA have assessed CVD risk in relation to vitamin D. In SLE patients (n=1850) the only prospective study observed no association between vitamin D deficiency and CVD, although weak associations with dyslipidemia and obesity were observed in some studies.
Conclusions No clear association between vitamin D deficiency and CVD was found in patients with RA and SLE, probably due to large heterogeneity in terms of sample sizes, designs, analyses and outcome measures. As conclusions were mainly drawn on cross-sectional data, there is an urgent need for adequate prospective studies to assess if vitamin D levels are associated with cardiovascular outcomes.
Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from www.handbook.cochrane.org.
Disclosure of Interest None declared