Association of vitamin D with cardiometabolic risk factors in rheumatoid arthritis

Individuals with rheumatoid arthritis (RA) are at a greater risk for cardiovascular disease (CVD). Vitamin D deficiency is a potential risk factor for CVD and metabolic syndrome. Since patients with RA have a high prevalence of vitamin D deficiency, we investigated the association of vitamin D levels with cardiometabolic risk factors in a cohort of RA patients with no prior history of CVD.

Serum 25-hydroxyvitamin D (25[OH]D) levels were measured among RA patients enrolled in a cohort study of subclinical CVD. The cross-sectional associations of 25(OH)D levels with traditional CVD risk factors such as insulin resistance (IR; estimated using the homeostatic model assessment [HOMA]), adipokines, markers of systemic inflammation, and endothelial activation were explored, adjusting for pertinent sociodemographic, lifestyle, and RA characteristics.

Among 179 RA patients, 73 (41%) had a 25(OH)D level <30 ng/ml. Only 23 patients (13%) had a 25(OH)D level ≥45 ng/ml. After adjusting for demographics and body mass index (BMI), 25(OH)D remained significantly associated with high-density lipoprotein (HDL) cholesterol and inversely associated with HOMA-IR, fibrinogen, E-selectin, and soluble intercellular adhesion molecule 1 (sICAM-1). Significant associations with HDL cholesterol, E-selectin, and sICAM-1 were maintained after adjusting for the Disease Activity Score in 28 joints (DAS28) and autoantibody status. These associations were similar between the groups subdivided by sex, ethnicity, BMI, DAS28 level, and autoantibody status.

These data suggest that vitamin D deficiency is common in RA and may be independently associated with several cardiometabolic intermediates in this population.