Interleukin 1 receptor antagonist relation to cardiovascular disease risk in patients with rheumatoid arthritis

Interleukin (IL) 1, and its family member, IL-1 receptor antagonist (IL-1ra), are involved in the pathogenesis and inflammation perpetuation of patients with rheumatoid arthritis (RA). Besides, IL-1 has been linked to an increased risk and greater severity of cardiovascular (CV) disease. We aimed to study if IL-1ra is related to the CV manifestations-including lipid pattern and insulin resistance or subclinical atherosclerosis-that accompanies the disease in a large series of patients with RA. Cross-sectional study that encompassed 430 patients with RA. Serum IL-1ra levels were assessed. A multivariable analysis was performed to analyze the relation of IL-1ra to subclinical carotid atherosclerosis, and to traditional CV factors including a complete lipid molecules profile and insulin resistance or beta cell function indices. Body mass index, abdominal circumference, and the presence of obesity were significantly and positively associated with circulating IL-1ra. Similarly, erythrocyte sedimentation rate, and disease activity scores were significantly related to higher IL-1ra serum levels after adjustment for confounders. Neither carotid intima-media thickness nor the presence of carotid plaque were associated with serum levels of IL-1ra. However, after multivariable analysis circulating IL-1ra was independently and positively associated with higher serum levels of total cholesterol, triglycerides, and apolipoproteins B and C-III. Similarly, IL-1ra was related to higher levels of beta-cell function in the univariable analysis, although, in this case, significance was lost after adjustment. Among patients with RA, IL-1ra is associated with both disease activity and several traditional CV risk factors such as obesity and the presence of higher lipid levels. Our findings suggest that IL-1ra can represent a link between the inflammation and the CV disease risk that are present in patients with RA.