Rheumatoid arthritis is a risk factor for early mortality due to cardiovascular disease. Interleukin-33 appears to protect against the development of atherosclerosis. The purpose of this study was to investigate the relationship between serum levels of interleukin-33 and its soluble receptor with the presence of subclinical carotid atherosclerosis in rheumatoid arthritis patients.
Rheumatoid arthritis patients without atherosclerotic disease were subjected to clinical and laboratory assessments, including carotid ultrasound. Interleukin-33 and its soluble receptor serum levels were measured by ELISA.
102 patients were included. The prevalence of carotid plaques was 23.5% and the median intima-media thickness was 0.7 mm. The median interleukin-33 and its soluble receptor concentration was 69.1 and 469.8 pg/ml. No association was found between serum interleukin-33 or its soluble receptor and intima-media thickness or plaque occurrence. Each 0.1 mm increase of intima-media thickness raised the odds of plaque occurrence by 5.3-fold, and each additional year of rheumatoid arthritis duration increased the odds of plaque occurrence by 6%. Each additional year in patients age and each one-point increase in the Framingham Risk Score were associated with a 0.004 mm and 0.012 mm increase in intima-media thickness. Methotrexate use was associated with a 0.07 mm reduction in intima-media thickness.
Interleukin-33 and its soluble receptor were not associated with subclinical atherosclerosis. Traditional risk factors for atherosclerosis and rheumatoid arthritis duration were associated with intima-media thickness and plaque occurrence; methotrexate use was associated with a lower intima-media thickness.