Background Although Cystatin C relation with atherosclerosis has been studied before in RA patients, cathepsin S association with subclinical atherosclerosis has not been previously considered in RA patients. This could help to better stratify or predict the development of cardiovascular diseases in RA.
Objectives To assess if serum cathepsin S and cystatin C, two novel markers of cardiovascular disease risk (CVDR), are associated with subclinical carotid atherosclerosis in RA patients.
Methods Serum cystatin C and cathepsin S levels, carotid intima-media thickness (cIMT) and carotid plaques were assessed in a cross-sectional study involving 178 RA patients. All of them were 18 years or older and fulfilled the 2010 ACR/EULAR classification criteria.
Results Patients with a mean ± SD age of 55 ± 11 years were included. Regarding cardiovascular risk factors, 35% of the patients had hypertension, 32% dyslipidemia and 15% diabetes. Disease duration was 7 (IQR 4–15) years. Patients had moderate-active disease as shown by DAS28 (3.74 ± 1.91). One third (35%) of them were taking prednisone, 86% were under disease-modifying antirheumatic drugs and 22% were taking anti-TNF-alpha or other biologic therapies. The mean cIMT was 0.670 ± 0.143 mm, and 66 patients (37%) had carotid plaques in the carotid ultrasound assessment. Both cystatin C and cathepsin S were significantly associated with hypertension, diabetes and dyslipidemia. However, neither positive rheumatoid factor nor prednisone use were associated with cystatin C or cathepsin S. A trend for lower levels of cystatin C was observed in patients undergoing anti-TNF-alpha therapy (log beta coef. -0.20 (-0.44–0.04), p=0.09). An association between disease activity scores with higher levels of cystatin C but not with cathepsin S was found. Cystatin C levels were also associated with cIMT in the subgroup of patients included in the higher quartile of cIMT (OR 1.31, 95%CI [1.00–1.72], p=0.04) after adjusting for traditional cardiovascular risk factors, age and sex. An association between serum cystatin C levels and carotid plaques was also found in the univariate analysis (OR 1.37, 95%CI [1.06–1.76], p=0.02). However, this significant association was lost after adjusting for traditional cardiovascular risk factors and age. Cathepsin S was not associated with cIMT or carotid plaques.
Conclusions High cystatin C serum levels identify a subgroup of RA patients with high risk of subclinical atherosclerotic disease.
Disclosure of Interest None declared