Background Rheumatoid arthritis (RA) is associated with the increased cardiovascular (CV) risk and the risk of chronic kidney disease (CKD), especially in older patients. Renal involvement seems to be connected with the inflammatory activity of the disease, treatment used and patients' age.
Objectives The goal of the study was to investigate an association between parameters of CV risk and glomerular filtration rate (GFR) in older RA patients.
Methods The study group consisted of 78 RA patients (61 women, 17 men), at the age over 50; the mean (SD) age was 58,0 (5,6) years. High disease activity score in 28 joints (DAS28 ≥5,1) was observed in 26 patients (33,3%); erosive form of RA in 71 (91,0%); long-term RA (duration ≥10 years) in 40 (51,3%). GFR was assessed with different methods, including measurement of serum concentration of creatinine (Cr), cystatin–C (Cys-C), estimated glomerular filtration rate (eGFR) using creatinine-based formulas calculated by Cockroft and Gault (eGFR-CG) and Modification of Diet in Renal Disease (eGFR-MDRD). The risk of CV diseases was assessed by evaluation of plasma concentration of N-terminal pro-brain natriuretic peptide (NT-proBNP), serum concentrations of total cholesterol and fractions, measurement of carotid intima-media thickness (cIMT) and calculation of the 10-year risk of fatal CVD using the Systemic Coronary Risk Evaluation (SCORE) model.
Results The mean (SD) serum Cys-C concentration was 0,83 (0,25) mg/l, Cr 0,74 (0,28) mg/dl, eGFR-CG 98,8 (28,2) ml/min/1,73 m2, eGFR-MDRD 100,6 (27,2) ml/min/1,73 m2). Increased level of Cys-C (≥1 mg/l) was observed in 15 patients (19,2%) and Cr (≥1 mg/dl) in 9 (11,5%). Stage ≥2 CKD, according to eGFR-CG was observed in 5 patients (6,4%) and eGFR- MDRD in 4 (5,1%). The mean (SD) concentration of plasma NT-proBNP was 155,9 (274,6) pg/ml, serum total cholesterol (TC) 210,6 (41,6) mg/dl, high-density lipoprotein cholesterol (HDL-C) 61,4 (16,8) mg/dl, low-density cholesterol (LDL-C) 123,3 (32,8) mg/dl, triglycerides (TG) 128,1 (58,7) mg/dl; cIMT value 0,88 (0,12) mm, SCORE 2,9 (2,8). Multiple linear regression analysis confirmed significant associations for: SCr with HDL-C (b= -0,006; p=0,02); eGFR-CG with patients' age (b= -1,8; p=0,008) and NT-proBNP (b= -0,04; p=0,0009); eGFR-MDRD with TG (b= -0,1; p=0,01) and NT-pro-BNP (b= -0,04; p=0,0003); Cys-C with erythrocyte sedimentation rate (ESR) (b=0,003; p=0,04) and NT-proBNP (b=0,0004; p<0,0001). We found no correlation between parameters of inflammation and RA activity (C-reactive protein, albumin, fibrinogen, DAS28, pain intensity) and GFR indicators.
Conclusions In older RA patients, the significant relationship was observed between the chosen indicators of GFR and parameters of CV risk. That points out to the increased risk of cardiovascular diseases in the studied group of patients, irrespectively of the current RA activity.
Disclosure of Interest None declared