Amino-terminal pro-brain natriuretic peptide as a prognostic marker in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is associated with increased cardiovascular (CV) morbidity and mortality, of which amino-terminal pro-brain natriuretic peptide (NT-proBNP) is a predictor. The objective of the study was to investigate associations between NT-proBNP and age, gender, markers of inflammation, disease activity, and kidney function in RA patients, without co-morbidities potentially influencing NT-proBNP concentration. The study group consisted of 90 patients with RA, without clinically relevant coronary heart disease, hypertension, diabetes, advanced chronic kidney disease. The comprehensive assessment of clinical and laboratory parameters of inflammation, disease activity, and kidney function was performed. Plasma samples were frozen for NT-proBNP analysis. Carotid intima media thickness (cIMT) was determined by high-resolution B-mode ultrasonography. The mean NT-proBNP concentrations were significantly higher in a group of RA patients with high disease activity (DAS28 > 5.1) and in a group of patients with subclinical atherosclerosis diagnosed by cIMT ≥ 0.6 mm. In all RA patients, NT-proBNP correlated positively with the age, C-reactive protein, erythrocyte sedimentation rate, cIMT, tricipital skin fold and negatively with hand-grip strength, hemoglobin, red blood cell count, albumin. In the group of women with RA, we found significant positive correlation between NT-proBNP and cystatin-C. Also, patients with NT-proBNP level ≥ 100 pg/ml had significantly higher cystatin-C than those with lower NT-proBNP. NT-proBNP level, in RA patients without co-morbidities potentially influencing this level, is correlated with age, disease activity markers of inflammation, and subclinical renal impairment. It means that risk of CV disorders is higher in older patients with more active RA.