Increased concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP) are associated with cardiovascular morbidity and mortality, but little is known about their relationship to chronic inflammation. Patients with rheumatoid arthritis (RA) have chronic inflammation, increased arterial stiffness, and accelerated coronary atherosclerosis. This study was undertaken to test the hypothesis that NT-proBNP concentrations are elevated in patients with RA and are associated with coronary artery calcification and markers of inflammation.
In 159 patients with RA (90 with early RA and 69 with longstanding RA) without heart failure and 88 control subjects, serum concentrations of NT-proBNP, interleukin-6 (IL-6), and tumor necrosis factor alpha (TNFalpha) were measured and coronary calcification was assessed. Associations between NT-proBNP levels and the other parameters were investigated.
NT-proBNP concentrations were elevated in patients with longstanding RA (median 142.8 pg/ml [interquartile range 54.8-270.5]) and those with early RA (median 58.1 pg/ml [interquartile range 19.4-157.6]) compared with controls (18.1 [3.2-46.0]) (P < 0.001). In patients with RA, NT-proBNP concentrations were associated with age (rho = 0.35, P < 0.001), levels of IL-6 (rho = 0.33, P < 0.001), TNFalpha (rho = 0.23, P = 0.003), and C-reactive protein (CRP) (rho = 0.21, P = 0.01), coronary calcium score (rho = 0.30, P < 0.001), systolic blood pressure (rho = 0.30, P < 0.001), and disease activity (rho = 0.29, P < 0.001). After adjustment for age, race, and sex, the associations between NT-proBNP concentrations and disease activity, TNFalpha, IL-6, and CRP remained significant, but those with systolic blood pressure and coronary calcium score were attenuated.
NT-proBNP concentrations are increased in patients with RA without clinical heart failure and may indicate subclinical cardiovascular disease and a chronic inflammatory state.