Heaemoglobin level influences plasma brain natriuretic peptide concentration

OBJECTIVE: It has been demonstrated that the haemoglobin (Hb) level is associated with the prognosis of congestive heart failure (CHF). Correction of anaemia has improved CHF outcomes even in patients without anaemia. Lower Hb level may play a more important role in left ventricular (LV) dysfunction than previously recognized. This study aimed to evaluate the association of Hb level with plasma brain natriuretic peptide (BNP) level as a marker of LV function adjusted for known determinants of BNP. METHODS AND RESULTS: Association of Hb level with plasma BNP level was studied in 279 outpatients of cardiology (mean age 61 +/- 16, 54% men) using multivariate regression analysis. Mean Hb level was 13.7 +/- 1.5 g/dl and 14% of patients had anaemia. Median BNP level was 28 pg/ml (range < 4 to 580 pg/ml). In total subjects, the multivariate model adjusted for age, sex, history of CHF, atrial fibrillation, serum creatinine level, LV wall motion abnormality, end-diastolic LV dimension, LV mass index, and cardiovascular risk factors showed that a lower Hb level was significantly associated with higher BNP level (p = 0.0243). In "normal" subjects who did not have a history of CHF, atrial fibrillation, LV wall motion abnormality, LV dilatation, valvular abnormality, or LV hypertrophy, a lower Hb level was significantly associated with a higher BNP level (p = 0.0012) after adjustment for age, sex, serum creatinine level, and cardiovascular risk factors. CONCLUSIONS: Lower Hb levels are associated with higher plasma BNP levels independent of age, sex, serum creatinine level, LV wall motion abnormality, LV hypertrophy, history of CHF, atrial fibrillation, and cardiovascular risk factors.