BNP (
B-type natriuretic peptide) and anaemia are both associated with adverse outcome in patients with chronic
heart failure. Whether low haemoglobin levels are independently predictive of elevated BNP levels in subjects without
heart failure is unknown. In the present study, we examined the relationship between haemoglobin and BNP levels in 234 patients with suspected
coronary heart disease without a history of chronic
heart failure, adjusting for known predictors of BNP levels. By univariate analysis, haemoglobin levels were inversely related to logarithmically transformed BNP values (r = -0.30, P < 0.0001). After adjustment for patient age, gender, body mass index, history of
myocardial infarction, use of
diuretics,
angiotensin-converting enzyme inhibitors and beta-blockers, estimated
creatinine clearance rate, extent of
coronary disease, left ventricular ejection fraction and left ventricular end-diastolic pressure, blood haemoglobin remained an independent predictor of plasma BNP (standardized beta-coefficient = -0.253, P < 0.0001). A similar relationship was observed between haematocrit and BNP (standardized beta-coefficient -0.215, P < 0.0001). We conclude that haemoglobin levels are independently predictive of plasma BNP levels in patients with suspected
coronary heart disease without
heart failure. Anaemia may contribute to elevated BNP levels in the absence of
heart failure, and may represent an important confounder of the relationship between BNP, cardiac function and prognosis.