Plasma N-Terminal Pro B-Type Natriuretic Peptide Reference Values in Subjects without Heart Disease

Abstract

Background: B-type natriuretic peptide (BNP) and its terminal fragment (NT-proBNP) are released from ventricular cardiomyocytes in response to increase in ventricular wall stress and to myocardial ischaemia. Both BNP and NT-proBNP have been described as reliable diagnostic and prognostic biomarkers in patients with heart failure. There are no previous reports on the reference values for both markers in the Nigerian population ; an essential pre-requisite for effective utilization of the biomarkers in the management of the indigenous patients. Objective: The aim of this study was to determine the upper reference value for NT-proBNP in apparently healthy Nigerian adults with neither cardiovascular nor renal disease. Subjects and methods: A group of 34 subjects were recruited into the study; equally divided between the sexes. They were aged between 19 and 42 years. Subjects’ blood pressure, weight and height were measured. Plasma NT-proBNP was analysed using the electrochemiluminescence immunoassay method on elecsys 2010 machine, while creatinine and blood glucose were measured by routine methods. Results: The mean values for BMI, plasma glucose, creatinine clearance, systolic blood pressure, diastolic blood pressure were 21.2 kg/m2 , 4.1 mmol/L, 91.2 ml/min, 119 mmHg, 79 mmHg respectively. The mean concentration of NT-proBNP in males and females were 24.7 pg/ml and 32.5 pg/ml respectively, while the upper reference value for NT-proBNP was found to be 99.5 pg/ml. Conclusion: We therefore suggest that NT-proBNP values below 100 pg/ml be considered as the cut-off point for normal ventricular function or structure in our clinical setting.