Atrial natriuretic peptide (ANP) in relation to blood pressure: a study in middle‐aged men with normal and elevated blood pressure

In order to investigate the potential role of atrial natriuretic peptide (ANP) in mild to moderate essential hypertension, a study was conducted in groups of normotensive and hypertensive middle‐aged men born in 1926 and 1927. Venous plasma concentrations of immunoreactive ANP (irANP) were studied in relation to measurements of cardiac structure and function, urinary electrolytes as well as some cardiovascular hormones. Plasma irANP did not differ between normotensive controls (31 ± 14 pmol l −1 ) and borderline or untreated hypertensive patients. However, irANP concentrations were slightly but significantly ( P < 0.05) lower in the borderline (26 ± 8 pmol l −1 ) compared to the untreated established hypertensives (35 ± 14 pmol l −1 ). No relationships were found between irANP and blood pressure, indices of left ventricular structure and function or hormone parameters in subgroups or the whole study group. Our data do not support the view that plasma irANP is increased in uncomplicated essential hypertension, since our groups of borderline or established hypertensive middle‐aged men without major cardiac involvement did not differ in irANP concentrations compared to normotensive controls. Thus, during the development or in the early stages of essential hypertension, ANP secretion does not seem to be abnormal.