Circulating atrial natriuretic polypeptide during exercise in patients with essential hypertension

We studied the relationship between haemodynamic measurements and plasma atrial natriuretic peptide (ANP) levels during exercise in patients with essential hypertension. The exercise protocol consisted of three fixed work loads (25, 50 and 75 W) using a supine bicycle ergometer. Plasma ANP levels and haemodynamic indices were measured before and during each stage of exercise. Plasma ANP levels and pulmonary artery wedge pressure (PAWP) significantly increased at the maximum work load. Significant correlations of PAWP and mean arterial pressure (MAP) to plasma ANP levels were observed at four points obtained before and during each stage of exercise (PAWP, r = 0.83, P less than 0.001; MAP, r = 0.48, P less than 0.01). Furthermore, a significant inverse correlation between shortening fraction (SF), estimated by M-mode echocardiography, and plasma ANP levels at 75 W work load was also observed (r = -0.66, P less than 0.01). These results suggest that the increase of circulating ANP levels during exercise in essential hypertensive subjects may be associated with elevated left atrial pressure and arterial pressure, or left ventricular systolic dysfunction.