A decreased metabolic clearance rate of aldosterone in benign essential hypertension.

Aldosterone secretion rate, metabolic clearance rate, and/or plasma concentration were determined in 16 patients with benign, uncomplicated essential hypertension and compared with those of control subjects. The mean metabolic clearance rate of aldosterone in 10 patients was significantly (P < 0.001) lower (mean 867 liters of plasma/day per m(2) +/-270 SD) than in a group of 7 healthy subjects (mean 1480 liters/day per m(2) +/-265 SD). Secretion rates in 13 patients (including the 10 already mentioned) tended to be low (83 +/-43 vs. 109 +/-54 mug/day) and plasma concentrations tended to be high (13.6 +/-4.6 vs. 7.5 +/-4.8 ng/100 ml), but neither of these differences was statistically significant. The lower metabolic clearance rate could account for elevated plasma concentrations of aldosterone even when the secretion rate is normal or low. Measurement of secretion rate or urinary excretion only is therefore insufficient to establish the presence and/or mode of evolution of hyperaldosteronism. Failure of the aldosterone secretion to adapt fully to a decreased aldosterone metabolic clearance rate (MCR) could explain the state of relative hyperaldosteronism in patients with benign essential hypertension, even when the secretion rate and the urinary excretion rate are in the normal range.