Primary hyperaldosteronism: differentiation between aldosterone-producing adenoma and idiopathic adrenocortical hyperplasia (author's transl)

The regulation of aldosterone secretion by sodium restricted and enriched diet was assessed in 21 patients with primary aldosteronism for differentiation between unilateral aldosterone-producing adenoma and adrenocortical hyperplasia causing autonomous aldosterone hypersecretion. Compared to 10 patients with idiopathic adrenocortical hyperplasia, urinary aldosterone excretion after 4 days of sodium restricted diet was significantly higher in 11 patients with established adenoma (41.3 +/- 16.3 micrograms/24 h vs 19.8 +/- 8.5 micrograms/24 h; P less than 0.005). After six days of sodium loading these differences became even more obvious (35.3 +/- 14.0 micrograms/24 h vs 12.7 +/- 3.7 micrograms/24 h; P less than 0.0005). Sodium excretion did not influence aldosterone secretion in the adenoma group. In patients with hyperplasia both parameters showed a negative correlation (r = -0.522; P less than 0.001). Differentiation without overlap between both patient groups was achieved by comparison of the quotient of aldosterone excretion and serum potassium level during sodium enriched diet.