Simple screening procedure for the diagnosis of primary aldosteronism.

A simple screening protocol for the diagnosis of primary aldosteronism was applied to 149 hypertensive patients. The diagnostic criterion for possible primary aldosteronism was the combination of supine plasma renin concentration less than 15 mIU/l (normal range 6-54) and plasma aldosterone concentration greater than 11 ng/100 ml (normal range 3-18). None of 63 persistently normokalaemic hypertensive patients fulfilled this criterion. Seventeen (20%) of 86 hypokalaemic patients showed hormonal values consistent with primary aldosteronism. The presence of an adrenal adenoma was verified in eight of these patients. Thus screening for primary aldosteronism can be restricted to hypokalaemic patients. The prevalence of primary aldosteronism in a hypertensive population was calculated to be less than 1%.