Application of captopril test in the diagnosis of primary aldosteronism

Objective:To investigate the value of captopril test in the diagnosis of primary aldosteronism.Methods: 27 patients with primary aldosteronism and 26 patients with essential hypertension,16 patients with essential hypertension combined nonfunctional adrenal adenoma,3 patients with nonfunctional adrenal adenoma were studied in order to compare the sensitivity and specificity of different plasma aldosterone cut-off levels in captopril test in the diagnosis of primary aldosteronism.Results: The sensitivity by postcaptopril aldosterone reduction of more than 20% and of the plasma aldosterone cut-off levels of 416 pmol/L、 438 pmol/L、 444 pmol/L was 96.3%、 88.9%、 88.9% and 85.2% respectively,and the specificity was 13.3%、 77.8%、 82.2% and 82.2%,respectively.With increasing of plasma aldosterone cut-off levels,the specificity increased,but at the cost of a lower sensitivity.Conclusions: Captopril test represents a useful test to confirm the diagnosis of primary aldosteronism.The optimal cut-off level should be identified according to different laboratory reference value.