The aldosterone to renin ratio in the evaluation of patients with incidentally detected adrenal masses.

Incidentally discovered adrenal masses are diagnosed with increasing frequency, especially among patients with hypertension. Thus, a reliable screening test for primary hyperaldosteronism (PA) is essential to avoid unnecessary diagnostic procedures to this population. The aim of the present study is the evaluation of aldosterone to renin ratio (ARR), using plasma renin concentration, in the diagnostic algorithm of patients with adrenal incidentaloma. A total of 123 individuals were studied: 17 patients with proven PA (age 55.5 +/- 1.4 years), 27 patients with nonfunctioning adrenal incidentaloma (age 60.3 +/- 1.8 years, 14 hypertensives and 13 normotensives) and 79 control subjects (age 58.7 +/- 1.4 years, 27 hypertensives and 52 normotensives). A receiver operating characteristic (ROC) analysis disclosed that an ARR > or =32 combines a sensitivity of 100% with a specificity of 96.2% for the diagnosis of PA. No difference in AlphaRR between hypertensive and normotensive individuals harbouring an adrenal incidentaloma and hypertensive and normotensive controls was found. Patients with adrenal incidentalomas with subtle glucocorticoid hypersecretion demonstrated similar ARR compared to patients with normal cortisol secretion. In conclusion, ARR is reliable for the exclusion of PA in patients with adrenal incidentalomas. Furthermore, subtle aldosterone hypersecretion, as indicated by increased ARR, in patients with adrenal incidentalomas is not associated with the presence of hypertension or subtle glucocorticoid hypersecretion.