Utilidad de la relación aldosterona y actividad renina plasmática en el diagnóstico de hiperaldosteronismo primario

El hiperaldosteronismo primario (HP) es la forma mas comun de hipertension arterial (HTA) secundaria. Recientemente varios estudios sugieren que la prevalencia de esta enfermedad varia entre 5% y 15% entre la poblacion hipertensa, y 20% para hipertension arterial refractaria. El objetivo de este estudio fue, ante la gran variabilidad de prevalencias sobre HP segun las publicaciones internacionales y pocos datos en la Argentina, aportar la prevalencia de HP en un hospital general del interior del pais, relacionandolo con el grado de HTA y presencia de normokalemia. En este estudio transversal se realizo dosaje de A/ARP en 123 pacientes hipertensos, suspendiendo toda medicacion que interfiriera en los dosajes hormonales; se utilizo como metodo confirmatorio el test de solucion salina (SS) para el diagnostico de HP y la tomografia computarizada (TC) de abdomen para el diagnostico etiologico del HP. Se detecto una relacion A/ARP elevada en 20 (16.4%) pacientes. En 18 se realizo el test de SS, confirmando el diagnostico de aldosteronismo en 8 (6.5% del total). En la TC, dos presentaron adenomas, y seis glandulas suprarrenales normales. Todos los pacientes con HP pertenecian al grupo II y III de HTA segun el VI Joint National Committee (VI JNC) y el 50% fue normokalemico. Encontramos una prevalencia de 6.5% de HP, asociado a grado II y III de hipertension, y valores de potasio normal en la mitad de los pacientes. Primary aldosteronism (PA) is a possible cause of endocrine hypertension. Recent studies have suggested a prevalence ranging between 5% and 15% of all hypertensive patients, and 20% in patients with refractory hypertension.The objective of this transversal study was to establish the prevalence of PA in a hypertensive population using the aldosterone / plasma renin ratio (ARR) as a screening method, considering that the prevalence rates for PA among hypertensive people present a wide range and that there are only few reports in Argentina. This ratio was then related with the degree of hypertension and with the presence or absence of hypokalemia. Serum aldosterone and plasma renin activity levels were measured in 123 hypertensive patients after discontinuing all medications that could interfere with the hormonal tests. Patients with an aldosterone/plasma renin activity ratio > 25 were submitted to the saline suppression test (SST) to confirm the diagnosis of PA, followed by computed tomography (CT) of the abdomen. Twenty patients presented an ARR > 25 (16.4%). Eighteen were submitted to the SST, eight had a diagnosis of PA confirmed with positive SST (6.5%). Of 8 patients who underwent an abdominal CT, two showed adenoma, and six normal adrenal anatomy. All the eight patients with a PA diagnosis belonged to group II and III of hypertension according to Joint National Committee VI (JNC VI), and only 4 (50%) were normokalemic. We found a 6.5% prevalence of PA, associated with grade II and III hypertension, and normal potassium values in half of the patients with PA.