Stimulated Renin: A Screening Test for Hypertension

Abstract

The usefulness of the furosemide screening test in ambulant hypertensive patients was prospectively studied. Outpatients were given 60 mg of furosemide by mouth, and 5 hours later plasma renin activity was measured. Subsequent investigation in hospital showed that the patients fell into four groups: extreme hyporeninemia (primary aldosteronoma), suppressed renin (confirmed suppressed-renin hypertension), normal renin (essential hypertension), and elevated renin (renovascular hypertension). The plasma renin activity measured by the test correlated well with standardized in-hospital measurement. This test identifies patients who may have primary aldosteronism, suppressed-renin hypertension, or renovascular disease as the cause of hypertension, thus indicating those requiring further in-hospital investigation. More significantly, it identifies those not requiring further study, thus decreasing hospitalization. Finally, it helps in the selection of specific antihypertensive therapy based on plasma renin activity.