Clinical Use of Renin Determinations

INCREASED awareness and understanding of the relationships between the individual components of the reninangiotensin-aldosterone system and its role in benign essential hypertension have revolutionized the diagnosis and clinical management of hypertension. Polite but serious controversy continues between the proponents of the importance of the renin-angiotensin-aldosterone system in the classification of the various types of benign essential hypertension and those who see limited application of the system in clinical practice. Differences in methods used, failure to distinguish between plasma renin activity (PRA) vs renin concentration, and failure to take into consideration the clinical status of the patient when testing is performed are some reasons for varying conclusions by clinicians in their attempts to classify hypertension into low-, normal-, and high-renin states. Nevertheless, once the pitfalls are identified and compensated for, accurate measurement of PRA—and classification of hypertension into low- and high-renin states—may be of considerable value in the diagnosis, prognosis, and