CONTROVERSIES IN THE DIAGNOSIS AND TREATMENT OF HYPERTENSION - A PERSONAL REVIEW OF JNC-V

In January 1993 the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure published its fifth report (JNC V). The report highlighted the importance of systolic hypertension and recommended that hypertension should be diagnosed-regardless of age- when systolic blood pressure readings are consistently greater than or equal to 140 mm Hg. JNC V reflected the opinion in JNC IV that several drug classes-including diuretics, beta blockers, angiotensin-converting enzyme (ACE) inhibitors, calcium antagonists, and at alpha blockers-are suitable for initiating antihypertensive therapy. However, JNC V gave preference to diuretics and beta blockers because these drug classes have been shown to reduce the incidence of stroke and cardiovascular events In clinical trials; similar studies with the newer drug classes have not yet been completed. This recommendation is highly controversial because the benefits of diuretic and beta-blocker use are most evident in the elderly, and the beneficial effects of these drugs on the incidence of coronary events are relatively modest. Further, growing experience with ACE inhibitors and calcium antagonists shows that these agents lack the metabolic: disadvantages of older agents and can exhibit antiatherosclerotic and antihypertrophic vasoactivity. Although to date the clinical benefits of the newer agents have been documented in conditions other than hypertension, the data are persuasive and indicate a probability that these drugs will improve prognosis in hypertensive patients. JNC V also emphasized lifestyle modifications; however, even when they decrease blood pressure, dietary and other nonpharmacologic strategies have not been shown to lower the Incidence of clinical events. Despite its controversial recommendations, JNC V has provoked a debate that should refocus attention on fundamental questions in hypertension.