New information gathered by the National Heart, Lung, and Blood Institute's Framingham Heart Study, and reported in the April 22 New England Journal of Medicine, indicates that a five- to tenfold increase in use of antihypertensive medication from the 1950s through the 1980s was accompanied by striking declines in the prevalence of the highest blood pressure levels (3 and 4) down to more moderate levels (1 and 2). High blood pressure at stage 3 is systolic blood pressure of 180 to 209 mm Hg or diastolic blood pressure of 110 to 119 mm Hg. Stage 4 high blood pressure is systolic blood pressure of at least 210 mm Hg or diastolic blood pressure of at least 120 mm Hg. The study further notes that the favorable trends in hypertension treatment and control were accompanied by a decline in hypertensive target organ damage in the form of left ventricular hypertrophy (LVH), which is an important risk factor for both cardiovascular disease and fatal coronary heart disease.
Despite this encouraging news, however, it is important to note that the majority of coronary heart disease and stroke occurs at lower stages of hypertension. And, although hypertension levels declined over the 4 decades between 1950 and 1989, recent data from the National Health and Nutrition Examination Survey (NHANES) reveal that a national downward trend in blood pressure control rates slowed in the 1990s and actually headed slightly higher. The Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI), which NHLBI released in November 1997, reported this disturbing trend.
JNC VI also noted a slight rise in the rate of stroke, increases in both end-stage renal disease and heart failure, and a leveling in the death rate for people with coronary heart disease. These indicators signal the clear need for physicians and patients to redouble efforts to prevent and treat hypertension.
The JNC VI guidelines urge a population-wide approach to prevent high blood pressure through lifestyle changes to affect overall cardiovascular deaths and disability. In addition, the JNC VI report offers specific information to physicians regarding when medication is indicated and stipulates which medications should be considered for patients who fit particular profiles. The new Framingham study clearly illustrates the positive impact of effective hypertension control.
The National Heart, Lung, and Blood Institute's Framingham Heart Study is 50 years old and is ongoing. It is yielding critical data on the prevention and treatment of cardiovascular disease. However, the Framingham Heart Study represents a predominantly white population and the new study's findings may not apply to minority groups who are more likely to suffer the most severe forms of hypertension.
About 50 million U.S. adults have hypertension. Untreated hypertension can damage the kidneys and lead to stroke, heart attack, and heart failure. Heart disease and stroke are the first and third leading causes of death, respectively, in the U.S.
Hypertension is defined as systolic blood pressure averages of 140 mm Hg or greater and/or diastolic blood pressure averages of 90 mm Hg or greater. The systolic pressure is the pressure of blood in the vessels when the heart contracts. Diastolic pressure is the pressure of the blood between heartbeats when the heart is at rest.