Published in this issue of Hypertension are the details of one part of the Third National Health and Nutrition Examination Survey, 1988-1991 (NHANES III).1 The preliminary data were published earlier, in a capsule fashion,2 as the “Prevention Paper,” along with the Joint National Committee’s Fifth Report on the detection and evaluation and treatment of hypertension.3 The following article details the data dealing with the prevalence of hypertension in the adult population of the United States.
There is much to glean and to digest from this report. Most striking are the data concerning the number of adults of both genders from the non-Hispanic black, non-Hispanic white, and Mexican-American populations who have been diagnosed with hypertension. There are also the time-established control data that reveal the number of people known to have an elevated blood pressure, those who receive antihypertensive therapy, and those who are treated with blood pressures under good control. Clearly, many among us who are clinicians, epidemiologists, and public health scientists, and those who are simply interested in the problem of hypertension and its control will find much on which to reflect.
The good news, perhaps the most striking among the large amount of data, is the finding that there has been a reduction in the overall number of adults in this country with an elevated arterial pressure. The number that has been bandied around in recent years has been 58 million Americans, a distinct rise from the earlier number of 23 million announced with the initiation of the National High Blood Pressure Education Program in 1972. The dramatic increase of 35 million adults was easier to explain in those days as a consequence of changing the definition of hypertension, which occurred after the publication of the results from the Hypertension Detection and Follow-up Program. That study indicated that the population at risk included those adults whose diastolic pressures fell between 90 and 104 mm Hg and whose systolic pressures were between 140 and 159 mm Hg. Thus, by defining hypertension as blood pressure of greater than or equal to 140 mm Hg systolic or 90 mm Hg diastolic, an additional 35 million Americans were included in the hypertension prevalence figure. But now, in 1995, there is a surprising 17.3% reduction in the number of hypertensive adults to 49.7 million. One explanation for this reduction could be a revised definition of the disease; but this is not so. Another might be in the methodology and techniques of measuring blood pressure in the participants. More blood pressure measurements were recorded in NHANES III than in previous reports, which would tend to reduce the number of people classified as hypertensive. In addition, the blood pressure recorders were given a standard training session, suggesting more accuracy in recording true blood pressure measurements. To be sure, there were some differences in these respects, but it seems hardly likely that these technical changes could account for a reduction of hypertension in almost 10 million adults. What seems more plausible is the unexpected primary prevention of essential hypertension by an enlightened public eager to promote personal wellness through lifestyle modifications. This involved the incorporation of a variety of nonpharmacological modalities such as weight reduction, sodium restriction, alcohol moderation, cigarette smoking cessation, and development of a regular exercise program. Data from commercial sources demonstrates such efforts in our society. So, the good news is that the primary prevention of essential hypertension was possible and was accomplished by individuals with high-normal pressures and high risk for the development of hypertension (ie, strong family history of hypertension and of premature deaths from cardiovascular disease).
The not so good news is less apparent. The concept in 1972 was that one half of the people with hypertension actually knew that their pressures were elevated, that one half of these people were receiving therapy for the elevated pressure, and that one half of these treated patients had their pressures under control was easy to remember. In fact, this mnemonic of 1/2 of 1/2 of 1/2 was the “backbone” of the effective national education program of those years. Although we have come a long way since 1972, the percentage of hypertensive adults with controlled blood pressures (less than 140/90 mm Hg) has increased to 24%. This is a totally unacceptable number. Although the definition of hypertension was more rigid than today, we still can do better in hypertension control. The challenge is obvious: we simply must continue with our detection and treatment efforts, and most important, those adults with prescribed antihypertensive therapy must remain on treatment. We have just learned from our colleagues in Minnesota of the possible reversal of the 20-year decline in stroke deaths,4 and this may be a bellweather of things to come. There are lessons to be learned regarding complacency from other Public Health paradigms. For example, tuberculosis, once very well controlled, has dramatically increased in the last decade. Without renewed efforts by the health care professions, the media, and the public, the gains of the earlier years will be nullified. Moreover, without these efforts there will be an increase in cardiovascular morbidity and mortality in this country. This is totally unacceptable at a time when we know further benefits are attainable and when we can reap the social and economic benefits of primary and secondary prevention of hypertension and its complications.
Burt VL, Whelton P, Roccella EJ, Brown C, Cutler JA, Higgins M, Horan MJ, Labarthe D. Prevalence of hypertension in the adult US population: results from the Third National Health and Nutrition Examination Survey, 1988-1991. Hypertension. 1995;25:305-313.
Luepker R. Stroke deaths reverse 20-year decline. Report to the American Heart Association Annual Science Writers Forum, Santa Barbara, Calif, January 15, 1995.