Who Has Hypertension Now?

A Change in Guidelines Puts New Focus on the Risks of High Blood Pressure

measuring blood pressure
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Roughly 30 million people in the United States who didn’t have high blood pressure before have high blood pressure now. This is not because of a high-sodium Thanksgiving meal, although that may have contributed to temporary blood pressure spikes in some cases. Rather, it’s because the definition of high blood pressure has changed as of November 2017.

The new threshold for hypertension is a systolic blood pressure at or above 130 and/or a diastolic reading at or above 80.

These are down from the traditionally higher numbers: 140 and 90, respectively. This conclusion was published in a comprehensive report issued jointly by the American College of Cardiology, the American Heart Association, and a number of other professional organizations in collaboration with the ​National Heart, Lung, and Blood Institute of the National Institutes of Health (NIH).

The full report explores the details of how blood pressure should be measured, the diverse potential causes of high blood pressure, and the sources and strength of evidence linking high blood pressure to adverse outcomes, including death from heart disease, kidney disease, and stroke. The conclusion that provoked the most media attention, debate, and apparent consternation, however, was that hypertension should be diagnosed starting at 130/80 rather than 140/90.

Putting Risk in Perspective

This scenario is reminiscent of much the same cause and effect when the definition of obesity was changed in 1998.

Some 25 million Americans became “obese” overnight not because their weight had changed, but because the characterization of their weight had. The motivation and basis in data for both changes are similar as well. Weight and blood pressure are both continuous measures over a wide spectrum. There is no single value that is ideal for everyone.

At the population level, however, there are clear associations between these measures and adverse health outcomes, including premature death.

In the case of weight, there is a convincing increase in health risk at or above a body mass index of 25, with another jump in risk at or about 30. For blood pressure, the risk of adverse outcomes roughly doubles at or above 130/80 compared to lower values in the normal range.

That is a valid reason to revise the definition and associated treatment recommendations, but certainly no reason for panic. While high blood pressure is considered the second leading cause of premature death globally behind tobacco use, and a major contributor to heart attacks and strokes, such risks rise with the severity of hypertension. The risk of such outcomes for those with perfectly normal blood pressure is predictably low, and the doubling of a small risk produces a risk that is still modest.

Still, even a modest risk increase matters enormously when tens of millions of people are affected. Consider that a risk increase of just one per thousand people per year means an extra thousand adverse health events every year for every million people exposed.

One in Two Are Affected

The new guidelines indicate that nearly half the population of the United States is hypertensive, so the exposure level is nothing less than massive.

There are four clear implications of this.

1) A Call to Turn the Tide

When the prevailing diet and lifestyle pattern of a population is putting half of its citizens at risk for debilitating illness and premature death, it is a clear mandate to change those patterns at the level of culture. We have little evidence that any population has ever managed to talk most of its citizens out of poor dietary choices and lack of physical activity when those are the cultural norms. Rather, the evidence we have indicates that people eat well and are active where those patterns are the norms or are willfully adopted culture-wide.

2) A Word of Caution

While the new guidelines have “given” 30 million more people a disease they didn't have before, that does not mean medication is warranted as treatment. Most cases of hypertension are associated with poor diet, suboptimal levels of physical activity, and excess weight. All of these are entirely responsive to therapeutic lifestyle change, as is high blood pressure itself.

As attention increasingly turns to the valid alternatives to pharmacotherapy, the response to these blood pressure guidelines should navigate around cures that are worse than the disease. All medication has potential side effects, and even minor ones are reasons to take pause when individual benefit is modest. In contrast, the side effects of lifestyle as medicine are additional benefits rather than risks.

3) A Revival of the Lower Sodium Diet

This reality check about the extreme prevalence of high blood pressure in our culture is a reality-check-by-proxy about the importance of dietary sodium as well. High-profile debate over recent years about the optimal intake level for sodium has translated in certain quarters into claims that dietary sodium should not be restricted at all. However, almost all authorities agree that sodium reduction is warranted for those with hypertension. That group is now half of the general population, and since much of the rest is young people who are likely headed in the same direction with age, many more are almost certainly at risk. Thus, sodium reduction makes sense for just about all of us, and deserves to be more of a priority, not less.

4) A Reminder to Know Your Numbers

Finally, and clearly, everyone should have their blood pressure checked and monitored routinely. Think of it this way: Being an American is a risk factor for hypertension. If you live here—or in any other developed country with similar diet and lifestyle patterns—you are at risk. Blood pressure assessments over time are a simple, reliable way to detect a dangerous trend early, and address it before it progresses and imposes any irrevocable harm. If you are an adult who does not know your average blood pressure or the last time it was checked, you are overdue.

The risks of high blood pressure have not suddenly gone up. Rather, the threshold has gone down because we have more and better data to indicate where risk is minimized. There is no basis for panic in the new report, but there is certainly a compelling basis to take the clear and nearly omnipresent threat of high blood pressure ​seriously, and give effective, lifestyle approaches to prevent, treat, and reverse it the respect they deserve.

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