Reaction to JNC-8 from a Practicing Family Doc

is Practicing physicians rely heavily on certain widely accepted guidelines to set goals and make treatment decisions for our patients.  Among the most respected and followed guidelines are those of the Joint National Committee on recommendations for the diagnosis and treatment of hypertension, often simply referred to as JNC.  The JNC came out with its 8th set of guidelines this week, JNC-8, replacing the previous set called JNC-7.  This is big news for patients, primary care physicians, cardiologists and nephrologists, and really everyone involved in the treatment of high blood pressure. As a nation the U.S. does a poor job of diagnosing and controlling hypertension. Less than half of the 67 million U.S. patients with high blood pressure have achieved goal blood pressure levels  according the Center for Disease Control.  New guidelines for the diagnosis and treatment of hypertension by the JNC is therefore big news.

The short story in JNC-8 is that the guidelines slightly loosens, from 140 to 150. The diastolic threshold remains at 90. These diastolic and systolic blood pressure thresholds are recommended for both the initiation of drug therapy and as the goal of drug therapy of hypertension in persons age 60 or older. This is higher than the JNC-7 cutoff for diagnosis and treatment in this age group which was 140.  Otherwise the guideline changes simplified the goals by no longer giving lower blood pressure goals for patients with diabetes or chronic kidney disease.

The methodology changes are worth making note of too. In their approach to making the JNC-8 guidelines the committee attempted to be more focused on evidence to support the recommendations, and less focused on expert opinion.  Despite attempting to be evidence focused many of the recommendations still lack an evidence basis and remain based on expert opinion. Of the 9 major recommendations, 5 are based on expert opinion. Only one, the recommendation to loosen the systolic blood pressure at which to initiate drug therapy in patients 60 or older to 150 is given a Grade A recommendation (strong evidence), two on Grade B (moderately strong) evidence, and one on Grace C or weak evidence. Even such basic recommendations as to treat persons less than age 60 at the 140/90 cutoff that remains unchanged from JNC-7 is based on expert opinion.

The higher systolic BP for initiation and intensification of therapy of hypertension in persons older than 59 will have a real impact on the number of older adults treated for hypertension, and will make it considerably less likely that patients will have additional drugs added to achieve the less than 140 goal we have used for the last several years.  I anticipate less patients having orthostatic hypotension symptoms of lightheadedness, falls or fainting related to systolic BP therapy with this easier to achieve 150 goal. Other changes in the JNC-8 guidelines include making the goal BP of treatment of patients with diabetes and chronic kidney disease the same as others, not the lower goal of 130/80 that was recommended in JNC-7.  I see this as another focus on keeping recommendations based on evidence, not the theory of experts, and should also reduce the likelihood of side effects of hypertension therapy.

Control of high blood pressure is important to prevent cardiovascular complications in patients with diabetes.  There seems to be a lack of evidence supporting the previous recommendation for the “lower is better” recommendation in JNC-7. I expect these “looser” guidelines will reduce the side effects of hypertension therapy, reduce cost of additional drugs and more frequent office visits to reevaluate after adding more medications, and make it easier to achieve goal blood pressure for many patients.

These are a few of the benefits I expect to see as the new guidelines are implemented:

  1. It should keep the number of pills required daily to achieve all of the recommended goals for diabetics lower. This is a big issue as many diabetics now take medication for their blood pressure, cholesterol and blood sugar control.
  2. It may help avoid yet more use of branded and therefore expensive medications.  It has in my experience fairly common, especially in older adults, to have tried several generics in several classes, to still have systolic BPs running in the 140’s  range, and so leading to adding a third or fourth antihypertensive branded drug to try to achieve the <140 systolic BP goal.
  3. Fewer older adults will be put on blood pressure medication for blood pressure control, avoiding the side effects of these drugs, cost of therapy, and perception of having a disease that required therapy.
  4. We will now be focusing out treatment of hypertension efforts on patients where there is a higher chance of benefit, and a lower likelihood of overdiagnosis and non-beneficial drug therapy.

Critics have already theorized that this “loosening” of BP goals will lead to even less focus on BP control, an area we already as a nation do a very poor job of managing.  I’m hopeful that the change in target BP will do the opposite. I hope it will allow us to focus our energy toward treating the patients where better control has evidence to support its benefit, and avoid high levels of effort, expense and potential side effects of marginally efficacious therapy.

Any readers who want a better understanding of hypertension should check out the two Khan Academy videos on a prior post, Understanding Hypertension.

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