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The Ninja: High Blood Pressure

April 22, 2010

High blood pressure, also called Hypertension, is a silent and deadly killer.

Why is it silent?  Why is it deadly?

I’m glad I asked!

High blood pressure is one of the most important risk factors for acquiring atherosclerosis (hardening of the arteries), which then leads to heart attacks and stroke.

Why is it silent?

Because, for the most part, you can’t “feel” high blood pressure.  It is a silent killer.  People can have severely high blood pressure and never know until it is too late.  In medical terminology, we would say that the patient is “asymptomatic”.

Why is it deadly?

Every so often, a group of cardiologists and internists get together and have a big meeting.  We call them the JNC (Joint National Commission ), and they evaluate all of the data we have on high blood pressure since we started to accumulate such data.  They pay particular attention to new studies and new data since the last time they met.  They then discuss these results and come up with new guidelines for physicians to follow regarding high blood pressure and how we ought to treat it.  The last such meeting was the 7th such meeting (they occur about every 5-7 years or so).  During this last meeting, they made several very specific observations and then made some not-so-specific recommendations:

The JNC decreed that “perfect” blood pressure was 115/75.  This represented a change from the 120/80 we had been taught for so many years.  It was at this new blood pressure that your risk of heart attack or stroke was most minimized.  Ok, cool.  Not too hard to swallow that.  The next set of information they ascertained set the medical world on its ear:

For every 20 points the systolic (top number on the blood pressure reading) was elevated, you doubled your risk for having a heart attack or stroke.  For every 10 points the diastolic (bottom number on the blood pressure reading) was elevated, this also doubled your risk for having a heart attack or stroke, compared to someone with a blood pressure of 115/75.

Yes, ladies and gentleman.  If your blood pressure is 135/85, you have 4 times the risk for a heart attack or stroke compared to someone with a blood pressure of 115/75.  If your blood pressure is 155/95, you have 8 times the risk.

Let that sink in a little, because it becomes important in the next paragraphs.

Having made this edict, based on multiple large independent medical studies, they turned around and made the following guideline on treatment:

Treat people to a goal blood pressure of 140/90, unless they have diabetes or kidney disease.  In those patients, treat to a goal blood pressure of 130/80.  JNC Link.

The guidelines for treatment did not seem to make a lot of sense to physicians.  Based on their guidelines, we should only treat their blood pressure down to a level where they are at 4 times the usual risk for a heart attack or a stroke!

Well, I can tell you, the Internists and Cardiologists of the world went a little nutty.  We are a pretty logical lot, and we like it when recommendations match up with our knowledge of basic science.  There has been enough controversy that most people think the next JNC meeting will probably come up with new guidelines.  It has also, apparently, delayed the next meeting since we were due for one several years ago!

So what is the take-home message?

1.  If you have high blood pressure, be sure you take your medications, even if you feel well.  Just like the Ninjas of ancient Japan, hypertension is a silent killer without any symptoms.

2.  If you don’t know if you have high blood pressure, see you doctor!  The screening for high blood pressure is amongst the easiest things we do in medicine, and the treatment saves countless lives, and extends lifespan!  If you do a little math (or in this case, if I do a little math for you), you can see that treating a 40 year old with a blood pressure of 155/95 down to a blood pressure of 115/75 can easily add 5-10 years to their life (in the absence of other risk factors) if it is caught early enough…before it does it’s damage and causes blockages in the arteries.  These are good years too, before a heart attack or a stroke.

3.  You can help prevent high blood pressure by exercising regularly, maintaining a fit weight and limiting your intake of salt.

Look at that…less than 800 words.

Good Health!

Dr. Mike

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2 Comments
  1. Your surprise at the suggestion of treating hypertension to a target that’s above the ideal would seem to dismiss the potential risks of the treatment. Although the risk of heart attack in a person 140/90 may be quadruple the risk of a person who is naturally 115/75, a BP that’s been carefully lowered to 115/75 with medication may come with the additional risks of the side effects of that medication. Recent studies have shown that the mortality of type II diabetics who are under tight control, as opposed to standard control, of their blood sugar may actually be higher, the probable reason being that tight control increases the risk of episodes of hypoglycemia, and those episodes of hypoglycemia come with their own complications. My point is that by comparing a person whose BP has been lowered through medication to a person whose BP is naturally low is like comparing apples to oranges. Obviously, your true ideal is for all of your patients to eat better, exercise more and naturally (or magically) have their BP drop to 115/75. But perhaps if you try and force someone’s BP from an extreme down to the ideal, you’ll cause other problems. Of course, all of this is merely conjecture on my part with not a scrap of research to back it up.

  2. The studies take those issues into account.
    The recent study on tight glycemic control looked at all cause morbidity, as you mentioned, and it was determined that tight glycemic control may not improve overall health. The study identified that, as it ought to.

    The studies on blood pressure look at all cause morbidity as well, and tight control of blood pressure was deemed to reduce overall mortality and morbidity in a dramatic fashion. Studies almost always look at endpoints as well as side effects.

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