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Cycling Wed General Medicine Healthy Living

CW: Put your arm in the machine

Hey Cyclists,

I know.

You ride a lot.

You eat well.

You stay thin.

So you rightfully call yourself athletic.

Congratulations.

Now, take the time in the off-season to go get your blood pressure checked.

Doing so is free in most grocery stores and pharmacies.  Plus, you get to grin at that funny voice that says:  “You must hold perfectly still…Do not move or talk during the test…I have to squeeze your arm a little.” (I can’t help myself; I always talk during the test.)

Don’t assume the red numbers will come up reassuring.

It’s surprising how many athletes can’t out-run or out-pedal their predisposition to inelastic blood vessels—high blood pressure.

Here are some basic steps to take for newly discovered high blood pressure:

  • Make an appointment with your primary care doctor. Don’t’ have a doctor?  Now you have a good reason to get one.
  • Go back and take a few more BP measurements at different times of the day. Write them down.  Check that, enter them in the smartphone.
  • Stop taking cold medicines that contain pseudofed.  These include common allergy medicines that have a “-D” at the end of their name.  (Allegra-D, Zyrtec-D)
  • Stop all arthritis drugs called NSAIDS (ibuprofen, Advil, naprosyn, Aleve).  These drugs can cause high blood pressure.
  • Be mindful of excessive salt intake.  Though salt restriction is more relevant to the non-athletic general population, there are clearly ‘salt-sensitive’ athletes.
  • Either discontinue, or cut back daily alcohol intake to less than 1.5 drinks per day.  Studies have shown that more than moderate daily drinking raises BP.  Sorry about that.

If all these conservative measures fail and the blood pressure remains high a medicine might be required.

The problem is that if your doctor treats your high blood pressure according to national guidelines this may mean taking the commonly used water pill, hydrochlorothiazide (HCTZ).  Ouch.  That’s a problem.

I suggest gently asking your doctor about the findings of this week’s important high blood pressure trial published in the Journal of the American College of Cardiology. In this meta-analysis (a review of previous studies), the researchers at Columbia University showed that—at the doses commonly used, and when used alone—HCTZ was the least effective blood pressure medicine.

The strength of this report stemmed from the inclusion of 24-hour BP monitors.  Interestingly, when single BP readings from doctor’s offices were considered, HCTZ looked reasonable, but on the more accurate 24-hour recordings it was significantly inferior to other commonly used BP medicines.

I’m glad to see this data because it supports my common-sense bias that water pills—when used alone—are lousy BP medicines.  They lower BP by increasing the elimination of fluids and electrolytes. That’s the paradox, their primary effect causes their most common side-effect: dehydration and electrolyte depletion—something most of us athletes try to avoid.

What’s more, heart rhythm doctors were brought up on the teachings from the famous 1982 MRFIT BP trial in which the highest mortality rates were found in the group of men with high blood pressure who were treated with HCTZ.  The presumption here was that low potassium levels from the diuretic increased the risk of sudden death from a rhythm problem.

For endurance athletes with high blood pressure, the most common problem is inflexible arteries, not excess salt and water. So it makes sense to use a medicine that acts on the primary problem; we call these blood-vessel relaxers, or vasodilators.  Examples include ACE-inhibitors, ARBs, and some Calcium channel blockers.

If you train hard, eat right, and still need a BP pill, it seems reasonable to ask your doctor to question the guidelines.

Maybe the guidelines are wrong?

Oops, can I say that?

JMM

Disclosure:

When my blood pressure warrants a medicine, I’ll start with a blood-vessel dilator, not a diuretic.  Unless of course there is a new wonder drug available, and I can afford it.

Just because thiazide diuretics aren’t very potent when used alone, they can be very useful as add-on agents when a single medicine fails to control BP.  That’s doctoring 201.

9 replies on “CW: Put your arm in the machine”

Just wanted to say I love the new banner at the pop of your blog – the EKG tracing.

Also, if memory serves me well, I think it was the huge and long-running ALLHAT study that supported chlorthalidone as an effective diuretic in reducing hard clinical endpoints in high blood pressure patients (endpoints like overall deaths, cardiovascular deaths, and heart attacks). I still don’t see it used much. Probably one of the cheaper drugs on the market, too.

-Steve

Thanks Steve. Yes, ALLHAT studied chlorthalidone, versus lisinopril and amlodopine. The JACC study that I quoted looked at the much more commonly used HCTZ. (I cannot remember the last chlorthalidone rx that I have seen.) Sure they are both thiazide diuretics, but they may not have the same effects. Also, in ALLHAT there were no differences in primary outcomes, just selected secondary outcomes with small differences in RR. Plus, the clinician in me likes studies that make sense. ALLHAT purports that lisinopril–an ACE-inhibitor indicated in CHF- enhanced heart failure risk. Hmm?

I can’t imagine JNC 8 will recommend HCTZ as the first line choice. It’s not that effective at low doses and increases SCD risk at high doses.

HCTZ also raises risk for incident diabetes, likely in part through potassium depletion (potassium is required insulin secretion with a well-defined mechanism) and *possibly* through direct damage to pancreatic beta islet cells.

None of this is new information, so I’ve been scratching my head for some time that we’re still using HCTZ for many patients. Maybe inertia is hard to beat.

Hey there PGYI. Thanks for the kind words, and let me welcome you to a fantastic tree-house.

Great points. Why have the guidelines not changed? That’s hard to say. As part of my research for the piece, I looked at the ALLHAT data. I remember reading it at the time (in 2002), and thinking that it didn’t make sense. Primary outcomes were the same. As I said to Steve there were some small differences in secondary outcomes.

The researchers, however, did not equivocate when they concluded that thiazides should be first line. But what’s happened in real life is that HCTZ has supplanted chlorthalidone. Though these drugs are in the same class, do they have the same effects?

My main points in the post were to emphasize that athletes still need to pay attention to health basics, that diuretics will not work well for their chosen avocation, and finally, to point out that clinical guidelines are unlike geometric theorems. They do not stand the test the time.

Thank you for your post. I am a 59 year old female triathlete with high maintenance, high blood pressure. It’s reassuring to know that the vasodilator in combination with a diruretic is an effective combination. I struggle with the potassium loss because of the diruretic and this has been mitigated with a small amount of potassium supplement and regular blood potassium testing.

Off-season for cyclists? Don’t know what you’re talking about. It’s sunny and 70 degrees here in the SF Bay Area and the “road challenges” on my local expressway just keep on coming!

What causes calcium to start depositing on the artery walls in the first place? Articles on the web say that it does, but not WHY. Why does calcium decide to start sticking to the artery walls instead of just moving on? Thanks for the post, I’ve started charting my bp again, along with mileage.

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