Caffeine and BP elevation

[Idiopathic]

---

Members do not see this ad.

What kind of elevation would you expect to see in a previously normo/hypotensive individual who drinks several caffeinated beverages a day (6-10). Conversely could an elevated BP be caused solely by caffeine intake, given the subject is an otherwise healthy young male, and could he see a normalization of the BP if caffeine was discontinued? Thanks.

(PS I know this isnt technically a 'medical' forum, but I thought some people could give me some insight into this)

 

[Da Vinci2]

Interesting question. I have never heard of people asking this. I would think it matters whether you are a chronic taker or not. I would expect one time taker of caffiene (such as me who doesn't drink soda or coffee), BP elevation would be higher than those who can tolerate higher levels of caffiene.

 

[ckent]

I also thought that it was an interesting question because I have never heard of doctors telling patients to avoid caffeine if they do have high blood pressure. I looked it up on the web, and this is what I found:
http://www.ineedcoffee.com/03/bloodpressure/

I think that even though caffeine is a sympathometic, it is only a very mild one, and caffeine is also a diuretic, so those two probably cancel each other out in terms of blood pressure.

 

[Idiopathic]

Would you see reflex BP increase caused by the elevation in HR? This is assuming chronic consumption.

edit: typically a reflex increased BP would be caused by a decreased chronotropic state, correct?

 

[ckent]

Originally posted by Idiopathic
Would you see reflex BP increase caused by the elevation in HR? This is assuming chronic consumption.

edit: typically a reflex increased BP would be caused by a decreased chronotropic state, correct?

According to that website, with chronic consumption, the answer is no. It does mention that you may experience a transient mild elevation in BP if you are a new caffeine drinker though. I'm not sure about the answer to your second question, but an increase in BP (systemic resistance) could be caused by decreased cardiac output, but there are many causes of increased BP. Typically, I would think that a reflex increased BP occurs during periods when cardiac output is increased, such as when you are exercising, which has more to do with metabolic demands and your sympathetic nervous system.

 

[bartholomew]

I'm unclear on how the term "reflex" is being used here...Also something to consider is the diuresis following coffee intake. Seeing a graph of hr and bp over time after drinking would be interesting...

 

[powermd]

I started measuring my blood pressure regularly after a period when I became worried I had high blood pressure (second year mid-terms..). On the days I drank coffee (12 oz cup, strong), my systolic went up 5-10 mmHg, causing my systolic to be as high as 140. I try to avoid coffee when possible now, but I love it so much and need the early morning boost.

I've found that bananas and celery seem to help lower my blood pressure. Celery contains a natural ACE inhibitor, and potassium is known to lower blood pressure.

 

[panch]

so, according to one prominent source: Current Medical Diagnostics and Therapeutics 2003
"Blood pressure should be measured with a well-calibrated sphygmomanometer with a cuff of proper size (the bladder width within the cuff should encircle at least 80% of the arm circumference) after the patient has been resting comfortably, back supported in the sitting or supine position, for at least 5 minutes and at least 30 minutes after smoking or coffee ingestion."

In my short clinical experience (hell i only started internship 6 months ago), almost all BP readings that we get on an outpatient basis are CRAP. At least where I am (and when I've gone to the doc recently, they are completely wrong in how they check BPs b/c they don't let you sit still for a few min nor ask about last smoke nor cup of joe before they take your BP). I am loathe to diagnose HTN or adjust somenone's BP meds if I haven't checked it myself w/ a properly sized manual cuff. Please follow the guidelines when checking BPs; case in point: in my ma we tried this simple experiment. I took her BP w/ the automatic cuff that she has at home immediately after she walked about 10 feet and sat down, then I took it a few min after resting sitting upright: systolic was at least 20 points and diastolic at least 10 points lower after sitting for a few min. If I had been her doc and looked at her BP readings from the nurse and from the home log I would've increased her anti-HTN meds, but when I measured the BP properly (granted that it was not w/ a manual cuff) I wouldn't have changed a thing.

Long story short: question every number that you get, especially if your suspicion is high. And ask when their last smoke and last intake of caffiene was. If you treat the wrong numbers and ignore the patient, you'll prolly have one admitted for orthostasis/syncope before you can say "relax and let me carry all the weight of your arm as I CHECK YOUR BLOOD PRESSURE".

 

[jalabert]

In the following study available on medline,

Coffee acutely increases sympathetic nerve activity and blood pressure independently of caffeine content: role of habitual versus nonhabitual drinking.

Corti R, Binggeli C, Sudano I, Spieker L, Hanseler E, Ruschitzka F, Chaplin WF, Luscher TF, Noll G.

the authors saw a 12 mmHg elevation in systolic and 4-7 mmHg in diastolic blood pressures in non-habituals from drinking either caffeinated or decaffeinated coffee, while no change was observed in habitual coffee drinkers. The interesting thing was, there was still a 50% increase in sympathetic nerve activity in the habituals. Another interesting thing was that there was a non-significant 6 mmHg increase in systolic BP in both habitual and non-habituals with direct caffeine injection.

So, to answer your original question, a habitual coffee drinker would likely not see elevated BP from drining coffee, but might observe BP elevations from other type of caffeine ingestion. The other point to get from this is that drinking decaf, does not protect from the presumed effects of caffeine in coffee-naive individuals.