Blood tension

Lisa!

What does increase our blood tension and might cause hypertension? Does period and stress increase our blood tension?
More questions are coming ...

CaptainQuasar

Having a higher blood sugar level increases blood pressure because it makes the blood more viscous. Higher dietary salt intake is correlated with higher blood pressure too.

Vasodilators like carbon dioxide - the carbon dioxide in soda / pop / fizzy drinks and beer - decrease blood pressure and increase the rate of blood flow. This is why (in the U.S. at least) soda fountains were originally in pharmacists' / chemists' shops - patients' medicine would be mixed into carbonated beverages. (Although I think that alcohol may increase the blood pressure that overwhelms the reduction by carbon dioxide in the case of beer.)

Not to overshadow Lisa's questions but I've got one of my own: does hypertension due to salt intake have anything to do with electrolyte balance?

Moonbear

Where have you heard such things?

No, blood pressure is not raised due to viscosity of added sugar. When you have high blood sugar, it's not THAT much!

Salt intake also does not cause high blood pressure. Some people with high blood pressure may have it exacerbated by excess sodium (i.e., table salt) intake, but this is because they already have an underlying problem with the ability to normally excrete the excess sodium as well as to retain water.

And, the carbon dioxide in fizzy drinks is not going to decrease your blood pressure either. Carbon dioxide delivered to the lungs (breathed) increases blood pressure. But this is a physiological adaptation to survive asphyxiation, not a source of abnormal blood pressure (hypertension).

Getting directly to the question asked, blood pressure doesn't seem to be affected by normal menstrual cycles, but some aspects of response to stressors and compensatory functions under more abnormal conditions may be influenced by stage of cycle.
Moldovanova I, Schroeder C, Jacob G, Hiemke C, Diedrich A, Luft FC, Jordan J. Hormonal Influences on Cardiovascular Norepinephrine Transporter Responses in Healthy Women. Hypertension. 2008 Feb 7
http://www.ncbi.nlm.nih.gov/pubmed/1...ubmed_RVDocSum

Carter JR, Lawrence JE. Effects of the menstrual cycle on sympathetic neural responses to mental stress in humans.J Physiol. 2007 Dec 1;585(Pt 2):635-41.

http://www.ncbi.nlm.nih.gov/pubmed/1...ubmed_RVDocSum

And, the long-term endocrine disruptions in abnormal menstrual cycles (i.e., amenorrhea) could have an effect on blood pressure.

O'Donnell E, Harvey PJ, Goodman JM, De Souza MJ. Long-term estrogen deficiency lowers regional blood flow, resting systolic blood pressure, and heart rate in exercising premenopausal women. Am J Physiol Endocrinol Metab. 2007 May;292(5):E1401-9.

http://www.ncbi.nlm.nih.gov/pubmed/1...ubmed_RVDocSum

But the overall picture right now is that while individual components of the cardiovascular system may be affected by stage of menstrual cycle, the totality of the system compensates for this and blood pressure is not affected in healthy women. In other words, there is a possibility that if someone already has something wrong with one of those compensatory mechanisms for controlling blood pressure, you might then see an effect of stage of menstrual cycle (ovarian hormones) on blood pressure.

Ounis-Skali N, Mitchell GF, Solomon CG, Solomon SD, Seely EW. Changes in central arterial pressure waveforms during the normal menstrual cycle. J Investig Med. 2006 Sep;54(6):321-6.
http://www.ncbi.nlm.nih.gov/pubmed/1...ubmed_RVDocSum

As for whether stress (I presume you mean psychosocial stress) can increase blood pressure, the answer is it depends. Again, it seems some people are more predisposed to this than others, and some recent studies are trying to determine why.

This is one such study:

Gianaros PJ, Sheu LK, Matthews KA, Jennings JR, Manuck SB, Hariri AR. Individual differences in stressor-evoked blood pressure reactivity vary with activation, volume, and functional connectivity of the amygdala. J Neurosci. 2008 Jan 23;28(4):990-9.
http://www.ncbi.nlm.nih.gov/pubmed/1...ubmed_RVDocSum

Weber CS, Thayer JF, Rudat M, Perschel FH, Buchholz K, Deter HC. Emotional irritation before mental stress is associated with enhanced peripheral norepinephrine.Scand J Psychol. 2007 Dec;48(6):459-66.

http://www.ncbi.nlm.nih.gov/pubmed/1...ubmed_RVDocSum

Kivimäki M, Head J, Ferrie JE, Shipley MJ, Steptoe A, Vahtera J, Marmot MG. Hypertension is not the link between job strain and coronary heart disease in the Whitehall II study. Am J Hypertens. 2007 Nov;20(11):1146-53.

And, it's worth noting that there's a good chance that the "over-reaction" to stress that may lead to things like hypertension could be already programmed prenatally by exposure to the "stress" hormones (i.e., glucocorticoids) during development. This may be why some people are predisposed to have elevated blood pressure while others under the same conditions do not.

jim mcnamara

Captain -

BP 101

MB gave you the studies, but an extra simple view is that arterial walls are flexible, and expand when the heart contracts and pushes blood out into the aorta. How much pumping force is required to move the blood out against the arterial wall pressure is the thing we measure as blood pressure.

If the arteries flex less, or push back harder, for whatever reason, the higher the readings. Blood volume changes affect BP also to a much lesser extent, when in non-life threatening ranges. Substantial blood viscosity changes are truly life-threatening.

CaptainQuasar

I didn't hear those things, I read them.

I didn't say that it was by a whole lot; see the Wikipedia article on blood pressure:


I didn't say it causes high blood pressure, I said it is correlated to high blood pressure. But actually, it turns out that the National Institutes of Health says that it does cause high blood pressure:


CO₂ is definitely a vasodilator; refer to this New York Times Science article - the reason why you'll become drunk more quickly if you drink a beer before having liquor is at least partially because of the vasodilation effect of the carbon dioxide in the beer.

Vasodilators definitely reduce blood pressure, drugs that are vasodilators are actually used to treat high blood pressure.

I'm not an expert or anything and I wasn't recommending a course of treatment, sorry if that wasn't clear. She asked about blood pressure and I provided a few facts about it, accurate scientific facts which I have read, not stuff I overheard when I was riding the subway or something. I know I wasn't giving some comprehensive essay about blood pressure but I think it's a bit much to act as if I'm dropping hearsay into the discussion.

Moonbear

This is why we discourage relying on Wikipedia for reliable science information here. It is riddled with errors when it comes to scientific topics. Any random person who hears some crazy rumor can edit it and fill it with misinformation. Increased viscosity can increase blood pressure, but even pretty severely diabetic concentrations of blood sugar are not going to have such an effect. How could you even get that much sugar into blood to meaningfully affect viscosity?

Did you read your own source? Nothing in there says sodium causes high blood pressure. What is says is that in people who already have high blood pressure, reducing sodium intake can reduce blood pressure. That's what I already said above. Sodium intake can worsen high blood pressure in those already predisposed to it. If you give a normal, healthy person a super salty dish, they will not develop high blood pressure.

Again, read your own article. It says that the IRRITATION in the STOMACH (a LOCAL effect) by carbon dioxide causes vasodilation of stomach blood vessels, which leads to more rapid absorption of alcohol into the blood stream. This is NOT a systemic affect that would influence blood pressure.

Systemically, the vasodilatory effects of increased carbon dioxide concentrations are insufficient to keep up with the increase in heart rate also caused by carbon dioxide. The net effect is an INCREASE in blood pressure.

Also please note that a Q&A article in the NY Times is NOT a reputable SCIENTIFIC source.

Here are some references to actual scientific articles that report increased blood pressure in responsed to increased CO2, which also lowers blood pH.

Kaye JM, Lightman SL. Corticosteroids and the cardiovascular response to stress: a pilot study of the 35% CO2 challenge in Addison's disease. Clin Endocrinol (Oxf). 2006 Sep;65(3):282-6.

http://www.ncbi.nlm.nih.gov/pubmed/1...ubmed_RVDocSum

A. J. CUNNINGHAM, M.D., F.R.C.P.C*, J. TURNER, M.D, S. ROSENBAUM, M.D and T. RAFFERTY, M.D TRANSOESOPHAGEAL ECHOCARDIOGRAPHIC ASSESSMENT OF HAEMODYNAMIC FUNCTION DURING LAPAROSCOPIC CHOLECYSTECTOMY British Journal of Anaesthesia, 1993, Vol. 70, No. 6 621-625

http://bja.oxfordjournals.org/cgi/co...e2=tf_ipsecsha

http://www.ncbi.nlm.nih.gov/pubmed/1...ubmed_RVDocSum

But that's the problem. You chose sources that are NOT accurate scientific sources, and did not have the knowledge to evaluate them to realize they are not accurate. Your understanding of the system is highly flawed. Please do not confuse people by presenting information on topics you don't fully understand as "factual" and certainly not without citing valid SCIENTIFIC sources (Wikipedia and newspaper articles don't count).

As Jim pointed out, blood pressure regulation is complex. Heart rate, stroke volume, vasodilation or vasoconstriction, blood volume, and vascular occlusions all contribute, and it's the NET effect that determines if blood pressure is increased or decreased or maintains proper homeostasis.

CaptainQuasar

Okay, just so we're clear here: you are agreeing that increased blood sugar does increase the viscosity of blood, and that this can increase blood pressure. You're just saying that it does not do so meaningfully. That's great, that's exactly the kind of thing I expected more learned people to add to what I was saying.

(And by the way, if I'm correct above, that also means that neither an error nor a crazy rumor has occurred in connection with Wikipedia here and I think it's a bit pejorative of you to talk like that if I made a statement that, as opposed to being anything at all like a crazy rumor, is true.)

I did read that before I quoted it and I've reread it several times now. And I really don't think it's saying that what you're claiming it does. I mean, it makes this very plain statement that I've already quoted: “Sodium chloride, or table salt, increases average levels of blood pressure.” And I don't see any qualification saying that is only true for people who already have high blood pressure. Yes, that article leads in with a vignette mentioning the number of people nationally who have high blood pressure but after scrutinizing it several times it does not look to me like the statements it is making are limited to people who already have hypertension.

But anyways, if what you're saying is true and long-term dietary consumption of salt does not affect blood pressure, that's good for me and several people I care about.

Okay, so although I was correct that CO₂ is a vasodilator, I was incorrect that its overall effect is to decrease blood pressure. I'm sorry, I apologize for that.

I didn't intend to convey that this is a simple topic and re-reading my post I really don't think I did. I also do not think that I have been as careless as you're portraying me to have been, and I'm skeptical of your assertion that I'm unable to evaluate these things; you have actually confirmed a couple of the things I said while simultaneously scolding me for having said them. You also appear to have read things in to what I said, the way you claimed I'd said something about salt causing high blood pressure when all I said was that there was a correlation.

But in the future I will refrain from saying anything on concrete medical topics unless I can cite a journal or something like the NIH web site to support my claims.

Moonbear

NO, that's NOT what I'm saying. I don't think you're reading very carefully here. Cite a REPUTABLE source for such a claim, and I may be convinced otherwise, but I have NEVER seen any reputable source make any such claim. Even high blood glucose is a miniscule percentage of actual blood components. It's NOT going to raise blood pressure through a viscosity change. You'd be dead from diabetic coma long before you reached a change in viscosity.

No, you need to read it in context of the statements before and after it, which you quoted as well, so I know you saw them. This is a TEN YEAR OLD press release you were quoting, not a scientific study. They were saying that was a popular concern being researched at the time, not that it by itself was a fact. The statement after it qualified it to indicate that SOME people are susceptible to this effect and others are not. It's NOT salt/sodium by itself that causes the problem, but that some people have a problem in how their body handles that salt consumption that is the problem.

If they do not already have a problem with blood pressure, then no, it is not something to worry about.

No problem there...glad to clarify on that.

Sorry, but you have not confirmed what you have said. I suggest picking up a textbook on physiology as a good starting place, and then work through actual scientific articles, not media reports. Popular press articles are NOTORIOUSLY inaccurate in describing biomedical research findings.

That is the best plan. Thanks for understanding.

CaptainQuasar

Very good! Thank you for being patient. I bow to your other objections.

NoTime

Since this part of th OPs question didn't seem to be addressed.
Stress in and of itself can raise blood pressure.
For example blood pressure readings taken on a doctors office visit tend to be higher (sometimes considerably) than readings from the same individual wearing a continuous blood pressure monitor.

Lisa!

Thanks all of you!

BTW, what's that blach square under CaptainQuasar's posts?

Aha! Thank you very much for the point!

Andy Resnick

I have only a little to add:

There appears to be a strong link between hypertension and sodium resorption within the kidney. I am looking at mechanosensation within the kidney and lung, and there is a link between sodium resorption and flow of ultrafiltrate. Constitutive upregulated activity of the sodium epithelial channel (ENaC), as occurs in Liddle's syndrome, leads to hypertension. There is also a link between polycystic kidney disease and hypertension. Several common antihypertensive drugs are not much more than diuretics- amiloride, for example.

In this model, hypertension has little to do with compliance of blood vessels (athrosclerosis), and everything to do with blood volume.

CaptainQuasar

That's just my signature. It uses a newer technology, you might say, called Unicode. On my computer and for some people with really new computers or with special software installed, the black square looks like the atom symbol, a Rutherford Model of an atom.

I haven't gone and experimented or anything but my guess is that installing this free font would allow it to be visible on most computers, which would also enable support for a variety of other scientific and mathematical symbols.

Lisa!

Thanks for the explanation!