Could scuba diving be bad for people with high blood-pressure?

[Charlie99]

Your hands will get wrinkled from being a long time in the water, but you will not absorb any significant amount of salt.

My experience is that my hands will get wrinkled from being in FRESH water, but will not get wrinkled from being in SALT water, at least not in just a few hours like in freshwater.

I'm pretty sure that this is because fresh water is less saline than plasma/blood, while saltwater is more saline. So once the oils on my hands get washed away, my hands will absorb water when in freshwater and in saltwater the water in my hands will migrate outward (I can't figure out a word that means the opposite of "absorb").

 

[Kingpatzer]

The opposite of absorb is exude, I believe.

But, technically speaking it is it absorbing the fluid? It is not wicking in through interstitial tissues but is being pulled into the cells through osmosis so that's not really absorption is it?

 

[TSandM]

I believe absorption can be passive as well as active.

I do not believe that the endothelial dysfunction has been shown to have any significant short or long-term implications for divers, although the researchers have some theories about it.

Endothelial dysfunction refers to alterations in the behavior of the cells that line blood vessels. A recently publicized study apparently shows findings suggesting that there is some damage and repair of the blood vessel lining going on, when people are exposed to high oxygen levels during diving. What this actually MEANS is not at all clear, but the researchers think it might have to do with the mechanisms of DCS (which are not well understood at all). Since there is no information suggesting that people who dive Nitrox have a higher incidence of DCS, this may be a baseless suspicion.

Immersion pulmonary edema is a condition where excessive water accumulates in the lungs, oozing out from lung blood vessels that are under too much pressure to hold it in. It's a poorly understood entity that Duke is currently trying to study. It can occur in swimmers OR divers, has no known triggers, and can be fatal. Look up denisegg's threads -- she has an excellent story of her own experience with this, as well as a lot of discussion about the condition and what is known about it.

 

[Kingpatzer]

While I have no data to support the hypothesis, I would suspect that a change in endothelial function of 2% or so (which is what the paper mentioned observed if I recall correctly) could be medically significant for those who already have circulatory issues they are dealing with. So while there may be an impact on DCS, my suspicion (based entirely on minimally educated guesses I admit) is that the threat to those with pre-existing problems may be higher than previously suspected.

 

[lulubelle]

A small study in atypical populations does not a meaningful conclusion make. It is premature to say anything one way or the other about the nitrox study mentioned here.

It will take a far larger and more representative study before the question is even firmly established. Then whatever is learned must be tied to meaningful outcomes which can guide decision making.

I suspect that the question will be quite complex as the impact of using nitrox on endothelial function is not one that occurs in isolation. In addition to the many other things going on, some likely good, and some likely bad, there are also the differences amongst divers which must be looked at. If I had to guess, I'd guess that it will be likely that at the end of the day, what will be learned will be that there are trade offs in all of these decisions, and that the risk benefit ratio for one diver may be different than the next depending on their health status and unique circumstances.

Back to the OP's original question, if I had hypertension (thankfully, I tend to be low), given the knowledge that we have today, I would be most concerned about addressing medication side effects, and in my level of blood pressure control. The question of acute pulmonary edema associated with diving and with blood pressure control is an important one.

 

[JCAT]

I will chime in as I have moderate HT that is controlled by a beta-blocker, actually the first one invented. It also combats migraines I would sometimes get. I take the LA version once a day.

I've never had an issue with diving and my medication, using nitrox or not. DAN doesn't see an issue either.

I believe salt exposure on the skin would need to be extremely prolonged to induce fluid retention, if possible at all.

I'm not a medical expert, but know my body and can answer any questions., if that would be helpful.

 

[MaxBottomtime]

From the Orange County dive list;
Though I am not a medical professional, I have just read 5 medical journal
articles on this subject, stimulated by Debbie's post. The work described in
the abstract was done by a particular group and their full article is out as
well as 2 prior journal articles that explore higher antioxidant doses,
normal doses, air diving, nitrox diving, endothelial disfunction and also
effects on right heart and pulmonary function and increases in pulmonary
artery pressure. The observations are relatively short term and the articles
state that long term effects are not demonstrated. Two other articles, by
other authors, explore these effects as well and appear to demonstrate
related short term effects. I have searched DAN files and see no discussion
of this. I have sent a query to DAN including the article citations. I can
send the list of articles to those who are interested but you may not be
able to read the articles as they may require subscriptions. I have access
through my university site subscriptions.

Gary Sanders

 

[zrsteve]

I have hypertension and am diabetic, all under control. Doc filled out my paperwork for my classwork and ask me a few questions about diving. Turns out the Doc is a Master Diver, and when I told him where I was getting my instructions, Doc told me the instructor was the owner of the shop and was his instructor 20 yrs ago. Got an everything under controlon the paperwork and haven't given it a thought since.