DCS and high cholesterol?

[miked]

I erroneously posted this in the science section, so I'll ask again here:


I'd like to know if there is any research,etc. indicating a connection between high cholesterol levels and increased incidence of/risk of DCS.
I did a search on SB, but found nothing more recent than 2001.

Thanks,
Mike

 

[cmalinowski]

There were similar discussions about body fat and DCS. Not sure if it's exactly the same, but the consesous was that they difference was negligible. Now, that assumes that you are in decent shape in general.

To me, the tables are based one very healthy, navy divers. Thus, just body fat or cholesteral won't necessarily increase DCS risk, but if you are out of shape, obese, and with high cholesterol along with other factors, your chances increase. Just like being dehydrated.

And, just as a note: I am out of shape... Not necessarily "fat", but out of shape

 

[CameronMartz]

There were similar discussions about body fat and DCS. Not sure if it's exactly the same, but the consesous was that they difference was negligible. Now, that assumes that you are in decent shape in general.

Body fat and cholesterol have different influences on decompression. Body fat is an additional place that blood must travel *through*, whereas cholesterol is a particle prone to clumping within the blood itself. Cholesterol makes the blood thicker and stickier, increasing the effort needed to get it through the capillaries.

It would be more accurate to say that research is *equivocal* regarding body fat's influence on DCS risk. There is plenty of research that found it does increase risk, though there is also good research that did not find a link. See http://www.scubaboard.com/showthread.php?t=93366, Post #7 for a partial list that includes two studies published just last year.

The problem that cholesterol might create for divers is twofold:
1. Cholesterol particles might act as seeds for bubble formation. In fact, it is possible that cholesterol and other blood lipids are entirely coated in bubbles to begin with as a natural function of the interaction between hydrophobic particles and water in the blood. See http://www.aip.org/pnu/2001/split/561-2.html for some interesting research in this regard.

2. A circulatory system compromised by a build-up of cholesterol might off-gas more slowly than a healthy one.

In discussing DCS risk factors of any kind, it is important to keep in mind that the overall risk of getting bent on a recreational dive is very small. Any increase in risk should be taken seriously but measured in terms of starting from that small, baseline risk.

Cameron