Have you ever heard of sleep apnea as the cycle that kills? Does that sound
like overly dramatic? Well, think about it. We've done plenty of videos on sleep and
the fact that chronic sleep deprivation causes insulin resistance, diabetes, heart
attacks, stroke, cardiovascular inflammatio,n and all the bad things that
go along with that, we know that that is associated with things like hormones,
decreased growth and restoration of - of our body tissues, and our metabolism. So
when we know that and we accept that about sleep, why can we not accept and
understand that that's very similar and, in many cases, exactly what's going on
with sleep apnea. We're going to talk about that cycle that kills in this
video. We're also going to talk a little bit about the anatomy associated with it.
We'll talk some about the article we did a video on recently - CPAP for prevention
of cardiovascular events. The SAVE article. You know, unfortunately, that article
didn't show any improvement in cardiovascular events so why didn't it?
We'll talk a little bit about that with this. The - the end of the article is
about an editorial on that CPAP article and why it didn't show anything. So, first
of all, this cycle that kills - here's the way it goes. You get decreased upper
airway muscle tone, obstruction and apnea or hypopnea. Hypopnea means decreased
breathing and apnea means no breathing at all. Obviously, if they went on long
enough, that would kill you. Hypoxia - decreased oxygen in the blood
and elevated co2 or an acidic area. See acid in the blood increased from not
breathing then you start to get increased ventilatory effort. So, you're
going (soun)
so that is the - that's - that's typical that you hear with people that
wakes them up. They get a relief of the obstruction
when they awaken. That relieves the hypoxia, reduces the CO2, the - the acidic
values of - in the blood, and then they - once they do that, they go back to sleep.
Now, that doesn't - that's not a big deal if that happens once but think about it.
Your typical person with sleep apnea will have this happen 30 times every
hour that they sleep. Now, you start adding that up times seven nights a week,
times 365 days a year, and it becomes much more easy to understand why sleep
apnea kills and anatomically what's going on. So this is a cross-section. if
you - if you cut through here and look at the - the palate; the hard palate. soft
palate, the tongue, the airway in gray here, and the jaw. So, what you can see
here is that the tissue of the soft palate drops down into the airway and
the tissue of the base of the tongue does as well.
I have sleep apnea, my daughter has it as well. We both have very high palates here
and that appears to have come from having a small jaw. Well, what does a
small jaw got to do with it? If you've got a small jaw, you don't have as much
room for the tongue. When the bones of the palate are being formed, the tongue
is pushing back up against it, causing that arch. So there's where you get the
obstruction. Now what does CPAP - CPAP is putting pressure in here to decrease -
hopefully push back on that soft palate in the base of that tongue; and we've
done several videos on that; and, again, we're talking about CPAP. It is the base,
the go-to treatment for this condition. In fact, there was a fairly definitive
article in the New England Journal in 2016. We covered it in
another video. The bottom line on it was this - they took 80 different
- it was the SAVE study - sleep apnea cardiovascular endpoints - and, basically,
what they showed was - there was no decrease in cardiovascular events. They
looked at about 1,500 people - well, about 2500 people total. Half of them, they put -
they gave CPAP, as well as usual treatment. Half of them, they just gave
the usual treatment. They did not see a significant decrease in heart attack,
stroke. What they did see was a big improvement - an undeniable improvement in
mental health, depression, anxiety, and physical attributes during the day so it
did help and that's why you see so many people that are clearly a big fan of
their CPAP. Now, here's the editorial and it really gets around the issue of why
didn't it help, in terms of saving lives, in terms of cardiovascular events. Maybe
it saved lives in terms of mental health, depression, anxiety, - great improvement in
life quality but what's - what was the problem with cardiovascular? Well, here we
go. Obstructive sleep apnea is a common
disorder. It's been associated with cardiovascular risk. CPAP is frequently
prescribed in patients but meta-analyses of these have shown some improvement in
arterial pressure which they saw in the SAVE study - especially diastolic pressure.
The effect is greater with better adherence. Observational studies have
shown significantly fewer cardiovascular events in patients adherent to CPAP
therapy but there were needs for large trials and that's what the - that was the
reason for the SAVE study. Now, in the SAVE trial, again, as I said, they just go on
here to describe what I said a minute ago - about 1300 in the study group, 1300
in the control group and no improvement in cardiovascular events.
Significant beneficial events on quality of life. Now, the trial raised several
issues. One major issue is this - were the results negative because CPAP doesn't
work for this? Were they negative because these people were already fairly well
down the road with cardiovascular disease? Or did they not work because
people weren't using enough of it? The average use was 3.3 hours per night.
Well, they did actually do a nested controlled trial within that and looking
at 560 p-61 patients who used CPAP for more than four hours. Now, you've got to
be careful in how you interpret it but that one did show and what appeared to
be a significant decrease in cardiovascular events. So, maybe, there's
some - some nested control studies within this trial which shows maybe it
does help but you got to use it. There's another - and you got to use it more than
three and a half hours. Rhere's another issue here as well. That other issue
is related to timing of CPAP. It's used in the beginning of the night. CPAP may
be left less effective then when used in - later in the night, and many of the trial
patients CPAP may not have been in use during the rapid eye movement or REM
sleep - the sleep stage that predominates in early morning hoursl and that's the
very restorative sleep. It's all the time - also the time when you tend to have
greater hypoxia, greater events, your brain is going deeper into
unconsciousness, and it's - as you might imagine, that's when you get more of
these cycles. So, there's another thing as well. To maximize the enrollment, the
investigators recruited 4 participants from a variety of
geographic regions. Some that had limited resources. They took a pragmatic approach.
They didn't do full polysomnography on all these people. They did some
studies, as well, and that's one of the questions. Did some of these areas with
lower resources not get a great diagnosis and was CPAP not as - not used
as well? So, finally, we appreciate that - that
choosing to conduct a secondary prevention trial allowed for a smaller
sample size because rates of cardiovascular events would be higher
than rates in primary prevention trial. And this is the one
that I'm concerned about. However - so primary prevention versus cardiovascular
secondary prevention. In other words, you know they've already got disease. Is it
going - if you can do CPAP, is it going to reverse that disease process and it says,
however, CPAP may have limited effect in patients with well-established
cardiovascular disease. Also, because of recruitment challenges, the investigate -
the investigators had to use an original sample size significantly less
than what they wanted. In fact, about half. Yhey had originally planned to do five
thousand and - if you remember in the other video, they started out with about
15,000 before they cut down to the final - about 3,000 that they
used in half in cases and half controls. Now, what does this mean for clinical
practice? Well, there's not a lot else. There's sleep hygiene, there's sleeping on
your side instead of on your back, there's oral devices which I mentioned
earlier that help pull the jaw forward and - and help in that area but the bottom
line is - is this enough to stop recommending CPAP? You tell me. You
know what's going on out there, docs are still recommending CPAP and I think
that's reasonable. Quality of life is very important and even if this turns
out to be true that it doesn't impact cardiovascular disease, which I don't
believe yet, quality of life is very important and it would be worth it. Yhank
you very much if you've made it this far.