Are you more of like a honk-shoo honk-shoo
Or more of like a mimimi?
It’s an important question!
No it’s actually a trick question because either way,
if you sound like that when you sleep,
you might be at risk of having obstructive sleep apnea.
You thought it was fun…
but it’s not!
Because, in addition to loud and irritating snoring,
It can come with some real health risks.
And the current standard of care is a machine called a CPAP.
It works by using pressurized air to keep
your breathing consistent while you sleep.
These machines are expensive and people don’t like using them,
but at least the quality of clinical evidence for them is… poor.
Wait…
because like many things in science…
It's complicated.
[♪ INTRO]
Obstructive Sleep Apnea, or OSA,
affects around 1 billion people worldwide.
It’s a condition in which your throat muscles relax too much
in your sleep and block your airways,
causing you to stop and start breathing
several times throughout the night.
Besides all the problems that come with getting poor quality sleep,
untreated OSA has been linked to complications
such as cardiovascular events and high blood pressure,
and it’s associated with diabetes too.
CPAP, which stands for continuous positive airway pressure,
is currently used as the standard of care to gently force
your airways to stay open in your sleep.
The treatment generally includes a mask to fit over your face,
along with tubing and machinery to filter and pressurize the air.
While they are the most common treatment,
CPAP machines are not exactly a popular option.
They can be uncomfortable and noisy,
with enough issues to fill up whole web pages of
tips on how to improve their fit and feel.
These machines will also run you
on average 800 US dollars without insurance,
which doesn’t include the ongoing need for replacement parts.
So, what with it costing you an arm and a leg,
you probably want to be darned sure that this machine
is actually able to fix all the health conditions that it claims to.
And that’s what a review published in 2022 by the U.S. Department
of Health and Human Services set out to investigate.
The team analyzed 52 publications to figure out whether CPAP is
effective in reducing the long term health effects of OSA.
And they reported that there wasn’t a ton of strong evidence
to support CPAP machines actually leading to improvements
in most of the outcomes they looked at.
To be clear, they did not say that there is
overwhelming evidence against CPAP machines.
Rather, the studies were too contradictory or conflicting
in their design to be able to say much of anything at all.
The studies were inconsistent in their definitions of OSA
and breathing measurements, even though there are
published standards that could totally be used.
Even some papers that cited the same source for their definitions
didn’t end up using the same criteria as another.
The studies also did not properly address whether the benefits
of CPAP differed based on the severity of the participants’ OSA
or other potential confounders.
Overall, it may come as no surprise that
the report recommended more research.
Specifically, we need more high-quality studies
to confirm the impact of CPAP, and we need to be clear
on which patients would benefit most from using CPAP devices.
Not everyone was happy about this report.
Physicians feared that people would misinterpret the results
to mean that CPAP machines definitively do not work,
which could lead to insurance providers
like Medicare refusing to pay for them.
In fact, sleep doctors stand by CPAP machines
as the gold-standard treatment for OSA.
And one reason might be that doctors look at
the evidence a little differently than the report’s authors.
For example, the report only included studies that conducted
follow ups for physical outcomes after at least 12 months.
And there weren’t any such papers with enough statistical power
to look at the effect of CPAP on high blood pressure.
But, in a meta-analysis published in 2024 that included studies
with shorter follow up times, researchers found that CPAP treatment
was associated with reduced blood pressure in less than three months.
In fact, you can dig up similar contradictions for nearly
everything you could want to study about CPAP and OSA.
Which is to say, you can, and we did.
When we tried to research exactly what long-term health conditions
are definitely improved by using CPAP machines,
we had, like, a really hard time finding much consensus.
Even an outcome as fundamental as daytime sleepiness
didn’t yield consistent findings.
One study in Australia included 31 participants who used their
CPAP machines for an impressive 7 or more hours a night.
20% of those participants still did not come down to typical levels
of daytime sleepiness, and more than half did not reach
typical levels of daily functioning due to sleepiness.
On the other hand, research groups in India and Taiwan
were able to find significant improvement in daytime sleepiness
in their 34 and 47 participants, respectively.
And while all the research groups used the same questionnaire
to evaluate sleepiness, their analysis methods were slightly different,
which makes it still difficult to directly compare.
So before we even ever get to stuff like cardiovascular disease,
it’s already incredibly hard to give one digestible answer
to the question of whether CPAP works.
Does it make you less sleepy? Yes or no?
So what gives?
Why is the golden child of obstructive sleep apnea treatment
not showing us consistent results among study participants?
Well, study design is one issue.
But we also need to turn to the definitions of two terms:
efficacy versus effectiveness.
Which sound the same, I know.
Maybe one is just like the pretentious older sibling of the other.
But in the lingo of medical interventions,
efficacy is basically how well
a treatment does under perfect conditions,
and effectiveness is how well it actually works in the real world.
In the case of OSA, efficacy is the absolute ability of a
CPAP machine to stop your airways from closing while you sleep.
Effectiveness takes into account both efficacy
and how well people actually stick to using the machine as prescribed.
And since we’ve established that CPAP machines
can be hard to get used to, it may not be surprising
that their effectiveness is a lot lower than their efficacy.
What, you don’t want to be attached to an
uncomfortable face-hugger all night?
Get used to it.
To count as being “adherent” to your CPAP machine prescription,
you only need to be using it for at least 4 hours a night.
Studies could be averaging the results
of everyone who qualifies as “adherent,”
whether they’re using their CPAP machines for four hours or eight!
And as Health and Human Services pointed out in their review,
in most studies, a lot of participants didn’t even clear the four hour bar.
So the results between studies could have been inconsistent
with each other due to inconsistent CPAP use.
Let’s look at one more health outcome to drive this point home.
In that Health and Human Services report,
they found that there was not enough significant evidence to say
that CPAP can reduce cardiovascular events in patients with OSA.
They looked at 12 studies to come to this conclusion,
of which only two found a reduced risk of
cardiovascular events with proper CPAP use.
When looking at all 12 together, the authors concluded
there wasn’t strong enough evidence to say anything conclusive.
Now, a different meta-analysis looked at three of those 12 studies.
And by themselves, the three did not find any significant reduction
in cardiovascular events due to CPAP use overall.
Two of the three studies showed that there was no significant
reduction in cardiovascular events, no matter if the participants
were adherent to CPAP use or not.
The other showed that there was a significant reduction
in cardiovascular events, but only for the people who
used their CPAP machine as prescribed.
The meta-analysis took the individual data from each of the
three studies and combined them all into one big group.
This gave them an effectively new set of numbers to crunch,
totaling more than 4,000 people.
And they found that when comparing the groups as-is,
CPAP did not seem to have a significant impact.
But, when they isolated just the participants who used their
CPAP machine for at least 4 hours a night,
they were able to find a significant reduction
in the risk of cardiac events.
It’s all in how you set up the numbers.
Relationships can appear and disappear
depending on how you look at your data,
so it’s important to do your statistics properly
and not just in a way that shows you there’s an effect.
Here’s the takeaway from all that:
It is well-determined that CPAP machines are highly efficacious
in preventing your airways from collapsing throughout the night.
But those benefits can disappear in studies of
people out there in the real world, being forgetful
and imperfect and not flawlessly-doctor-order-following
as people tend to do.
But important question, are there any alternatives?
One treatment option that I haven’t mentioned yet,
for reasons of dramatic tension,
are oral devices that reposition your
tongue and jaw to keep your airways open.
They kinda look like a mouth guard or a retainer – no tubes needed!
It’s officially called oral appliance therapy, or OAT,
and while it may be less efficacious than a CPAP machine
at preventing breathing obstruction throughout the night,
it could be more effective,
since patients are more likely to be consistent with it.
OAT is only meant for people with mild
to moderate obstructive sleep apnea,
but if you qualify and are having trouble sticking with a CPAP machine,
this may be a great thing to ask your doctor about.
Maintaining a CPAP machine regimen
can be difficult for a lot of people.
Studies suggest that only about 50% of people
prescribed CPAP treatment are using it consistently enough,
and that number could be even lower
for people with milder sleep apnea symptoms.
But people who use OAT instead of CPAP have been found
to use their oral appliances for a whopping 95% of their sleep time!
To fully assess the benefits of switching to OAT,
doctors and patients would need to discuss whether the loss in efficacy
is made up for by the increased consistency in using oral appliances.
This full-picture assessment is why some scientists
are advocating for considering effectiveness
instead of just efficacy when deciding on the best treatment.
Another bonus is that while oral appliances
may be initially more expensive than a CPAP machine,
you only need to replace them every 5 years, whereas you may
need to replace CPAP machine parts every 6 months.
Analyses suggest that OAT matches the initial cost
of a CPAP machine after just four months.
In terms of health outcomes beyond your beauty rest,
some initial studies suggest that oral appliance therapy is comparable
to using a CPAP machine for daytime sleepiness, blood pressure,
and cardiovascular mortality rates.
Y’know, to the extent that we know that for CPAP either…
It’s messy.
One drawback is that the costs and coverage of oral appliances
can vary a lot, depending on the model you get,
your insurance provider, and what region you live in.
Also, if you have severe sleep apnea,
oral appliance therapy likely won’t work for you.
Defer to your doctor on all this stuff.
I am not a doctor. I’m not here to sell you on any of this stuff.
Talk to them.
So, there you have it.
The story of the CPAP machine is a complex one.
Until researchers are able to conduct more conclusive studies
on CPAP and OAT, it’s hard to make any sweeping recommendations
or conclusions about whether they’re good or bad.
We need higher quality, longer-term studies to be able to really
understand what symptoms can and can’t be fixed by
different treatment options for obstructive sleep apnea.
But I’ll repeat what I said earlier –
CPAP is still the gold standard, being the best option we have,
and sleep doctors still want you to use it.
If OAT works better for some people, awesome, sweet dreams.
But do what your doctor says!
And until researchers can hammer out a clearer consensus on CPAP,
slap that bad boy on and at least try to get a good night’s rest.
If you’re interested in learning even more about the science of sleep
and how to help yourself do a better job of it,
you might like this video on the mouth taping trend.
Does that work?
Ah, it– I don’t know!
Head on over to find out, and thanks for watching.