Can Sleep Apnea Cause Alzheimer’s?
September 23, 2008
A few days ago, I ran across two studies about obstructive
sleep apnea (OSA) and brain structure in my sleep medicine
journals that had me wondering: Could there be a link
between Alzheimer’s Disease (AD) and obstructive sleep
The first study showed that people with OSA (see below) had
a much higher incidence of silent lacunar infarcts on an
MRI scan. Lacunar infarcts are very small areas of
clotted small blood vessels in the brain. Essentially,
these are microscopic strokes.
The second article showed that people with OSA had
multiple areas of brain tissue that received significantly
lesser amounts of blood flow. If a small vessel in your
brain doesn’t get very much blood flow, then there’s a
higher chance of clotting as well. A natural consequence of
this process is that you’ll get scarring and changes that
can overlap with findings that are seen in AD. Also, if you
get less blood flow in your brain region, then you’ll have
less neurotransmitter production and less need for glucose.
One of the hallmarks of (AD) is what’s found under the
microscope during an autopsy. Two common findings of those
with AD are neurofibrillary tangles (NFTs) and senile
plaques (SPs). These are the scar tissue-like end-stage
findings for many types of nerve damage. Although not
specific to Alzheimer’s alone, NFTs and SPs are routinely
stated as being one of the distinctive markers for this
devastating condition. However, despite the millions or
even possibly billions of dollars of research in this area,
we still don’t know why this happens, what causes it or
even how to prevent it.
As I was reading through these two articles, in conjunction
with all the latest research about AD, I couldn’t help but
to see a distinct merger between OSA and AD. This, in turn
made me think about a short satirical video by a renowned
osteopath Dr. Joseph Mercola and then all I could think
about were skid marks on the side of the road.
The Skid Marks of Healthcare
This 10 minute video describes a town called Allopath. Due
to budget cuts and an absence of stop signs at one
especially busy intersection, the town experiences an
alarming number of traffic accidents and injuries. As a
result, a consultant with the Motor Division (MD) is
brought in to diagnose the problem, and after careful
analysis, he proclaims that the reason for all the traffic
accidents is due to the presence of tire skid marks and his
solution?: Cover up the deadly skid marks with teflon.
Bolstered by the facts of this MD’s research the
townspeople rally together to rid the town from offending
skid marks. In doing so, new industries begin to crop up in
From a Teflon factory to ambulances and hospitals to car
repair shops repairing the cars damaged by the increase in
traffic accidents, the town’s economy booms. Yet, as the
town’s economy grows, the rate of traffic accidents, rather
than going down, inversely gets worse as the slick Teflon
only causes more accidents. Eventually, the town’s economy
crashes as many of the townspeople become disabled. In
short, this video reveals a sad but true account of what’s
happening with our health care system today.
Some of the cutting edge AD research in the prevention of
worsening memory and cognitive functioning focuses on
enhancing certain neurotransmitters and metabolic
processes, such as acetylcholine or glucose. Drugs that
lower enzymes or proteins that naturally degrade
acetylcholine are shown to help with memory and cognition.
Other research focuses on the biochemical and genetic
properties of these NFTs and SPs, which are acknowledged to
be the end-stage result of nerve damage and ultimate death.
The reasoning is that by preventing NFTs and SP, we can
In so far as these very complex studies go, however, none
has yet to explain how and why all these factors for AD
interrelate. Until you consider, however, the possibility
that Alzheimer’s may be one of many symptomatic end stages
of obstructive sleep apnea (OSA).
OSA and AD: How Are they Alike?
Research reveals that people at risk for AD are also at
risk for the routine cardiovascular conditions like high
blood pressure, diabetes, and heart disease. Some
researchers have stated that AD is a disease of the small
vessels in the brain. Similarly, if you have OSA, you are
more likely to have all of these heart problems, along
with a higher likelihood to have strokes, or be obese.
Another interesting symptom to note is that OSA promotes
the kind of inflammation and clotting not unlike the kind
of small blood clotting and neurotransmitter degeneration
that’s commonly associated with those with Alzheimer’s.
With all these similarities between OSA and Alzheimer’s
Disease, it’s not too far-fetched to consider them
complimentary if not to see that one may be an aggravating
factor for the other. There’s even evidence of a common
gene linking AD with OSA.
Yet, even with all these studies showing strong
correlations between OSA and AD, 80-90% of people with OSA
are still not diagnosed in this country, and if my
hypothesis is right this number probably includes many
patients who are “at risk” for Alzheimer’s (i.e. family
history, evidence of memory loss etc.) In fact, if would
be even more important to screen for OSA when you are much
younger, before neurologic impairment, heart disease, or
more importantly, before Alzheimer’s sets in. In all of
these scenarios, the time and money required in screening
these potential patients for OSA would be miniscule
compared to the rewards of preventing Alzheimer’s for even
a small proportion of this population.
We Can Learn A Lot From a Dummy
As Mercola’s cartoon video showed, much of what we believe
about scientific research is grounded in the premise that
if it’s not too complex, it can’t be scientific. Even in
the case of Alzheimer’s research and studies of OSA, much
of the research is focused on what you can do after the
disease has already set in. It may be that prevention
methods, like eating right, exercising and sleeping well,
seem too simple of a cure for such a complex problem like
I don’t mean to offend all the good-intentioned doctors and
researchers working on a “cure” for AD. Granted,
eventually, there will be many drugs out there to slow the
progression of AD, just like all the medications that we
have for high blood pressure and heart disease. But could
it be that by allowing these drugs to be so freely
dispensed after the onset of disease, we’re providing a
false sense of security for those “at risk” patients who
may have otherwise put more effort into maintaing a
Similarly, by just covering up the tire skid marks, rather
than installing stop signs at that dangerous intersection,
the town of Allopath thought they could “cure” traffic
accidents. Of course, neither are fail safe measures for
traffic accidents. Although not as sophisticated as
Teflon,however, stop signs would have at least forced the
citizens of Allopath to become more responsible drivers.
Teflon just made the problem spiral out of control.
So the next time you hear screeching tires, stop to note
the skid marks. Better yet, opt for prevention rather than
easy cures. Moreover, if you have a history of AD in your
family, and have noticed lately that you’re exhibiting
signs of chronic fatigue or impaired memory or are
experiencing classic symptoms of OSA, get a sleep study (to
get a listing of sleep study centers in your area visit: ).
Since AD is not (yet) currently reversible, it’s important
to become proactive in preventing anything that can cause
or aggravate it while you’re young to prevent any future