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by Udoh O. Obioha, M.D.
Illustrations by Jeff Ham
OBESITY and Obstructive Sleep Apnea
What is Obstructive Sleep Apnea?
Obstructive sleep apnea is a serious, potentially life-threatening
condition that is far more common than generally understood.
Obstructive sleep apnea is a breathing disorder caused by brief
interruptions of breathing during sleep. It owes its name to a
Greek word, apnea, meaning, “want of breath.”
Obstructive sleep apnea occurs when air cannot flow into or out of a person’s nose or mouth although efforts to breathe continue. In a given night, the number of involuntary breathing pauses or “apneic events” may be as high as 20 to 30 or more per hour. These breathing pauses are almost always accompanied by snoring between apnea episodes, although not everyone who snores has this condition. Obstructive sleep apnea can also be characterized by choking sensations. The frequent interruptions of deep, restorative sleep often leads to early morning headaches and excessive
daytime sleepiness.
Early recognition and treatment of
sleep apnea is important because it may
be associated with irregular heartbeat,
high blood pressure, heart attack, and
stroke.
Who gets obstructive sleep
apnea?
Obstructive sleep apnea occurs in all age
groups and both sexes but is more common
in men. It has been estimated that
as many as 18 million Americans have
sleep apnea. People most likely to have
or develop sleep apnea include those who
snore loudly and also are overweight, or
have high blood pressure, or have some
physical abnormality in the nose, throat,
or other parts of the upper airway.
What causes obstructive
sleep apnea?
Certain mechanical and structural problems
in the airway cause the interruptions
in breathing during sleep. In some
people, apnea occurs when the throat
muscles and tongue relax during sleep
and partially block the opening of the airway.
When the muscles of the soft palate
at the base of the tongue and uvula
(the small fleshy tissue hanging from
the center of the back of the throat) relax
and sag, the airway becomes blocked,
making breathing labored and noisy and
even stopping it altogether. Sleep apnea
can also occur in obese people when an
excess amount of tissue in the airway
causes it to be narrowed. With a narrowed
airway, the person continues his or
her efforts to breathe, but air cannot easily
flow into or out of the nose or mouth.
Unknown to the person, this results in
heavy snoring, periods of no breathing,
and frequent arousal’s (causing abrupt
changes from deep sleep to light sleep).
Ingestion of alcohol and sleeping pills
increases the frequency and duration of
breathing pauses in people with sleep
apnea.
Obesity, particularly upper body obesity,
is a risk factor for obstructive sleep
apnea and has been shown to have a
significant effect on its severity. Most
patients with sleep apnea are obese,
when obesity is defined as body weight
greater than 120 percent of ideal. Large
neck girth in both men and women who
snore is highly predictive of sleep apnea.
In general, men with a neck circumference
of 17 inches or greater and women
with a neck circumference of 16 inches
or greater are at a higher risk for sleep
apnea.
What are the effects
of obstructive sleep apnea?
Because of the serious disturbances in
their normal sleep patterns, people with
sleep apnea often feel very sleepy during
the day and their concentration and
daytime performance suffer. The consequences
of sleep apnea range from annoying
to life threatening. They include
depression, irritability, sexual dysfunction,
learning and memory difficulties,
and falling asleep while at work, on the
phone, or driving. It has been estimated
that up to 50 percent of sleep apnea
patients have high blood pressure. Although
it is not known with certainty if
there is a cause and effect relationship, it
appears that sleep apnea contributes to
high blood pressure. Risk for heart attack
and stroke may also increase in those
with sleep apnea.
When should obstructive
sleep apnea be suspected?
For many sleep apnea patients, their
spouses are the first ones to suspect
that something is wrong, usually from
their heavy snoring and apparent struggle
to breathe. Coworkers or friends of
the sleep apnea victim may notice that
the individual falls asleep during the day
at inappropriate times (such as while
driving a car, working, or talking). The
patient often does not know he or she
has a problem and may not believe it
when told. It is important that the person
see a doctor for evaluation of the
sleep problem.
Management of obstructive
sleep apnea
A clinical diagnosis of OSA can sometimes
be made in patients with a short,
thick neck who complains of snoring and
excessive daytime sleepiness. However,
nocturnal polysomnography, in which
multiple physiologic parameters are
measured while the patient sleeps in a
sleep laboratory, is the gold standard for
diagnosing the disorder. Sleep centers
express test results with an apnea-hypopnea
index (AHI), which is the total number
of apneic and hypopneic episodes divided
by total hours of sleep time. Most
centers use a cutoff of 5 to 10 events per
hour before considering treatment with
continuous positive airway pressure
(CPAP). With CPAP, the patient wears a
snugly fitting nasal mask attached to a
fan that blows air into the nostrils to keep
the airway open during sleep.
Nasal continuous positive airway
pressure (CPAP) is the most common effective
treatment for sleep apnea. In this
procedure, the patient wears a mask over
the nose during sleep, and pressure from
an air blower forces air through the nasal
passages. The air pressure is adjusted
so that it is just enough to prevent the
throat from collapsing during sleep. The
pressure is constant and continuous.
Nasal CPAP prevents airway closure while
in use, but apnea episodes return when
CPAP is stopped or used improperly.
Weight loss is the obvious treatment
for OSA in obese and overweight patients.
Weight loss and strict avoidance
of alcohol and hypnotic medications are
the first step in the management of OSA.
Weight loss may be curative if the patient
is able to lose and maintain about 10-20
percent of his/her bodyweight.
Udoh O. Obioha, M.D. is one of the few boardcertified
bariatric physicians in the U.S. Bariatric
medicine is a specialty devoted to the treatment
of overweight, obesity, and related co-morbid
medical conditions.
Dr. Obioha offers a scientifically
designed, comprehensive, non-surgical
approach to weight management, one that
balances professional guidance and personal
accountability for sustained success. He has
helped thousands of patients reach and maintain
their weight loss goals since the 1980s.
Dr. Obioha has published numerous articles
on bariatric medicine and is a co-author
of Passing Your Nutrition and Bariatric Board
Examinations. He is currently an assistant clinical
professor of family medicine at the University of
North Dakota School of Medicine and Health
Sciences.
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