The widening American waistline may be feeding an epidemic of sleep
apnoea, potentially robbing millions of people of a good night's rest, a new
The research didn't definitively link the rise in obesity
to sleep apnoea, and it only looked at 1 520 people, almost all white, in
Wisconsin. But study author Paul Peppard believes the findings show a big spike
in sleep apnoea cases over the past two decades - as much as 55% - and may
translate to the entire United States.
"There are probably 4 million to 5 million people who are more likely to have
sleep apnoea due to the obesity epidemic," estimated Peppard, an assistant
professor of population health sciences at the University of Wisconsin-Madison.
"It's certainly an uncalculated cost of the obesity epidemic, an epidemic of its
How the study was done
The researchers looked at adults aged 30 to 70 who were monitored as they
slept. About 600 to 700 underwent sleep tests between 1988 and 1994, with some
continuing to take part along with hundreds of new participants from 2007 to
The study considered the participants to have moderate-to-severe breathing
problems if they had trouble breathing 15 or more times an hour while
Sleep apnea is the main cause of breathing problems during sleep. People with
the condition often have trouble staying in deep sleep because their throats
close, blocking their airways and requiring them to partially awaken to start
breathing properly. They don't realise they're waking up and may become very
sleepy during the day.
Besides sleepiness, sleep apnea can contribute to heart and other health
problems if untreated and increase the risk of work- and driving-related
accidents, according to the US National Heart, Lung, and Blood Institute.
'Addressed and controlled'
The researchers extrapolated their findings to the entire United States and
estimated that 10% of men aged 30 to 49 currently have symptoms of sleep apnoea.
The study estimates the number is 17% of men aged 50 to 70. For women, the
estimate is 3% among those aged 30 to 49 and 9% among women aged 50 to 70.
Among all groups, heavier people were much more likely than thinner people to
suffer from the symptoms.
The study estimates that these numbers have gone up by 14% to 55% from
1988-1994 to 2007-2010. Peppard estimated that 80% to 90% of the increase in
symptoms is due to the growth in obesity.
But it's hard to know for sure how much of a role that obesity plays in
causing more symptoms. While obesity is "almost certainly the biggest factor" in
causing sleep apnoea, Peppard said, "there's long list of things that cause sleep
apnea or are related to sleep apnea, like being older, being male, having a
narrower upper airway, having a genetic predisposition to it..."
What to do? If you don't feel rested after sleeping, Peppard said, talk to
The good news is that sleep apnea is treatable. One treatment, known as
continuous positive airway pressure (CPAP), is a machine that blows air into the
throat to keep it open while people sleep. "It's very effective, but some people
don't like to use it," Peppard said.
There's another option that will help in many cases, he said: Weight
Joyce Walsleben, an associate professor of medicine at New York University
who studies sleep problems, agreed. "Obesity has to be addressed and
controlled," said Walsleben. "That is a message for doctors and patients."
Although the study tied obesity to higher risk of having sleep apnoea, it did
not establish a cause-and-effect relationship.
For more about sleep
apnea, try the US National Library of Medicine.