Snorers Wake Up: Your Heart Could Be Telling You Something
April 11, 2000 (Minneapolis) -- If you snore, you might want to wake up to
the latest news: those nighttime noises may be more than just an annoyance. In
the largest study to date, sleep experts have confirmed that disturbed
breathing during sleep is associated with high blood pressure in middle-aged
and older persons regardless of race or sex. But the researchers, like others
before them, failed to determine the cause -- an important step that can lead
to better treatment. The study was published in the April 12 issue of the
Journal of the American Medical Association
Researchers have been studying sleep-connected breathing problems since the
early 1980s. Sleep apnea -- the obstruction of airflow through the nose and
mouth -- takes place during sleep and occurs in one in 10 women and one in four
men. Although many people are unaware of their breathing abnormalities,
researchers who studied people during slumber have found a link between sleep
apnea, snoring, and high blood pressure.
Scientists at Johns Hopkins School of Hygiene and Public Health in Baltimore
and elsewhere conducted the largest study on the sleep disorder -- a total of
over 6,100 subjects, including men and women over age 40 and of different
ethnic backgrounds, were included. F. Javier Nieto, MD, PhD, and colleagues
collected data about smoking habits, alcohol use, weight, body mass, and
history of snoring. They measured blood pressure and studied the histories of
high blood pressure in study participants. A self-administered sleep habits
questionnaire helped researchers gather medical history and snoring history.
Then, during sleep, monitors measured sleep stages, breathing, and blood
Researchers found that nearly half of the subjects had more than five
episodes of apnea per hour of sleep. More disturbing, the researchers also
found "a clear association between increasing frequency of [apnea] events
and hypertension," particularly among patients classified as obese.
Nieto tells WebMD being overweight is the main cause of sleep apnea, and
this study shows yet another consequence of obesity.
In the same journal, sleep expert Clifford W. Zwillich, MD, describes the
study as "powerful" because information was collected from such a large
group, but he also criticizes the trial because the reason for the link remains
unknown -- something that has major public health implications, he says.
Other experts agree on the seriousness of the condition. "Patients need
to ask themselves if they have a breathing problem [during sleep], and also ask
their spouse, because sometimes they know best," expert Meir Kryger, MD,
tells WebMD. "If people do have symptoms of sleep apnea, they should see
their doctor for appropriate treatment." Kryger is professor of medicine at
the University of Manitoba, in Winnipeg, and a member of the board of directors
of the National Sleep Foundation.
Now, experts must find out why there is a link between hypertension
and sleep-disturbed breathing. Until then, Nieto suggests that people consult
their physician if they snore loudly, feel sleepy during the day, and are
- Sleep apnea, which occurs when airflow is interrupted through the nose and
mouth during sleep, occurs in one in 10 women and one in four men.
- New research has shown an association between sleep apnea and high blood
pressure in people middle-aged or older, particularly among obese people,
although scientists cannot explain the association.
- Researchers encourage anyone who snores loudly, feels sleepy during the
day, and is overweight to consult their doctor.