180｜Practice

Dissemination and promotion of screening forsleep disorders
1. Background and goals
Sleep apnea syndrome (SAS)(1) is a pathological condition characterized by intermittent episodes of loudsnoring and a pause in breathing (i.e., apnea) due to upper airway obstruction by the tongue sliding into
the back of the throat. This results in shallow sleep and insufficient oxygen supply to the brain, so individuals with SAS are unable to obtain sufficient sleep, experience excessive daytime sleepiness, and easily fall asleep, resulting in low concentration and a high incidence of accidents due to careless driving
and falling asleep at the wheel.
Several million people are estimated to have SAS in Japan. Even though continuous positive airway
pressure (CPAP)(2) therapy has been established to treat SAS, only about 300,000 patients are currently
treated by CPAP. This is in part because sleepiness due to SAS can be easily mistaken as an age-related
chronic fatigue symptom, and also because many individuals with SAS do not readily feel sleepy after
living with chronic sleep loss for years and therefore do not consult a physician, leaving SAS untreated.
Against this background, a first step would be to establish a system to screen individuals with SAS whorequire further treatment. However, it is impossible to impose the burden of comprehensive testing on
every person who is suspected of having SAS because a definitive diagnosis of SAS requires elaborate
and costly overnight testing at a specialized medical facility. For this reason, a simple screening system isrequired to narrow down those individuals who need comprehensive testing. This study aims to developand disseminate an SAS screening test and promote the treatment of SAS.

2. Research content
2-1. Special seminar on sleep-disordered breathing
In 2012, at the Nara Trucking Association, the International Association of Traffic and Safety Sciences
hosted a special seminar entitled “Sleep-Disordered Breathing and Health Problems among Truck Drivers” and provided comprehensive information about SAS to trucking business owners, health

Project Leader: Takeshi Tanigawa
Professor, Department of Public Health, Graduate School of Medicine, Juntendo University(1) Sleep apnea syndrome (SAS): a disease characterized by episodes of apnea during sleep. Apnea is defined as a pause in breathing thatlasts more than 10 seconds. SAS is diagnosed when apnea occurs more than 5 times in 1 hour or 30 times in 7 hours during sleep.
(2) Continuous positive airway pressure (CPAP): a method used to prevent airway obstruction by sending pressurized air (positive airway pressure) via a tube to a mask worn on the nose in order to compress the soft tissues surrounding the root of the tongue and thereby
open the airway.

Dissemination and promotion of screening for sleep disorders｜181

100.0%100.0%

90.0%

90.0%

23.0%

80.0%
70.0%
60.0%
50.0%

77.0%

40.0%
30.0%

80.0%

All subjects (100%)
responded with“useful” !

60.0%

Change in awareness ofSAS was reported by
96.4% of the subjects.

50.0%
40.0%

60.0%

30.0%

20.0%

20.0%

10.0%

10.0%

0.0%

36.4%

70.0%

0.0%

Very usefulSomewhat useful

Was there any change in your awareness of SAS?
A lot

Figure 1. Impact of the special seminar

A little

Figure 2. Change in awareness of sleep apnea
syndrome

supervisors, and truck drivers. A survey conducted after the meeting revealed that the meeting was anexcellent learning experience for the attendees (Figs. 1, 2).
2-2. Administration of a screening test
After the seminar, attendees were recruited for an SAS
screening test, and the openings for 200 test subjects werefilled in just 3 days, revealing high levels of interest in SAS
among meeting attendees.
In this study, a flow sensor, used as a simple tool tomonitor breathing and screen for SAS, was mounted overthe nose and mouth to examine for apnea and hypopnea
during sleep based on the degree and frequency of changes
in air flow (Fig. 3). The notable feature of this testing is thatSAS screening can be performed at home using a small takehome device with a little burden on the subject.

Figure 3. Simple diagnosis with a flowsensor

In addition to the use of a flow sensor, a self-administered questionnaire survey was performed in order to look for a correlation between SAS and perceived
sleep quality. This questionnaire is the Japanese version of the Sleep Disorders Screening Survey used atHarvard University in the United States and employs the Epworth Sleepiness Scale as a measure of daytime sleepiness and also asks about subjects’ sleep and driving patterns.
2-3. Results(1) Subjects
The survey results showed that 48 subjects (24%) were living with moderate to severe sleep-disorderedbreathing. The severity of respiratory disturbance was positively correlated with the degree of obesity
but not with other factors, such as age, smoking or drinking habits, blood pressure, and neckcircumference.

182｜Practice(2) Association between subjects’ experiences and sleep-disordered breathing
Many subjects with a high respiratory disturbance index had suspected in the back of their mind thatthey had SAS or narcolepsy. Moreover, a relatively large number of subjects had been informed about
their apnea or snoring even by someone who was in the next room. Respiratory disturbance index was
not significantly correlated with the sleepiness scale score.
(3) Sleepiness and severe sleep-disordered breathing
The findings of this study revealed that more than 90% of the subjects with sleep-disordered breathing
did not actually experience intense daytime sleepiness.
2-4. Comprehensive testing
Diagnostic criteria for SAS are based on polysomnography (PSG) (3) testing. PSG evaluates
the quality and amount of sleep by using

PSG involves electroencephalography as the major component,
electrooculography, electrocardiography, and the measurements of breathing
patterns, peripheral blood oxygen saturation, and body posture. PSG requires
a special examination room, a technician trained in PSG, and skills in data
recording and analysis.

numerous sensors and electrodes to measure air
flow in the nose and mouth, snoring, arterial
oxygen saturation, breathing motion in thechest and abdomen, and posture (Fig. 4). A special examination room and a technician trainedin PSG are needed to conduct PSG, and therefore, it is not only costly but also time-consumFigure 4. Overnight PSG: a time-consuming and costly
definitive diagnostic method for SAS
ing and a large burden on patients.
Although 13 subjects were suspected ofhaving severe SAS according to the screening test
SAS screening of 200 subjects
conducted by the Nara Trucking Association, only 2of them subsequently underwent PSG (Fig. 5). Thisoutcome stands in sharp contrast to the high levels ofinterest in SAS shown by the subjects prior to thescreening test, most likely reflecting the large burden
imposed by PSG.

3. Conclusion
In this study, a special seminar was offered to trucking business owners, health supervisors, and truck
drivers affiliated with the Nara Trucking Association,

Screening test results
2 subjects (1%)
Grade A:
26 subjects (13%)
Grade B:
76 subjects (38%)
Grade C:
35 subjects (18%)
Grade D:

Grade E:

Unable to grade:
Cancellation:

13 subjects (6.5%)
40 subjects (20%)
8 subjects (4%)

Outpatient Sleep Clinic, Tenri Municipal Medical CenterNumber of contacts:
4 subjects (2%)
Appointment for PSG:
2 subjects (1%)
PSG performed:
2 subjects (1%)

Figure 5. Approach taken by the Nara Trucking
Association(3) Overnight polysomnography (PSG): an overnight screening test performed on admission to a special examination room to examine
sleep patterns by using electroencephalography, electrooculography, and electromyography of the mentalis, as well as breathing patterns
by collecting data on airflow through the mouth and nose and the movement of the chest and abdomen. PSG is used to determine theseverity of SAS and the appropriate treatment.

Dissemination and promotion of screening for sleep disorders｜183

followed by a questionnaire survey and screening test administered to approximately 200 truck drivers.
In this way, we attempted to establish a system with the following flow: awareness-raising about SAS
screening → screening test → comprehensive examination and treatment.
With regard to the correlation between sleep-disordered breathing and daytime sleepiness, morethan 90% of the present subjects with moderate to severe sleep-disordered breathing answered that they
did not experience daytime sleepiness. This clearly indicates that subjective tests are not enough toscreen for SAS, and therefore, more objective screening tests, such as the flow sensor method, are needed
to detect individuals with undiagnosed SAS. This study also suggests that society as a whole needs to beaware of SAS because some aspects of the disease cannot be addressed by individuals who have SAS.

4. Future outlook
The awareness-raising activity presented in this study is an example that can be applied to any region
across Japan. Our goals are to develop and disseminate an effective SAS screening system and to reduce
the number of traffic accidents via the promotion of early detection and early treatment of sleep-disordered breathing. In collaboration with the relevant administrative agencies, we will also recommend
approaches for the early detection of sleep disorders for which awareness among drivers is low.