Toshiji Hayakawa

Habitual snoring in an outpatient population in Japan

Abstract In order to investigate the occurrence and history of sleep problems in Japan, the 11‐Centre Collaborative Study on Sleep Problems (COSP) project was carried out. Complaints of snoring are examined, and its prevalence, risk factors and screening reliability are discussed. The subjects who participated in the study were 6445 new outpatients from a general hospital. They were asked to answer a sleep questionnaire that consisted of 34 items with seven demographic items; each item was composed of four grades of frequency. In order to offset possible seasonal variations in sleep habits, data were collected across four seasons. Sleep patterns, insomnia, hypersomnia, parasomnia and circadian rhythm sleep disorders were covered. Habitual snoring was seen in 16.0% of males and 6.5% of females. Male predominance was noted. From these data, the relationship between habitual snoring and sleep complaints was statistically analyzed. Habitual snorers (HS) were observed to wake up more frequently during sleep (17.8% of males, 21.5% of females) than were non‐habitual snorers (NHS; 6.6% of males, 9.7% of females). Mid‐sleep awakening of HS was also more frequent than it was for NHS; however, there were no differences in difficulty in falling asleep and early morning awakening. Body mass index, cigarette smoking and alcohol consumption were also correlated with habitual snoring.

Sleep problems in the aged in relation to senility

Abstract As a part of an epidemiologic survey of dementia in a community of aged persons, correlation between sleep complaints and physical illness and senility were studied. A total of 3302 randomly sampled aged individuals (aged 65 yean) were studied using a questionnaire. In this sample the prevalence of poor sleep and habitual snoring did not increase with age. The prevalence of excessive daytime sleepiness showed an increase with age. Male predominance of habitual snoring and female predominance of poor sleep were observed. Female predominance of excessive daytime sleepiness was noted among the aged 70 and over. Age‐related excessive daytime sleepiness was significantly correlated with senility.

Evaluating mental fatigue in patients with obstructive sleep apnea syndrome by the Maastricht Questionnaire

Abstract Mental fatigue in patients with obstructive sleep apnea syndrome (OSAS) was investigated and compared with subjects without OSAS. The study series comprised 189 habitual snoring patients and 75 controls. To measure subjective mental fatigue and somnolence, subjects were asked to complete the Maastricht Questionnaire (MQ) and the Epworth Sleepiness Scale (ESS), respectively, and patients also underwent diagnostic polysomnography. According to the apnea and hypopnea index, patients were classified into the following groups: primary snorers, or having mild, moderate, or severe OSAS. The lowest MQ and highest ESS scores were found in those patients with severe OSAS. It is proposed that the lowest MQ score is due to mental fatigue impairing awareness in patients with severe OSAS, probably because of attention loss.

Rapid eye movement‐localized apnea in a female patient with chronic insomnia

A middle‐aged female patient with chronic insomnia showed rapid eye movement (REM)‐ localized obstructive sleep apnea. She visited the Sleep Disorders Clinic and complained of insomnia with loud snoring. Once, in the past, her sleep complaints had disappeared after weight reduction but, 6 months later, she complained of excessive daytime sleepiness. Overnight polysomnography revealed REM‐localized apnea. Careful follow up is strongly recommended for a female patient with chronic insomnia who shows REM‐localized apnea.

Treatment of Human Circadian Rhythm Sleep Disorders

In humans, external factors that are likely to affect on the biological rhythm (time cues) include the following: (1) the time on a clock, (2) light—dark cycle, (3) social interaction, (4) timing of dietary intake, and (5) sleep—wake schedule. Although the light—dark cycle is thought to be the strongest time cue in plants and animals, social interaction is believed to be the most potent time cue in humans (Aschoff, 1965). However, recent studies have revealed that light also exerts a strong influence on the human circadian rhythm (Lewy et al., 1980; Czeisler et al., 1986).