PubMed Health⌕ Search

Biomedical subjects

H Shinkoda

Publications and source records attributed to H Shinkoda.

9 recordsLinked to original sources
PubMed2001

Age and gender difference in habitual sleep-wake rhythm.

We analysed the effects of age and gender on the habitual sleep-wake rhythm in 2252 randomly selected subjects living in Shimonoseki, Japan. Subjects were divided into 21 age groups with a matching number of males and females for each. During the period from primary school to adolescence, the bedtime became delayed and sleep length decreased with age. After that period, with increasing age, bedtime became earlier and sleep length increased. The number of awakenings and the length of daytime naps increased markedly with epoch after 50 years and 70 years of age, respectively. Gender differences were considered to be due to the women's social and domestic customs in Japan.

Adolescent↗
PubMed2000

Sleep-wake habits of schoolchildren according to grade.

Five hundred and twelve students aged from 6 to 18 years were administered the morningness-eveningness questionnaire and a sleep log. The mean morningness-eveningness score decreased with grade; this decrease was significant around the seventh grade. The habitual waking time showed no difference among grades but the habitual bedtime became later with grade; thus, the sleep length on weekdays decreased with grade. The percentage of students falling asleep during school lessons significantly increased from the eighth to 12th grade. We found that a delay of sleep phase, reduction of sleep length, increased daytime sleep, and transition to evening type occurred at around the seventh grade.

Adolescent↗
PubMed1999

Changes in sleep-wake cycle during the period from late pregnancy to puerperium identified through the wrist actigraph and sleep logs.

The purpose of this study was to understand the sleep-wake cycle during the period from late pregnancy to about 3 months of postpartum by evaluating the number of actigraphic activities in four women (one multipara and three primi gravidae), and to compare the results with the findings from sleep logs. An irregularity of the sleep-wake cycle with increased number of wakings at night was notable during about 1 month after delivery, compared to the late pregnancy period, and subsequently this number tended to decrease. These results were indicative of the association between the lactation cycle to neonates and the sleep-wake cycle.

Adult↗
PubMed1999

Sleep and chronotype for children in Japan.

To investigate the change in sleep-wake habits, Morningness-Eveningness preference, and sleep status by grade, 512 students aged from 6 to 18 years, were tested using the Morningness-Eveningness Questionnaire and Sleep Questionnaire. The habitual waking time showed no difference by grade, but the students above Grade 7 reported a significantly later habitual bedtime and had a shorter length of sleep on weekdays than the students below Grade 6. The students above Grade 7 reported a significant difference between habitual and preferred waking times but did not show a difference between habitual and preferred bedtimes. Although the sleep length during weekends became shorter from Grade 1, the sleep length of students above Grade 8 showed a significant difference between the weekdays and weekends; they had more than nine hours of sleep on the weekends. The percentage of students taking a nap during a school lesson significantly increased across Grades 8 to 12. The mean score on the questionnaire decreased across grades and the decrease was significant at Grade 7. Both the habitual and preferred bedtimes and waking times were later from the Morning, Intermediate, to the Evening types across grades. The difference by chronotype in preferred waking time increased for groups from the primary, junior high, to the high school. Also, the sleep lengths both weekdays and weekends decreased from the Morning, Intermediate, to the Evening type for all grades. We suggested that the delay of sleep phase, reduction of sleep length, increased daytime napping, and transition to Evening type were remarkably represented around Grade 7.

Adolescent↗
PubMed1998

Evaluation of human activities and sleep-wake identification using wrist actigraphy.

The purpose of this study is to investigate the count-characteristics of wrist actigraphy in basic human activities and to discuss the agreement of sleep-wake identification between polysomnography (PSG) and wrist actigraphy during nocturnal sleep. There was a distinct distribution of actigraphy counts over the studied activities. The evaluation of sleep-wake scoring using the wrist actigraphy agreed 96.9% with the polysomnographic scoring during nocturnal sleep.

Activity Cycles↗
PubMed1998

Effects of aging on morningness-eveningness and sleep habits in Korean and Japanese workers.

The Morningness-Eveningness Questionnaire and Life Habits Inventory were given to Korean and Japanese workers. The distributions of scores on the questionnaire for these two groups were normal and its mean slightly moved to the Morning type with aging. It is noteworthy, however, that the mean scores of Korean workers was lower than those of the Japanese workers. The self-reported waking times and bedtimes for the two groups gradually became earlier with aging. From these results it could be said that aging was an factor that led to the difference of circadian phase.

Adult↗
PubMed1998

Sleep in relation to age, sex, and chronotype in Japanese workers.

The Morningness-Eveningness Questionnaire and Life Habits Inventory were administered to 622 Japanese workers matched for sex and age. We investigated the distributions of the scores on the Morningness-Eveningness Questionnaire and sleep-wake habits by age and sex. Subjects were classified into five age groups and three chronotypes. The distributions and mean scores on the questionnaire advanced slightly toward the Morning type from the young to the aged group. The habitual bedtimes and waking times were significantly earlier in all the chronotypes from the young to the aged group, and the preferred bedtimes and waking times were also clearly earlier from the young to the aged group. The length of sleep was shorter for the Evening than the Morning types, especially in the group below 24 yr. The differences in habitual and preferred sleep length were greater than 1 hour for all age groups, especially the two groups under 34 yr. The number of awakenings during night sleep increased from the young to the aged group for all chronotypes. The older Evening type tended more toward frequent napping and longer naptime. The variabilities of bedtime and sleep length were larger for the young and Evening type than for the old group and Morning types. Further, the mood upon waking and satisfaction with sleep length were better in the aged Evening type than the young Morning type. The women under 44 yr. woke up earlier than the men of the same age, and the women of the 35-54 yr. groups had a shorter length of sleep than others. These may be related to childcare and housework. These results indicated that the phase of circadian rhythms had moved forward from the young to the aged group, and the individual's rhythm, of those that were aged Morning types, showed better agreement with sleep-wake rhythms than did others.

Adult↗
PubMed1997

Scores on morningness-eveningness and sleep habits of Korean students, Japanese students, and Japanese workers.

The Morningness-Eveningness Questionnaire and Life Habits Inventory were given to three groups of the same mean age: 533 Korean students, 468 Japanese students, and 311 Japanese workers. The distributions of scores on the questionnaire for these three groups are normal; however the Japanese students' distribution was slightly skewed towards the Evening type. The self-reported waking times and bedtimes for the three groups were late in the order of Morning, Intermediate, and Evening types. It is noteworthy, however, that the Korean students woke earlier than the Japanese students, and the workers always went to bed and woke earlier than the students. For the groups the variations in bedtime, waking time, and length of sleep were large, the sleep latency was long, and mood of the participants upon waking was bad in the order of the Morning. Intermediate, and Evening types. The scores of the Korean students were distributed more highly in the Morning type than were the Japanese students', but the students' sleep habits in both countries were quite similar. The subjects categorized as Evening types had more irregular sleep habits than those of the Morning type. In comparison with the student groups, Japanese workers of the same mean age had higher scores and slightly different sleep habits. The change in sleep habits could be seen as a result of the demands of employment, and the probable basis for difference in scores.

Adolescent↗