PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Sleep length”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMed1990

Sleepiness and REM sleep recurrence: the effects of stage 2 and REM sleep awakenings.

Determinants of daytime sleepiness include sleep length, sleep continuity, and circadian factors. Sleep stage composition has not been seen as influencing subsequent daytime functioning; however, earlier studies did not focus explicitly on sleepiness. The present experiment studied the effects of selective sleep-stage restriction on an objective measure of sleep tendency, and explored the relationship between sleepiness and subsequent REM recurrence during REM deprivation. Daytime sleep latency was measured by a modified Multiple Sleep Latency Test prior to and following two nights of awakenings from either REM or Stage 2 sleep in 16 normal young adults. Sleep latency following these awakenings was also measured. REM sleep and Stage 2 awakenings produced comparable levels of sleepiness, both during the Awakening Nights and subsequent daytime Multiple Sleep Latency Testing. Pooling the groups, daytime and nocturnal sleepiness measures were correlated within individuals. In the REM-Awakening Group, Pre-Awakening daytime sleepiness was associated with the tendency for REM sleep to recur following experimental awakenings. Comparable levels of sleepiness may result from nonspecific processes such as sleep curtailment and fragmentation, or alternatively from separate REM and Stage 2 mechanisms. The relationship between REM sleep and sleepiness is discussed in the context of both state and trait models.

Adult↗
PubMed1988

Work at sea: a study of sleep, and of circadian rhythms in physiological and psychological functions, in watchkeepers on merchant vessels. II. Sleep duration, and subjective ratings of sleep quality.

Sleep length and sleep quality scores were collected on board ships over periods of up to two weeks from 38 watchkeepers working a '4-on/8-off routine' and 29 dayworkers. All watchkeepers exhibited fragmented sleeping patterns, which indicated a lack of adaptation of the sleep/wakefulness cycle to the hours of work. There were only slight differences in total sleep length between watchkeepers and dayworkers, however, both groups did not obtain an adequate amount of sleep. Within the watchkeeping crews the 3rd Officers had by far the shortest sleep length. Concerning sleep quality, daytime sleep was generally given the lowest ratings, whereas sleep starting before midnight was on average evaluated as the best, both by watchkeepers and dayworkers. Watchkeeping personnel do not normally have any "days off" during a voyage so that missed sleep might even amount to a sleep deficit. A solution for this problem could perhaps be a new, stabilized system that allows a single uninterrupted sleep, which is required for full recuperation, to be taken each day.

Circadian Rhythm↗
PubMed2004

Validity of child sleep diary questionnaire among junior high school children.

BACKGROUND: The validity of sleep quality and quantity indices as reported by schoolchildren has not been established. The purpose of this study is to evaluate the relationship between subjective sleep habits estimation and objective measurement data in schoolchildren. METHODS: The study consisted of 42 healthy junior high school children aged 13-14. Sleep log information was gathered over 7 consecutive days, using a sleep-monitoring device (Actiwatch) and a questionnaire which covered the following aspects for sleep quality and quantity: bed time, sleep latency, sleep start, sleep end, wake up and assumed sleep length. The means of the sleep indices for 5 weekdays were used for analysis. Pearson's correlation coefficients and paired t-tests were used to evaluate the correlation and difference between subjective and objective sleep parameters. RESULTS: The correlation coefficient between subjective and objective records was 0.49 (p < 0.001) for sleep latency, 0.99 (p < 0.001) for sleep start time, 0.99 (p < 0.001) for sleep end time, and 0.97 (p < 0.001) for assumed sleep length. The difference between subjective and objective records was 7.67 min (95% confidence interval [CI]: 4.64-10.71) for sleep latency, and 0:02 min (95% CI: -0:01-0:05) for sleep start time, 0:02 min (95% CI: 0:01-0:03) for sleep end time, and 8.19 min (95% CI: 4.93-11.45) for assumed sleep length. CONCLUSIONS: Although children tended to overestimate sleeping hours, the correlation between subjective and objective sleep indices except sleep latency was quite high. Thus, children's sleep questionnaire can be applied to surveys for sleep habits screening.

Adolescent↗
PubMed1988

Worry, anxiety, and preferred length of sleep.

Sixty-three female and 43 male undergraduates responded to a "worry" scale, a trait anxiety measure, and a question asking preferred length of sleep to clarify conflicting findings regarding the relationship between worry and anxiety and length of sleep (e.g., Hartmann, 1973; Hicks & Pellegrini, 1977; Kumar & Vaidya, 1984). Worry and length of sleep were positively correlated, supporting Hartmann's contentions. Anxiety was related to sleep in a U-shaped curvilinear fashion. Anxiety and worry were substantially correlated (r = .60) for subjects above the median on worry but were not correlated for subjects below the median. Worry may be the underlying construct in the positive relationship between anxiety and length of sleep for highly anxious persons. Comparison of high worry-low anxiety and low worry-high anxiety groups also suggests that our understanding of the relationships among sleep, anxiety, and worry may benefit from the simultaneous consideration of worry and anxiety factors.

Adolescent↗
PubMed2002

Changes of sleep or waking habits by age and sex in Japanese.

We analyzed the effects of age and sex on habitual sleep/wake rhythm and Morningness-Eveningness scores of 2,252 subjects (6-89 years) randomly selected in Shimonoseki, Japan. Subjects were divided into 21 age groups with a matching number of men and women in each age group. The most common sleep parameter patterns by age showed a v- or inverted v-pattern with a turning point in young adulthood or at the period of puberty. During the period between 6 yr. of age to puberty or young adulthood, the bedtimes on weekdays and weekends and the waking times on weekends were delayed, Morningness-Eveningness scores shifted to the evening type, and sleep length on weekdays decreased. After that period, across groups of increasing age, bedtime and waking time on weekdays and weekends became earlier, sleep length on weekdays and sleep latency increased, Morningness-Eveningness scores shifted to morning type, and the number of awakenings increased. The number of daytime naps increased in the 16-19 yr. group, decreased slightly after that age group, but increased again in older groups. The weekday bedtimes of women above 40 yr. of age was significantly later and their sleep lengths significantly shorter than those of men of the same age. Average sleep latency was longer for women than men. The number of awakenings was larger in women above 50 yr. of age than men of the same age group. The turning point of age, gained from the two linear regressions on data for subjects that have a minimum sum of squared error, was between 16 and 25 yr. of age. Average phase of sleep/wake rhythm shifted backward and sleep length decreased in groups from age 6 to puberty or young adulthood. After early adolescence, the average phase of the sleep/wake rhythm shifted forward, sleep latency became longer, and daytime napping increased. Number of awakenings increased rapidly for women's groups over 40 yr. of age and for men's groups after 50 yr. of age. Sex differences in our research are in apparent conflict with previous data and are discussed from the perspective of women's social and domestic roles in Japan.

Adolescent↗
PubMed2025

The impact of sleep duration on the incidence of new-onset chronic kidney disease in community-dwelling adults: a nationwide cohort study.

BACKGROUND: This research examined the association between sleep duration and new-onset chronic kidney disease (CKD) among community-dwelling middle-aged and elderly individuals in Korea. METHODS: This prospective cohort study utilized data from the Korean Genome and Epidemiology Study (KoGES) from 2001-2002 (baseline) to 2019-2020 (tenth follow-up visit). New-onset CKD was the primary outcome,&#xa0;defined as an estimated glomerular filtration rate <60&#x2009;mL/min/1.73 m2 or the proteinuria. Study populations were classified into six self-reported sleep length categories: <5h, 5h&#x2009;&#x2264; to <6h, 6h&#x2009;&#x2264;&#x2009;to <7h, 7h&#x2009;&#x2264; to &#x2264;8h, 8h&#x2009;<&#x2009;to <9h, and 9h/day &#x2264;. Cox proportional hazards models were used to ascertain the hazard ratios (HRs) and 95% confidence intervals (CIs) for CKD incidence across these categories. RESULTS: Over a median follow-up duration of 17.41&#x2009;years, CKD was identified in 551 (14.4%) of 3835 participants (mean age 48.7 &#xb1; 7.5&#x2009;years). After adjusting for confounding variables, a U-shaped relationship between sleep lengths and CKD was identified. Participants with insufficient (<5h) and excessive (9h &#x2264;) sleep length exhibited HRs for CKD incidence of 1.44 (1.09-1.89) and 1.85 (1.04-3.27), respectively, compared to individuals with normal sleep length (7h&#x2009;&#x2264;&#x2009;to &#x2264;8h). Age and sex differences were observed in the association between sleep length and CKD incidence. The association between sleep duration and new-onset CKD was significant only in participants aged 40 to 64&#x2009;years, with no significant association observed in individuals aged 65&#x2009;years and older. CONCLUSIONS: This research identified a relationship between the amount of sleep and CKD in Korean adults. Maintaining an appropriate sleep duration of 7-8&#x2009;h/day is important for preventing new-onset CKD.

Humans↗
PubMed2006

[Relationship between length of sleep and oxidative stress marker, urinary 8-hydroxy-2'-deoxyguanosine].

OBJECTIVES: In this study, we aim to examine whether the length of sleep modifies the level of urinary 8-hydroxy-2'-deoxyguanosine (8-OH-dG). METHODS: Subjects were 146 workers who were engaged in management, clerical work, laboratory work, or business at a certain company. We obtained information on the subjects concerning gender, body mass index, drinking and smoking habits, and the lengths of habitual and previous night sleep among others using self-reported questionnaires, which were then confirmed by interview. Urine specimens were collected in the morning and those from the second or later void were used to measure 8-OH-dG and creatinine levels. The amount of 8-OH-dG normalized by creatinine content was used as the indicator of 8-OH-dG excretion (Spot Urine 8-OH-dG: SU8-OH-dG). We excluded subjects who took sleeping pills the previous night or habitually, and those whose levels were beyond the three-standard-deviation range. The subjects were then classified into three equal-sized groups according to the length of sleep, either habitual or the previous night. RESULTS AND CONCLUSION: (1) A long or a short previous night's sleep, drinking alcohol more than once a week, and habitual use of medicine increased SU8-OH-dG level among female subjects. (2) A short previous night's sleep and habitual smoking, and a short previous night's sleep and habitual use of medicine had interactions which increased SU8-OH-dG level among male subjects but the length of a previous night's sleep itself did not have an effect on SU8-OH-dG level. (3) The length of habitual sleep had no effect on SU8-OH-dG level.

8-Hydroxy-2'-Deoxyguanosine↗
PubMedDate not supplied

Sleep disturbances in hospitalized patients with cancer.

PURPOSE/OBJECTIVES: To describe the relationship between nocturnal disturbances and sleep (length and quality) in hospitalized patients with cancer. DESIGN: Descriptive, correlational. SETTING: A regional oncology center located in a large teaching hospital. SAMPLE: Fifty hospitalized patients with cancer (58% female, x age = 48 years), all with solid tumors. METHODS: The investigator observed and recorded the number and characteristics of nocturnal disturbances using the Sleep Environment Observation Tool and the Taxonomy of Patient Participation. Patients completed the Verran and Snyder-Halpern Sleep Scale, which measures perceived sleep length and quality. MAIN RESEARCH VARIABLES: Number and timing of nocturnal disturbances, patient participation in care, sleep length, and sleep quality. FINDINGS: Number and total duration of nocturnal disturbances as well as level of patient participation in nocturnal care were negatively correlated with sleep quality. Sleep length was not correlated with any other variable. CONCLUSIONS: Nocturnal disturbances had a negative effect on sleep quality. IMPLICATIONS FOR NURSING PRACTICE: The number and duration of disturbances and the level of patient participation in care should be minimized during nighttime hours.

Adult↗
PubMed1994

The meaning of good sleep: a longitudinal study of polysomnography and subjective sleep quality.

The present study sought to investigate the meaning of subjectively good sleep, using a longitudinal and intraindividual design. Eight subjects slept in an isolation unit according to an irregular schedule of 6 h sleeps and 1 h naps, designed to give normal amounts of time in bed (1/3 of total), but variable sleep quality. Eight sleeps and eight naps were used for longitudinal simple and multiple regression analyses with standard polysomnographical sleep variables as predictors and subjective sleep quality as dependent variables. The results showed that subjective sleep quality (and related variables) was closely related to sleep efficiency, but not sleep stages. At least 87% efficiency was required for ratings of 'rather good' sleep. In addition, sleep quality ratings improved with closeness (of the awakening) to the circadian acrophase (17.00-21.00 hours) of the rectal temperature rhythm. The subjective ease of awakening differed from most other other variables in that it was related to low sleep efficiency. Objective and subjective homologues of sleep length and sleep latency showed high mean intraindividual correlations (r = 0.55 and 0.64, respectively). It was concluded that objective measures of sleep continuity were closely reflected in perceived sleep quality and that sleep quality essentially means sleep continuity.

Journal Article↗
PubMed1989

Sleep-wake patterns and subjective sleep quality of day and night workers: interaction between napping and main sleep episodes.

Five hundred and ninety-three women electronics workers were studied to determine if there was any association between their subjective sleep quality and their sleep patterns. They were 108 day workers, 107 permanent night workers, 216 workers on weekly phase-advance (night/afternoon/morning), and 162 workers on two-weekly phase-delay (morning/afternoon/night) rotating shift schedules. The study was part of a larger survey on night workers involving a self-administered questionnaire. The proportion of nappers was higher in night workers than in day, morning, and afternoon shift workers. Nappers had shorter main sleep, but their total sleep duration was generally the same as that of nonnappers. Compared to nonnappers, a higher proportion of day and morning shift workers who napped did not sleep well. Permanent night workers, with the highest proportion of nappers, had more workers sleeping well than rotating night workers. Subjects who slept well were those with longer total and main sleep and generally started the main sleep earlier. The results indicate a relationship between subjective sleep quality, sleep length, main sleep start, and napping behavior. Whether this relationship is causal is difficult to establish as sleep quality may also reflect the general health status, and this may result in differences in sleep behavior.

Adult↗
PubMedDate not supplied

Shiftwork and the older worker.

The number of workers employed on shiftwork is large, and it appears to be increasing. The impact of shiftwork on the occupational safety and health of workers is complex and involves both biological and behavioral variables. Current conceptual models propose that the impact of shiftwork, where night work is involved, increases with exposure. At some point the worker is said to reach a tolerance limit beyond which shiftwork is no longer safe. Sleep variables have proven to be sensitive markers for the effects of night shiftwork. Data from U.S. workers show a statistically significant interaction among age, gender, and shift for the workday sleep length of workers on permanent day, afternoon/evening, and night shifts. Sleep length declines with age for both male and female night workers, as well as for male workers on afternoon/evening shifts. In addition, female night workers in the 18-49 age range sleep significantly less than same-age male night workers. Nap behavior also varies with shift, but age and gender effects do not appear to account for the variance. The results support the assumption that most night shiftworkers are at risk even though they often give the appearance of being able to tolerate nocturnal work hours. However, it is not yet clear how age and gender are related to the social, circadian, and environmental factors that influence the sleep length of shiftworkers.

Adolescent↗
PubMed1990

Sleep reduction in night-shift workers: is it sleep deprivation or a sleep disturbance disorder?

Two explanations of the reported reduction in night-shift workers' sleep length have emerged. One argues that these reductions in sleep are related to sleep disturbances which may require medical treatment as disorders. The other argues that sleep reduction is mainly due to a sleep deficit caused by the voluntary choice to delay sleep onset and reduce the sleep duration which requires a systems approach aimed at increasing sleep length and reducing the effect of a sleep deficit at the workplace. Using survey data from 1078 industrial shift workers, this study demonstrates that permanent night workers reporting sleep difficulties, as well as those who do not, report sleep reductions. This finding is interpreted as supporting, in part, the position that night-shift workers suffer primarily from a self-induced sleep deficit.

Adolescent↗
PubMedDate not supplied

Locomotive engineers and their spouses: coffee consumption, mood, and sleep reports.

Locomotive engineers (train drivers) on irregular work schedules reported a general coffee consumption rate higher than that reported by a comparison sample of permanent shift factory workers. The present study examines the impact of this consumption on workday and non-workday sleep behaviour and mood ratings. Twenty-seven engineers and their spouses each completed daily logs for 30 consecutive days. Daily logs were then sorted into workday and non-workday categories. Workday sleep length was significantly shorter than non-workday sleep length for both engineers and spouses. For the engineers only, coffee consumption on workdays was higher than on non-workdays. This increased coffee consumption was correlated with longer sleep latency, increased negative mood, and decreased positive mood on both work and non-workdays. This was not true for spouses. These results may be related to a days-off carry-over effect of caffeine or a general consumption behaviour characteristic.

Adult↗
PubMed1983

Genetic and environmental determination of human sleep.

Self-reported sleep data from 2238 monozygotic and 4545 dizygotic adult twin pairs indicated a significant hereditary effect on sleep length [overall heritability estimate (h2 = 0.44)] and on sleep quality (h2 = 0.44). When the data were examined in subgroups defined by sex, age (18-24 years and 25 or more years of age), and cohabitation status of the twin pair, the highest heritability estimates for sleep length were for twins living together aged 25 or older. For twins living apart the heritability estimates were statistically significant in all women and men aged 25 or older. For sleep quality significant heritability estimates were found for all groups except women living together.

Adolescent↗
PubMed1995

We are chronically sleep deprived.

Data from recent laboratory studies indicate that nocturnal sleep periods reduced by as little as 1.3 to 1.5 hours for 1 night result in reduction of daytime alertness by as much as 32% as measured by the Multiple Sleep Latency Test (MSLT). Other data document that 1) 17%-57% of normal young adults have MSLT latencies of < or = 5.5 minutes, whereas < or = 50% have MSLT values of > or = 10 minutes and 2) 28%-29% of young adults reported normally sleeping < or = 6.5 hours on each weeknight. More extensive reduction of daily sleep amount is seen in nightshift workers. A minimum of 2%-4% of middle-aged adults have hypersomnolence associated with sleep apnea. Together, these data show that significant sleep loss exists in one-third or more of normal adults, that the effects are large and replicable and that similar effects can be produced in just 1 night in the laboratory. In light of the magnitude of this sleep debt, it is not surprising that fatigue is a factor in 57% of accidents leading to the death of a truck driver and in 10% of fatal car accidents and results in costs of up to 56 billion dollars per year. A recent sleep extension study suggests that the average underlying sleep tendency in young adults is about 8.5 hours per night. By comparison, the average reported sleep length of 7.2-7.4 hours is deficient, and common sleep lengths of < or = 6.5 hours can be disastrous. We must recognize the alertness function of sleep and the increasing consequences of sleepiness with the same vigor that we have come to recognize the societal impact of alcohol.

Adult↗
PubMed1999

Thermoregulatory model of sleep control: losing the heat memory.

Thermoregulatory mechanisms were hypothesized to provide primary control of non-rapid-eye-movement sleep (NREM). On the basis of this hypothesis, we incorporated the thermoregulatory feedback loops mediated by the "heat memory," heat load, and loss processes associated with sleep-wake cycles, which were modulated by two circadian oscillators. In addition, hypnogenic warm-sensitive neurons (HWSNs) were assumed to integrate thermoregulation and NREM control. The heat memory described above could be mediated by some sleep-promoting substances. In this paper, considering the possible carrier of the heat memory, its losing process is newly included in the model. The newly developed model can generate the appropriate features of human sleep-wake patterns. One of the special features of the model is to generate the bimodal distribution of the sleepiness. This bimodality becomes distinct, as the losing rate of the heat memory decreases or the amplitude of the Y oscillator increases. The theoretical analysis shows the losing rate of the heat memory control's rapidity of model response to a thermal perturbation, which is confirmed by simulating the responses with various losing rates to transient heat loads ("heat load pulse"). The sleepiness exhibits large responses to the heat load pulses applied in the early and late phases of wake period, while the response is significantly reduced to the pulse applied in the supposed wake-maintenance zone. This bimodality of the response appears to reflect the sensitivity of the HWSNs. In addition, the early pulse raises the immediate sleepiness rather than the nocturnal sleepiness, while the heat load pulse applied in the later phase of waking period significantly raises the sleepiness during a nocturnal sleep. In simulations of sleep deprivation, the discontinuous relationship between recovery sleep length and deprivation time is reproduced, where the critical sleep deprivation time at which the recovery sleep length jumps is extended as the losing rate increases. This is possibly due to the dissipation of the heat memory accumulated by the sleep deprivation. The simulation results here qualitatively reproduce the experimental observations or predict the intriguing phenomena of human circadian rhythms. Therefore, our model could provide a novel framework for investigating the relationship between thermoregulation and sleep control processes.

Algorithms↗
PubMed1992

Correlations between morningness-eveningness character, sleep habits and temperature rhythm in adolescents.

The correlations between morningness-eveningness character (Horne & Ostberg score), sleep habits and temperature acrophase of 62 adolescents (mean age 13 years and 6 months) were investigated on three occasions at 6-month intervals. Horne & Ostberg scores ranged from 29 to 74 with a similar distribution on the three occasions. Temperature acrophase mode occurred around 15:00 p.m. Earlier sleep onset time and wake-up time and earlier temperature acrophase were associated with morningness. The more evening type the adolescent was, the shorter was the sleep length on schools days and the longer was the sleep length on non-school days. Correlations between temperature acrophase and morningness-eveningness character were found in a subgroup of adolescents and require further confirmation. The correlations between morningness-eveningness and sleep habits were present on the three occasions investigated, indicating that these are stable correlations and that morningness-eveningness questionnaires can provide suitable information for studies of this age group.

Adolescent↗