Short Sleep Length Research Articles

Quick returns, sleep, sleepiness and stress - An intra-individual field study on objective sleep and diary data.

Quick returns (<11 hours of rest between shifts) have been associated with shortened sleep length and increased sleepiness, but previous efforts have failed to find effects on sleep quality or stress. A shortcoming of most previous research has been the reliance on subjective measures of sleep. The aim of this study was to combine diary and actigraphy data to investigate intra-individual differences in sleep length, sleep quality, sleepiness, and stress during quick returns compared to day-day transitions. Of 225 nurses and assistant nurses who wore actigraphy wristbands and kept a diary of work and sleep for seven days, a subsample of 90 individuals with one observation of both a quick return and a control condition (day-day transition) was extracted. Sleep quality was assessed with actigraphy data on sleep fragmentation and subjective ratings of perceived sleep quality. Stress and sleepiness levels were rated every third hour throughout the day. Shifts were identified from self-reported working hours. Data was analyzed in multilevel models. Quick returns were associated with 1 hour shorter sleep length [95% confidence interval (CI) -1.23- -0.81], reduced subjective sleep quality (-0.49, 95% CI -0.69- -0.31), increased anxiety at bedtime (-0.38, 95% CI -0.69- -0.08) and increased worktime sleepiness (0.45, 95%CI 0.22- 0.71), compared to day-day transitions. Sleep fragmentation and stress ratings did not differ between conditions. The findings of impaired sleep and increased sleepiness highlight the need for caution when scheduling shift combinations with quick returns.

Difficulty Falling Asleep, Nocturnal Awakening, Sleep Dissatisfaction, and Irritability in the General Population.

Sleep disturbance is characterized by problems with sleep quantity and quality. However, the exact mechanisms and factors underlying sleep dissatisfaction in the general population remains unclear. This cross-sectional study collected sleep data and irritability level from individuals who visited hospitals for medical checkups or with unexplained physical symptoms using self-report questionnaires. This study included 328 individuals (157 males and 171 females). Bivariate correlation analyses revealed that irritability (ρ = 0.420; p < 0.0001), short sleep length (ρ = 0.405; p < 0.0001), difficulty falling asleep (ρ = 0.443; p < 0.0001), and nocturnal awakening (ρ = 0.528; p < 0.0001) were strongly correlated with sleep dissatisfaction. Multiple linear regression analyses among the overall individuals, following bivariate correlation analyses, indicated that stress at home (β = 0.245; p < 0.0001), irritability ( β= 0.172; p = 0.0021), difficulty falling asleep (β = 0.215; p < 0.0001), later bedtime (β = 0.140; p = 0.0331), and nocturnal awakening (β = 0.386; p < 0.0001) were independently correlated with sleep dissatisfaction, whilst short sleep length was not (β = 0.107; p = 0.1024). Further multivariable analyses revealed that difficulty falling asleep and nocturnal awakening were independently associated with each other. The obtained results were reproduced in the subgroup analyses among the 151 individuals taking medical checkups. In summary, major factors underlying sleep dissatisfaction in the general population included difficulty falling asleep and nocturnal awakening. Irritability was associated with difficulty falling asleep and sleep dissatisfaction. Carefully evaluating each of these sleep-related subscales and irritability may be beneficial in managing individuals with sleep problems.

Deficiency Serum Vitamin 25 (OH) D Levels Increase Risk Factors of Poor Quality Sleep in Resident at Sanglah Hospital

Introduction/aim: Serum vitamin D level, estimated as 25(OH) D, is related to an increase in number of physiological mechanisms of sleep. The circadian period of the sleep can be deferred with sun exposure and vitamin D supplementation. The mechanism of lower vitamin D level causing sleep disturbances is unknown, several possible mechanisms have been proposed. Receptors of vitamin D are commonly found in most human tissues, including central nervous system. Low level of vitamin D is related with an increased risk of sleep problems, such as low sleep quality, short sleep length and excessive drowsiness. This study aims to Methods: This study is an analytical study with a case-control design in resident st Sanglah Hospital from July-September 2021 Result: A total of 54 subjects were divided into case and control groups, age 25-35 years. From the statistical analysis using SPSS program on bivariate analysis with Chi-square obtained OR 12.6 (95% Confidence Interval=3.4-46.0; p=&lt;0,001). Multivariate analysis showed that cortisol serum had P-value &lt;0,001 Conclusion: Deficiency serum vitamin 25(OH) D levels increase risk factors of poor quality sleep thirteen times in resident at sanglah hospital Keywords: poor sleep quality, resident, vitamin 25 (OH) D, young people.

Day-of-week mood patterns in adolescents considering chronotype, sleep length and sex

In this study, the day-of-week effect on positive and negative affect, taking into account the moderating effect of chronotype, sleep length and sex, was analyzed. Ninety-four adolescents (16.1 ± 1.24 years old) attending high schools in the morning filled out diaries to assess the natural day-to-day fluctuations in mood and sleep. Using multilevel modeling, the results indicated that positive affect increased and negative affect decreased over the weekend. Negative affect was moderated by chronotype such that negative affect decreased less over the weekend in evening adolescents. Short sleep length was related to negative affect, and girls reported higher negative affect. Individual differences in weekly mood patterns should be taken into account when designing psychosocial interventions for adolescents.

Sleep Disturbances in Children With Autism Spectrum Disorder at a Malaysian Tertiary Hospital.

Introduction: Children with autism spectrum disorder (ASD) have a variety of co-morbid medical problems, including sleep disturbances. Prevalence of sleep disorders has been reported to be higher in this group as compared to the general population. Identifying sleep problems in children with ASD may help increase awareness and improve the overall quality of care for them. The aim of this study was to determine the prevalence of sleep problems and associated factors in a group of Malaysian children aged 6–16 years, with ASD.Method: This is a cross-sectional study at the Child Development Centre of UKM Medical Centre (UKM MC) on ASD children aged 6–16 years. Demographic data was obtained and the Sleep Disturbances Scale for Children (SDSC) questionnaire was completed by the main caregiver. Logistic regression analysis was used to determine factors related to higher total SDSC scores.Results: A total of 128 patients were recruited (111 boys) with a median age of 8 years 3 months (IQR: 2 years 10 months). Forty-seven (36.7%) of them obtained total SDSC scores in the pathological range with 19 (14.8%) scoring high for overall disturbances and 28 (21.9%) for at least one subtype of sleep disorders: 25 (19.5%) DIMS, 18 (14.1%) SBD, 10 (7.8%) DOES, 5 (3.9%) DOA, 6 (4.7%) SWTD, and 3 (2.3%) SHY. More than half of the children (57.8%) were reported to have sufficient sleep duration of 8–11 h, but longer sleep latency of at least 15 min (82.8%). Half of the ASD children also had co-morbidities in which one-third (34.4%) had attention-deficit hyperactivity disorder (ADHD). Using logistic regression analysis, four factors were significantly associated with higher total SDSC scores; female gender (p = 0.016), older age group (11–16 years old) (p = 0.039), shorter sleep length (p = 0.043), and longer sleep latency (p < 0.001).Conclusion: The prevalence of sleep disturbances is high among Malaysian children with ASD, especially DIMS. Female gender, older age group, shorter sleep length, and longer sleep latency were found to be associated with the sleep disturbances. Evaluation of sleep problems should form part of the comprehensive care of children with ASD.

Kanashibari Phenomenon as a Sleep Disorder: Recurrent Idiopathic Sleep Paralysis

The phenomenon called kanashibari in Japan is otherwise known as sleep paralysis and, is an established symptom of narcolepsy. Its physiological correlate is an unusual occurrence of rapid eye movement (REM) sleep, i.e., sleep onset REM periods (SOREMPs). Various symptoms of the phenomenon are explained by the mechanisms of REM sleep. SOREMPs can be observed in various situations, which indicate a lower amplitude of circadian rhythms, such as during interupted sleep, acute reversal of sleep and wakefulness cycle, and disrupted sleep of depressive patients and in newborn babies. The lifetime prevalence of the phenomenon in the general population is as high about 40%. The phenomenon can be a mysterious and frightening experience far affected people and called as various names according to the folklore beliefs of local communities, e.g., nightmare in Europe, hexendrücken in Germany, cauchemar in France, and old hag in Newfoundland. Japanese college students are known for their very short sleep length and disturbed sleep wake rhythms. Many students claim to have experienced daytime sleepiness. Some of them meet the criterion concerning sleep latencies and frequency of SOREMPs for multiple sleep latency test (MSLT) as narcolepsy. SOREMPs are frequently seen in healthy college students with certain lifestyles. Practitioners should be cautious to diagnose narcolepsy if the student shows disturbed sleep wake schedules.

Poor tap water quality experiences and poor sleep quality during the Flint, Michigan Municipal Water Crisis

ObjectivesAfter inadequate official response to community concerns over water quality following changes in Flint's municipal water supply, this study sought evidence for a relationship between water quality and community mental health. DesignThe Speak to Your Health Community Survey is a community-based participatory component of the health surveillance system in Genesee County, Michigan. This cross-sectional survey recruits participants from every residential Census Tract of the county and strives for demographic representativeness. ResultsRespondents (n=834) rated their tap water quality (taste, smell, appearance) as poor (36%), fair (18%), good (20%), very good (17%), and excellent (10%). They rated their sleep quality as poor (12%), fair (28%), good (39%), very good (18%), and excellent (4%), and had an average (SD) sleep length of 408(90) minutes. Controlling for age, sex, years of education, and whether respondents were African American and Hispanic/Latino/a, lower perceived tap water quality was associated with lower sleep quality and shorter sleep length. ConclusionResults indicate that adverse health conditions related to the water crisis extend beyond lead poisoning in children and include deterioration of sleep conditions among adult residents.

College Students’ Prevalence of Sleep Hygiene Awareness and Practices

Research has consistently found that college students report short sleep length and poor sleep quality. As a result of their poor sleep quality, there is concern that college students may struggle with issues associated with academic performance, physical health, and mental health. Previous research has investigated a multitude of factors that may contribute to poor sleeping behaviors, including sleep hygiene awareness and practices. The current study found that participants were obtaining less than the recommended average hours of sleep. Results indicated an almost equal number of participants reported poor sleep quality, average sleep quality, and good sleep quality. Results also indicated that between 40-50% of the sample reported difficulties related going to bed, falling asleep, maintaining sleep, reinitiating sleep, and returning to wakefulness. Although participants in the present study reported sleep hygiene awareness, their knowledge is not associated with their sleep practices. Based on these results, it may be implied that improving or increasing sleep hygiene knowledge is not an intervention that would be effective in improving sleep hygiene practices.

Morningness–eveningness and sleep habits at school: a comparative study between Mexico and Spain

Morningness–eveningness and sleep habits relationship were studied between Mexican and Spanish adolescents. A total sample of 611 Mexican and Spanish adolescents (13–15 years old; 14.12 ± 0.75) participated in this comparative study and filled out the preferred timing of sleep and activity using item 19 of Morningness–Eveningness Questionnaire and reported sleep habits from open questions about typical bed and rise times during the weekdays and weekends. Spanish adolescents reported differences in sleep habits according to sex and chronotype, whereas Mexican adolescents only reported differences regarding chronotype on weekends. When country effect was analyzed, the most relevant result was the short sleep length on weekdays of Mexican adolescents (7:11 vs. 8:05), who reported earlier weekday rise time (6:11 vs. 7:15) but similar weekday bedtime (23:00 vs. 23:09) compared to Spanish adolescents. Sleep habits among Mexicans seem more influenced by a social factor related to school schedule than environmental factor related to latitude.

The relationship between self-reported sleep quality and reading comprehension skills

Inadequate sleep undermines many cognitive functions, including memory, concentration, and attention, which are vital in everyday activities. We hypothesized that poor quality or shorter sleep length may impair reading-related skills, resources, and outcomes, specifically verbal working memory span, verbal efficiency, and reading comprehension. Contrary to the hypotheses, neither short sleep length nor self-reported sleep quality were related to reading skills performance. However, longer sleep times were significantly related to lower verbal efficiency, and participants with the poorest sleep quality fared significantly better on the reading comprehension task than participants with moderate sleep quality. Given the paucity of research examining sleep and reading specifically, as well as these surprising data, more research in this area is warranted.

The effect of self-reported habitual sleep quality and sleep length on autobiographical memory

A large number of studies have recently shown effects of sleep on memory consolidation. In this study the effects of the sleep quality and sleep length on the retention of autobiographical memories are examined, using an Internet-based diary technique (Kristo, Janssen, & Murre, 2009). Each of over 600 participants recorded one recent personal event and was contacted after a retention interval that ranged from 2 to 46 days. Recall of the content, time, and details of the event were scored and related to sleep quality and sleep length as measured with the Pittsburgh Sleep Quality Index. Hierarchical regression analyses indicated that poor sleep quality, but not short sleep length, was associated with significantly lower recall at the longer retention periods (30–46 days), but not at the shorter ones (2–15 days), although the difference in recall between good and poor sleepers was small.

The Pattern of Entrainment of the Human Sleep-Wake Rhythm by the Natural Photoperiod in the North

Recently, it was shown that the sleep-wake rhythm of the inhabitants of the temperate zone is entrained to sun time. In the North, significant seasonal changes in the photoperiod may interfere with entrainment of the circadian system to sunlight. This investigation assessed the influence of photoperiod characteristics on the sleep length and sleep-wake rhythm of residents of high latitude. The study was conducted in four towns and six villages located between 59.5°N and 67.6°N latitude between the months of October and May from 2009 through 2011 and included 2822 subjects aged 10 to 97 yrs, 1621 of whom were females and 1201 males. The chronotype and sleep length of the subjects were assessed using the Munich Chronotype Questionnaire. The instructions for the questionnaire stressed the need to specify the sleep-wake schedule during the week preceding the date of completing the questionnaire. The study found that the length of sleep and the chronotype of the inhabitants surveyed in Northern European Russia depend on age, sex, type of settlement, and place of residence. The time of sunrise was a stronger predictor of sleep length and chronotype than the time of sunset and day length. A later chronotype and shorter sleep length were found for the subjects during the equinox (sunrise at 06:00 h) than under long-photoperiod conditions (sunrise at 04:00–05:00 h). During short-photoperiod conditions (sunrise at 07:00–10:00 h), no significant changes in the self-reported sleep-wake rhythm were found. The time of sunrise had the strongest impact on the sleep-wake rhythm of 30- to 97-yr-old persons. Sunrise had a stronger influence on chronotype and sleep length in January to May, when the days become longer, than in October to December, when the days become shorter. Age- and season-associated changes were found in the entrainment of the sleep-wake rhythm by photoperiod in the North. (Author correspondence: borisenkov@physiol.komisc.ru)

Prevalence and correlates of self‐induced vomiting as weight‐control strategy among adolescents in Taiwan

This study was designed to assess the prevalence and correlates of self-induced vomiting to control body weight among adolescents in Taiwan. Over the past decades, the rate of obesity among children in Taiwan has nearly tripled. Educational authorities have devoted considerable effort to prevent the increase in childhood obesity. An observational exploratory design to investigate the problem of using unhealthy weight-reduction strategy. This study consists of a cross-sectional study aimed at collecting national representative data. We chose 120 representative schools using a three-stage stratified systematic sampling design with probability proportionate to the size of the population in Taiwan. Participants consisted of 8673 girls and 7043 boys, aged 10-18 old. Of the participants, 13% reported using self-induced vomiting, the prevalence being highest in participants aged 10-12 (15·9%) and lowest in participants aged 16-18 (7·5%). Several factors were significantly and positively associated with the use of self-induced vomiting as a weight-loss strategy, specifically subjects who (1) watched television, used computer, surfed the Internet or played video games for greater than or equal to two hours/day, (2) consumed fried food every day and (3) ate night-time snacks every day (odds ratio = 1·55, 2·10 and 1·51, respectively; p < 0·05). Eating breakfast every day and sleeping for more than eight hours a day were both protective factors against the use of self-induced vomiting to control body weight (odds ratio = 0·43 and 0·86, respectively; p < 0·05). Self-induced vomiting was prevalent among adolescents who had tried to lose weight; sedentary lifestyle, shorter sleep length and unhealthy eating habits may contribute significantly to this behaviour among these adolescents. School nurses who are helping adolescents lose weight should also pay attention to the possibility they are using self-induced vomiting as a weight-control strategy.

Relationships between sleep, physical activity and human health

Although sleep and exercise may seem to be mediated by completely different physiological mechanisms, there is growing evidence for clinically important relationships between these two behaviors. It is known that passive body heating facilitates the nocturnal sleep of healthy elderly people with insomnia. This finding supports the hypothesis that changes in body temperature trigger somnogenic brain areas to initiate sleep. Nevertheless, little is known about how the core and distal thermoregulatory responses to exercise fit into this hypothesis. Such knowledge could also help in reducing sleep problems associated with nocturnal shiftwork. It is difficult to incorporate physical activity into a shiftworker's lifestyle, since it is already disrupted in terms of family commitments and eating habits. A multi-research strategy is needed to identify what the optimal amounts and timing of physical activity are for reducing shiftwork-related sleep problems. The relationships between sleep, exercise and diet are also important, given the recently reported associations between short sleep length and obesity. The cardiovascular safety of exercise timing should also be considered, since recent data suggest that the reactivity of blood pressure to a change in general physical activity is highest during the morning. This time is associated with an increased risk in general of a sudden cardiac event, but more research work is needed to separate the influences of light, posture and exercise per se on the haemodynamic responses to sleep and physical activity following sleep taken at night and during the day as a nap.

Short Sleep Is Associated with Obesity among Truck Drivers

Recent studies suggest that short‐sleep duration is independently associated with obesity in the general population. The population of truck drivers is of particular interest, because they frequently work irregular shifts that in turn are associated with short‐sleep duration. In addition, truck drivers have a high prevalence of sedentary habits, poor diet, and obesity. The present study aimed at verifying the association between sleep patterns and factors associated with obesity in this population. The study sample consisted in 4,878 truck drivers who participated in a campaign promoted by a highway company in the State of São Paulo, Brazil. This campaign offered highway truck drivers a medical and laboratorial evaluation. The truck drivers completed a questionnaire concerning demographic data, sleep duration, consumption of medications, and medical problems, such as diabetes, cardiopathy, and hypertension; as well as the Berlin questionnaire, which is able to discriminate low and high risk for obstructive sleep apnea. Blood samples were collected to measure glucose and cholesterol levels. Also, body weight and height were registered to calculate the body mass index (BMI). The mean age (±SD) of the truck drivers studied was 40±10 years. Out of the truck drivers analyzed, 28.3% (n=1,379) had a BMI ≥30.0 Kg/m2 (obesity). Among the 4,878 drivers included in the study, 1,199 (24.6%) were on medications and 334 (6.8%) were diabetic. Drivers (26.9%) with the greater BMI had a short sleep length. The independent factors associated with obesity were sleep duration <8 h/day (OR=1.24), age >40 years (OR=1.20), glucose levels >200 (OR=2.02), cholesterol levels >240 (OR=1.57), snoring (OR=1.74), and hypertension (OR=2.14). Smoking was not associated with obesity (OR=0.69), and diabetes was considered a control variable. In conclusion, this study supports the hypothesis that short sleep duration as well as age >40 years are independently associated with obesity. This particular combination (short‐sleep duration and obesity) is independently associated with several healthcare problems, including high levels of cholesterol, glucose, snoring, and hypertension. However, due to the cross‐sectional nature of this study, no cause–effect relationship can be drawn from these results.

Sleep-Wake Patterns of Student Workers and Non-Workers

Adolescents usually exhibit late sleep phase and irregular sleep patterns. As a result, they do not get enough sleep and report daytime sleepiness. This condition could be aggravated in working students who have a more limited time for sleep. In this survey, we investigated the impact of evening classes and employment on the sleep patterns of adolescents. We compared female (n = 17) and male (n = 14) non-worker students to female (n = 28) and male (n = 20) worker students who attended the same high school. The volunteers (aged 17.4 years ± 11 months) answered a sleep log during a 16-day period. Worker students slept and woke up earlier, had a shorter nocturnal sleep length and a shorter daily (nocturnal plus diurnal) sleep length compared to non-working pupils. The four groups of students delayed sleep onset time on weekends, but only worker students delayed wake-up time on Sundays. The wake-up time was similar among groups on Sundays. While student workers tended to increase the sleep length in the weekends, non-working students increased it on Mondays and/or Tuesdays. The results showed that sleep schedules and sleep length were different according to the work status. Going to bed later on Saturday by the four groups of students suggests the influence of social activities, while a later wake-up time on Sundays could result from a shorter sleep length on workdays.

The Influence of Study Schedules and Work on the Sleep–Wake Cycle of College Students

College students usually exhibit an irregular sleep-wake cycle characterized by great phase delays on weekends and short sleep length on weekdays. As the temporal organization of social activities is an important synchronizer of human biological rhythms, we investigated the role played by study's schedules and work on the sleep-wake cycle. Three groups of female college students were investigated: (1) no-job morning group, (2) no-job evening group, (3) job evening group. The volunteers answered a sleep questionnaire in the classroom. The effects of day of the week and group on the sleep schedules and sleep length were analyzed by a two way ANOVA for repeated measures. The three groups showed delays in the wake up time on weekends. No-job evening and morning groups also delayed bedtime, but the job evening group slept at the same time on weekdays as on weekends. Sleep length increased on weekends for morning group and job evening group, whereas the no-job evening group maintained the amount of sleep from weekdays to weekends. This survey showed that the tendency of phase delay on weekends was differently expressed according to study's schedules and work.