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- Kaida, Kaida, et al.
(author)
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Performance prediction by sleepiness-related subjective symptoms during 26-hour sleep deprivation
- 2008
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In: Sleep and Biological Rhythms. - : Springer Science and Business Media LLC. - 1446-9235 .- 1479-8425. ; 6:4, s. 234-241
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Journal article (peer-reviewed)abstract
- Sleepiness is a major cause of lower productivity and higher risk of accidents in various work situations. Developing sleepiness monitoring techniques is important to improve work efficiency and to reduce accident risk, so that people can take a rest/break in appropriate timing before an accident or a mistake occurs. The aims of the present study are (1) to explain subjective sleepiness using sleep-related symptoms, and (2) to examine which symptoms are useful to predict performance errors. Participants were healthy paid volunteers (six males, six females; mean +/- SD, 31.5 +/- 10.74 years). Participants took part in 26-h sleep deprivation. During sleep deprivation, they carried out several performance tasks every 3 h and an hourly rating of questionnaires to evaluate subjective symptoms including two types of Karolinska sleepiness scale (KSS). The present study confirmed that performance errors can be predicted by subjective symptoms. While mental fatigue was correlated to KSS scores linearly, eye-related subjective symptoms showed quadratic correlations to KSS. By taking into consideration this noteworthy relationship between subjective symptoms and sleepiness, more accurate introspection of sleepiness and performance errors prediction (detection) may be possible.
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| 2. |
- Marshall, N.S., et al.
(author)
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Changes in sleep duration and changes in weight in obese patients: The Swedish Obese Subjects Study
- 2010
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In: Sleep and Biological Rhythms. - : Springer Science and Business Media LLC. - 1479-8425 .- 1446-9235. ; 8:1, s. 63-71
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Journal article (peer-reviewed)abstract
- Sleep duration has been linked to obesity and/or weight gain in a number of cross-sectional and longitudinal observational studies. The Swedish Obese Subjects Study (SOS) is a non-randomized controlled trial of surgical interventions (surgical group) for weight-loss compared with standard conservative weight loss management (control group). We investigated whether changes in sleep duration were associated with weight loss in severely obese patients. This is a longitudinal treatment study reanalyzed as two 10-year cohorts, surgical (n= 1139) and control (n= 952). Self-reported habitual sleep duration, body weight, total cholesterol, HDL (high density lipoprotein) cholesterol, triglycerides, fasting glucose, and blood pressure were measured at baseline, 2 years, and 10 years. At baseline patients were obese (inclusion: body mass index [BMI]≥34 for men and ≥38 for women) and middle aged (37–60 years). The surgical group had substantially greater weight reduction after 10 years (–19.1 kg) compared with the control group (+1.2 kg). Changes in sleep duration between baseline, 2 years, and 10 years were not associated with body mass or with changes in weight in either cohort. Changes in cardiovascular disease (CVD) risk factors were not associated with changes in sleep duration. Changes in sleep duration over 2 and 10 years were not associated with weight loss in these obese patients. The data from the SOS study offers no support to the hypothesis that sleep-duration modification is associated with obesity reduction in severely obese people.
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| 3. |
- Nagai-Manelli, Roberta, et al.
(author)
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Sleep length, working hours and socio-demographic variables are associated with time attending evening classes among working college students
- 2012
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In: Sleep and Biological Rhythms. - : Springer Science and Business Media LLC. - 1446-9235 .- 1479-8425. ; 10:1, s. 53-60
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Journal article (peer-reviewed)abstract
- It is the aim of the present study to assess factors associated with time spent in class among working college students. Eighty-two working students from 21 to 26 years old participated in this study. They were enrolled in an evening course of the University of São Paulo, Brazil. Participants answered a questionnaire on living and working conditions. During seven consecutive days, they wore an actigraph, filled out daily activity diaries (including time spent in classes) and the Karolinska Sleepiness Scale every three hours from waking until bedtime. Linear regression analyses were performed in order to assess the variables associated with time spent in classes. The results showed that gender, sleep length, excessive sleepiness, alcoholic beverage consumption (during workdays) and working hours were associated factors with time spent in class. Thus, those who spent less time in class were males, slept longer hours, reported excessive sleepiness on Saturdays, worked longer hours, and reported alcohol consumption. The combined effects of long work hours (>40 h/week) and reduced sleep length may affect lifestyles and academic performance. Future studies should aim to look at adverse health effects induced by reduced sleep duration, even among working studentswho spent more time attending evening classes.
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| 4. |
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| 5. |
- Demir, Ahmet U., et al.
(author)
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Prevalence of sleep disorders in the Turkish adult population epidemiology of sleep study
- 2015
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In: Sleep and Biological Rhythms. - : Springer Science and Business Media LLC. - 1446-9235 .- 1479-8425. ; 13, s. 298-308
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Journal article (peer-reviewed)abstract
- © 2015 Japanese Society of Sleep Research. Sleep disorders constitute an important public health problem. Prevalence of sleep disorders in Turkish adult population was investigated in a nationwide representative sample of 5021 Turkish adults (2598 women and 2423 men, response rate: 91%) by an interviewer-administered questionnaire. Insomnia was defined by the DSM-IV criteria, habitual snoring and risk for sleep-related breathing disorders (SDB) by the Berlin questionnaire, excessive daytime sleepiness (EDS) by the Epworth sleepiness scale score, and restless legs syndrome (RLS) by the complaints according to the International Restless Legs Syndrome Study Group criteria. Mean age of the participants was 40.7 ± 15.1 (range 18 to 90) years. Prevalence rates (men/women) were insomnia 15.3% (10.5%/20.2%; P < 0.001), high probability of SDB 13.7% (11.1%/20.2%; P < 0.001), EDS 5.4% (5.0%/5.7%; P: 0.09), RLS 5.2% (3.0%/7.3%; P < 0.001). Aging and female gender were associated with higher prevalence of sleep disorders except for habitual snoring. Prevalence rates of the sleep disorders among Turkish adults based on the widely used questionnaires were close to the lower end of the previous estimates reported from different parts of the world. These findings would help for the assessment of the health burden of sleep disorders and addressing the risk groups for planning and implementation of health care. Sleep and Biological Rhythms
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| 6. |
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| 7. |
- Lin, C. -Y, et al.
(author)
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Advanced psychometric testing on a clinical screening tool to evaluate insomnia : sleep condition indicator in patients with advanced cancer
- 2020
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In: Sleep and Biological Rhythms. - : Springer. - 1446-9235 .- 1479-8425. ; 18, s. 343-349
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Journal article (peer-reviewed)abstract
- Purpose: To examine the psychometric properties of the Sleep Condition Indicator (SCI) using different psychometric approaches [including classical test theory, Rasch models, and receiver operating characteristics (ROC) curve] among patients with advanced cancer.Methods: Through convenience sampling, patients with cancer at stage III or IV (n = 859; 511 males; mean ± SD age = 67.4 ± 7.5 years) were recruited from several oncology units of university hospitals in Iran. All the participants completed the SCI, Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Hospital Anxiety and Depression Scale (HADS), General Health Questionnaire (GHQ), and Edmonton Symptom Assessment Scale (ESAS). In addition, 491 participants wore an actigraph device to capture objective sleep.Results: Classical test theory [factor loadings from confirmatory factor analysis = 0.76–0.89; test–retest reliability = 0.80–0.93] and Rasch analysis [infit mean square (MnSq) = 0.63–1.31; outfit MnSq = 0.61–1.23] both support the construct validity of the SCI. The SCI had significant associations with ISI, PSQI, ESS, HADS, GHQ, and ESAS. In addition, the SCI has satisfactory area under ROC curve (0.92) when comparing a gold standard of insomnia diagnosis. Significant differences in the actigraphy measure were found between insomniacs and non-insomniacs based on the SCI score defined by ROC.Conclusion: With the promising psychometric properties shown in the SCI, healthcare providers can use this simple assessment tool to target the patients with advanced cancer who are at risk of insomnia and subsequently provide personalized care efficiently.
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| 9. |
- Nordin, Maria, et al.
(author)
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Psychometric evaluation and normative data for the Karolinska Sleep Questionnaire
- 2013
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In: Sleep and Biological Rhythms. - Hoboken : Springer Science and Business Media LLC. - 1446-9235 .- 1479-8425. ; 11:4, s. 216-226
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Journal article (peer-reviewed)abstract
- The study objective was to validate the Karolinska Sleep Questionnaire with regard to dimensionality, internal consistency, and construct and criterion validity. Another objective was to provide normative data. Data from the cross-sectional Vasterbotten Environmental Health Study in Sweden were used. The 3406 participants in this study, 18 to 79 years old, constituted a random sample stratified for age and sex. Along with the Karolinska Sleep Questionnaire, the participants responded to the Hospital Anxiety and Depression Scale, the Perceived Stress Scale, and the Shirom Melamed Burnout Questionnaire for assessing construct validity. Factor analyses of the questions in the Karolinska Sleep Questionnaire that relate to nocturnal sleep revealed the dimensions sleep quality, non-restorative sleep, and sleep apnea. A separate factor analysis on the questions regarding day time sleepiness revealed a sleepiness dimension. The sleep quality, non-restorative sleep, and sleepiness dimensions showed approximate normal distributions, whereas the distribution for sleep apnea was positively skewed. All dimensions showed good internal consistency. Satisfactory construct validity was found for all dimensions. Using the DSM-IV criteria of insomnia, relevant questions in the Karolinska Sleep Questionnaire were combined into an index of nocturnal symptoms of insomnia as were questions of sleep apnea. Prevalences of insomnia and sleep apnea correspond well to those of other studies, indicating good criterion validity. The favorable psychometric properties of the dimensions and indexes from the Karolinska Sleep Questionnaire suggest their use for assessing sleep quality, non-restorative sleep, sleep apnea, sleepiness and nocturnal symptoms of insomnia.
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| 10. |
- van Leeuwen, Wessel M. A., et al.
(author)
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Physiological and autonomic stress responses after prolonged sleep restriction and subsequent recovery sleep in healthy young men
- 2018
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In: Sleep and Biological Rhythms. - : Springer Science and Business Media LLC. - 1446-9235 .- 1479-8425. ; 16:1, s. 45-54
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Journal article (peer-reviewed)abstract
- PurposeSleep restriction is increasingly common and associated with the development of health problems. We investigated how the neuroendocrine stress systems respond to prolonged sleep restriction and subsequent recovery sleep in healthy young men.MethodsAfter two baseline (BL) nights of 8 h time in bed (TIB), TIB was restricted to 4 h per night for five nights (sleep restriction, SR, n = 15), followed by three recovery nights (REC) of 8 h TIB, representing a busy workweek and a recovery weekend. The control group (n = 8) had 8 h TIB throughout the experiment. A variety of autonomic cardiovascular parameters, together with salivary neuropeptide Y (NPY) and cortisol levels, were assessed.ResultsIn the control group, none of the parameters changed. In the experimental group, heart rate increased from 60 ± 1.8 beats per minute (bpm) at BL, to 63 ± 1.1 bpm after SR and further to 65 ± 1.8 bpm after REC. In addition, whole day low-frequency to-high frequency (LF/HF) power ratio of heart rate variability increased from 4.6 ± 0.4 at BL to 6.0 ± 0.6 after SR. Other parameters, including salivary NPY and cortisol levels, remained unaffected.ConclusionsIncreased heart rate and LF/HF power ratio are early signs of an increased sympathetic activity after prolonged sleep restriction. To reliably interpret the clinical significance of these early signs of physiological stress, a follow-up study would be needed to evaluate if the stress responses escalate and lead to more unfavourable reactions, such as elevated blood pressure and a subsequent elevated risk for cardiovascular health problems.
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