31 research outputs found

    Sleep Timing in Late Autumn and Late Spring Associates With Light Exposure Rather Than Sun Time in College Students

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    Timing of the human sleep-wake cycle is determined by social constraints, biological processes (sleep homeostasis and circadian rhythmicity) and environmental factors, particularly natural and electrical light exposure. To what extent seasonal changes in the light-dark cycle affect sleep timing and how this varies between weekdays and weekends has not been firmly established. We examined sleep and activity patterns during weekdays and weekends in late autumn (standard time, ST) and late spring (daylight saving time, DST), and expressed their timing in relation to three environmental reference points: clock-time, solar noon (SN) which occurs one clock hour later during DST than ST, and the midpoint of accumulated light exposure (50% LE). Observed sleep timing data were compared to simulated data from a mathematical model for the effects of light on the circadian and homeostatic regulation of sleep. A total of 715 days of sleep timing and light exposure were recorded in 19 undergraduates in a repeated-measures observational study. During each three-week assessment, light and activity were monitored, and self-reported bed and wake times were collected. Light exposure was higher in spring than in autumn. 50% LE did not vary across season, but occurred later on weekends compared to weekdays. Relative to clock-time, bedtime, wake-time, mid-sleep, and midpoint of activity were later on weekends but did not differ across seasons. Relative to SN, sleep and activity measures were earlier in spring than in autumn. Relative to 50% LE, only wake-time and mid-sleep were later on weekends, with no seasonal differences. Individual differences in mid-sleep did not correlate with SN but correlated with 50% LE. Individuals with different habitual bedtimes responded similarly to seasonal changes. Model simulations showed that light exposure patterns are sufficient to explain sleep timing in spring but less so in autumn. The findings indicate that during autumn and spring, the timing of sleep associates with actual light exposure rather than sun time as indexed by SN

    The relationship between dementia severity and rest/activity circadian rhythms

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    Patients with dementia have been shown to have disturbed sleep/wake rhythms. There is evidence of impairment in endogenous generation of rhythms and deficient environmental cues in this population. This study sought to examine patterns of rest/activity rhythms as they relate to dementia severity. Three days of actigraphy were collected from 150 nursing-home patients with dementia and used to compute rhythm parameters. Dementia severity was estimated with the Mini-Mental State Examination (MMSE). The relationship between rhythm parameters and dementia severity was examined. Rhythm parameters were not associated with dementia in the sample as a whole, but relationships emerged when the sample was divided on the basis of overall rhythm robustness (F-statistic). Within the group with less robust rhythms, those with stronger rhythms had less severe dementia. In the group with more robust rhythms, milder dementia was associated with having an earlier acrophase (timing of the peak of the rhythm) and narrower peak of the rhythm (shorter duration of peak activity). These results suggested a three-stage model of rest/activity rhythm changes in dementia in which dementia patients have a rapid decline in rhythmicity followed by a slight return to stronger rhythms. In the later stages of dementia, rhythms decline even further

    Sleepiness is a signal to go to bed: data and model simulations

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    Study Objectives Assess the validity of a subjective measure of sleepiness as an indicator of sleep drive by quantifying associations between intra-individual variation in evening sleepiness and bedtime, sleep duration, and next morning and subsequent evening sleepiness, in young adults. Methods Sleep timing and sleepiness were assessed in 19 students in late autumn and late spring on a total of 771 days. Karolinska Sleepiness Scales (KSS) were completed at half-hourly intervals at fixed clock times starting four hours prior to participants’ habitual bedtime, and in the morning. Associations between sleepiness and sleep timing were evaluated by mixed model and non-parametric approaches and simulated with a mathematical model for the homeostatic and circadian regulation of sleepiness. Results Intra-individual variation in evening sleepiness was very large, covering four or five points on the 9-point KSS scale, and was significantly associated with subsequent sleep timing. On average, a one point higher KSS value was followed by 20 min earlier bedtime, which led to 11 min longer sleep, which correlated with lower sleepiness next morning and following evening. Associations between sleepiness and sleep timing were stronger in early compared to late sleepers. Model simulations indicated that the directions of associations between sleepiness and sleep timing are in accordance with their homeostatic and circadian regulation, even though much of the variance in evening sleepiness and details of its time course remain unexplained by the model. Conclusion Subjective sleepiness is a valid indicator of the drive for sleep which, if acted upon, can reduce insufficient sleep

    A novel BRCA-1 mutation in Arab kindred from east Jerusalem with breast and ovarian cancer

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    BACKGROUND: The incidence of breast cancer (BC) in Arab women is lower compared to the incidence in the Jewish population in Israel; still, it is the most common malignancy among Arab women. There is a steep rise in breast cancer incidence in the Arab population in Israel over the last 10 years that can be attributed to life style changes. But, the younger age of BC onset in Arab women compared with that of the Jewish population is suggestive of a genetic component in BC occurrence in that population. METHODS: We studied the family history of 31 women of Palestinian Arab (PA) origin affected with breast (n = 28), ovarian (n = 3) cancer. We used denaturing high performance liquid chromatography (DHPLC) to screen for mutations of BRCA1/2 in 4 women with a personal and family history highly suggestive of genetic predisposition. RESULTS: A novel BRCA1 mutation, E1373X in exon 12, was found in a patient affected with ovarian cancer. Four of her family members, 3 BC patients and a healthy individual were consequently also found to carry this mutation. Of the other 27 patients, which were screened for this specific mutation none was found to carry it. CONCLUSION: We found a novel BRCA1 mutation in a family of PA origin with a history highly compatible with BRCA1 phenotype. This mutation was not found in additional 30 PA women affected with BC or OC. Therefore full BRCA1/2 screening should be offered to patients with characteristic family history. The significance of the novel BRCA1 mutation we identified should be studied in larger population. However, it is likely that the E1373X mutation is not a founder frequent mutation in the PA population

    The European Insomnia Guideline : An update on the diagnosis and treatment of insomnia 2023

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    Publisher Copyright: © 2023 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.Progress in the field of insomnia since 2017 necessitated this update of the European Insomnia Guideline. Recommendations for the diagnostic procedure for insomnia and its comorbidities are: clinical interview (encompassing sleep and medical history); the use of sleep questionnaires and diaries (and physical examination and additional measures where indicated) (A). Actigraphy is not recommended for the routine evaluation of insomnia (C), but may be useful for differential-diagnostic purposes (A). Polysomnography should be used to evaluate other sleep disorders if suspected (i.e. periodic limb movement disorder, sleep-related breathing disorders, etc.), treatment-resistant insomnia (A) and for other indications (B). Cognitive-behavioural therapy for insomnia is recommended as the first-line treatment for chronic insomnia in adults of any age (including patients with comorbidities), either applied in-person or digitally (A). When cognitive-behavioural therapy for insomnia is not sufficiently effective, a pharmacological intervention can be offered (A). Benzodiazepines (A), benzodiazepine receptor agonists (A), daridorexant (A) and low-dose sedating antidepressants (B) can be used for the short-term treatment of insomnia (≤ 4 weeks). Longer-term treatment with these substances may be initiated in some cases, considering advantages and disadvantages (B). Orexin receptor antagonists can be used for periods of up to 3 months or longer in some cases (A). Prolonged-release melatonin can be used for up to 3 months in patients ≥ 55 years (B). Antihistaminergic drugs, antipsychotics, fast-release melatonin, ramelteon and phytotherapeutics are not recommended for insomnia treatment (A). Light therapy and exercise interventions may be useful as adjunct therapies to cognitive-behavioural therapy for insomnia (B).Peer reviewe

    The Effects of Parental Intervention on Sleep Patterns and Electronic Media Exposure in Young Adolescents

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    Objective: This study evaluated the effectiveness of a parent-focused intervention aimed at the promotion of healthy sleep patterns and controlled exposure to electronic media (EM) in young adolescents. Participants: The sample included 70 dyads of parents (68 mothers and 2 fathers) and adolescents. Intervention and control groups each consisted of 35 young adolescents with a mean age of 10.7 (0.9) years old. Methods: Three waves of data collection included baseline, post-intervention, and 3 month follow-up. In each wave, adolescents reported habitual electronic media exposure and sleep patterns for a week and wore an actigraph for five nights. Parents in the intervention group participated in a six-session interactive workshop, while parents in the control group received equivalent written information by mail. Results: The intervention led to earlier bedtimes (p < 0.001), increased sleep efficiency (p < 0.01), increased sleep duration (p < 0.001) and reduced video games exposure (p < 0.01). Benefits were maintained at the follow-up. Conclusion: Interventions tailored for parents can create lasting positive changes in sleep patterns and EM exposure in young adolescents

    Cannabis and Alcohol Use and Their Associations with Sleep:A Daily Diary Investigation of Single-Use and Co-Use in College Students

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    Introduction: Sleep continuity problems are widespread among college students and may be influenced by single-use and co-use of alcohol and cannabis. We examined the within-person associations of alcohol and cannabis use with subsequent sleep experiences in the everyday life of college students. Materials and Methods: A sample of 80 college students reported prior-night alcohol and cannabis use and sleep experiences for 14 consecutive days. Mixed-effects models examined the within-person relationships between alcohol and cannabis use (single- and co-use) and subsequent (1) sleep-onset latency, (2) total sleep time, (3) number of awakenings, and (4) early awakenings that night. Results: Compared to no-use evenings, alcohol and cannabis, used separately or together (co-use), were associated with shorter sleep-onset latency and longer total sleep time. Students reported more nightly awakenings after alcohol-only use compared to no-use and after co-use, and they reported fewer early awakenings after no-use and co-use. Conclusions: In line with previous experimental findings, we found that alcohol and cannabis use in the everyday life of college students were associated with sleep-inducing effects, and that alcohol use was associated with disturbed sleep continuity. The results suggest that cannabis may curb alcohol's detrimental effect on the number of awakenings and may reduce the incidence of early awakenings. Yet, due to lack of control for potentially important confounders (e.g., quantity of cannabis/alcohol consumed, withdrawal) the current results may be best seen as preliminary and further research is needed before causal inferences can be reached.</p
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