Sleep Medicine Reviews RSS feed: Current Issue. Sleep Medicine Reviews provides International coverage of sleep disorders, their aetiology, diagnosis, treatment and implications for related conditions at an individual and public health level. Articles review the clinical information published in peer-reviewed journals devoted to the many disciplines involved in sleep medicine, including: pulmonology, psychiatry, psychology, physiology, otolaryngology, paediatrics, geriatrics, cardiology, dentistry, nursing, neurology and general medicine. The journal publishes narrative reviews, systematic reviews and editorials covering area of controversy and debate, as well as areas of future research. http://www.smrv-journal.com/?rss=yesElsevier Inc.en © 2012 Elsevier Ltd. All rights reserved. Sleep Medicine Reviews1087-0792163June 2012 © 2012 Elsevier Ltd. All rights reserved. healthpermissions@elsevier.comhttp://www.smrv-journal.com/article/PIIS108707921200024X/abstract?rss=yesObtaining sufficient sleep of adequate quality is increasingly becoming recognized as an important domain of healthy behavior. The Institute of Medicine has released two separate reports in recent years focused on the public health and safety implications of untreated sleep disorders and insufficient sleep. Further, adequate sleep has been included as a national health priority in Healthy People 2020.Sleep duration across the lifespan: Implications for healthMichael A. Grandner10.1016/j.smrv.2012.02.001Sleep Medicine Reviews 16, 3 (2012)2012-06-01Sleep Medicine Reviews2012-06-01163S1087-0792(12)X0003-0Guest editorial199201http://www.smrv-journal.com/article/PIIS1087079211000347/abstract?rss=yesSummary: Background: Sleep deficits are associated with a wide range of detrimental physical and mental health outcomes. There is concern that children are not getting enough sleep, and that sleep duration has been declining. However, evidence is sparse.Methods: A systematic review of world literature was conducted to locate studies reporting the sleep duration of children aged 5–18 years. Monte Carlo simulation was used to generate pseudodata from summary data, which were combined with raw data and analysed by linear regression of sleep duration on year of measurement at the age × sex × day type × country level.Results: Data were available on 690,747 children from 20 countries, dating from 1905 to 2008. From these data, 641 regressions were derived. The sample-weighted median rate of change was −0.75 min nightly per year, indicating a decrease of more than 1 h per night over the study period. Rates of change were negative across age, sex and day type categories, but varied according to region, with Europe, the USA, Canada and Asia showing decreases and Australia, the UK and Scandinavia showing increases.Conclusion: Over the last 103 years, there have been consistent rapid declines in the sleep duration of children and adolescents.In search of lost sleep: Secular trends in the sleep time of school-aged children and adolescentsLisa Matricciani, Timothy Olds, John Petkov10.1016/j.smrv.2011.03.005Sleep Medicine Reviews 16, 3 (2012)2012-06-01Sleep Medicine Reviews2012-06-01163S1087-0792(12)X0003-0Cinical reviews203211http://www.smrv-journal.com/article/PIIS1087079211000682/abstract?rss=yesSummary: This is a systematic review of the scientific literature with regard to normal sleep patterns in infants and children (0–12years). The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Mean and variability data for sleep duration, number of night wakings, sleep latency, longest sleep period overnight, and number of daytime naps were extracted from questionnaire or diary data from 34 eligible studies. Meta-analysis was conducted within age-bands and categories. In addition, fractional polynomial regression models were used to estimate best-fit equations for the sleep variables in relation to age. Reference values (means) and ranges (±1.96 SD) for sleep duration (hours) were: infant, 12.8 (9.7–15.9); toddler/preschool, 11.9 (9.9–13.8); and child, 9.2 (7.6–10.8). The best-fit (R2=0.89) equation for hours over the 0–12 year age range was 10.49–5.56×[(age/10)^0.5−0.71]. Meta-regression showed predominantly Asian countries had significantly shorter sleep (1h less over the 0–12 year range) compared to studies from Caucasian/non-Asian countries. Night waking data provided 4 age-bands up to 2 years ranging from 0 to 3.4 wakes per night for infants (0–2 months), to 0–2.5 per night (1–2 year-olds). Sleep latency data were sparse but estimated to be stable across 0–6 years. Because the main data analysis combined data from different countries and cultures, the reference values should be considered as global norms.Normal sleep patterns in infants and children: A systematic review of observational studiesBarbara C. Galland, Barry J. Taylor, Dawn E. Elder, Peter Herbison10.1016/j.smrv.2011.06.001Sleep Medicine Reviews 16, 3 (2012)2012-06-01Sleep Medicine Reviews2012-06-01163S1087-0792(12)X0003-0Cinical reviews213222http://www.smrv-journal.com/article/PIIS1087079211000736/abstract?rss=yesSummary: Objectives: Little evidence exists to support the common assertion that adult sleep duration has declined. We investigated secular trends in sleep duration over the past 40 years through a systematic review.Methods: Systematic search of 5 electronic databases was conducted to identify repeat cross-sectional studies of sleep duration in community-dwelling adults using comparable sampling frames and measures over time. We also attempted to access unpublished or semi-published data sources in the form of government reports, theses and conference proceedings. No studies were excluded based on language or publication date. The search identified 278 potential reports, from which twelve relevant studies were identified for review.Results: The 12 studies described data from 15 countries from the 1960s until the 2000s. Self-reported average sleep duration of adults had increased in 7 countries: Bulgaria, Poland, Canada, France, Britain, Korea and the Netherlands (range: 0.1–1.7 min per night each year) and had decreased in 6 countries: Japan, Russia, Finland, Germany, Belgium and Austria (range: 0.1–0.6 min per night each year). Inconsistent results were found for the United States and Sweden.Conclusions: There has not been a consistent decrease in the self-reported sleep duration of adults from the 1960s to 2000s. However, it is unclear whether the proportions of very short and very long sleepers have increased over the same period, which may be of greater relevance for public health.Secular trends in adult sleep duration: A systematic reviewYu Sun Bin, Nathaniel S. Marshall, Nick Glozier10.1016/j.smrv.2011.07.003Sleep Medicine Reviews 16, 3 (2012)2012-06-01Sleep Medicine Reviews2012-06-01163S1087-0792(12)X0003-0Cinical reviews223230http://www.smrv-journal.com/article/PIIS1087079211000608/abstract?rss=yesSummary: Objective: To systematically examine the relationship between sleep duration and subsequent weight gain in observational longitudinal human studies.Methods: Systematic review of twenty longitudinal studies published from 2004–October 31, 2010.Results: While adult studies (n = 13) reported inconsistent results on the relationship between sleep duration and subsequent weight gain, studies with children (n = 7) more consistently reported a positive relationship between short sleep duration and weight gain.Conclusion: While shorter sleep duration consistently predicts subsequent weight gain in children, the relationship is not clear in adults. We discuss possible limitations of the current studies: 1) the diminishing association between short sleep duration on weight gain over time after transition to short sleep, 2) lack of inclusion of appropriate confounding, mediating, and moderating variables (i.e., sleep complaints and sedentary behavior), and 3) measurement issues.Longitudinal associations between sleep duration and subsequent weight gain: A systematic reviewLorrie Magee, Lauren Hale10.1016/j.smrv.2011.05.005Sleep Medicine Reviews 16, 3 (2012)2012-06-01Sleep Medicine Reviews2012-06-01163S1087-0792(12)X0003-0Cinical reviews231241http://www.smrv-journal.com/article/PIIS108707921100058X/abstract?rss=yesSummary: The pathophysiology of obstructive sleep apnea (OSA) has been associated with dysregulation of the hypothalamic pituitary adrenal (HPA) axis; however a relationship between OSA and altered cortisol levels has not been conclusively established. We conducted a systematic review using the PRISMA Guidelines based on comprehensive database searches for 1) studies of OSA patients compared to controls in whom cortisol was measured and 2) studies of OSA patients treated with continuous positive airway pressure (CPAP) in whom cortisol was measured pre and post treatment. Five electronic databases were searched along with the reference lists of retrieved studies. The primary outcomes were 1) differences in cortisol between OSA and control subjects and 2) differences in cortisol pre-post CPAP treatment. Sampling methodology, sample timing and exclusion criteria were evaluated. Fifteen studies met the inclusion criteria. Heterogeneity of studies precluded statistical pooling. One study identified differences in cortisol between OSA patients and controls. Two studies showed statistically significant differences in cortisol levels pre-post CPAP. The majority of studies were limited by assessment of cortisol at a single time point. The available studies do not provide clear evidence that OSA is associated with alterations in cortisol levels or that treatment with CPAP changes cortisol levels. Methodological concerns such as infrequent sampling, failure to match comparison groups on demographic factors known to impact cortisol levels (age, body mass index; BMI), and inconsistent control of variables known to influence HPA function may have limited the results.Is obstructive sleep apnea associated with cortisol levels? A systematic review of the research evidenceLianne M. Tomfohr, Kate M. Edwards, Joel E. Dimsdale10.1016/j.smrv.2011.05.003Sleep Medicine Reviews 16, 3 (2012)2012-06-01Sleep Medicine Reviews2012-06-01163S1087-0792(12)X0003-0Cinical reviews243249http://www.smrv-journal.com/article/PIIS1087079211000700/abstract?rss=yesSummary: Rapid development of computer technologies leads to the intensive automation of many different processes traditionally performed by human experts. One of the spheres characterized by the introduction of new high intelligence technologies substituting analysis performed by humans is sleep scoring. This refers to the classification task and can be solved – next to other classification methods – by use of artificial neural networks (ANN). ANNs are parallel adaptive systems suitable for solving of non-linear problems. Using ANN for automatic sleep scoring is especially promising because of new ANN learning algorithms allowing faster classification without decreasing the performance. Both appropriate preparation of training data as well as selection of the ANN model make it possible to perform effective and correct recognizing of relevant sleep stages. Such an approach is highly topical, taking into consideration the fact that there is no automatic scorer utilizing ANN technology available at present.Sleep scoring using artificial neural networksMarina Ronzhina, Oto Janoušek, Jana Kolářová, Marie Nováková, Petr Honzík, Ivo Provazník10.1016/j.smrv.2011.06.003Sleep Medicine Reviews 16, 3 (2012)2012-06-01Sleep Medicine Reviews2012-06-01163S1087-0792(12)X0003-0Technical review251263http://www.smrv-journal.com/article/PIIS1087079212000081/abstract?rss=yesSummary: Nitric oxide (NO) production involves four different NO-synthases (NOSs) that are either constitutive (neuronal, nNOS; endothelial, eNOS; mitochondrial, mNOS) or inducible (iNOS) in nature. Three main processes regulate NO/NOSs output, i.e., the l-arginine/arginase substrate-competing system, the l-citrulline/arginosuccinate-recycling system and the asymmetric dimethyl-/monomethyl-l-arginine-inhibiting system. In adult animals, nNOS exhibits a dense innervation intermingled with pontine sleep structures. It is well established that the NO/nNOS production makes a key contribution to daily homeostatic sleep (slow-wave sleep, SWS; rapid eye movement sleep, REM sleep). In the basal hypothalamus, the NO/nNOS production further contributes to the REM sleep rebound that takes place after a sleep deprivation (SD). This production may also contribute to the sleep rebound that is associated with an immobilization stress (IS). In adult animals, throughout the SD time-course, an additional NO/iNOS production takes place in neurons. Such production mediates a transitory SD-related SWS rebound. A transitory NO/iNOS production is also part of the immune system. Such a production contributes to the SWS increase that accompanies inflammatory events and is ensured by microglial cells and astrocytes. Finally, with aging, the iNOS expression becomes permanent and the corresponding NO/iNOS production is important to ensure an adequate maintenance of REM sleep and, to a lesser extent, SWS. Despite such maintenance, aged animals, however, are not able to elicit a sleep rebound to deal with the challenge of SD or IS. Sleep regulatory processes in adult animals thus become impaired with age. Reduced iNOS expression during aging may contribute to accelerated senescence, as observed in senescence-accelerated mice (SAMP-8 mice).Nitric oxide in the regulation of the sleep-wake statesRaymond Cespuglio, Donia Amrouni, Anne Meiller, Alain Buguet, Sabine Gautier-Sauvigné10.1016/j.smrv.2012.01.006Sleep Medicine Reviews 16, 3 (2012)2012-06-01Sleep Medicine Reviews2012-06-01163S1087-0792(12)X0003-0Physiological review265279